GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: stalwart on January 05, 2014, 09:44:45 PM
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I recently got a 2nd Gen 60c, and fell in love. I like the solid construction, the weight and balance, and, frankly, the looks of this gun. It just fits me... so, as usual, I dove into the deep end.
I set it up with a modded QB78 bulk fill cap, and coated the receiver, hammer and bolt with Teflon bearing powder coat. The result is a nice little single shot... and it inspired me to take these a bit further. I grabbed up a couple handfuls of early 60s, and started this project in earnest.
This will be my first PCP, so I'll be learning as I go. Any input will be most appreciated!
I started with mounting a MRod .22 magazine. I have seen no examples of this mod (thinking this is the first ever), and measurements showed it would be a close fit. It fits, and works nicely... but there is no room for error. I am contemplating a longer barrel, so haven't cut the DOM tube yet. I want the most possible reserve, not for a large shot count, but so I can see just how hard I can make it hit for 10 shots. I bought a pump from FDAR, so I'm set to play.
Any ideas are most welcome...
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If that MRod magazine fits and will function, that new PCP is going to be the best thing since sliced bread.... *grin*....
Bob
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And just about anyone can afford sliced bread.
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I've cycled it hundreds of times (using the same pellets), it spits them out.
Grinning here, too!
;D
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Does the bolt load them to the correct depth, without any hanging up?.... How does it stay in place, by clipping over the barrel stub like on an MRod?....
Bob
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I am running the bolt stock, it has a very long probe. You have to hold it back a bit against the hammer spring to insert or remove the mag, but I may cut some of the probe off. It actually may be longer than needed.
It's held by the barrel, exactly as the MRod does.
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I'm shocked, but in a good way !!! .... I guess I better get one of these on order.... *chuckle*....
Bob
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I'm shocked, but in a good way !!! .... I guess I better get one of these on order.... *chuckle*....
Bob
Get 2, they're tasty.
;D
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Whoa!
Keeping in mind I have never held a Mrod Mag.
No mods to the rifle are needed for this to work?
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You have to cut the receiver and the barrel.
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You have to cut the receiver and the barrel.
If it can't be done with hand tools. Will probably leave me out then. I'll be watching this thread though!
I wonder if there is any difference between the 1st and 2nd gen. That affect this mod.
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Even so.... just the fact that it is do-able is a big deal....
Bob
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If that MRod magazine fits and will function, that new PCP is going to be the best thing since sliced bread.... *grin*....
Bob
If Mike starts shipping with this mod he may need a bigger shop and more help ;)
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There isn't any reason, I can see, why this won't work for both Gens.
Glad I could bring something to the "family" table!
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If Mike starts shipping with this mod he may need a bigger shop and more help
stalwart, you better give him a heads-up.... This is a really BIG deal, IMO.... If all he has to do is mill out a slot and shorten the barrel, this is a no-brainer.... How about the bolt sealing into the barrel?.... how is that achieved?....
Bob
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Eric
i understand why you have to cut the breech/receiver
but
why do you need to cut the barrel ?
Dick
You have to cut the receiver and the barrel.
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I sent Mike a pic quite a while ago. He didn't say anything... not sure what he's thinking.
Here's a pic of the stock bolt, and the mag. Plenty of protrusion into the chamber, for sealing.
The barrel needs to be cut to provide the mount stub for the mag.
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The biggest problem I can see is possible damage to the O-ring from sliding through the magazine.... The MRod bolt slides into an O-ring inside the barrel.... Is the OD of the barrel 7/16" to fit the .22 cal MRod mag?.... or does it need to be turned down?.... Even if the gun needs a new bolt and machining of the barrel, just the fact there is enough meat in the receiver to machine a notch to fit the magazine puts you most of the way there....
Bob
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So far, I have seen no damage to the ring... and there is barely enough meat there. I had to cut to prove it, measurements showed it would be close.
The barrels have to be turned down to make the mount stub.
As to marketing this... I am in the process of tooling up to do this cost effectively. It's a simple mod, but I'd like to recoup something for being the first to risk the R&D... too much to ask?
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Nope, not too much to ask at all.... and the best of luck to you.... Keep everyone here posted as to your progress....
Bob
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As to marketing this... I am in the process of tooling up to do this cost effectively. It's a simple mod, but I'd like to recoup something for being the first to risk the R&D... too much to ask?
It is Not!
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Bet on it, Bob.
This is the most nurturing place I have ever been, for encouraging growth in new directions... wouldn't dream of getting secretive.
:)
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I'm happy to hear that.... You can bet if I can get hold of one the receiver is going to see my mill pretty quickly, though.... *LOL*....
Bob
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LOL... Bob, I'd rather stand between a Momma hog and her piglets, than between you and your mill.
8)
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I recently got a 2nd Gen 60c, and fell in love. I like the solid construction, the weight and balance, and, frankly, the looks of this gun. It just fits me... so, as usual, I dove into the deep end.
I set it up with a modded QB78 bulk fill cap, and coated the receiver, hammer and bolt with Teflon bearing powder coat. The result is a nice little single shot... and it inspired me to take these a bit further. I grabbed up a couple handfuls of early 60s, and started this project in earnest.
This will be my first PCP, so I'll be learning as I go. Any input will be most appreciated!
I started with mounting a MRod .22 magazine. I have seen no examples of this mod (thinking this is the first ever), and measurements showed it would be a close fit. It fits, and works nicely... but there is no room for error. I am contemplating a longer barrel, so haven't cut the DOM tube yet. I want the most possible reserve, not for a large shot count, but so I can see just how hard I can make it hit for 10 shots. I bought a pump from FDAR, so I'm set to play.
Any ideas are most welcome...
I have a great idea! Make one for me! ;D
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That IS a great idea!!
In fact, it was... way back when you nailed down #1.
Smarta$$
;D
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Guys, what is the OD (7/16 full length?) and max length of Mrod barrels from Crosman? What size and type of breech ring is best? Probe dia?
Bob has me thinking about bolts... the MRod set up would run with a lot less lube. Less gunk in the mag, smoother action, etc... and, the stock bolts are not only loose (especially gen1), they are sometimes malformed (but, easy to bend).
If the barrels will work, they'd save a lot of shop time.
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Good news!
I'll be watching too
CW
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This is one of the reasons for selling the rifle the way it is, gives you all something to do and keeps you off the streets...
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LOL!
At least around here, it's working far better than a curfew ever could...
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If there's a way that Mike would be able to stock these modded rifles (obv. giving you a kickback for your time and effort when one sells), I'm all-in. I'm impatient, and don't like playing the shipping game: When I click "order", it's nice to know that the process is done.
If there's a way to get a clean package--modded rifle, 1 mag, and pump--for $275-$300, I know you'll both be swamped. (I'm guessing Rifle-$100, Mag-$15, Pump-$140, Extra cheddah for your work-?)
The second a package is available through Mike, I'll order one to have on-hand for friends that show up and want to shoot, too.
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.177 and .22 cal Crosman barrels are 7/16" OD and the ones for the MRod should be 20" long, if they are the same as the .25 cal (which is 1/2" OD)....
Bob
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stalwart.. Let us know when you are ready to go.... this sounds like something I gotta have.
Snakebite
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+1 on letting us know how things go and when you are ready!
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Thanks, Bob.
Guys, I am on this thing, and there are refinements I will need to make before I will be comfortable selling these as complete... but, I will let you all know when I'm ready to stake my rep on them.
I'm getting real encouragement here and in PMs... I want to thank you all for that. I'm about to dive into some more tooling (wait! I'm supposed to be retired!) that should help drive my (our) costs down. This won't be a budget mod, but there seems to be no reason why it should hurt badly to own one.
Anyone know what size and type of rings are best for the Mrod breech (.177, .22 and .25)? I'm still enamored with the idea of a smooth bolt.
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The O-rings are standard sizes, # 010, 009, and 008.... so the bolt nose is 1/4", 7/32", and 3/16" respectively.... I use MRod magazines on my Hayabusa and Disco Double, and there are a few things you need to know, however.... The .177 and .22 cal are the same thickness (fore and aft) and are interchangeable on teh outer dimensions, but the .25 cal is thicker (about 0.070" IIRC).... The .177 and .22 cal fit on a 7/16" boss on the barrel, but the .25 cal barrel (and the magazine recess) is 1/2" OD.... The hole in the magazine is 1/64" larger than the ID of the O-ring so the bolt slides easily through it.... The magazines are all the same height and diameter, although there is a smaller one, the 8-shot .22 cal one for the PRod.... It is in between in thickness compared to the others, fits on a 7/16" barrel, and the slot below the barrel is shallower.... I do not know if Crosman make that magazine in .177 cal, it they do, that might be your best choice....
In order to keep the cost of the conversion down, I would strongly suggest you either stay with the bolt, probe, and barrel as supplied, or machine a groove in the inside of the barrel for the O-ring and replace the bolt only.... Once you make the tool bit (a fancy bit of grinding of a HSS bit), it's a piece of cake, providing the barrel isn't machined too large on the ID of course.... Swapping out the barrel for a Crosman MRod barrel (which in .177 and .22 aren't that great in quality if they are anything like their 22XX / Disco barrels) would be expensive, and the barrels may be shorter (I don't know the length of the XS60C barrel)....
Bob
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If this would also work for the first gen guns I would also be VERY interested!!!!!
CW
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Thank you, Bob... you saved me real time here. I think you're right... I'm going to try the internal ring set up first. Although I'm fairly certain I'll go for a custom bolt, first I have an idea to try on the stockers. I just wish they weren't so loose in the receiver.
The 60 barrels are 22", already too short for my personal project. An aside: It will have an 8.4CI tube... what would be a reasonable FPE goal for 10 shots in .22?
Brian, the proto shown is a gen1. Start saving your pennies! ;D
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It will have an 8.4CI tube... what would be a reasonable FPE goal for 10 shots in .22?
Eric, at an efficiency of 1.04 fpe/ci, you can get 10 shots averaging 30fpe with 500psi of air usage. That efficiency figure is somewhat arbitrary and while fairly good, it's not stellar so I think it's feasible.
If you want to play around with some hypothetical scenarios, you can use the little calculator at the bottom of my pellet tracking spreadsheet (copy attached).
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I most certainly do. Thanks!
Got some time in and came to the conclusion (obvious?) that the smart way to do this is to cut a standardized mounting stud, and make probes for various calibers and depths.
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Seems reasonable.... Will the nose/probes be interchangeable (set screws) or bonded in place with something like a locktite bearing mount?.... Interchangeable is a nice feature if a guys want to experiment with different calibers....
A Disco reservoir is 8.2 CI, and with a lot of valve mods I got a 10 shot string, starting from 1600 psi, that was 900-930-900 using 18.1 gr. JSB Heavies, which averages 34 FPE.... I have no idea if you can make an XS60C breathe that well, but it gives you a good goal, now, doesn't it?.... *LOL*....
Bob
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I'm glad we have some talented guys working on this project. Some fart smellas...er...smart fellas! ::) :P
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I'll be bonding mine, but can always offer the option of set screw or adjustable threaded stub. Maybe offer additional blank noses for those who like to experiment?
I'm also considering bonding (or pressing and pinning) my barrel, and then cutting the port. In what now almost seems like a previous life, I spent a lot of time getting air to behave (high performance IC). Matching the ports would end up perfectly, this way... and it would eliminate 2 o-rings (never a bad thing). Less plenum between the valve and the pellet is also desirable, correct? I'll get the most solid connection possible between the sight and the bore. The option to float would be simple... pull the band. It would certainly take full advantage of the rigidity inherent in the gun's design.
I'm having fun here... can you tell? Anything around 30fpe would thrill me.
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Guys, I had to show this off...
I really like the way the stock set up looks, until you hang a Fosters off it... so, I modded it to hide the fitting. Just fits.
Clean, no?
;D
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Guys, I had to show this off...
I really like the way the stock set up looks, until you hang a Fosters off it... so, I modded it to hide the fitting. Just fits.
Clean, no?
;D
Squeaky clean! ;D
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I like it a lot.
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Anxiously waiting!!
CW
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Guys, I had to show this off...
I really like the way the stock set up looks, until you hang a Fosters off it... so, I modded it to hide the fitting. Just fits.
Clean, no?
;D
Now why didn't China do it that way...nice innovation or evolution this shooter is going thru.. keep it up.
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...gotta remember that Mike _might_ be able to get them to listen, so simple, cost-effective mods could very well make an appearance on future generations...
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Thanks to the help of some of the Big Dogs here, this thing is coming along nicely.
Just gotta love this place!
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Thanks to the help of some of the Big Dogs here, this thing is coming along nicely.
Just gotta love this place!
Now that's quite an artillery piece you have there! Looking good!
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I am so glad I listened to Bob, and tried the Mrod system.
You can slap this thing home... nothing but slick. Turns out the loose bolts on these don't mean a thing... the mag makes a great guide/fixture.
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I am so glad I listened to Bob, and tried the Mrod system.
You can slap this thing home... nothing but slick. Turns out the loose bolts on these don't mean a thing... the mag makes a great guide/fixture.
I am so saving my pennies for this! Sick slick! 8)
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It seems to work. Pretty well, actually. And, everything fits nicely... the stock looks like it was cut for the mag, and there is nice clearance with the scope. I'm pretty tickled.
In fact, there is a slight change of plan. This thing is a bunch of fun on CO2... I'm going to build another into PCP. The tools I mentioned are trickling in, so I'll be doing a short run soon.
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Makin' me drool here..... That looks real sweet.
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first the p17 now this ,u guys are doing great work ,u have buyers for your projects just give us a price $ ...im in the market for some new toys and this seems like one of them ;).....in april i,ll be spending so please dont tease anymore ;D ;D ....jorge
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It seems to work. Pretty well, actually. And, everything fits nicely... the stock looks like it was cut for the mag, and there is nice clearance with the scope. I'm pretty tickled.
In fact, there is a slight change of plan. This thing is a bunch of fun on CO2... I'm going to build another into PCP. The tools I mentioned are trickling in, so I'll be doing a short run soon.
Man, I am lusting like crazy! :o The perfect companion to my 2078 pair! ;D
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I'm not familiar with the marauder mag, but this mod looks like a must have.
How does the mag cycle? manual or automatic? Cheers, Duke.
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The 10-shot, MRod magazine is self-indexing via an internal spring....
Bob
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Geewhiz, say the word, and I'll put a "Jorge Box" next to George's. There's always something simmering in it... ;D
Guys, just a warning: Unless you own a Crosman revolver, in CO2 this rig will be your most effective Rapid Pellet Disposal System. Having to pump will slow you down... somewhat.
This thing is a blast.
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Geewhiz, say the word, and I'll put a "Jorge Box" next to George's. There's always something simmering in it... ;D
Guys, just a warning: Unless you own a Crosman revolver, in CO2 this rig will be your most effective Rapid Pellet Disposal System. Having to pump will slow you down... somewhat.
This thing is a blast.
Well, when the 60C runs out of pressure, I'll just pick up this, and keep shooting!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/Stealth%201/DSC_7611_zpsbb004a9d.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/Stealth%201/DSC_7611_zpsbb004a9d.jpg.html)
And if I get tired of that, I'll grab this!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078%20Melick%20Tuned/DSC_7665a_zpscfb9e9f3.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078%20Melick%20Tuned/DSC_7665a_zpscfb9e9f3.jpg.html)
And then this. I think I have the bases covered!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg.html)
Gotta love those Chinese! ;D
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Please contact me when you are ready to modify these rifles for a magazine and let me know what you need to charge.I have a generation 1 which shoots very accurately and is worth modifying.
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Sweet this is a got to have! looking to find out where to send the money!
Just outstanding!!
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Here's where we are:
The last of the tooling to build .22s will be here Wednesday, and I have stripped down 6 (gen1) in prep for that. I won't have prices I can publish, and stick to, until these are done and I have hard numbers on my costs and time.
These 6 will be built to the specs of the first one. They will have Teflon bearing powder coating applied to the receiver and bolt handle (as shown), and will not have the bulk cap mod and PCP tubes... which will be offered as additional cost options. I will entertain offers on 4 of these (PM me). I will also be doing conversions to any rifles (or receiver/barrel/bolt sets) received in time for the first Teflon run.
I need to be clear about something, from the beginning: I have physical limits I can not count on to exist from day to day, so I work when they let me. Although odds are very good, on any given day, that I can put some quality time in the shop... I do have occasional days when I am smart to avoid tools sharper than a fork. ;D
It all boils down to a very simple rule for me: I work on customs in the order they come in, and I don't work to deadlines. I am working on setting up for limited production runs (including training someone), but this will be in the future... and only if demand warrants. I strongly suspect it will (shoot one, and you'll see why) but, for now, guns and conversions will all be built on the above basis.
I really appreciate the encouragement and support I have been given, guys. I can't wait to get these things into shooter's hands. I'm convinced these guns are worthy of a great deal of refinement... and will be subjecting some to all I can think of, in search of the perfect guns for me... right here in plain view. Pack a lunch, and stay tuned... these have caught me up in the same way as my beloved 17s have.
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Here's where we are:
The last of the tooling to build .22s will be here Wednesday, and I have stripped down 6 (gen1) in prep for that. I won't have prices I can publish, and stick to, until these are done and I have hard numbers on my costs and time.
These 6 will be built to the specs of the first one. They will have Teflon bearing powder coating applied to the receiver and bolt handle (as shown), and will not have the bulk cap mod and PCP tubes... which will be offered as additional cost options. I will entertain offers on 4 of these (PM me). I will also be doing conversions to any rifles (or receiver/barrel/bolt sets) received in time for the first Teflon run.
I need to be clear about something, from the beginning: I have physical limits I can not count on to exist from day to day, so I work when they let me. Although odds are very good, on any given day, that I can put some quality time in the shop... I do have occasional days when I am smart to avoid tools sharper than a fork. ;D
It all boils down to a very simple rule for me: I work on customs in the order they come in, and I don't work to deadlines. I am working on setting up for limited production runs (including training someone), but this will be in the future... and only if demand warrants. I strongly suspect it will (shoot one, and you'll see why) but, for now, guns and conversions will all be built on the above basis.
I really appreciate the encouragement and support I have been given, guys. I can't wait to get these things into shooter's hands. I'm convinced these guns are worthy of a great deal of refinement... and will be subjecting some to all I can think of, in search of the perfect guns for me... right here in plain view. Pack a lunch, and stay tuned... these have caught me up in the same way as my beloved 17s have.
I'm packing lunch, dinner, breakfast. You name it. Pitching my tent too, and hoping to have some money fall off the tree and into my lap. This will be worth the wait!
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Sounds ok with me!
I'll be in line once you iron things out!! ;)
CW
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Geewhiz, say the word, and I'll put a "Jorge Box" next to George's. There's always something simmering in it... ;D
Stalwart,i will pm u very soon ! ;) me want one we will talk buddy....
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3 left.
8)
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Wow. Very cool.
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Hello Corey!
Get ahold of Mike direct. But he was selling the PCP xs60c with a pump for $240. That's 100 for the rifle and 140 (package only price) for the pump. And you add pellets and energy to pump and your shooting!
CW
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There's a thread for those: http://www.gatewaytoairguns.org/GTA/index.php?topic=57400.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=57400.0)
I have 2 sets of parts left for this first run of repeaters, and am taking offers for completed CO2 guns. They will not be budget guns... I am building them to the specs of my personal gun.
I can supply the modded caps, and full length PCP tubes for them, but the run on those will be done when I have finished the run on repeater conversion parts.
I am also taking in guns for conversions, as well as parts (barrel, receiver and bolt). The least expensive route to a repeating PCP (at least until someone tries to copy and undercut me) is to buy Mike's special, strip it down, and send me the parts to mod.
Until I set up a site, and get a V thread, PM is the way to go, so... Corey, YGPM.
Edit, oops... Corey's edit came in while I was responding. The point remains.
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Sorry, I goofed. I thought I was PMing you with all those questions.
Thanks for the I info and I've got my head out the sand and have switched over to PM.
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Guys, anyone who is in the first run, and doesn't plan to use the plastic front sight, can holler before the barrel run, and I'll cut the front to 11mm dia for use with the myriad of Crosman accessories (TKO, brakes, etc)... free of charge. I'm cutting mine for a TKO (I'm a recent, but ardent convert).
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Guys, anyone who is in the first run, and doesn't plan to use the plastic front sight, can holler before the barrel run, and I'll cut the front to 11mm dia for use with the myriad of Crosman accessories (TKO, brakes, etc)... free of charge. I'm cutting mine for a TKO (I'm a recent, but ardent convert).
I take it that is a 7/16 OD at the muzzle?
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Yessiree. About a million cool things out there (at last count) that will slide right on.
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Yessiree. About a million cool things out there (at last count) that will slide right on.
How do you spell 'Tacticool'? 8)
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Well, when the 60C runs out of pressure, I'll just pick up this, and keep shooting!
And then this. I think I have the bases covered!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg.html)
Gotta love those Chinese! ;D
[/quote]
George I sure like the 2 rifles you have here, my I ask what are they and also where did you have the stock work done at,
Marty
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Well, when the 60C runs out of pressure, I'll just pick up this, and keep shooting!
And if I get tired of that, I'll grab this!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078A/DSC_7665a_zpscfb9e9f3.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078A/DSC_7665a_zpscfb9e9f3.jpg.html)
And then this. I think I have the bases covered!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg.html)
Gotta love those Chinese! ;D
George I sure like the 2 rifles you have here, my I ask what are they and also where did you have the stock work done at,
Marty
[/quote]
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Well, when the 60C runs out of pressure, I'll just pick up this, and keep shooting!
And if I get tired of that, I'll grab this!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078%20Melick%20Tuned/DSC_7665a_zpscfb9e9f3.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078%20Melick%20Tuned/DSC_7665a_zpscfb9e9f3.jpg.html)
And then this. I think I have the bases covered!
(http://i1364.photobucket.com/albums/r726/George_Bowen/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/My%20toys/AR2078A/DSC_7663a_zpse2d5f592.jpg.html)
Gotta love those Chinese! ;D
George I sure like the 2 rifles you have here, my I ask what are they and also where did you have the stock work done at,
Marty
[/quote]
Well, Marty, the good news is those stocks are both factory. The top rifle is my Mike Melick tuned AR2078 in .22. I added the bipod. The bottom is my AR2078A in .177 that I got from the 'other guy'. The MM tuned rifle is a lot smoother, but both guns are accurate and a lot of fun to shoot. Either one can be had for under $250. You can't beat the value of these quality guns.
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Wow Thanks for the info George. I was looking at getting a PCP I have 550.00 to spend and will be my last purchase for a while, Wife is starting to think I nuts, or till I sell my MTR-77 and .177 Gamo Bone collector Bull Whisper. LOL Whishing I had come across GTA before hand.
Sweet rifles my friend.
Marty
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Marty, the only gun I know of that can get you into PCP for that budget, unless you have an air supply, is Mike's.
I got 1 in today, for conversion, and can tell you that you will not beat his deal.
If you want it to repeat... you know who to talk to.
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The first conversion showed up today... nice little gun.
Here's a before:
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It seems to work. Pretty well, actually. And, everything fits nicely... the stock looks like it was cut for the mag, and there is nice clearance with the scope. I'm pretty tickled.
In fact, there is a slight change of plan. This thing is a bunch of fun on CO2... I'm going to build another into PCP. The tools I mentioned are trickling in, so I'll be doing a short run soon.
My next gun.
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Yup.
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Wow Thanks for the info George. I was looking at getting a PCP I have 550.00 to spend and will be my last purchase for a while, Wife is starting to think I nuts, or till I sell my MTR-77 and .177 Gamo Bone collector Bull Whisper. LOL Whishing I had come across GTA before hand.
Sweet rifles my friend.
Marty
Thanks, Marty. Don't forget that PCP means you'll need to spend for a pump or tanks, and/or a Shoebox compressor. PCP=$$$$$ :(
In my case PCP stands for 'Poor Cannot Purchase'. ::) CO2 is a lot cheaper and you will get on average a better shot count. Power is lower, but that's the way it is.
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Wow Thanks for the info George. I was looking at getting a PCP I have 550.00 to spend and will be my last purchase for a while, Wife is starting to think I nuts, or till I sell my MTR-77 and .177 Gamo Bone collector Bull Whisper. LOL Whishing I had come across GTA before hand.
Sweet rifles my friend.
Marty
Thanks, Marty. Don't forget that PCP means you'll need to spend for a pump or tanks, and/or a Shoebox compressor. PCP=$$$$$ :(
In my case PCP stands for 'Poor Cannot Purchase'. ::) CO2 is a lot cheaper and you will get on average a better shot count. Power is lower, but that's the way it is.
The first conversion showed up today... nice little gun.
Here's a before:
So filling it with my Oxygen Tanks won't work? wrong gas? it is a 3000 psi or 220 bar? I guess I will need to pick this bad boy up then.
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The first conversion showed up today... nice little gun.
Here's a before:
I see your's has that same glue-like white stuff on the bottom of the recoil pad. I'm going to try some googone to remove mine. I agree, it's a nice gun. I should get my yoke today or Monday for my tank. Can't wait to shoot and test this thing. Mike says he has 40 cases of 5 left, I'm going to get another one.
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That gunk is on a few guns here... let us know how the goo-gone works?
Got the receivers cut, and hand dressed them before a chemical strip. This step takes a little time, but not only makes a gun look and feel higher quality... it significantly aids coatings in resisting chipping in use.
Doing it before stripping let's you see how even you're getting it all.
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So filling it with my Oxygen Tanks won't work? wrong gas? it is a 3000 psi or 220 bar? I guess I will need to pick this bad boy up then.
Filling it with your Oxygen tank could get you killed. Definitely WRONG GAS. Oxygen is flammable whereas High Pressure Air (HPA) is not, nor is Nitrogen. Somewhere there are some pics of a PCP that someone filled with pure oxygen - they are not a pretty sight!
OK. Took a quick look, here's a link to an article on the subject - complete with pics of what oxygen can do to an air rifle. https://www.pyramydair.com/blog/2008/01/can-nitrogen-be-used-in-pcps/ (https://www.pyramydair.com/blog/2008/01/can-nitrogen-be-used-in-pcps/)
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Guys, doesn't all this tech stuff belong on the tech thread, where people will see it?
No one is gonna see it here...lol.
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Oh ok thanks, forgive my ignorance,
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Guys, I had to show this off...
I really like the way the stock set up looks, until you hang a Fosters off it... so, I modded it to hide the fitting. Just fits.
Clean, no?
;D
Where can I get something like this? Mine is still without a nipple cover
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So filling it with my Oxygen Tanks won't work? wrong gas? it is a 3000 psi or 220 bar? I guess I will need to pick this bad boy up then.
Filling it with your Oxygen tank could get you killed. Definitely WRONG GAS. Oxygen is flammable whereas High Pressure Air (HPA) is not, nor is Nitrogen. Somewhere there are some pics of a PCP that someone filled with pure oxygen - they are not a pretty sight!
OK. Took a quick look, here's a link to an article on the subject - complete with pics of what oxygen can do to an air rifle. https://www.pyramydair.com/blog/2008/01/can-nitrogen-be-used-in-pcps/ (https://www.pyramydair.com/blog/2008/01/can-nitrogen-be-used-in-pcps/)
HOLY C**P!!
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Oh ok thanks
They say there are three kinds of people:
- Those who learn from reading about others' experiences.
- Those who learn from watching others' experiences.
- Those who have to urinate on the electric fence themselves.
That last one could be changed to read "Those who have to fill their PCP with oxygen themselves". ;)
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Guys, I had to show this off...
I really like the way the stock set up looks, until you hang a Fosters off it... so, I modded it to hide the fitting. Just fits.
Clean, no?
;D
Where can I get something like this? Mine is still without a nipple cover
I'll be making a run of these, as soon as the rifles are finished. Stay tuned.
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Guys, doesn't all this tech stuff belong on the tech thread, where people will see it?
No one is gonna see it here...lol.
Eric, I hope what I posted isn't seen as a "hijack"- it was in response to a question on using oxygen to fill a PCP. There's a lot more on this sight on the subject, but I figured it'd be good to include the info here as well since the question was asked here. By the way, I'm following the progress of this project with great interest. Unfortunately, importing such a contraption down this way has come up against recent regulation changes... :( Only licensed importers can do so now... otherwise I'd have been chiming in on the "I want one!" part... such is life abroad.
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Guys, doesn't all this tech stuff belong on the tech thread, where people will see it?
No one is gonna see it here...lol.
Eric, I hope what I posted isn't seen as a "hijack"- it was in response to a question on using oxygen to fill a PCP. There's a lot more on this sight on the subject, but I figured it'd be good to include the info here as well since the question was asked here. By the way, I'm following the progress of this project with great interest. Unfortunately, importing such a contraption down this way has come up against recent regulation changes... :( Only licensed importers can do so now... otherwise I'd have been chiming in on the "I want one!" part... such is life abroad.
Honestly, it may be technically a hijack, but the pic, and the fact that it's a safety question of real significance make that immaterial. You don't leave a question like that hanging... no matter where.
There are a bunch of folks who are getting into PCP lately, including myself... and there are some very good posts by the Big Dogs on the subject. I think that pic, and a lot of the advice belong in a sticky.
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Paul, the old saying "When life gives you lemons, ..." may apply.
I'd look into what it takes to get the license... You'd be the guy with all the cool AGs.
8)
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I'll be sending in for the FD PCP this week, so perhaps a second rifle needs to be ordered and sent to you. Of course finances may dictate otherwise but i really like the idea of making it a repeater.
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John, I am certain you will not regret getting your gun from Mike, and I strongly suspect you would enjoy having a repeating 60... based on the local reaction to mine.
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John, I am certain you will not regret getting your gun from Mike, and I strongly suspect you would enjoy having a repeating 60... based on the local reaction to mine.
Like the local reaction to the Stealth? You have a good bunch there who know a good thing when they see it! 8)
Guys, when Eric tells you the locals like something he has built, you'd best snap it up! :o ;D
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They are a good group to bounce good stuff off of. Around here, the last thing you go cheap on is armament, and PBs are a fact of life. One by one, I'm getting them to take AGs seriously. ;D
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They are a good group to bounce good stuff off of. Around here, the last thing you go cheap on is armament, and PBs are a fact of life. One by one, I'm getting them to take AGs seriously. ;D
Well my money is on you, brother.
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Guys, who has the best deal on QD fittings? Now that I'm buying multiples of everything, it's starting to matter.
Also, just ordered mags, and grabbed a .25 for an attempt at a bigger bore 60. Don't know yet if I can fit it with replaceable barrels, but will soon. In any case, a pinned barrel will allow it. Now I need advice on .25 barrels (what, where, how much?).
I'm taking Bob's advice (again, as usual... ;D) and got a Prod mag coming, too. The manufacturing tolerances in the receivers are big enough that this may allow a lot less final fitting, and save time (AKA: Cash). We'll see...
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Guys, who has the best deal on QD fittings? Now that I'm buying multiples of everything, it's starting to matter.
Also, just ordered mags, and grabbed a .25 for an attempt at a bigger bore 60. Don't know yet if I can fit it with replaceable barrels, but will soon. In any case, a pinned barrel will allow it. Now I need advice on .25 barrels (what, where, how much?).
I'm taking Bob's advice (again, as usual... ;D) and got a Prod mag coming, too. The manufacturing tolerances in the receivers are big enough that this may allow a lot less final fitting, and save time (AKA: Cash). We'll see...
A little off the path here, but how hard would it be to add a tank block and use 9oz paintball CO2 tanks?
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It's do-able. Not cheap, but I can make something, if nothing can be adapted.
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It's do-able. Not cheap, but I can make something, if nothing can be adapted.
I was just curious for down the road.
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I would think the QB or JDS tank block could work.... I'll know when I get my FD-PCP and measure the tube ID.... Of course the CO2 tube may be different.... Clearance for the tank will depend on barrel height relative to the top of the main tube....
Bob
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Guys, who has the best deal on QD fittings? Now that I'm buying multiples of everything, it's starting to matter.
You might want to have a look here:
http://www.aliexpress.com/wholesale?SearchText=paintball+quick+disconnect&catId=100005480&initiative_id=AS_20140219020724 (http://www.aliexpress.com/wholesale?SearchText=paintball+quick+disconnect&catId=100005480&initiative_id=AS_20140219020724)
Made in China but realistically so are probably 90% of the ones you find at domestic sources so why pay their markup? Since Foster fittings are commonly marketed as paintball parts (850 - 1000psi), you'll probably want to confirm the SWP with the vendor before purchasing.
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Guys, who has the best deal on QD fittings? Now that I'm buying multiples of everything, it's starting to matter.
Also, just ordered mags, and grabbed a .25 for an attempt at a bigger bore 60. Don't know yet if I can fit it with replaceable barrels, but will soon. In any case, a pinned barrel will allow it. Now I need advice on .25 barrels (what, where, how much?).
I'm taking Bob's advice (again, as usual... ;D) and got a Prod mag coming, too. The manufacturing tolerances in the receivers are big enough that this may allow a lot less final fitting, and save time (AKA: Cash). We'll see...
A little off the path here, but how hard would it be to add a tank block and use 9oz paintball CO2 tanks?
There is a post showing one who has added a HPA tank bottle. Looks like its close to the barrel. You may have to look for a 2" max O.D. bottle to run tanked CO2.
http://www.gatewaytoairguns.org/GTA/index.php?topic=60023.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=60023.0)
I was thinking if someone was to make a fitting for a regulator or tank bottle to connect to the factory fill cap. Mike has or had (he has supplied one to me) a tube that is 3 5/8" long and threaded on both sides. It might limit max power being short but it will keep the bottle from sticking way out. If interested you may want to ask Mike if the short tube is a little thicker than the factory CO2 tube for running higher pressure HPA. It did seem to be a little snugger fit into the barrel band.
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Thanks, Jason. I took a long look at that, and there will be real savings to be had. The shipping time will require a bit of planning, but I'll grab a few domestics for now, and do just that.
Every penny in gets folded back into this little deal, so every penny saved means progress... 8)
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Guys, who has the best deal on QD fittings? Now that I'm buying multiples of everything, it's starting to matter.
You might want to have a look here:
http://www.aliexpress.com/wholesale?SearchText=paintball+quick+disconnect&catId=100005480&initiative_id=AS_20140219020724 (http://www.aliexpress.com/wholesale?SearchText=paintball+quick+disconnect&catId=100005480&initiative_id=AS_20140219020724)
Made in China but realistically so are probably 90% of the ones you find at domestic sources so why pay their markup? Since Foster fittings are commonly marketed as paintball parts (850 - 1000psi), you'll probably want to confirm the SWP with the vendor before purchasing.
I also found things of interest on this site, I wish I saw this before I made some recent purchases. Oh well, it's bookmarked now.
Thanks Jason
P.S. I wonder if Mike has seen this site.
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Beat me to it Jason... :P
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Hey guys, it was Tony that pointed out that site to me. Just passing it along.
Tony, have you tried any of their wares yet? I got in some 3000psi gauges today. If they agree reasonably well with the gauge I got from McMaster a while back, I'll be using them to replace the silly 6k gauges that come on the Ninja bottles.
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Hey Jason.
I have not ordered anything as of yet, and was going to ask you the same. Let us know how those gauges work out.
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It's do-able. Not cheap, but I can make something, if nothing can be adapted.
Every time I see this post come back up I'm hoping to read your ready to take on customers... ::)
Please let us know when that day comes!!!
CW
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Hey guys, it was Tony that pointed out that site to me. Just passing it along.
Tony, have you tried any of their wares yet? I got in some 3000psi gauges today. If they agree reasonably well with the gauge I got from McMaster a while back, I'll be using them to replace the silly 6k gauges that come on the Ninja bottles.
I've read that operating pressure should be less than the maximum on a scale. Don't remember where now, but the quickest thing I could google just now is this: http://www.ashcroft.com/tech/upload/AshBulG_7.pdf (http://www.ashcroft.com/tech/upload/AshBulG_7.pdf)
"ASMEB40.100 recommends that normal operating pressure be confined to 25%-75% of the scale. If pulsation is present in the process, maximum operating gauge pressure should not exceed 50% of the full-scale range."
FYI, I am looking at doing the same thing. I have a new 2.5" gauge for my SCUBA yoke and was thinking of adding a similar one to my 13CI tank. Those little 6k gauges are impossible to read accurately!
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Just thinking out loud here, but, what would you guys think of an 8 shot .25 carbine (20" Mrod barrel) with a bonded barrel? I plan to build a 24" or more .25... but can't stop pondering this.
It would cut way down on shop time... and the barrels are reasonably priced.
What could a rig like this be expected to do?
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The velocity difference between a 20" barrel and a 24" will depend entirely on how high you push the FPE.... The more power, the more difference with the longer barrel....
Bob
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The longer barrel, longer range rifle is a promise to myself... and will spare no useful expense. This is something I'm contemplating as more of a camp gun... with no frills whatsoever. For example... the time taken to make it possible to change calibers might be better spent elsewhere. When another receiver is $50... and has a shooting gun's worth of parts included in the price... spending much time to allow a $20 barrel change (requiring re-tuning) appeals less to me than if the gun cost me $500+.
My question is more about what kind of performance could be expected for 8 shots from a gun that has had basic hotrodding, with only 20" of barrel?
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Now that I actually HAVE my FD-PCP, I am somewhat doubtful if you can pull off an 8-shot string within a 4% ES in .25 cal, with the extra power, and hence extra air required.... I'm only getting 9 shots with 4% ES with 15.9 gr. JSBs at 27.5 FPE, from 1500 psi down to 1100.... The gun breathes really well, which is great for producing power, but that narrows up the shot string for a given ES.... My recently converted .25 cal Disco is getting 8-9 shots at just under 50 FPE with a 23.8" LW barrel.... and that is with a 2000 psi fill, refilling at 1200, and a larger reservoir than the 60C....
Bob
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Bob;
can u plese tell me how you are determining that you have 1100 psi remaining, have you added a guage somewhere and if so, where and how?
Thanks
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Bob;
can u plese tell me how you are determining that you have 1100 psi remaining, have you added a guage somewhere and if so, where and how?
Thanks
Bill -
I don't know if this is what Bob has done, or if he is just using measurements from when he refills.
http://www.gatewaytoairguns.org/GTA/index.php?topic=61955.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=61955.0)
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Now that I actually HAVE my FD-PCP...
Bob
'Bout time, eh?? Was it the border thing that took so long?
What do you think about the bolt face thing? There's plenty, right?
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I was just noting the pressure when the gauge on the filling tank slowed up, so it's not super accurate.... My new gauge will help....
The only thing I have noticed about the bolt so far is that the probe is wayyyyyyyy longer than it need to be to load a pellet ahead of the barrel port.... However, the chamber is also VERY deep, if you seat a pellet until the skirt just touches the end of the chamber, it's about 1/8" past the barrel port....
Are you shortening the barrels, moving the shoulder, and redrilling the port?.... or are you just removing the loading tray....
Bob
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I shorten, then refit properly. Lot of slop in the stock set up.
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I may be wrong and one should talk to Mike. But Mike's recommendation on 1500 psi is based on operation with the stock hammer and spring. The gun may be able to hold a lot more PSI.
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I may be wrong and one should talk to Mike. But Mike's recommendation on 1500 psi is based on operation with the stock hammer and spring. The gun may be able to hold a lot more PSI.
That's my understanding, too.
Al (airgun-warriors) said he'd go for my suggestion, and blow one up. I offered to chip in, I think it's vital data. Adding frills is fun, but I'd like some hard (safe) numbers. I guess we'll see if he's serious, soon. He has access to proper testing, I don't... or I'd do it. I'm in these for the long haul.
I plan to double up all mounting points before attempting anything, but have decided to try a simple .25 @ 1500 (or so... :D) to see what kind of a base it makes.
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Mike did say
the a tube had been hydro'd to 4k psi, and was rated to 6k. ;)
Found it. It's in this thread. http://www.gatewaytoairguns.org/GTA/index.php?topic=57905.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=57905.0)
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Yes, I'm sure that is probably true.... but is that before or after it was threaded to remove about half the wall thickness?.... We still don't know what material it is.... I just ran the numbers on mine, they are in this thread.... http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0)
The big problem, as I see it, is the valve mounting screws.... Assuming they are just mild steel, the safety margin is only 1.8:1 at 1500 psi....
Bob
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Yes, I'm sure that is probably true.... but is that before or after it was threaded to remove about half the wall thickness?.... We still don't know what material it is.... I just ran the numbers on mine, they are in this thread.... http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0)
The big problem, as I see it, is the valve mounting screws.... Assuming they are just mild steel, the safety margin is only 1.8:1 at 1500 psi....
Bob
Does adding screws to maybe the sides of the valve help the chances of being safe at a higher pressure?
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Does anyone have any suggestions for stripping the coatings on these? The stuff is impressively resistant to Aircraft Remover. It's working, but is taking a lot of effort in places (nooks and crannies), and more time than I thought it would.
I'm prepping for Teflon bearing powder coat, so there can be no remnants.
TIA
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Adding screws would eliminate that problem, but using 2000 psi would then push the threaded portion of the tube to less than a 2:1 safety margin (assuming mild steel tubing), and then fatigue becomes an issue.... The solution to that would be CrMoly tubing, or a thicker wall tube (and hence more weight and less air volume)....
It's a converted CO2 gun, guys.... Protect it with a 1.8 K burst disc, which limits you to 1500 psi regulated.... or flll it (carefully) to 1500 psi.... Anything more than that, do the math on ALL the components and make SURE you know what you're doing.... same thing as if you were working on a QB/AR.... There is a reason it's only $100....
Bob
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Guys, is there any reason why a tube couldn't be made that would extend into the receiver, around a reduced OD valve, and basically act as the entire pressure container? The receiver could easily be bored out a bit, and if the tube was bonded to it, it would only have to do what a typical breech does.
I'm trying to figure out how to get both more volume and pressure. I have an idea that would (maybe) allow a tank block offset enough to work with the close tolerances the integrated receiver creates, and take the worry out of having that threaded joint.
Crazy?
Edit: It's going to be easier than I thought. There is plenty of room to set 7/8" (3/4" ID) DOM steel tube into the receiver without cutting it down. I've read here this stuff is good for 6K (and I have a bunch of it), so I should have quite a margin to work with... and stock valves will slide right in.
Started a mandrel, but will need a longer boring bar. It's always something!
;D
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To my understanding by rsterne is that the weak point of the exposed thread under higher pressure that if the is banged or dropped under pressure if may cause a failure at that point. So if the striker adjustment was exposed outside the stock and the receiver was screwed to the stock at the inner striker block. Would the stock give the connection to receiver to air tube a solid platform being that the tube's barrel band is screwed to the stock also?
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The valve is so close to fitting a 7/8" OD x 0.065" wall tube you will only have to skim off a couple thou if any.... This is a good idea, but whoever told you the tube was good for 6K was dreaming.... The normal rating is 2000 psi at a 4:1 safety margin as used in the Disco....
http://www.goodyearrubberproducts.com/files/Parker/ParkerTubeCatalog4300/Parker%20Tube%20Catalog%204300examin1.Page470.pdf (http://www.goodyearrubberproducts.com/files/Parker/ParkerTubeCatalog4300/Parker%20Tube%20Catalog%204300examin1.Page470.pdf)
Using my standard calculations, and assuming mild steel (1010) for the tubing, I get a safety margin of 2.6:1 at 3000 psi, so I certainly wouldn't use it above that.... If you step up to CrMoly tubing, then the 4:1 rating as per the chart linked above is 3000 psi, and that is what is typically used for a PCP tube on a QB78.... Since you have a bunch of the DOM, you could use it but PLEASE protect the gun with a 3K burst disc on any regulator output to make sure the pressure will never exceed that....
Bob
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To my understanding by rsterne is that the weak point of the exposed thread under higher pressure that if the is banged or dropped under pressure if may cause a failure at that point. So if the striker adjustment was exposed outside the stock and the receiver was screwed to the stock at the inner striker block. Would the stock give the connection to receiver to air tube a solid platform being that the tube's barrel band is screwed to the stock also?
Well anyways this is the best camera I could find. If its blurry sorry. But pics shows the XS60C with an end cap, one pic showing a sleeve to keep the screw head extended out, and one pic showing the stock screwed to the striker block. This is a home made stock but I sure the factory stock can be modified.
If anything exposing the screw might make tuning easier. JMO
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I'm not too concerned about the tube failing from an accident when the stock is in place.... I'm more concerned that if people overfill the gun that fatigue cracking may set in where the threads are exposed just in front of the receiver.... It the tube cracks there, it could eventually let go in a catastrophic failure.... The force pulling the tube apart there is 870 lbs. at 2000 psi, and the stored energy in the reservoir at that pressure is 5700 FPE....
I like your idea of the exposed velocity adjuster, BTW....
It should also be possible to silver solder a sleeve into the reservoir that is long enough to go about 1/4" past the threads to increase the wall thickness there.... At the front of the reservoir, a new fill fitting with the O-ring moved back behind the threads is an easy fix.... Add some high-tensile screws and you should be all set.... Then the next weak point becomes the bearing load of the valve screws in the aluminum receiver.... It just goes on and on, right, once you try and go past 1500 psi....
Bob
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To quote my self the rifle is what it is. As for myself if and when I get to my regulated bottled project will probably not exceed the recommended 1500 PSI. I guess I should just keep my mouth shut but figure some people are going to go over the limit no matter what and thought this might be a way something to keep things safer. thanks
Oh I forgot to add if interested the longer adjustment screw has a nut behind the spring which was locked in with a set screw.
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I need to look a little closer but, I've thought about just cutting the stock back above the power setting adjustment and adding a lever to the locking nut so that left would be loose, and right would be tight. Then just drilling a hole to insert a small screw driver to adjust the screw. I don't want to chop it up any more that ness. Mike has some stocks available, I might have to grab one. Maybe even make a wood plug for the hole.
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I need to look a little closer but, I've thought about just cutting the stock back above the power setting adjustment and adding a lever to the locking nut so that left would be loose, and right would be tight. Then just drilling a hole to insert a small screw driver to adjust the screw. I don't want to chop it up any more that ness. Mike has some stocks available, I might have to grab one. Maybe even make a wood plug for the hole.
That's a good thought. Or how about drilling a hole big enough for a deep socket so you can run your screw driver through the middle. May need a vise grip or plier grip the socket. Oops just took a look maybe too long a hole with the contour of the stock.
Guys, is there any reason why a tube couldn't be made that would extend into the receiver, around a reduced OD valve, and basically act as the entire pressure container? The receiver could easily be bored out a bit, and if the tube was bonded to it, it would only have to do what a typical breech does.
I'm trying to figure out how to get both more volume and pressure. I have an idea that would (maybe) allow a tank block offset enough to work with the close tolerances the integrated receiver creates, and take the worry out of having that threaded joint.
Crazy?
Edit: It's going to be easier than I thought. There is plenty of room to set 7/8" (3/4" ID) DOM steel tube into the receiver without cutting it down. I've read here this stuff is good for 6K (and I have a bunch of it), so I should have quite a margin to work with... and stock valves will slide right in.
Started a mandrel, but will need a longer boring bar. It's always something!
;D
Maybe work the idea the opposite way and weld on a aluminum extention.
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Welding, aluminum, and pressure vessel.... Somehow I wouldn't want to be in the same room.... but then that's just me....
Bob
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Looking at the setup, there is not enough clearance for a socket on the locking nut at the lower side where the bolt for the trigger group is. A lever would need to be welded to the correct flat on the nut. I have a few options. I have a mig welder, JB weld and 2 part propoxy. I think I can make this idea work. Gonna order a stock from Mike. Basically, I would like my power adjustment to flexible for pellet weight for different applications. And if I accidently put 1700 psi in my gun, I would like to screw the adjuster all the way in and work down to a usable pressure as opposed to firing the gun 243 times (exageration)
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Guys, I know a lot more than I did a week ago, and have come up with something I hope you think is special:
It looks like my initial guess (and price) on my conversions is close enough that what I've sold and quoted them for will have to stand. To the average guy, that figure may seem high, but to the average shop owner it can all be explained in 1 word: California.
However... I have decided to produce a special edition conversion specifically for the guy who loves to custom finish. I'm going to call it the "Bobcat", in recognition of a display of real class I have recently seen. ;D
Here's the deal:
10% will go to GTA, as a donation toward operating costs.
The conversion will have a fixed 20" .22 barrel (port size determined by the buyer), fit the Prod magazine (not included), and will not be powder coated. I will deburr to a "shop safe" level, and suggest the buyer grab a Scotchbrite pad, a beverage, and a sunny spot in which to massage the coating to smoothness before paint. Or maybe bead blast?
These will be done according to the most cost effective scheduling I can arrange here. Patience may be required. Payment is Paypal only. This price is for converting parts only... I can tear down and re-assemble rifles at additional cost.
I will do 20 of these conversions. That's it... that's all. :)
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I'm going to call it the "Bobcat",
I just about sprayed coffee all over my keyboard this morning when I read this, and here's why.... Yesterday we made our weekly shopping trip to Princeton (12 miles) and since we had one of the prettiest days I've ever seen here in the mountains of south-central BC we took the camera and got some spectacular shots, like the one below.... On the way home, we saw a Bobcat on the side of the road and since we had the camera, and we rarely see one, let alone having a camera with us, I pulled over to get a photo.... Wait!, it gets better!.... The snowplow had graded the road, pushing the snow right across the ditch, filling it up, so when I pulled over towards (what I thought was) the snowbank, I of course drove the right hand wheels of my car into the ditch, where they promptly sunk to the axles, leaving us stuck on the roadside halfway home.... I hitched a ride back home with a dump truck, roused my neighbour across the lane, loaded up his 4WD with ropes, chains and shovels and went back to dig and pull us back onto the road.... Everything went fine, no damage to the car, in fact the only damage was to my ego.... Then this morning I find out my version of the repeater has been dubbed the Bobcat so now I'll NEVER be able to forget this incident, as each time I see my son's FD-PCP Repeater it will remind me !!!
(http://i378.photobucket.com/albums/oo221/rsterne/IMG_4179_zps27a8024e.jpg) (http://s378.photobucket.com/user/rsterne/media/IMG_4179_zps27a8024e.jpg.html)
Seriously, stalwart, it was a hoot working on this conversion, and I'm flattered with the name.... Donating $10 per conversion to the GTA is a wonderful way to show our appreciation for such a great place to share by "paying it forward".... and my compliments and gratitude to you for that.... I never did get the photo of the Bobcat though, so this one will have to do....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/IMG_4192_zps95605b18.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/IMG_4192_zps95605b18.jpg.html)
Bob
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You guys are amazing. All I know about airguns is put a CO2 in, load a pellet, aim, and shoot. Anything beyond that to me is black magic. I can barely turn a screw lol. ::) Not mechanically inclined enough to even come close to doing what you guys do with apparent ease. So what are you guys, engineers or something? ???
The Bobcat is really cool! ;D
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I'm going to call it the "Bobcat",
I just about sprayed coffee all over my keyboard this morning when I read this, and here's why.... Yesterday we made our weekly shopping trip to Princeton (12 miles) and since we had one of the prettiest days I've ever seen here in the mountains of south-central BC we took the camera and got some spectacular shots, like the one below.... On the way home, we saw a Bobcat on the side of the road and since we had the camera, and we rarely see one, let alone having a camera with us, I pulled over to get a photo.... Wait!, it gets better!.... The snowplow had graded the road, pushing the snow right across the ditch, filling it up, so when I pulled over towards (what I thought was) the snowbank, I of course drove the right hand wheels of my car into the ditch, where they promptly sunk to the axles, leaving us stuck on the roadside halfway home.... I hitched a ride back home with a dump truck, roused my neighbour across the lane, loaded up his 4WD with ropes, chains and shovels and went back to dig and pull us back onto the road.... Everything went fine, no damage to the car, in fact the only damage was to my ego.... Then this morning I find out my version of the repeater has been dubbed the Bobcat so now I'll NEVER be able to forget this incident, as each time I see my son's FD-PCP Repeater it will remind me !!!
(http://i378.photobucket.com/albums/oo221/rsterne/IMG_4179_zps27a8024e.jpg) (http://s378.photobucket.com/user/rsterne/media/IMG_4179_zps27a8024e.jpg.html)
Seriously, stalwart, it was a hoot working on this conversion, and I'm flattered with the name.... Donating $10 per conversion to the GTA is a wonderful way to show our appreciation for such a great place to share by "paying it forward".... and my compliments and gratitude to you for that.... I never did get the photo of the Bobcat though, so this one will have to do....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/IMG_4192_zps95605b18.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/IMG_4192_zps95605b18.jpg.html)
Bob
Man, you REALLY got me stuck here ! I don't know which picture I like more.
Thanks for both tho.
Bill
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A more superstitious person might take this coincidence as a good sign. ;D
That pic makes me homesick for a place I haven't seen for decades. It's not the snow... just the memory of the marrow cleansing air makes the stuff I'm breathing here unsatisfactory at best.
Bob, let's be blunt. Given my skill level and tooling, there is no way I can ever pay back the expert help I've been freely given by many here. My only option to express my gratitude, in a tangible way, is to pay it forward.
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A more superstitious person might take this coincidence as a good sign. ;D
That pic makes me homesick for a place I haven't seen for decades. It's not the snow... just the memory of the marrow cleansing air makes the stuff I'm breathing here unsatisfactory at best.
Bob, let's be blunt. Given my skill level and tooling, there is no way I can ever pay back the expert help I've been freely given by many here. My only option to express my gratitude, in a tangible way, is to pay it forward.
Eric,, Isn't that what life is about. ;)
Bob,, Thank you for the lovely view.... And the information that you freely share.
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Indeed, Bart! Indeed.
Been trying for days to get some decent powder shot. Our drought picked a "good" time to take a break... humidity can effect the way powder lays on. I think it's as much the electrostatic changes as anything. Dry weather just allows a better looking finish.
Got a break this afternoon, for a bit (clouds are rolling in) and am just now pulling some rather pretty pieces out of the oven. Nice when the weather and the shop time line up... even for a bit.
Happy guy here... surrounded by some VERY happy ranchers. ;D It's been a great winter for AG... but, to be fair, it is their turn now. Price hay, and you'll know why many of CAs cows are headed to Texas... rather shocking numbers, at least to me.
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Something for you guys to consider.... If you tether an FD-PCP or an XS-60C to a paintball tank with an 800-850 psi output you will get tons of shots with better performance than CO2.... It only takes about 700 psi of HPA to equal CO2 velocities.... The only thing to remember is that you can (and should) back out the power adjuster to conserve air.... All regulated guns will show a trend like the one below if you graph velocity vs. hammer spring preload....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79NinjaDelrin1200_zps999456be.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79NinjaDelrin1200_zps999456be.jpg.html)
Once you have enough hammer strike for the pressure you are running, adding more doesn't increase the velocity, it just wastes air (the plateau above).... You want to back out the preload until you JUST notice the velocity dropping and operater the gun on the "knee" of the power curve (4-5 turns out above).... Not only will you get 99% of the maximum power at that pressure, and more shots, you will end up with a much quieter report as well....
Can you imagine how much fun this would be with the repeater.... how consistent the velocity (and accuracy) would be.... and how quickly you could go through pellets?.... *grin*
Bob
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Bob, I have always liked your graphs. The best part, lately? I think I'm starting to understand them! ;D I sure like what this one shows.
Guys, if my PM box is full, please send inquiries straight through email.
A couple things about the Bobcat runs: First, payment puts you in line to be served at your convenience... you do NOT have to rush your parts here to keep your place in line. I much prefer you send guns/parts that you already know are worth the conversion. We have time to do this right... let's do just that.
Second, the barrels will be bonded using a quality high (working) temp epoxy. This will allow you to do powder coating... or any other finish that doesn't exceed 450F during cure. This leaves you a ton of good finish options... and, if you pull off something you are proud of, don't hesitate to post pics here. I'd love to see 'em, and bet I'm not alone.
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Bob, I have always liked your graphs. The best part, lately? I think I'm starting to understand them! ;D I sure like what this one shows.
Guys, if my PM box is full, please send inquiries straight through email.
A couple things about the Bobcat runs: First, payment puts you in line to be served at your convenience... you do NOT have to rush your parts here to keep your place in line. I much prefer you send guns/parts that you already know are worth the conversion. We have time to do this right... let's do just that.
Second, the barrels will be bonded using a quality high (working) temp epoxy. This will allow you to do powder coating... or any other finish that doesn't exceed 450F during cure. This leaves you a ton of good finish options... and, if you pull off something you are proud of, don't hesitate to post pics here. I'd love to see 'em, and bet I'm not alone.
If you can understand these graphs, then there is no hope for you to return to normal life with the rest of us morons! :P ::) ;D
I am guessing that powder coating involves more equipment and know how than I possess?
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It really be nice if you could post pictures of it a step by step of what you used and how you did it. your wright up is good but for me and I think for many of us I need to see it done to understand. A vid would tops. something for you to think about.
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Not so sure that is something you should ask for when this is now a commercially available product.... just sayin'.... If you want a general idea, check out my FD-PCP thread where I installed a magazine.... http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0)
Bob
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Guys, I have to thank you for the response to the Bobcat offering. It looks like the last of the supplies needed for the runs will be in just before your parts start to arrive... gotta love that! ;D
Also, to anyone who is contemplating going for removable barrels, there is something else to consider here:
The XS60C barrels range from almost concentric, to not even close. I cut 1 to be removable (on center), and there was not enough barrel left to do it.... 1 side was not even touched by the bit. It worked fine for a fixed set up, but wouldn't work as removable. The offset wasn't huge, but as the mags work best when perfectly aligned, I have to cut them on center.
If you want a nice dual caliber set up, I recommend getting quality barrel blanks.
Bob, is there any reason a customer would want a port smaller than stock? Your tuning posts have shown us that a larger port isn't in everyone's best interest... would anyone want one smaller?
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Guys, I had to show this off...
I really like the way the stock set up looks, until you hang a Fosters off it... so, I modded it to hide the fitting. Just fits.
Clean, no?
Nice were did you get the end cap from/
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You can probably still get 20+ FPE with a 7/64" barrel port (0.109"), the gun breathes that well.... However, it doesn't seem to increase the shot count as much as it does on a Disco, for example.... I modded my ports larger and got 32+ FPE with 18 gr. JSBs, but only 7 shots.... When I then fitted a 0.104" barrel port restrictor it dropped to 24 FPE and went back up to 9 shots.... However, that was about what I started with.... I never succeeded in getting the sweet spot past about 400 psi (1500 down to 1100) for a 9 shot string at 4% ES.... except with the bstaley O-ring buffer....
Bob
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One of these is not like the others...
The .25 project begins. ;D
The cap comes on the stockers.
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Those mag receivers look great. I was wondering if anyone would be interested in a single shot loader? Loading pellets with a scope can be kind of tricky.
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Paul, that's precisely why the first conversion was purchased. I guess I'm not the only old timer who's tired of fumbling pellets?
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Stalwart tried to send a personal message but it got rejected. So I'll post it here.
I have made a single shot loader and all made by hand or small power tools. It's not bullet proof in usage being that the hole for the bolt is some what large and the .177 can flip in the loading hole if not careful. The loading tray had to be cut of the barrel also. But it is still a lot easier to load than without it. You probably can machine something better out of aluminum because most of my parts are acrylic plastic or improve on the idea with your skills. I would think if you like the concept you could market it if you like. I think it would cost a lot less to the buyer than the magazine route (not sure). Will try and send some pics if I can get into your personal messages if interested. Thanks
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I just pruned the PM, but... it won't last. Guys, please just email me with the little link.
Paul, I'd love to see your idea, but are you certain you wouldn't rather refine and market it? I'd be more than happy to help, if I can... and you can always just sub production if it's a hit. I will consider myself under a non-disclosure agreement until released in writing... send some pics!
R&D is my passion... ;D
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I just pruned the PM, but... it won't last. Guys, please just email me with the little link.
Paul, I'd love to see your idea, but are you certain you wouldn't rather refine and market it? I'd be more than happy to help, if I can... and you can always just sub production if it's a hit. I will consider myself under a non-disclosure agreement until released in writing... send some pics!
R&D is my passion... ;D
If I were a machinist I still wouldn't want to go through the hassle of marketing. Then again I kind of think if I were one the idea may be better improved. You may not think its a great idea but if there are things you like just use them. If I have trouble with the PM what email link do I use?
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You have to cut the receiver and the barrel.
What about the PRod Magazine would it by chance be a little smaller, so that you wouldn't have to cut as much out of the breech, or is it too small??
William
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Eric cannot figure how to post pics in your PM box. So will post them here. First two pics show front and back with back with a half cut scope ring using the clamping section. So all it is a loader that clamps to the dovetail with a loader that flips open and flips down to load pellet. Oh did I mention the barrel loading tray needs to cut off?
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William, the Prod mag works well in these, and is very compact... ask Bob!
Paul, that is clever... pure and simple. I'm impressed. It's compact and simple. A machinist could make it pretty, but you've got it solid. It's got me thinking. Well done.
Click on the little envelope under my name, and it will set up an email. Drop me a line.
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Humm,, did i go wrong purchasing the Discovery?? Humm ???
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You will get a lot more shots from the Disco without having to refill, they are quite different guns.... The FD-PCP is more of a hobbyist's gun for someone who likes to tinker, IMO.... Not that it can't be made into a good hunter, just keep in mind the smaller reservoir and lower fill pressure....
Bob
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Well, things are rolling here. ;D The parts for 2 conversions showed today, as well as the last of the supplies needed to do this right. When more customer parts come, I'll start the receiver run, as I have some of my own stripped and ready to cut.
Got the longer boring bar in, and set a full thickness tube into a receiver tonight. Last hurrah until the runs are over... but. it looks like a 3K 60C is in the cards.
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3K? Sounds like winner.
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I won't pretend, even for a minute, that I know how to make one shoot at 3K... but, as I relied entirely on our Beloved Safety Officer for all safety related specs, I am quite confident it won't explode if it falls over.
;D
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A quick pic for those who have skin in the game. Roughed in... I will finish them on my Sherline.
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Nice!!
I think one of those is mine!
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Yup... it's in there, somewhere...
:)
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:)
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:)
;D Yup, mine is in there!
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LOL I forgot to order some prod mags, better do it soon
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LOL I forgot to order some prod mags, better do it soon
I have a couple MRod mags awaiting! ;D
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Another incredible project! I need to save my pennies! In the future I'm going to need one of these as well as one of your P17's ;)
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I have been offering some help regarding the safety of this and other designs on this and other Forums on the Internet, and I just want it to be understood that I am NOT an engineer, I am simply offering my opinions about the loads involved and the potential problems and pitfalls of given designs and applications.... You are on your own in regards to safety on any modifications to any airgun or pressure vessel....
Bob
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As a newb to the whole PCP concept in airgunning, I have followed your posts Bob, and I am completely convinced that you have probably forgotten more than I will ever even know about the technology and the safety concerns. I would never even consider going above what you suggest as the safety margins of this or any other gun. Thank you for getting involved and giving your expertice so freely.
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+1... and then some.
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Plugging along here... quick status update for repeater guys: The bolts are cut, will be doing noses and a massive Teflon run (S1s too) this weekend, weather permitting. Barrels are still coming in, hope to do them all by next weekend (remember... no promises!). Anything not here by about Thursday, will have to wait for next run.
Got a shipment I plan to use to speed things up, from now on. The rough cut slot is good for all variants, as is the bolt base mod, so I will be doing both in advance as soon as these first rigs are shipped. From then on, any orders will have the barrels cut, and the bolts and receivers replaced with pre-prepped parts... and they will be shipped asap. As the barrel is the only unique part (accuracy wise), this will mean nothing but quicker turn-around. And, in the future, I will be offering drop in kits for those in a real hurry.
I am also putting together a larger coating oven, to allow much larger batches, as well as coating larger parts. The intention is to offer better deals (and more options) on coatings. Thanks to the response from you fellas, I feel more than safe in investing much more in this AG thing.
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Another update:
Barrelpalooza is proceeding as planned. All the repeater conversions are cut and ringed, and I'm now setting the barrels. Epoxy is hardening as I write. If you will need mags, you might want to get them ordered.
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Another update:
Barrelpalooza is proceeding as planned. All the repeater conversions are cut and ringed, and I'm now setting the barrels. Epoxy is hardening as I write. If you will need mags, you might want to get them ordered.
Got 2 waiting! ;D
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Only 2??
;)
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Only 2??
;)
Maybe I should rephrase that to the first 2 lol. ;) ;D
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There ya go!
;D
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There ya go!
;D
Good thing they are cheap and plentiful.
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Last update for the Bobcat guys:
Got some legs under me, and finished off the first batch. They will come with 2 extra o-rings (009) slid on the bolt. The noses are fitted and polished... 2 should be a lifetime supply. A drop of oil once in a while should make the spares unnecessary for quite a while.
Also, I hate sloppy mags, and I fitted these precisely. If you plan to paint, be sure to mask off the mag well. Chemical treatments add no thickness, but any finish with a heavy film will cause problems with fit. I suggest polishing the well with Simichrome or similar to make it pretty and easy to clean.
I experienced zero nagging with this batch. The first guys to risk their money on this have paid for all the tooling and refinement needed to make this process easy and reasonably fast for the next buyers. I want to thank the brave ones for their patience. ;D
As with my pistols, the first to take the chance will get $pecial treatment in my shop from now on. Let me know if you guys need anything.
Thanks again, guys.
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thanks for the update
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Last update for the Bobcat guys:
Got some legs under me, and finished off the first batch. They will come with 2 extra o-rings (009) slid on the bolt. The noses are fitted and polished... 2 should be a lifetime supply. A drop of oil once in a while should make the spares unnecessary for quite a while.
Also, I hate sloppy mags, and I fitted these precisely. If you plan to paint, be sure to mask off the mag well. Chemical treatments add no thickness, but any finish with a heavy film will cause problems with fit. I suggest polishing the well with Simichrome or similar to make it pretty and easy to clean.
I experienced zero nagging with this batch. The first guys to risk their money on this have paid for all the tooling and refinement needed to make this process easy and reasonably fast for the next buyers. I want to thank the brave ones for their patience. ;D
As with my pistols, the first to take the chance will get $pecial treatment in my shop from now on. Let me know if you guys need anything.
Thanks again, guys.
Good things come to those who wait! ;D
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Got the 'cats on the way, so I had a little time for the 3K... set the tube in deep enough to provide an excess of backup for the (2) 1/4" screws that will be going into the sides.
It will need to be cut for the slot clearance and have a flat cut to clear the mag, but this looks like a viable set up.
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For an adjustable depth striker (or block), what would be the max useful distance (+ and/or -) from stock?
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Got the 'cats on the way, so I had a little time for the 3K... set the tube in deep enough to provide an excess of backup for the (2) 1/4" screws that will be going into the sides.
It will need to be cut for the slot clearance and have a flat cut to clear the mag, but this looks like a viable set up.
Are you connecting the valve to tube so there is no pressure in the breech?
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Yes. All the pressure is contained by 1 piece of full thickness steel. As Bob mentioned, I'll have to take just a few thou off the ODs of the block and valve to get them to slide in the tube. The block will get pinned by 2 more fasteners, and it and the valve will mount with the stock hardware... which will then also mount the tube.
I bounced a lot of different configs off Bob... he was very patient with me... and ended up working with his recommended fasteners plus the stock hardware.
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I was thinking along this line but using a short tube and a JDS drop block for a 13cid Tank.
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Refined the receiver design a bit...
Extended the tube to function as a sleeve to allow the striker and the pin to ride in precise polished steel, instead of painted aluminum. I'll use slip coating on the striker to get the most and the most consistent speed. If your pin is riding in a jagged slot (or is busy making itself one), you'll see why the first Bobcat customer I showed this to has delayed shipment while I set his up to stop chewing on itself.
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It didn't even occur to me when I cut the excess off the receiver I would end up with matching barrel bands.
;D
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Just thinking out loud here...
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Very cool.
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Just thinking out loud here...
What grip frame is that, will it fit a 2240, where did you get it, and how much was it?
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It's a long discontinued aftermarket paintball part. I got a handful a long time ago, 1 of which is part of a 2240 project that now has very little Crosman left in it. They weren't cheap back in the day... and my little pile is worth even more to me. They fit me like they were cut to.
It seems I'm not the only one who likes the idea of 3K. I got the thumbs up (for safety), and sold 2 so far. Looks like a busy summer ahead... No more bon-bons and Oprah for me. :'(
;)
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It's a long discontinued aftermarket paintball part. I got a handful a long time ago, 1 of which is part of a 2240 project that now has very little Crosman left in it. They weren't cheap back in the day... and my little pile is worth even more to me. They fit me like they were cut to.
It seems I'm not the only one who likes the idea of 3K. I got the thumbs up (for safety), and sold 2 so far. Looks like a busy summer ahead... No more bon-bons and Oprah for me. :'(
;)
Bummer. Looks like it would fit my hand too. :(
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It's a long discontinued aftermarket paintball part. I got a handful a long time ago, 1 of which is part of a 2240 project that now has very little Crosman left in it. They weren't cheap back in the day... and my little pile is worth even more to me. They fit me like they were cut to.
It seems I'm not the only one who likes the idea of 3K. I got the thumbs up (for safety), and sold 2 so far. Looks like a busy summer ahead... No more bon-bons and Oprah for me. :'(
;)
Bummer. Looks like it would fit my hand too. :(
Here ya go,you will have to buy or make the innerds tho.
http://www.ebay.com/itm/Kingman-Spyder-Bob-Long-Battle-Grip-Replacement-Single-Trigger-45-Frame-NEW-/301122245715?pt=LH_DefaultDomain_0&hash=item461c48d453 (http://www.ebay.com/itm/Kingman-Spyder-Bob-Long-Battle-Grip-Replacement-Single-Trigger-45-Frame-NEW-/301122245715?pt=LH_DefaultDomain_0&hash=item461c48d453)
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It's a long discontinued aftermarket paintball part. I got a handful a long time ago, 1 of which is part of a 2240 project that now has very little Crosman left in it. They weren't cheap back in the day... and my little pile is worth even more to me. They fit me like they were cut to.
It seems I'm not the only one who likes the idea of 3K. I got the thumbs up (for safety), and sold 2 so far. Looks like a busy summer ahead... No more bon-bons and Oprah for me. :'(
;)
Bummer. Looks like it would fit my hand too. :(
Here ya go,you will have to buy or make the innerds tho.
http://www.ebay.com/itm/Kingman-Spyder-Bob-Long-Battle-Grip-Replacement-Single-Trigger-45-Frame-NEW-/301122245715?pt=LH_DefaultDomain_0&hash=item461c48d453 (http://www.ebay.com/itm/Kingman-Spyder-Bob-Long-Battle-Grip-Replacement-Single-Trigger-45-Frame-NEW-/301122245715?pt=LH_DefaultDomain_0&hash=item461c48d453)
Sweet! Thanks. Can the innards from a 2240 be used?
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No.
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No.
Oh well, useless to me. I have 0 skills.
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I've been pondering adjustable strikers and blocks for a while now, and there are a few ways to do it... all easy as 1-offs, but expensive and cumbersome to either make or adjust (or both) for limited production. I think I've been barking up the wrong tree...
I have some materials coming... and I'm going to try an adjustable length valve stem. Can anyone think of a down side? Please?
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:)
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:)
Looks like a poor man's PRod!
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Oh what I would give to be a poor man......
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Looks VERY familiar ... mine too used a Paintball markers .45 frame.
See this for some inspiration ;) http://www.gatewaytoairguns.org/GTA/index.php?topic=40431.msg377421#msg377421 (http://www.gatewaytoairguns.org/GTA/index.php?topic=40431.msg377421#msg377421)
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Nice work, Scott.
I've been wanting a bullpup for a while. The ergonomics play well to my situation, I spend a lot of time seated.
The 60s are just begging for that attention, being compact already... I'm looking forward to seeing what comes out of the diverse group that have been hooked by these. I can smell them cooking, already...
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After shooting my new FD-PCP some last night .... DANG what a difficult single pellet loading issue with a scope on top.
Magazine mod here we come !!!
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After shooting my new FD-PCP some last night .... DANG what a difficult single pellet loading issue with a scope on top.
Magazine mod here we come !!!
I know which gun I will be shooting the most. ;) After having an MRod for about a week and putting a few pellets through it I fell in love with the magazine. Now I will have the best of both worlds with my 60C repeater. It fits my style perfectly. I don't care how fast the pellet travels or how hard it hits. I don't want to mess with pumping or if I got the pressure right. I just drop in my carts and shoot. I don't need cold weather performance because I don't shoot when its cold anyway. All I care about is ease of loading and shooting and how accurately it hits the target. The rest of that voodoo I leave to you witch doctors to figure out lol. :P ::) Just send me some good mojo and I am happy! 8)
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After shooting my new FD-PCP some last night .... DANG what a difficult single pellet loading issue with a scope on top.
Magazine mod here we come !!!
I have a hard time inserting single pellets with open sights, especially the small ones. That's a major buzz-kill with any and all scoped single-shot rifles, and that's why following this thread has become a compulsion. While I'm waiting for this FD PCP repeater to solidify, I'm thinking that a "pellet pen" might make the waiting easier.
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We got used to it. Not so bad. We put the pellet in on one side of the scope while looking from the other side. No disrespect intended towards the repeater project, I am totally impressed by the work done here. But, putting pellets in one at a time kind of adds enjoyment to our shooting. We chat between shots. You know, high fives n junk. And it slows the process a bit. I would much rather be putting a pellet in than refilling the gun with air every 5 minutes. On the other hand, if I used this as a full time hunter, the repeater option may be a must have.
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That was a good take on having a pleasant shoot with friends.......should probably do that more often.
Excitement over an FD PCP isn't inspired by a rush to spew out lead. It results from my bumble-fingered difficulty with inserting smaller pellets into an airgun breach.....gets my goat every time I shoot.
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We got used to it. Not so bad. We put the pellet in on one side of the scope while looking from the other side. No disrespect intended towards the repeater project, I am totally impressed by the work done here. But, putting pellets in one at a time kind of adds enjoyment to our shooting. We chat between shots. You know, high fives n junk. And it slows the process a bit. I would much rather be putting a pellet in than refilling the gun with air every 5 minutes. On the other hand, if I used this as a full time hunter, the repeater option may be a must have.
I shoot alone most of the time, but it's no big deal to load one at a time. With CO2 you need that delay to allow the pressure to come back up anyway. I like a repeater for a change in pace. Yeah, I don't see any advantage to making this gun a PCP in my book. CO2 carts are cheap and easy to find. I am a very casual shooter and am not on a tear to fire x amount of pellets over the summer. My goal is to get my fun shooting range set up as soon as the ground dries enough out back. It's turning into a swamp right now.
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I'm with Yarp. Bench rested, my 79 was ok, but in hand it was easy for me to fumble pellets.
Before I knew about the MRod mags, I got to looking at my non-lethal "deterrent" Spyder experiment, and got the idea to cut a receiver to load pellets from my "weak" side. Before I finished it, the beginnings of the repeater came about. I got a mag, then another receiver... then my 60 came along.
I'll finish the side loader some day... maybe.
The Spyder is filled with 50 hard rubber balls the cops use for crowd control...lol. It'll put a world of hurt on you, without drawing blood. Shreds a cardboard box... saw pics of a test subject with deep bruising (Yellow with purple dots...lol.), decided against testing it on myself (meow).
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Larry Johnson: I could have sworn you said meow.
Foster: Do I look like a cat to you, boy? Am I jumpin' around all nimbly bimbly from tree to tree?
Foster: Am I drinking milk from a saucer?
Foster: Do you see me eating mice?
Foster: You stop laughing right meow!
Larry Johnson: Yes sir.
Foster: Meow, I'm gonna have to give you a ticket on this one. No buts meow. It's the law.
Super Troopers (2001)
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I see you like the same kind of artful, socially important, thought provoking and enlightening movies I do.
;D
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Just thinking out loud here...
Bullpup?
AR stocked carbine?
Phazer? :o
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LOL I forgot to order some prod mags, better do it soon
I have a couple MRod mags awaiting! ;D
I hope I'm not the bearer of bad news but if you ordered the Bobcat I believe it will take the Prod mags.
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LOL I forgot to order some prod mags, better do it soon
I have a couple MRod mags awaiting! ;D
I hope I'm not the bearer of bad news but if you ordered the Bobcat I believe it will take the Prod mags.
You aren't. I did not order the Bocat.
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Mail man dropped off the Bobcat repeater mod parts from stalwart this AM!
Nice looking job Eric, thanks. are the 2 o rings on the bolt ,spares for the barrel end? In cocking,the bolt/mag, and entry to breech is a very smooth operation.
Now I have to remember how to assemble it.
Going to put it together and tune it, then clean up the breech paint and repaint it.
I have a new valve from Mike ready, as I screwed up the original modding the exhaust port. I didn't mess up the 2nd one.
I'd like to figure a scheme to be able to fill bulk co2 also, have dual fuel capability. I made up a new tube end plug in brass, going to use a foster fill valve w/check valve in it, gauge, and burst disk on the very end.
Again Nice work Eric, thanks so much
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Just thinking out loud here...
Bullpup?
AR stocked carbine?
Phazer? :o
Phazer? Hmmmm, hadn't thought of that...lol. I'm currently trying to come up with a trigger that can be used in all configs, including bullpup, pistol, and carbine. I really like Crosman's modular design, and want something along those lines, but really stout.
Mail man dropped off the Bobcat repeater mod parts from stalwart this AM!
Nice looking job Eric, thanks. are the 2 o rings on the bolt ,spares for the barrel end? In cocking,the bolt/mag, and entry to breech is a very smooth operation.
Now I have to remember how to assemble it.
Going to put it together and tune it, then clean up the breech paint and repaint it.
I have a new valve from Mike ready, as I screwed up the original modding the exhaust port. I didn't mess up the 2nd one.
I'd like to figure a scheme to be able to fill bulk co2 also, have dual fuel capability. I made up a new tube end plug in brass, going to use a foster fill valve w/check valve in it, gauge, and burst disk on the very end.
Again Nice work Eric, thanks so much
It was my pleasure. If you need anything, you know where to find me.... and, thank you!
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Having a good day here, the UPS guy brought everything I need to get serious.
(2) .25 MRod barrels. If anyone wonders what happened to the very first FD PCP that came in... it got hit by "mission creep". I'm twinning my .25 3K camp gun project, we're both going for 8 hard punches... as hard as we can get. I'm dubbing this design "Wolverine"... I'm from MI, and always respected them. They don't look for trouble, but if you mess with them, they'll mess you up. Even bears know that no one really "wins" a fight with them.
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I love my S510, and all, but I've got to say that this entire thread is such a huge bucket of awesome-sauce, it's beyond words.
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Between us, Drew, if my customers ever find out how much fun I'm having, they'll charge me... and I'll have to get a real job.
;D
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Having a good day here, the UPS guy brought everything I need to get serious.
(2) .25 MRod barrels. If anyone wonders what happened to the very first FD PCP that came in... it got hit by "mission creep". I'm twinning my .25 3K camp gun project, we're both going for 8 hard punches... as hard as we can get. I'm dubbing this design "Wolverine"... I'm from MI, and always respected them. They don't look for trouble, but if you mess with them, they'll mess you up. Even bears know that no one really "wins" a fight with them.
I'm tingling!!
WOLVERINES!! (Red Dawn)
The name brings fear and respect in all proportions so the name befits thy rifle.
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Yup. Sometimes just big enough is just right.
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Yup. Sometimes just big enough is just right.
Here is what I picture in my mind. Wolverines!
(http://i1364.photobucket.com/albums/r726/George_Bowen/RedDawnWOLVERINES_zps31b78116.jpg) (http://s1364.photobucket.com/user/George_Bowen/media/RedDawnWOLVERINES_zps31b78116.jpg.html)
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Between us, Drew, if my customers ever find out how much fun I'm having, they'll charge me... and I'll have to get a real job.
;D
Shhhhhh... your secret is safe with me. This is a PM, right...?
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Oops... :-[ ...there are 3 customers on this page... ;D
Guys, it looks like these can be made to shoot some much larger stuff. With the 3K tube style, not only can we get more striker stroke, but the design basically allows us to decide where we want the valve and port. Move the mag or tray forward, and the valve follows... so, we can fit any weight striker we want. It boils down to: If you extend the bolt nose up to 2", you can extend the striker up to 2". The stock length receiver will take it, and we will never need the kind of weight that we'd have room for. 2" of 3/4" steel carries a lot of momentum.
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Well, Lloyd converts the .25 cal MRod mags to a 7 shot .30 cal, and I designed a 70 gr. boattail bullet to fit the mag.... *grin*..
It shouldn't be too much of a trick to increase the ports to 7/32", and at 3000 psi over 100 FPE should be a piece of cake....
Bob
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The fun never ends! I can't believe how far this post has come from the original post. Sure makes me wish I could get my meat hooks on one of these rifles to see what the fuss is all about. :) Thanks for sharing this with us, especially those of us who are mostly limited to vicarious explorations in this area.
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Bob, it's gonna happen. I have some guns to get out, then I'll treat myself to something svelte, stout, and nasty.
Paul, you are certainly welcome... and, thanks for the encouragement. The fact is, I get a great deal of fun out of this entire process.
I found another solution to fumbly pellets: Bigger pellets! LOL... I'm kinda isolated here, AG wise, and just got to handle .25s for the first time... barracudas. HUGE! I just don't get why they don't make .177s this big?? I'd buy them!
Oh wait...
;D
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Here's the set up I mentioned before, sleeving the Bobcat to prevent erosion of the pin slot and striker's hole. Reamed the receiver and inset a turned stock CO2 tube (decent steel). 24 hours til the epoxy sets, then slots and holes, then... she's outa here!
Compared to the painted aluminum, this thing is slick as snot. Customer is getting, as he put it, the "Slickery Kit"... slip coated striker and bolt handle. Should be very consistent, and last forever.
They say "The Devil's in the details". I've found accuracy lurks there, too.
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Here's the set up I mentioned before, sleeving the Bobcat to prevent erosion of the pin slot and striker's hole. Reamed the receiver and inset a turned stock CO2 tube (decent steel). 24 hours til the epoxy sets, then slots and holes, then... she's outa here!
Compared to the painted aluminum, this thing is slick as snot. Customer is getting, as he put it, the "Slickery Kit"... slip coated striker and bolt handle. Should be very consistent, and last forever.
They say "The Devil's in the details". I've found accuracy lurks there, too.
I'm tingling again!!!!
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Dude!! The only way that's not creepy is if this is your gun!
Now, are you going to tell everyone, or shall I?
C'mon, say it with me... " Hi, I'm Mike, and I'm a custom airgun addict."
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Dude!! The only way that's not creepy is if this is your gun!
Now, are you going to tell everyone, or shall I?
C'mon, say it with me... " Hi, I'm Mike, and I'm a custom airgun addict."
ok :(
My name is Mike, and I'm an airgunaholic. :-[
BUT, I really like the GTA Twelve Step Program as the steps lead me to more airguns and airgun mods!! ;D
Whew!! I feel much much better. I need a cup of coffee after all that.
I can't wait to get my hands on the Bobcat and thanks for doing the striker liner. I didn't want to see any more striker damage at the cocking pin slot.
Gonna mod some valves tomorrow. Life is good.
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My pleasure! It worked out nicely. Those tubes are typically a bit small on the OD, but the ID is exact. The transition is practically seamless.
Glad you feel better now... You are gonna get along just fine around here. Bet on it. ;)
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My pleasure! It worked out nicely. Those tubes are typically a bit small on the OD, but the ID is exact. The transition is practically seamless.
Glad you feel better now... You are gonna get along just fine around here. Bet on it. ;)
All this stuff you just talked about is for the PCP version, not the CO2?
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It applies to both. Mike was getting some chewing on another gun, so we worked this out... but any 60 will be more accurate as you reduce the variances in striker speed. Another positive effect is ridding the gun of the gritty feel as you cock it.
Whether or not the galling will ever affect the gun's abilities, I can't stand the feel of steel chewing aluminum. It sets off alarms in the minds of anyone who works with metal. In race motors, it's the feeling of impending destruction.
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It applies to both. Mike was getting some chewing on another gun, so we worked this out... but any 60 will be more accurate as you reduce the variances in striker speed. Another positive effect is ridding the gun of the gritty feel as you cock it.
Whether or not the galling will ever affect the gun's abilities, I can't stand the feel of steel chewing aluminum. It sets off alarms in the minds of anyone who works with metal. In race motors, it's the feeling of impending destruction.
I agree. Metal on metal grinding is not a nice feeling. I'm looking forward to feeling the smoothness! ;D
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A day later...
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A day later...
I like it!!
When I get her home I'll put her back together test all, check for chinks in her armor, tear her back down, plastic bead blast, degas the aluminum, degrease, plug off areas I don't want coating in then give her a good coat of Duracoat or Ceracoat and she will be sleek, fast and dressed with class.
And yes, I'm tingling!! ;D ;D
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Let's see if we can keep that going for a while... ;D
It's "shop safe", but smoothing it is up to you. If I may suggest? Polish the heck out of the liner. The striker will imbed Teflon into the micro pores, and it will speed things up even more if you do.
I was making 10-15' sections of blue razor wire turning the OD. Good steel, and it will take a mirror polish if you want one. You don't need to get extreme, but a nice shine will have an effect you will feel right off.
I really like the results of your blaster on your .25. Nice and fluffy, but it retained crisp edges. Perfect for any coating I've played with.
This is gonna be a sweet little rifle. 8)
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Let's see if we can keep that going for a while... ;D
It's "shop safe", but smoothing it is up to you. If I may suggest? Polish the heck out of the liner. The striker will imbed Teflon into the micro pores, and it will speed things up even more if you do.
I was making 10-15' sections of blue razor wire turning the OD. Good steel, and it will take a mirror polish if you want one. You don't need to get extreme, but a nice shine will have an effect you will feel right off.
I really like the results of your blaster on your .25. Nice and fluffy, but it retained crisp edges. Perfect for any coating I've played with.
This is gonna be a sweet little rifle. 8)
I'll make sure to polish it once it gets here.. On tubes that size I use a shotgun swab with course to fine (extra fine in my case) polishing compounds and she'll shine like a jewel in a belly dancer's belly button. ;D The peace of mind knowing there'll be no more gouging and or galling of the receiver is priceless because in my opinion there may be more cases of receiver damage coming forth.
DISCLAIMER!! My comments in no way reflect badly on the FDPCP as I knew when I purchased mine (I own 3) they were project rifles. I'm ironing out 'my rifles bugs' and doing what GTA'ers do by making a project gun into a really good shootin iron.
I've started whipping up my Bobcat's valve today (rstern's Maxi Valve) but I got some stuff yet to arrive before I finish. All the preliminary stuff should have been done by now, but the Mrs. had other ideas for my time and just like the TV commercial says "A happy wife means a happy life" plus I learned a long long time ago 'Don't tick off the cook." <BG>
Looking forward to getting the Bobcat and running it through its paces. Thanks stalwart! Thanks a million!! You're the Bell of the Ball (in a Manly way of course).. :-[ ;D
Ya'll GTAers oughtta jump on board to stalwart's Bobcat because his design is a must have to the FDPCP for anyone that wants a magazine.
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I'm very interested in working my way to a .25 FD PCP repeater. It would be good to see a noob-friendly summary.
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I'm very interested in working my way to a .25 FD PCP repeater. It would be good to see a noob-friendly summary.
Yeah, like the whatzit slides into the gizmo, and I polished the whatchamacallit so now it's smooth as a baby's butt, oh and I took the goesinta and cut it down so the goesonta fits. There, now that's what I call noob friendly! ::) :P ;D
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Yarp.
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I'm very interested in working my way to a .25 FD PCP repeater. It would be good to see a noob-friendly summary.
When the 1st one is done, I'll sum it up here. Anything you need to know in the meantime, I'll be happy to answer in email. Poke the little envelope.
You're the Bell of the Ball (in a Manly way of course).. :-[ ;D
In a Manly way?? Oops... I spent the rent on this gown and these cursed heels! I can't return the dress, it's covered in cutting oil and chips. Maybe the shoes will clean up enough...
Yeah, like the whatzit slides into the gizmo, and I polished the whatchamacallit so now it's smooth as a baby's butt, oh and I took the goesinta and cut it down so the goesonta fits. There, now that's what I call noob friendly! ::) :P ;D
Well put! That would have taken me 3 paragraphs to say. May I quote you on my site?
I'm not sure how much a flow thru bolt will speed things up, but Mike will find out for us.
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I'm very interested in working my way to a .25 FD PCP repeater. It would be good to see a noob-friendly summary.
When the 1st one is done, I'll sum it up here. Anything you need to know in the meantime, I'll be happy to answer in email. Poke the little envelope.
You're the Bell of the Ball (in a Manly way of course).. :-[ ;D
In a Manly way?? Oops... I spent the rent on this gown and these cursed heels! I can't return the dress, it's covered in cutting oil and chips. Maybe the shoes will clean up enough...
Yeah, like the whatzit slides into the gizmo, and I polished the whatchamacallit so now it's smooth as a baby's butt, oh and I took the goesinta and cut it down so the goesonta fits. There, now that's what I call noob friendly! ::) :P ;D
Well put! That would have taken me 3 paragraphs to say. May I quote you on my site?
I'm not sure how much a flow thru bolt will speed things up, but Mike will find out for us.
I'll have my lawyer contact you to work out the royalties. :P
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Have him contact mine directly at: goodluckwiththat@biteme.com.
I'm sure they'll work something out...
;D
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Have him contact mine directly at: goodluckwiththat@biteme.com.
I'm sure they'll work something out...
;D
His email is killalllawyers@billycarter.com :P ::)
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LOL... that makes 2 historical Williams that felt that way...
I love this place... always good for a chuckle.
;D
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The first experimental .25 bolt. I'm not sure if it's worth it to shape the inside of this nose to aid flow, but I'm tempted to fill the nose halfway with epoxy, and mill a nice curve with a ball end mill (that I don't yet own).
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Nice, but was it necessary to reduce the diameter of the portion where the barrel port will be that much?.... I assume the larger OD is where the O-ring is?.... If the nose can be larger, so can the flow-through hole, right?....
Bob
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Yes, the larger portion fits the ring, and begins at the rear of the port. On the .25, that reduction matches the play of the bolt. To go bigger without interference, and get that last bit of speed, will require either a liner, a sleeve or a custom bolt. The nose could be tapered, and the mag's wheel could be chamfered, I suppose.
I'm seeking a good universal (and cost effective) fit, first. Then, we head for the bleeding edge.
I'm always open to ideas here... ;D
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If the problem is feeding through the mag, possibly just a radius on the front edge to start it?.... As long as you can get a 3/16" hole through the bolt it probably won't matter anyway....
Bob
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What the heck... let's try it. The tube wasn't cheap, but there's 7' 10 3/4" left of it. ;D
The 1st one slaps home, just the way I like 'em. We'll go bigger until that changes... see where we end up.
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.190 port, and .197 passage. This is the limit... any bigger passage (smaller bevel) turns it into a hole punch. You can feel it contact the mag's wheel, but it still slaps home.
.25 guys will get both this and a probe. The probes will probably be faster, but the flow thru seat any pellets perfectly. There's just enough room for a slotted receiver port, so I can slot the bolt port to match.
As Bob knows, when I said there was barely room for all this, I wasn't kidding.... but, enough is enough!
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Will this stuff fit a second gen XS60C or only the first gen?
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What is your goal for port sizes on the exhaust port and barrel port?.... any throat work?....
Bob
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What is your goal for port sizes on the exhaust port and barrel port?.... any throat work?....
Bob
Funny you should mention that... the limit appears to be .190 x .240 for a slot, and I have a crazy idea for throating these (somewhat) cost effectively. More if it works... tooling is the thing right now.
What do you think is the max port we could actually put to use?
Will this stuff fit a second gen XS60C or only the first gen?
Gen1, Gen2, and Umarex Fusion. Frankly, I'm surprised no one has asked about building a .22 Fusion repeater. It's on my bucket list. 8)
BTW, if anyone wants to put a prebuilt Bobcat, or MRod set up on a credit card... I have orders gelling for PA, McMC, and Little Machine Shop. We could work something out that would happen very quickly. I built spares of everything.
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You need at least 3/16", more than that is gravy.... On my Hayabusa I managed boresize porting straight through, but that is a 130 FPE in .257 cal.... You can't utilize that much power in .250 cal.... the bullets aren't heavy enough....
Porting is one of those strange things.... open it up lots and you gain power but lose shots, and lower the pressure of the peak velocity.... Adding hammer spring then increases the power even more as you move the peak to higher pressure, but of course even fewer shots.... It's all a balance....
Bob
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Is there any reason a flow thru bolt, with replaceable noses with graduated ports, couldn't be used to tune?
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.22 Fusion? We might be able to work something out. I want to go the other direction. Take the barrel and LDC setup from a fusion and put it on an XS60C pcp. Mostly for the fact that making it a PCP is done and I like the wood stock better.
How much is a bobcat? If you don't want to answer here just email me, or pm or I can email you.
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The Bobcats are .22 only, as the PRod mags are only available in .22.
I have some Mrod set ups that are cut and coated, and a few cut and still raw (you smooth and paint). You can choose to have a fixed or removable barrel. Turnaround is pretty quick now, thanks to the early buyers. Email me if that would work for you.
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It occurred to me that an alternative to graduated noses for the bolts, for tuning, a threaded nose with the largest possible opening could be shimmed (or lock-nutted) to "misalignment" with the exhaust port in accurate amounts to restrict the flow to whatever is best.
Is this a dumb idea?
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Have you honestly ever had a dumb idea?
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Similar idea to my probeless retracting bolt with a screw adjuster so it can't be fully retracted.... I was able to dial the power down to about 5 FPE from over 100.... No reason that rotating the nose of the bolt to gradually choke off the barrel port can't work the same way....
I don't suppose you could just vary the angle of rotation of the entire bolt by changing how far the handle drops down in the slot?.... Maybe not enough height to be 100% effective and still lock reliably?....
Bob
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Have you honestly ever had a dumb idea?
I would say no... but there is a divorce lawyer, an easy dozen ER docs, and countless bystanders who would vehemently disagree with me. Putt on over to my shop sometime, Bill... it's becoming a museum of huh??
:-[ ;DSimilar idea to my probeless retracting bolt with a screw adjuster so it can't be fully retracted.... I was able to dial the power down to about 5 FPE from over 100.... No reason that rotating the nose of the bolt to gradually choke off the barrel port can't work the same way....
I don't suppose you could just vary the angle of rotation of the entire bolt by changing how far the handle drops down in the slot?.... Maybe not enough height to be 100% effective and still lock reliably?....
Bob
Just checked. You guessed it... takes too much of the throw.
When I grow up, I want to try a retractable bolt like yours. Elegant.
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Then when we start to vary the port location there will be room for a bolt with a thumbwheel (and detents) to allow quick, easy adjustments. We could stagger a couple detents for fine tuning, or just make it a 4 speed.
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How about a 2-speed.... Plinking and WFO.... An insert to restrict the flow for plinking....
Bob
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A .190 port goes from open to fully closed in roughly 90*. Lots of room for graduating. A fine thread wouldn't allow much extension in 90... not enough to worry about.
What's the max port for a .177? Maybe a 3 speed?
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Most PCPs are pretty happy with a port that is 75% of boresize.... 0.134" for .177, 0.162" for .22 cal, and 0.188" for .25s.... The thing is, you REALLY need to choke up the port to do very much.... Here is what happened on my .30 cal Disco Double....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/30DiscoDoubleAdjusterSettings_zpsef00c07a.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/30DiscoDoubleAdjusterSettings_zpsef00c07a.jpg.html)
Note that it took choking the port to only about 8% of WFO area to cut the velocity by 50% (and the FPE to 25% of maximum).... With the bolt fully closed, it was just getting blowby between the OD of the probe and the ID of the chamber.... WFO was a 0.220" port on a .30 cal (73%)....
Bob
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I like what I'm seeing here.
What's your gut tell you CO2 would require?
With just good tolerances, we could very nearly shut it off. I think this is gonna work... ;D
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A .190 port goes from open to fully closed in roughly 90*. Lots of room for graduating. A fine thread wouldn't allow much extension in 90... not enough to worry about.
What's the max port for a .177? Maybe a 3 speed?
This thread was interesting up until the point you guys started speaking in Greek. :P :o
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A .190 port goes from open to fully closed in roughly 90*. Lots of room for graduating. A fine thread wouldn't allow much extension in 90... not enough to worry about.
What's the max port for a .177? Maybe a 3 speed?
This thread was interesting up until the point you guys started speaking in Greek. :P :o
And they said I was too dumb to ever become bilingual... HA!
:P
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CO2 doesn't "require" different port sizes, it just doesn't produce as much velocity for the same pressure as HPA because it acts "thicker".... I've found that 700 psi HPA works virtually identical to CO2 at room temp (70*F = 850 psi).... What you will find is that the hammer strike required for CO2 is MUCH less or you will be wasting gas like crazy.... after all, it takes much less to open the valve against 850 psi than it does against 1500 (or 3000!).... The thing is, unless you start dialing back the hammer strike when you change over to CO2 you will never notice how much gas you are wasting....
If you want the ultimate CO2 plinker / target shooter then dial the hammer strike back maybe 100 fps below what the gun is capable of and then start playing with it at different temperatures.... When you get it just right, the velocity will be stable over a WIDE range of temperatures, and the shot count will astound you !!! .... What you have done is get the valve to self-regulate vs. temperature just like an unregulated PCP does vs. pressure.... Cute trick !!!
Bob
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This thread was interesting up until the point you guys started speaking in Greek. :P :o
I haven't read any Greek,,,,, just some Geek, but I understand Geek. ;D ;D ;D
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Good advice!
With CO2 being thicker, does it take less of a percentage (of WFO) to close it enough to halve it's speed? In other words, would CO2 have a similar curve?
Bart, I'm this close to needing a translator... glad you're here!
;)
It's precisely my lack of knowledge of the behavior of different gasses at different pressures that makes all this interesting. If, for example, CO2 did not require as much restriction to drop steeply in power... the tolerances needed for the bolt (with a true plinker setting) might be cheaper to reach (and sell). Don't know... but I have to think that way. I wasn't born rich, but if I was, it would all be gone by now anyway...lol. Into tooling.
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Likely that is the case, but I never tried it.... If you put any faith in "sonic choking" of the flow through ports then CO2 requires a larger percentage of boresize for a given velocity, because the speed of sound in CO2 is lower, about 917 fps instead of 1130.... For example a 75% boresize port will in theory be "sonically choked" at about 636 fps (pellet velocity) in air and only about 516 fps in CO2.... That means that IN THEORY the velocity in the port will reach the speed of sound at that velocity.... It is based on the area of the port compared to the caliber.... 75% diameter is only 56% of the area, so the idea is that the air will reach the speed of sound at only 56% of the speed of sound in the gas....
It's a neat theory, but if it's true there should be a HUGE decrease in efficiency when that happens because the shock waves in the port would restrict the flow even more than usual.... I'm not so sure it really means anything.... I suppose there could be some effect where when the pellet reaches that velocity (part way down the barrel) then less air flows through the port, and more of the work has to come from the air in the barrel expanding.... Perhaps that is why the efficiency drops off drastically after the valve has been open for 1/3 - 1/2 of the barrel length.... I haven't thought about it that way before.... Don't you love learning as you type?....
Bob
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I do.
I had not heard of sonic choking until now. I've been re-reading and digesting...
Time to cut metal and ponder all this. I believe I can make a nice proto to fit a single shot, and it will help determine the distance of the repeater's port move. I figured only a big bore would need striker room, but now there's another reason to stretch a bit.
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And we come back to the sonic velocity in gasses. I have not been able to find the speed of sound in compressed air. :( I have been able to find nomograms for atmospheric pressures. IMHO the speed of sound should drastically increase at the pressures we use. We are getting closer to liquefaction pressures, aren't we. ::) The SOS is density dependent, therefore higher density equals higher SOS. ;D If I am out to lunch, point me to the math. ;D
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The speed of sound mostly varies with TEMPERATURE, not pressure.... It changes with altitude, and people think that is because of reduced pressure, but it is actually because of reduced temperature.... I have not been able to find good information on the speed of sound at increased pressures either.... If anyone has that, please point us in the right direction.... I read in one paper that the speed of sound is relatively unaffected by pressure even at 1000 psi.... Air acts nearly as an Ideal Gas up to 3000 psi, only above that does the "close packing" of the molecules start to become important....
Bob
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I wonder if the lack of info is because of the difficulty of designing the experiment. ::) A large pressure vessel, with a sound source and a mike. How hard could it be to seal the wire holes? ::) ;D :P Would your shoebox be able to fill the vessel required,,,, in a reasonable time frame? ;D ;D ;D ;D :P :P :P
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From what I have read, the speed of sound in an ideal gas varies with temperature, not pressure.... so based on that there should be no significant change in HPA below 3000 psi....
Bob
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Sonic Choking discussion moved here.... http://www.gatewaytoairguns.org/GTA/index.php?topic=66737.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=66737.0)
Sorry for the temporary hijack.... *grin*
Bob
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No apology necessary... ;D. Every time you post stuff like this, some of it rubs off on me.
Currently simmering in my cracked cranium are both sonic choking, and Ideal Gas. 2 things I wasn't aware existed until now...lol.
Ever get the feeling that there is a "lightbulb" moment coming, but you have no clue to it's ETA? Where things start to make sense, but not yet enough to prove it? Happens a lot here, and, frankly, I get real enjoyment out of that feeling. Love GTA, and I'm becoming rather fond of guys here who keep it interesting by sharing what could easily be used, instead, to intimidate or humiliate.
In essence: Thanks for the hijack, Bob. Please... let it soak in a bit, and then do it again?
;D 8) ;D
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I graduated high school in 2006, I was 50 years old. (slow learner) However, in the 10th grade in 1972, I was presented with a challenge to reduce tool change time on an 8 station Bullard. I was paid $75 for this mechanical drafting class project. You may not believe this but, my idea was to make a 3 sided cutting tool that could be changed by simply loosening a set screw and rotating it 33*. That cutting tool is industry standard today. Life happened and I never finished high school. When I went to work for a Honda supplier as a die maker/tech, a high school diploma was a requirement to advance to level 2. I went and took the GED and passed it. Altho I couldn't work my way thru the pencil sharpening stage of what you guys are achieving, I get it and I love reading it.
Thanks.
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Stalwart
I am interested in your Prod mag conversion. Have you got tooled up to make the mods cost effective yet or not. I would like to know what you would have to charge for this to perform this mod. I sure many others out there would have a interest in having this service available for a reasonable cost. Please let me know
Thanks Mike
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Bill, I think Betty Lou should thank her lucky stars we don't live within a half hour of each other. I buy Midnight Oil by the drum here. ;D
Guys, I got the adjustable bolt function proto made. I just don't have the legs to test it today... soon, I hope. I went with 4mm port and passage, to match the stock barrel... to keep it simple. It's set up to go from open (shown) to closed within the space needed to reset the screw. Single shots can have a really cool click adjuster (by shortening the tray slightly to fit) and the repeaters, if stretched, can have it too. I used a repeater barrel in this one just to speed up getting into testing. I'll find out how many degrees it takes to get a good range of power, and build to that number. Stay tuned, this is gonna happen.
Mike, best I can do atm is the Bobcat @ $***. With 10% going to GTA, Paypal getting it's slice, and my time/costs to handle CS, receiving and shipping (not to mention the cost of production)... the only way I can make these any cheaper is to sub some of the operations out. I looked into that, and given the current economy, I can't afford to have 50 pieces made... freezing this project until most are sold... so I can sit and hope someone doesn't undercut me (easy, if you don't give a d**n about how stuff fits, prefer imitation to innovation, and incurred no R&D costs) and leave me beside the road choking on a bunch of quality work.
The daring ones who bought the first batch covered the tooling needed to get to this point. They made a reasonable turnaround time a reality. If someone wants to get real daring, and order 20... we can talk about knocking the price down. If I can't make my shop rate on these, I have a lifetime's worth of other (albeit less fun ;D) work that will. This is my 40th year of self employment, and I have never had a sign, or even needed a business card. My work has always spoken for itself... and my customers have always, unbidden, taken care of advertising.
I have seen posts that say things like "If I had a mill, I'd do it myself". I want to know who makes a mill that can cut an ID ring groove... or cut a precision chamber. I gots to get me one! ;) I can't even find a mass produced ID groove cutter small enough, or an OTS chamber reamer. I strongly suspect that anyone who can't even see the tooling and processes involved here, probably can't do a quality imitation of my work... so, they just give me a chuckle... no worries.
Sorry about the long answer to your question, Mike! It's been building up for a while, fueled by the comments I get stating that I'm charging too much for mods to a "$100" rifle (thereby demeaning not only my work, but the entire concept I have spent so much developing)... said by guys who have no problems applying hundreds to $40 pistols (using only a screwdriver). ;D
Short answer, more appropriate: $*** Bobcat, $*** drop in...smoothed (no exchange needed), $*** Teflon, slick kit, assemble and shoot.
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Folks who complain about your prices don't have a clue about what quality work is and what it takes to get it. Yeah, it's "only a $100 rifle" - and that is what makes it so attractive to work on. :) Shucks, what keeps us playing with Crosman 2240's and 1377's and such? Because we can pick them up cheap and play around with them, learn something and maybe turn them into good shooting platforms - with what to many is "pocket change". Notice that there aren't that many folks dinking around with Theobens, Daystates and FX's - because they tend to start out needing less than the cheaper rifles and few folks have the $$$ necessary to make them willing to risk messing up the rifle while learning how to make it sing a different tune.
The prices you charge, by the way, are on the customer's rifle - correct? So take a $100, add your max $180 to it and you're still talking not much more than the cost of a Discovery but in a repeater format all slicked up. Yeah, it'll only take 1,500 PSI - but can be tuned to provide a couple of magazines worth of ammo as rsterne has shown us.
With the state of the airgun game in my current country of residence I'm not much of a customer prospect for you - but I'm a great admirer. It's been fun sitting on the sidelines watching this come together. And thanks for donating to the GTA through your project as well.
I'm one of those guys who wishes he had a mill and lathe - but also realizes that the quality of work that a master mechanic turns out takes a lot time to acquire and a lot of chips - not to mention the "random art pieces" that result from the learning process. ;D
Again, thanks for "thinking out loud" on the forum. It's truly a pleasure to see these projects come to fruition.
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I can totally agree with you...:) I wish I could get one of those mills you mentioned..:) I started out in life wanting to be a machinists but that did not work out. Finally after I got old and retired I was able to pick the trade up again but on very limited basis. People do not realize the time it takes to do the work up and prototype stuff. Not to mention the testing etc. I prolly have more scrap from my projects than actual finished and working parts. Yes I understand where you are coming from.
But I know guys who will put a $2000.00 scope on a $200.00 air rifle...:) And there is always a demand for good quality work and parts. Lots of folks with $100.00 pistols that have literally hundreds of dollars of modified parts they have bought for them.
It is good to think out loud.
Gene
Bill, I think Betty Lou should thank her lucky stars we don't live within a half hour of each other. I buy Midnight Oil by the drum here. ;D
Guys, I got the adjustable bolt function proto made. I just don't have the legs to test it today... soon, I hope. I went with 4mm port and passage, to match the stock barrel... to keep it simple. It's set up to go from open (shown) to closed within the space needed to reset the screw. Single shots can have a really cool click adjuster (by shortening the tray slightly to fit) and the repeaters, if stretched, can have it too. I used a repeater barrel in this one just to speed up getting into testing. I'll find out how many degrees it takes to get a good range of power, and build to that number. Stay tuned, this is gonna happen.
Mike, best I can do atm is the Bobcat @ $110. With 10% going to GTA, Paypal getting it's slice, and my time/costs to handle CS, receiving and shipping (not to mention the cost of production)... the only way I can make these any cheaper is to sub some of the operations out. I looked into that, and given the current economy, I can't afford to have 50 pieces made... freezing this project until most are sold... so I can sit and hope someone doesn't undercut me (easy, if you don't give a d**n about how stuff fits, prefer imitation to innovation, and incurred no R&D costs) and leave me beside the road choking on a bunch of quality work.
The daring ones who bought the first batch covered the tooling needed to get to this point. They made a reasonable turnaround time a reality. If someone wants to get real daring, and order 20... we can talk about knocking the price down. If I can't make my shop rate on these, I have a lifetime's worth of other (albeit less fun ;D) work that will. This is my 30th year of self employment, and I have never had a sign, or even needed a business card. My work has always spoken for itself... and my customers have always, unbidden, taken care of advertising.
I have seen posts that say things like "If I had a mill, I'd do it myself". I want to know who makes a mill that can cut an ID ring groove... or cut a precision chamber. I gots to get me one! ;) I can't even find a mass produced ID groove cutter small enough, or an OTS chamber reamer. I strongly suspect that anyone who can't even see the tooling and processes involved here, probably can't do a quality imitation of my work... so, they just give me a chuckle... no worries.
Sorry about the long answer to your question, Mike! It's been building up for a while, fueled by the comments I get stating that I'm charging too much for mods to a "$100" rifle (thereby demeaning not only my work, but the entire concept I have spent so much developing)... said by guys who have no problems applying hundreds to $40 pistols (using only a screwdriver). ;D
Short answer, more appropriate: $110 Bobcat, $160 drop in...smoothed (no exchange needed), $180 Teflon, slick kit, assemble and shoot.
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Thanks for understanding, guys. :)
I'm tickled pink here... Shooting from my desk, no chrony, at 5m, I just tuned the bolt back and forth from slow enough to watch the arc... to huge muzzle blast and ripped bean can. CO2, decent tolerances (but nothing extreme).
Chuckles tonight... numbers tomorrow.
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Hear! Hear!
But understand stalwart is correct in what he says in opening his heart. There's a lot that goes into turning out a safe high quality product. Look at the collaborated openness in forum and think about the behind the scenes collaborations that go on to turn out a safe high quality product. I have a lathe and mill but not the years of experience (tooling, metallurgy, setup experience, etc.) to turn out stalwart's more than reasonably priced product so I was more than willing to take the plunge for a Bobcat plus he has another of my 60's for another conversion when that comes, and it will come, stay tuned. This man's genius is still not tapped and don't forget the genius of others whom are more than willing to share their years of experience for our passion, airgunning. Stay tuned, there's more to come.
Bill, I think Betty Lou should thank her lucky stars we don't live within a half hour of each other. I buy Midnight Oil by the drum here. ;D
Guys, I got the adjustable bolt function proto made. I just don't have the legs to test it today... soon, I hope. I went with 4mm port and passage, to match the stock barrel... to keep it simple. It's set up to go from open (shown) to closed within the space needed to reset the screw. Single shots can have a really cool click adjuster (by shortening the tray slightly to fit) and the repeaters, if stretched, can have it too. I used a repeater barrel in this one just to speed up getting into testing. I'll find out how many degrees it takes to get a good range of power, and build to that number. Stay tuned, this is gonna happen.
Mike, best I can do atm is the Bobcat @ $110. With 10% going to GTA, Paypal getting it's slice, and my time/costs to handle CS, receiving and shipping (not to mention the cost of production)... the only way I can make these any cheaper is to sub some of the operations out. I looked into that, and given the current economy, I can't afford to have 50 pieces made... freezing this project until most are sold... so I can sit and hope someone doesn't undercut me (easy, if you don't give a d**n about how stuff fits, prefer imitation to innovation, and incurred no R&D costs) and leave me beside the road choking on a bunch of quality work.
The daring ones who bought the first batch covered the tooling needed to get to this point. They made a reasonable turnaround time a reality. If someone wants to get real daring, and order 20... we can talk about knocking the price down. If I can't make my shop rate on these, I have a lifetime's worth of other (albeit less fun ;D) work that will. This is my 30th year of self employment, and I have never had a sign, or even needed a business card. My work has always spoken for itself... and my customers have always, unbidden, taken care of advertising.
I have seen posts that say things like "If I had a mill, I'd do it myself". I want to know who makes a mill that can cut an ID ring groove... or cut a precision chamber. I gots to get me one! ;) I can't even find a mass produced ID groove cutter small enough, or an OTS chamber reamer. I strongly suspect that anyone who can't even see the tooling and processes involved here, probably can't do a quality imitation of my work... so, they just give me a chuckle... no worries.
Sorry about the long answer to your question, Mike! It's been building up for a while, fueled by the comments I get stating that I'm charging too much for mods to a "$100" rifle (thereby demeaning not only my work, but the entire concept I have spent so much developing)... said by guys who have no problems applying hundreds to $40 pistols (using only a screwdriver). ;D
Short answer, more appropriate: $110 Bobcat, $160 drop in...smoothed (no exchange needed), $180 Teflon, slick kit, assemble and shoot.
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Guys just have no concept of the time it takes to do machine work by hand.... or the costs of CNC machines to automate the process.... If you asked them to work for a couple of dollars an hour they would look at you like you were a space cadet, but that's about what I make when I sell one of my prototypes, if I'm lucky.... and ALL of that money gets rolled back into tooling.... That is why I refuse to do work for others making parts or guns.... Even being retired there aren't enough hours in the day to do my own projects....
Sounds like the rotating bolt nose is working great.... Can you index it without removing it from the gun?....
Bob
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Guys, the temptation to express my gratitude with a hideously long (and , let's face it... mushy) post is great, but your obvious understanding of this situation makes me believe I can better do it in 1 sentence:
Gentlemen, it is an honor to be in present company... every one of you.
Now, let's have some fun! Bob, the stocker's got enough room to fully adjust, in seconds. At 0*, it runs 355fps, at 45* it hits 490, at WFO... 586. ;D The gun needs tuning and bigger ports, but worked perfectly to show a curve very much like your graph... maybe a bit gentler (the CO2?). I need to get some stock to make the clicker, but I highly recommend this arrangement, as shown, to anyone with a lathe. When time permits, I'm going to build a .177 and start counting shots. I couldn't be happier with this.
Guys, retirement never meant ceasing work, it is about being able to choose who I work for. So... No kidding here... if anyone refers to Mr. Melick's efforts as a "$100 rifle" within earshot of me, in a tone anything less than appreciative...
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Stalwart I feel the same way about all the armchair machinists and know it alls out there. Can be darn frustrating, I just got done building a prototype for an inventor,so he can get his patent work completed.
like to drive me NUTS!! (not that it's a very long trip some days) I tackle some projects that by the time I'm done,I wish I'd never met the person. BUT after reading this thread and other threads here and other sites I cannot get over some of the talent and skill involved.
An old machinist friend and mentor of mine told me one time that he was willing to share his knowlage with anyone( but the quickest way to get thrown out of his shop was to say to him "all you gotta do is" his reply GET OUT!!!) rant over!
great thread and site!! keep up great work
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It's pretty clear I'm in good company... ;D I'm not suggesting we unionize and strike, but it might not be a bad idea to periodically point out the fact that, like figure skating, it's not quite as easy as it looks from the stands.
The stocker, turned all the way down, runs at exactly the speed of a 10" .22 P17. They make authoritative 20M gallery guns, spin the spoons like crazy. I'm getting chuckles out of it big time. I'm really glad I tried this, I now have a rifle that plinks with the best, but can be turned, in seconds, into something that can humanely guard a garden from the usual suspects.
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Well, I was wrong. There is room in a single shot for either a clicker, or a set screw arrangement... without modding the barrel.
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Well, I was wrong. There is room in a single shot for either a clicker, or a set screw arrangement... without modding the barrel.
Nice job!! And a very innovative way to control flow externally.
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Thanks! The nose is cut to fit closely, and I'm thinking about slotting the ports. At 355fps, I don't need it to go slower... but I want to see how fast I can make it go without affecting the lowest setting.
I'll follow Bob's recommendations on tuning, get numbers, and we'll get a good look at how much difference adjustments can make. I'd be happy with 350-600 fps, but you know me... can't leave well enough alone.
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The chambers in 60s vary a lot in depth. I cut this nose to just gently nudge the pellets in this one just until they grab. 4mm passage, 4 x 5.5mm port.
With the 4mm round port, the gun adjusted from 4fpe to just under 11fpe with 14.3 gr CPUMs.
I have to dress and polish up the ports, cut the nose free and set up the mounting, then pull the gun down and match the ports. A 4 - 12 fpe rifle would be nice, but I'm hoping I get more on top... it's a lot of work for just a couple.
Any guesses what this could do on CO2? Anyone?
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Hi All
I was wondering if anyone had their "Bobcat" conversions up and running yet? Haven't seen any reports, but may have missed them.
I received mine a few weeks ago, but sadly have issues with the tube/receiver threads. Not anything to do with stalwarts fine machining job, that part is a thing obf beauty.
My problem is the threads on tube are undersized and receiver threads oversize, making for a loose thread in of the tube, and when trying to seal on the square o ring, tube just spins-- basically stripped.
I have a solution, my wizard buddy machinist is going to make a new oversize thread on tube, by about 1/2 mm and the same thread on a piece of steel rod the same bigger size---then use the rod as a tap to chase the receiver threads to fit the tube.
Unfortunately my buddy is in the midst of moving his shop to a larger space, and will be busy for a few more weeks.
So are are there any reports on the Bobcat users out there, love to hear how they are doing
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You don't want to fool around with poor quality threads where the tube and receiver meet.... The end force at 1500 psi is about 750 lb.f.... which means it should be engineered to stand 3 times that, or over a ton.... Make sure your machinist buddy is aware of that.... The threads need to be strong enough to lift a small car....
Bob
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Yes Bob , we've talked about just that problem
I should have taken care to see that the threads were rugged and fit well when I received the gun, But I just stripped it down and sent the parts out for the mod.
If it doesn't workout to a good fit, I'll just scrap the project and learn that lesson. A couple hundred buck loss is nothing compared to an accident
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There is plenty of meat for him to work with... I'm betting he can give you a fit that will be quite reassuring.
All this extra work will give you good reason to finish it up nicely... it will be a great little gun. Worth the trouble... IMHO.
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Matched the ports and throated the valve and chamber. Took quite a while, but it's relaxing work.
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Should I bow or genuflect, Sir Stalwart.
Amazing work..
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Should I bow or genuflect, Sir Stalwart.
Amazing work..
Just kiss his ring. :-* :P
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G, whatever gave you the impression I could afford jewelry??
I turned the single shot up to max, and got a high of 692fps, and a low of 427. I'll have to turn it down a bit, I like the 4fpe. And, although it looks odd, the cheap sight makes it easy to snap shoot with decent accuracy. As a gallery gun, it's a blast.
There's an adjustable repeater in the foreseeable future. :)
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G, whatever gave you the impression I could afford jewelry??
I turned the single shot up to max, and got a high of 692fps, and a low of 427. I'll have to turn it down a bit, I like the 4fpe. And, although it looks odd, the cheap sight makes it easy to snap shoot with decent accuracy. As a gallery gun, it's a blast.
There's an adjustable repeater in the foreseeable future. :)
Was that with CO2?
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Yup. I'll try a stock bolt, to get an idea where this took me (then I'll tune it down a bit), but it's going to live as a plinker with the option of pest control if needed.
Nice thing about carts is that it can be activated after years, if needed, with the tightening of the cap. Have <$60 into it, could toss it behind a truck seat without a second thought. I grabbed it for testing cuz the stock was so so... good excuse to not worry about looks. It's a beater with very good manners... what's not to like about that?
8) ;D
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I had some nylon 6-32 cap screws handy, and tried something I figured wouldn't be too hard. I partially tapped the holes (tapered) so the screws would jam quite solidly just before coming even with the ID, then snipped the heads off. Finished on the lathe.
I used 6 to test, and it works. Feels pretty good. I'm going to try a couple more, for fun, on the next one... you could make this thing bristle with them, if you liked.
Cost pennies. ;D
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I had some nylon 6-32 cap screws handy, and tried something I figured wouldn't be too hard. I partially tapped the holes (tapered) so the screws would jam quite solidly just before coming even with the ID, then snipped the heads off. Finished on the lathe.
I used 6 to test, and it works. Feels pretty good. I'm going to try a couple more, for fun, on the next one... you could make this thing bristle with them, if you liked.
Cost pennies. ;D
"dang" you stalwart!! Your adding so much to my list of stuff to do I'll never get these rifles together!! LOL!!!!
I have to rework my Bobcat poppet (I did the valve myself folks)), it ain't holding air. I'd misplaced the package with PBT that rewinder sent me but I found it today and will be turning some new poppets out of that.
Signed, Having Fun in Illinois.
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As simple as the bolt is, you could make a larger O.D. bolt, if the bolt hole in the receiver is round.
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I had some nylon 6-32 cap screws handy, and tried something I figured wouldn't be too hard. I partially tapped the holes (tapered) so the screws would jam quite solidly just before coming even with the ID, then snipped the heads off. Finished on the lathe.
I used 6 to test, and it works. Feels pretty good. I'm going to try a couple more, for fun, on the next one... you could make this thing bristle with them, if you liked.
Cost pennies. ;D
"dang" you stalwart!! Your adding so much to my list of stuff to do I'll never get these rifles together!! LOL!!!!
Signed, Having Fun in Illinois.
Dear Having Fun in Illinois,
It gets worse. We are so far before the apex of the rifle's developmental curve that it can't even be seen from here. Stay tuned (or, run!).
Ann Landers
As simple as the bolt is, you could make a larger O.D. bolt, if the bolt hole in the receiver is round.
Oh yeah. But, where's the fun in that? ;D
It'll happen... but as it takes more time, it'll cost more. As these early experiments (everyone's) will show, the guns can be successfully taken quite seriously... and custom bolts will not seem so overpriced. I fully expect to see guys producing quality hunters that are stout enough to affix a bayonet to, yet agile, starting very soon.
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Dang Stalwart,
My mind is turning to mush with pages and pages and threads and threads of reading and rereading about these guns. :o ;D
I'm beginning to wonder if I am retaining any of it :'( ;D.
I'm still waiting for my .22 to arrive, (UPS delivery has now been "updated" to tomorrow, hopefully).
It will be quite a while before I can really do much to the rifle in the way of mods, once it does get here. Yeah, the budget is really that tight, and I won't be able to justify spending much on it for a while... so basically "stock it will stay" for a while.
So, for those of us new FDPCP owners who might be in similar situations, what would be your recommendations on the order of things to address straight out of the box ?
here's what I'm figuring will happen when it gets here,
1- open box
2- feel chesher cat smile
3- pick up rifle
4- wipe off drool
5- throughly clean barrel
6- then look like Ralphie pointing it at everything in sight, and imagining myself taking out Black Bart and his buddies
Since it will be here for at least a week or two before I will be able to take it out to go shooting,
and I'll probably take it apart just to see how it's put together,
What would you suggest be the order of things to inspect and address ?
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Dear Having Fun in Illinois,
It gets worse. We are so far before the apex of the rifle's developmental curve that it can't even be seen from here. Stay tuned (or, run!).
Ann Landers
Dear Ann,
I'm tingling <snicker snicker> with anticipation in what's around the corner in this rifle's leaps and bounds development. With that said I so choose to run towards, not away, then embrace this crazy little thing we call airgun fun.
Yours truly,
Having Fun in Illinois.
P.S. Hold my drink and watch this!! ;D
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Dang Stalwart,
My mind is turning to mush with pages and pages and threads and threads of reading and rereading about these guns. :o ;D
I'm beginning to wonder if I am retaining any of it :'( ;D.
I'm still waiting for my .22 to arrive, (UPS delivery has now been "updated" to tomorrow, hopefully).
It will be quite a while before I can really do much to the rifle in the way of mods, once it does get here. Yeah, the budget is really that tight, and I won't be able to justify spending much on it for a while... so basically "stock it will stay" for a while.
So, for those of us new FDPCP owners who might be in similar situations, what would be your recommendations on the order of things to address straight out of the box ?
here's what I'm figuring will happen when it gets here,
1- open box
2- feel chesher cat smile
3- pick up rifle
4- wipe off drool
5- throughly clean barrel
6- then look like Ralphie pointing it at everything in sight, and imagining myself taking out Black Bart and his buddies
Since it will be here for at least a week or two before I will be able to take it out to go shooting,
and I'll probably take it apart just to see how it's put together,
What would you suggest be the order of things to inspect and address ?
Hi Ron,
I have 3 of them and this is basically all I've done and all I'm going to do.
Clean that barrel thoroughly.
Check for a burr inside around the transfer port hole.
Polish the contact point on the trigger seer and add just a touch of moly.
Snip 2 coils off of the trigger spring. Adjust the trigger screw so it makes about 3/16 contact with the seer. (or to your liking)
While you have the bolt out, get rid of the leftovers from the safety (a small spring, a half moon looking thing on a post and a set screw/stop up thru the bottom of the bolt) this has no use and it will jam up your gun if it becomes loose. These are located in the groove on the bolt. If you look at the picture above of the bolt that Stalwart posted, you will see the small hole in the bolt that this stop screw goes in. Moly the bolt.
Put a small nylon shim between the barrel band and the barrel where the stock screw goes in. This will keep the barrel from making contact with the tube/fill cap.
Polish all around the hammer and add a bit of moly.
Drop 3 #113 buna O-rings down the back of the tube before you put the hammer back in. (bstaley mod)
If you remove the rear sight, cut or grind 3/16 inch off of the screws and put them back in. You will see the flats on the barrel when you have it out. the screws help hold it in and straight. Also, inspect the 3 O-rings on the barrel.
Set your power adjuster to about 1 1/2 turns in from all the way out as a starting point for shot count, flat bell curve and power.
Congratulations... you just spent $1.50 for 3 O-rings and a great tune.
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AFAIC, if you add Ron's 6 points to Bill's checklist... you can't go wrong! My Boxer loves the part where I "shoot" up the place (full auto) when I pull a gun out of the box... he knows we're headed to the shop, and he loves it there. He's already nearly as goofy as I am (and I've had a lot more practice).
"Hold my drink and watch this!! ;D" LOL!! Famous last words... on a quiet night, an ER staff can hear them for miles.
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Whoa guys I have a lot of reading ahead of me. My x60c has been down for while had to send it back to mike for surgery... Well looks like I'll get back to you when I knock these 17 pg's out! Wish me luck
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Bill,
thanks for all the tips on the "Budget tune".
It arrived yesterday, and I went down my list.
Cleaned the barrel, wiped up drool, checked for pressure (came w/550ish psi), brought it up to 1500,
(I will let it sit a day or two and re-check for leaks),
and am now basically stuck on my #6 ;)
I may possibly start on your "things to do" list later today or tonight.
Forgive me if this is me just being ignorant, ... and I'm certainly not trying to start a "pro HDD vs. con HDD" argument here.
but it has been my understanding that the "BStaley mod" only benefits guns that are not properly tuned.
(or at least that seems to be the more common opinion, amongst some of the more experienced PCP tuners here).
My Mrod does not have the Bstaley mod, due to it was tuned by Timmymac since new.
( he is a pretty vocal opponent to all HDD type devices).
So I guess my question is,.... "Why would the XS60C be any different ?"
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The M-Rod, has spring tension, a velocity screw, and hammer adjustment screw. An XS60 has an adjustable spring. Is it possible tuners don't like it, because anyone can make an air rifle shoot with the O-Rings, instead of sending them to a tuner and paying $$$$$$ to "tune" it? I am going with the O-Rings and possibly restricting the transfer port, because I want instant gratification! If it had a larger tank, I would regulate, like I did to my marauder, but I don't want to loose air space in the tank.
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And remember, you paid $100 for a tinkerer's gun, nothing more... nothing less. Some were lucky enough to get an awesome shooter right out of the box. Some were not but, with very little effort, they all seem to end up working well. We are all here to help each other. If someone has one that is unsatisfactory, maybe the right questions weren't asked of the right people. I still have one that likes to 'BUURRRP' towards the end of the shot string but, I haven't done all I can to it yet. I have a new spring, I have a delrin spacer, just not installed yet. I haven't polished the hammer yet. I also have a .177 barrel that I would miss if I shot myself in the head with but, I haven't polished the crown and I haven't checked the tranfer port for a burr. Gotta save some things for a rainy day.
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The M-Rod, has spring tension, a velocity screw, and hammer adjustment screw. An XS60 has an adjustable spring. Is it possible tuners don't like it, because anyone can make an air rifle shoot with the O-Rings, instead of sending them to a tuner and paying $$$$$$ to "tune" it? I am going with the O-Rings and possibly restricting the transfer port, because I want instant gratification! If it had a larger tank, I would regulate, like I did to my marauder, but I don't want to loose air space in the tank.
Funny,... I was thinking it might be due to not having all the same adjustability of a higher quality gun.
And remember, you paid $100 for a tinkerer's gun, nothing more... nothing less. Some were lucky enough to get an awesome shooter right out of the box. Some were not but, with very little effort, they all seem to end up working well. We are all here to help each other.
Exactly right you are Bill,
And that is where the beauty of these guns is, and why it has fueled the frenzy that it has, amongst us.
I mean really,... just look at some of the guys who are singing it's praises ! We've got guys here who have well over $10k wrapped up in their collections, but yet they are still "tickled pink' with this little beater's performance !
Think about it,.. just how funny and ironic is that ? LOL!
I fully agree it is what it is,... nothing more, nothing less.
It is a $100 project/tinker toy, that has a pretty darned impressive track record already... and comes with some unique benefits that we dont normally have with our more expensive rifles.
I bought this rifle for a few reasons.
I wanted a decent shooting PCP that I won't be so protective of, or worried about tossing it in the truck, dragging it around, or it getting dings and scratches. I got it to be my "beater gun" ;D
It operates at a much lower max. pressure than most, so that means those of us with big SCBA tanks, can now use the "bottom half" of our tanks and keep right on shooting.
By what the calculators indicate, This is to the tune of 18-19 fills for me,... now how cool is that ? ! ? !
No need to run off to the refill facility as quickly.
How could we go wrong ?
All this, and it is still quite tunable, and modifiable ? Heck Yeah ! I kinda have an itch to crank this little dude up to it's max power, forget about a high shot count, see what it will do and where it will zero with the big Skenko Newboy Seniors at 28 gr., and taking it to the goat farm to be my "Whama-Bamma-Skull-Slamma" on the GS's there. ;D
I wanna see if it will just Knock their Noggins clean off ! haha.
Thank you so much for all your help and suggestions. I feel like I'm playing "Catch-up" with everyone here, haha.
I will follow your lead, and do the Bstaley as suggested, and all the other tips too.
I've not taken it apart yet, but I did do a little tinkering.
I did the shim under the barrel band like you said to stop the barrel from riding the fill cap, removed the rear sights and borrowed the 3-9X40 Simmons from my little pumper, drilled and mounted studs for my extra bipod, added a sling....
(http://i111.photobucket.com/albums/n148/tri5ron/airguns%20-%20other/hollowstock3_zpsae511e0f.jpg)
(http://i111.photobucket.com/albums/n148/tri5ron/airguns%20-%20other/hollowstock4_zpsbd2c8c20.jpg)
And guess what I discovered when I drilled the rear stud ???
The rear of the stock is hollow !
I don't think I've read anywhere about that or seen it mentioned.
(http://i111.photobucket.com/albums/n148/tri5ron/airguns%20-%20other/hollowstock2_zpsfcc19a2d.jpg)
(http://i111.photobucket.com/albums/n148/tri5ron/airguns%20-%20other/hollowstock1_zps9088ac23.jpg)
It sure would be neat if someone was to come up with a little "flap open" sidedoor, or something like the patch holder doors on the old muzzle loader Kentucky rifles !... That little compartment just might be a neat place to store some pellets.
AWwww, the wandering mind and ramblings of a Tinkerererer ! ;D ;D ;D
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Well will ya lookie there. I even have an extra stock I am going to modify to put an on-the-fly power adjuster on. I started sanding the other end to see what the wood looked like but, I've not taken the butt pad off yet. Of all the mods and tinkering on this thread with this gun and I never knew that was there. You are absolutely correct, a perfect stash compartment. Some kind of hinge and click closer.... hmmmmm
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A military steel buttplate will do the trick. Most of the older rifles had a trapdoor in the butt for the cleaning and oiling supplies. The M1 Garand was the first to come to mind. (http://www.e-sarcoinc.com/m1buttplateassemblynew.aspx) It actually may be just the ticket. ;D
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@avator, you will start a thread on that when you get it going right?
Some sort of flap would be an awesome idea, metal plate sounds good, but not as cool.
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I received my Bobcat a week ago but the Honey-do's got in the way of my airgun fun. But I learned a long time ago from my grandfather and father never make the cook unhappy. ;D
First and foremost the overall work is of an artisan who pays great attention to detail, a great job stalwart. All machining, fit and finish is of the highest quality and everything works perfect.
The 7/16" Prod magazine retention button at the breech end of the barrel is concentric ,with the bore and not the barrel O.D. and the Prod magazine fits perfect on the button and in the machined slot in the receiver. The new chamber needs no attention and the chamber sports an internal o-ring at its entrance which seals perfect with the bolt (no o-ring on the bolt on the Bobcat folks) with no pellet hangups upon chambering. Have I mentioned the Bobcat is perfect? ;D
This is just a preliminary review, or Cliff Notes of Bobcat, as more accolades are deserving for this ingenious little repeater that can. Get on board folks because this is well worth the money.
I also received the Slickery Kit which includes Teflon coated bolt(s) and striker that float effortlessly in the receiver. Yes I said two (2) bolts which were sent for me to test, one a probe (now installed) and one a flow through which I will test once I get a viable tune on my end. If you skip back through this thread you'll see pics of these bolts, and the rest of the Bobcat build, and I can assure you it's art with utilitarian purpose in metal.
I'm glad I got on board, if you haven't you should.
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Thank you for the kind words Mike! I'm glad you like it enough to put some time into it... there is so much more that can be done.
I have been looking into striker travel, and it looks like I can double it over stock. Depending on the trigger group position, they come stock with ~13mm max... There is room to go up to 30mm (maybe 32 with extended handle slot), with elongated slots and a custom striker. It looks like there is no need for this, with a typical .22... turning them down seems to be the norm... but I want to find out how much force we can generate without stretching these, for larger calibers. Mr. Stearne has been very informative, with the usual result: Another tool/supplies order. ;D
Been doing tank homework, and I'm coming to the conclusion that he has the right idea for small caliber hunters: Separate refill tank as opposed to carrying all the air on the gun. The thing, as I've stated, I like best about this design is it's agility. Although I can no longer seriously hunt, I still love guns meant just for it.
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Thank you for the kind words Mike! I'm glad you like it enough to put some time into it... there is so much more that can be done.
I have been looking into striker travel, and it looks like I can double it over stock. Depending on the trigger group position, they come stock with ~13mm max... There is room to go up to 30mm (maybe 32 with extended handle slot), with elongated slots and a custom striker. It looks like there is no need for this, with a typical .22... turning them down seems to be the norm... but I want to find out how much force we can generate without stretching these, for larger calibers. Mr. Stearne has been very informative, with the usual result: Another tool/supplies order. ;D
Been doing tank homework, and I'm coming to the conclusion that he has the right idea for small caliber hunters: Separate refill tank as opposed to carrying all the air on the gun. The thing, as I've stated, I like best about this design is it's agility. Although I can no longer seriously hunt, I still love guns meant just for it.
You're very much welcome and deserving of the accolades. A repeater under $250 (FDPCP, Bobcat mod and a couple of Prod mags) is unbeatable.
I also applaud the collaboration between you and Bob in the evolution of the FDPCP. And to Mike Melick kudos in offering this little PCP that can.
I've started a thread requesting advice on tuning my Bobcat as she's breathin heavy but workin hard, very hard, she's a beast. http://www.gatewaytoairguns.org/GTA/index.php?topic=67888.new;topicseen#new (http://www.gatewaytoairguns.org/GTA/index.php?topic=67888.new;topicseen#new)
I have to agree with the limitations of the onboard air. I agree so much I've already put together a Guerilla 22ci tank, Ninja 1500 psi reg and whipped up a filler whip ;D, all which can go into a back pack for refills in the field.
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I would like to see your guerilla tank setup. Please share a pic with details and costs.
thanks
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Messing around with the adjustable single shot, and got a couple 5 shot strings on 1.5K air (stock tube):
0*: 598,602,593,582,576... took 10 pumps to refill.
WFO: 872,865,843,813,782... took 14 pumps.
As a "garden guard", it will work fine. If there is anything left around after 5 shots... I'm not worthy, and whatever is still there qualifies as profoundly handicapped (it's freakin loud!). I'll get a rake, and push it out, before anyone sees us fumbling about. ;D
This guns stays. With the reflex, I can hit with both eyes open... and CPUMs can literally be dropped into the chamber. For gallery shooting, I'll run it on bulk CO2, carts for outdoor plinking, and sitting by the door 1.5K will be perfect. There is a gopher out there I'd like to intro to HPA.
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Sorry for the quick interuption, I just can't help myself...... MY P-!7 IS FREAKING AWESOME !!!! Thank You Stalwart !!!! ....that is all.
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You're certainly welcome, Bill! ;D Frankly, it delights me every time an experienced shooter finds out what makes these so special... and in this case I got a twofer!
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I would like to see your guerilla tank setup. Please share a pic with details and costs.
thanks
For all ye seek ye might as well go to the rsterne original write up, reply #46 in this thread http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.40 (http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.40)
I found the Guerilla 22ci tank on clearance in a Goggle search, the old style Ninja regulator was found on clearance also then boosted to 1.5K using another rsterne thread. http://www.gatewaytoairguns.org/GTA/index.php?topic=40074.msg377677;topicseen#msg377677 (http://www.gatewaytoairguns.org/GTA/index.php?topic=40074.msg377677;topicseen#msg377677)
My pics, then back to the scheduled repeater project. ;)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3699_zpse31e6b17.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3699_zpse31e6b17.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3697_zpsb16e766a.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3697_zpsb16e766a.jpg.html)
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Got some time in on the adjustable single shot... the striker was shaving aluminum, and the gun was locking at ~1750psi. I dropped a coated striker in... doesn't lock @ 2000 psi (high as I intend to try), and after a few rounds of watching the speeds go up (as the Teflon filled the chewed aluminum), it hit it's max. 946,953,967,968,946. It's hanging around 28fpe with CPUMS.
This thing is ready for somewhat bigger pests than I had expected. 8) ;D
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I've got a 500psi difference in the gauge readings between the FDAR pump and the JDS tank.
Is this unusual?
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I can't read the numbers in the photo, but the mini-6K tank gauges aren't very accurate.... The only way to be SURE is to test the gauge on the pump vs. a known gauge....
Bob
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I don't have anything known to compare to, but I did mount a new McMC 4k gauge, and it reads about 20% less. I guess the smart thing to do is to use the FDAR gauge for now, as the benchmark, as it's likely to be the safest. I have to deal with this, though... my resultant numbers may be very conservative.
At 1.8K (?), I'm running 5 shots at ~28fpe. That seems to be pretty peppy! With this gun, I won't need hyper accuracy measuring the charge, but for experiments, I'll need something better.
Any suggestions?
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Eric,
Check your PM's.
If you think that might work, Feel free to post it up in the thread.
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That will work. I'm on it.
Guys, Ron uses an adapter to hook his pump into a dive shop's calibrated setup, to compare readings. I'm a little inland to have a dive shop nearby, but I have friends (including a diver) in Morro Bay. It will be a while, but I'll get results, and post.
Thanks, Ron!
8)
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That will work. I'm on it.
Guys, Ron uses an adapter to hook his pump into a dive shop's calibrated setup, to compare readings. I'm a little inland to have a dive shop nearby, but I have friends (including a diver) in Morro Bay. It will be a while, but I'll get results, and post.
Thanks, Ron!
8)
Just to clarify, It's not my pump that the dive shops use my adapter for.
I told stalwart about my Male/Male Foster adapter that the shops use to fill my SCBA tank.
In other words, they fill my SCBA tank THROUGH the same hose/gauge setup, that connects my tank to my PCP's.
I got the adapter from Tim at Mac-1, when I bought my tank from him.
This might be a idea for all of you who use Hand Pumps,... and want to verify if your pumps gauges are reading accurately.
My thinking is, that the dive shops regularly have their compressors/gauges checked for calibration, due to the fact that they are filling Dive Tanks all the time.
By taking his Hand Pump to a dive shop, and using a Male/Male Foster adapter to connect the Hand Pump to their Filler Hose, he can then pump the Hand Pump up to a given pressure, thus pressurizing the shops Fill Hose.
This would then read out on the shops compressor gauges, and he can compare what the Hand Pumps gauge reads vs. the dive shops gauge.
Any variation can be noted, and then give a better idea of the actual pressure he is putting into the rifle.
of course, you'll probably have to talk to the shop manager to have them allow you to do this, as a regular employee may not quite feel comfortable letting you **come behind the counter**.
So be nice when you ask, and offer to by him lunch of at least offer him $5 bucks for his time.
I get my tanks filled up at a sporting goods store called "Sports Chalet". They have many locations here in Kaliforniaistan. They all have a large Scuba Diving department, and they all have 4500psi commercial Bauer compressors. It cost me $5 to fill a tank.
Doesn't matter if it is my 88 cu ft, or my peanut tank, or if they are empty, or if it has some pressure ... it is still $5 bucks. No problem.
I normally DO still have 1600psi or so in it, due to I've only been using it to fill my 2 Mrods.
My "sweet spot" ends around 1650-1700 psi, and I don't yet have a chrony, so I can only judge this when the poi starts to drop, :( so to play it safe, I normally top them off when they get down to around 1800-1750psi.
(BUT NOW THAT I HAVE A XS60C... Yay !),....
.... they will probably be seeing my tanks down to around 600-500psi. LOL.
ok, not trying to change the course of the thread, so back to our regular programming ;D
Hope this might help any fellow members.
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That will work. I'm on it.
Guys, Ron uses an adapter to hook his pump into a dive shop's calibrated setup, to compare readings. I'm a little inland to have a dive shop nearby, but I have friends (including a diver) in Morro Bay. It will be a while, but I'll get results, and post.
Thanks, Ron!
8)
Or, maybe go to your local Fire Department and ask where, or who, they have to fill their tanks... and go there to try it.
Just a thought.
[on edit]
Oops,... they probably don't use Foster fittings to fill there tanks.
(nevermind)
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Ron, thanks for spelling it all out. Useful post, for sure!
Guys, the cheapest precision gauge at McMC is $100... in case you wondered. LOL... to many of us in Kaliforiastan, that's become significant money (you can push your truck's gas gauge past halfway with that kinda bank!).
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Ron, thanks for spelling it all out. Useful post, for sure!
Guys, the cheapest precision gauge at McMC is $100... in case you wondered. LOL... to many of us in Kaliforiastan, that's become significant money (you can push your truck's gas gauge past halfway with that kinda bank!).
I couldn't find the words so I'll let someone say it. http://www.network54.com/Forum/79537/thread/1132692918/Pressure+Gauge+Accuracy (http://www.network54.com/Forum/79537/thread/1132692918/Pressure+Gauge+Accuracy)
I'm currently looking at two of these http://www.mcmaster.com/#atmospheric-pressure-gauges/=s1zb0b (http://www.mcmaster.com/#atmospheric-pressure-gauges/=s1zb0b) , one in 3K and one in 6K with a 1% +/- mid scale grade A. I'm already using a Harbor Freight gauge, LOL!!, hooked up to my remote filler whip and I haven't blown a 1.8K burst disc yet, another LOL!!, so purchasing the two McMC gauges I have pretty much a mid range reading for the airgun pressures we work in. Here's pics of my whip setup, this will also work on with the pump filler whip to verify the pump gauge.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3705_zps05a5f32c.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3705_zps05a5f32c.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3706_zpse7d48dc7.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3706_zpse7d48dc7.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3703_zps4b54094f.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3703_zps4b54094f.jpg.html)
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As far as the Bobcat I'm making progress with its tune and a bell curve.
1.5K down to 1K (I also setup and am using a 13ci Ninja tank with Ninja reg set to 1.5K using the HF gauge setup. I'll switch the reg to the 22ci bottle when or if needed. )
.046" shim behind 3 - #113, 70 duro o-rings for Bstaley. (.131 valve stem protrusion from striker block)
trigger group full forward (Low Power adjustment)
adjuster all the way to rear (Low Power adjustment)
14.3 CPHP
probe bolt (stalwart's)
teflon coated striker (stalwart, I'm thinking your teflon coated bolt STRIKER is making a BIG difference! You ought to sell them)
18 shots, 730.12 average, 4.2% ES, 16.9 FPE
I'm trying for the 20 FPE range with hopefully 16 accurate shots with OEM barrel.
Any and all input will be greatly appreciated, as a matter of fact I'd never be this far without all your generous input.
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As amazing as this is, I choose to go the uber technical route. I fill the gun til the cheap guage says I have somewhere between 15k and 16k (depending on lighting and blood preasure) and shoot it til it mouse farts, then I fill it again. I must admit, I spend way too much on pellets and little dime sized stickers. But please continue... it makes for great reading. LOL...... just kidding guys.
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The next thing I would do is, use a caliper and start moving the trigger unit aft, (in say .020" increments) until it hit either 20 fpe or 16 shots within 4%. (Or full back.)
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I promised myself that when the first order for a .177 came, I'd twin it and keep one for myself. Done... and, done! ;D
Would someone please explain to Bill that air guns were never meant to be shot for pure enjoyment, and that if you aren't pulling out precious hair while obsessing over numbers that can only be found using electronic equipment... you're doing it wrong! Please?
:P
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The next thing I would do is, use a caliper and start moving the trigger unit aft, (in say .020" increments) until it hit either 20 fpe or 16 shots within 4%. (Or full back.)
I will do this. Thanks.
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I promised myself that when the first order for a .177 came, I'd twin it and keep one for myself. Done... and, done! ;D
Would someone please explain to Bill that air guns were never meant to be shot for pure enjoyment, and that if you aren't pulling out precious hair while obsessing over numbers that can only be found using electronic equipment... you're doing it wrong! Please?
:P
Ignorance is bliss, and I am very blissful in regards to numbers and having fun being ignorant! :P
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numbers shmumbers... I just want to shoot something............with all due respect.
Naa.. you know how I feel about what you guys bring to our sport/hobbie/addiction.
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Well guys, it's almost done... I need your help with shroud/LDC ideas, but she shoots! ;D
I went with a slip coated receiver and striker, set the safety up to quietly click going on or off... without the auto feature (not a fan), and cut a sweet barrel to 11mm.
I can run it dry in about 10 seconds... not LHO speed, but a good way to dispose of pellets. It feeds wad cutters smoothly, should be tons of fun!
Anyone seen an off center shroud they liked? This set up fits o-rings in the barrel band, but I can fab a full length shroud as well. I could sure use some guidance here, my first .177 repeater will get my very first shroud...
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You could try a half shroud like TKO makes for the Fusion/xs60.The best LDCs have used came from Neil Clague.If you are going to make your own you may have your own ideas for a design.Or you could use it without one and just yell"Fire in the hole"before each shot.Anyway, nice looking work.
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Thanks, T.
I want to make something myself. I have a TKO (currently on a long barreled P17) and am extremely surprised how effective they are. It's simple enough.
I'm wondering if there are "rules of thumb" that I can use for a starting point. It wouldn't be hard to simply oversize everything, but I want to keep these agile... and I want this one very quiet.
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Out of the bunch of mags I have here, I found one way off tolerance. If you look closely, you can see the wide variance in the wheel's pellet slots. Some slots required me to poke the pellets in before they would let the cover close. It also had enough offset to the clear cover that it fit tightly in the mag slot. Only takes a couple mins to sweeten them up.
I used a rat tail file (fine) to open the pellet slots, and then laid a piece of 240 grit sand paper on a hard surface, and scrubbed the bottom of the assembled mag on it until everything was even.
Slick as snot, now. :)
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Out of the bunch of mags I have here, I found one way off tolerance. If you look closely, you can see the wide variance in the wheel's pellet slots. Some slots required me to poke the pellets in before they would let the cover close. It also had enough offset to the clear cover that it fit tightly in the mag slot. Only takes a couple mins to sweeten them up.
I used a rat tail file (fine) to open the pellet slots, and then laid a piece of 240 grit sand paper on a hard surface, and scrubbed the bottom of the assembled mag on it until everything was even.
Slick as snot, now. :)
A nice catch and thanks for sharing.
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My pleasure, Mike. As you know, I like my stuff to fit nicely... I enjoy activating stuff, and hearing a little, precise "click". The repeaters are cut to fit a pretty large variety of mag "sizes" without slop, and this one stuffed in the slot OK... but scrubbing it even makes it click like the rest.
By no means do I find fault with Crosman on this. These mags are a heck of a deal, and found everywhere. If 10% need a little sweetening to meet my standards... I'm all in!
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Ran into a .25 cal mag the other day that I couldn't get to work, it would stick and not index properly... I had it apart, reset the spring, even increased the tension, sanded the back of the wheel, fiddled with the tension on the screw.... no go, nada.... Finally found out that the brass pin was pressed in a fraction too far (ie below flush on the outside of the clear plate) and binding on the wheel.... Pushed it back a bit, then set it flush with the outside of the clear cover and no more problems....
Bob
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Thanks, Bob!
I haven't run into that yet... but, I'm going to eventually. Good eye!
8)
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Added a long tube with the threads fitted to the receiver (oversize), and a barrel band precisely reamed to fit it.
I had a weird idea for the shroud... to give me some more volume, without offsetting it into the sight plane too much, I'm hunting some oval tube.
I'm not sure it's going to be worth the work, but homework is cheap, right? If it works, it will be... um... distinctive?
:o
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Are there any .177 pellets that don't fit in an MRod mag?
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t would be a Polymag, if any would not. I only have .22 M-Rod mags, sorry.
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Oval tube sounds like an awesome idea. Will that let it be shrouded without a riser?
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Thanks, Pat. There is .350" of room, I'll get some and see what happens.
I'm sorta hoping for an excuse to come up with a PRod .177 mag... they look so good and clean in a 60... like it was made for them.
Steve, yup. The tubing is on it's way, and it is the perfect size to lay in even with the top of the receiver. If I turn the barrels for it (tight fit), there will be 2 separate chambers that can be tuned to disagree (exhaust at different times).
I'm taking a decidedly low tech approach to all this... I spent decades hurrying up low pressure air (22psi, max), and I plan to just do the opposite of all I learned there. I'll create just what an intake/exhaust specialist avoids at all costs: Aero confusion.
;D If nothing else, I'll learn something, and amuse the experts (again).
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I just measured 2 Polymags, and both were .345.
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Thanks!
If these will rotate properly, it looks like anyone wanting an 8 shot .177 will have to just leave a couple slots empty.
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G shaped slot locks bolt back easily, without making operation clumsy.
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That last thing looks awesome.
Possibly stupid question follows, can you machine the OD of a barrel without changing the ID? I read somewhere here that since airgun barrels are not stress relieved machining the OD would change the ID. I am only asking because I am up in the air about the repeater thing, neat idea but not sure I want it that much, on the other hand a full length oval shroud that works is a "I'm throwing money at my screen, but nothing is happening." situation.
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No. Depending on how the barrel is made, you will get changes to the ID to some degree. The initial size of the bore will determine if that is a problem (or a blessing). I have not come across a loose 60 bore yet, so I haven't seen any ill effect.
Not a stupid question... try again? ;D
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;D
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All repeaters will be shipped with these 2 upgrades, from now on. Slip coated strikers have proven their worth.
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All repeaters will be shipped with these 2 upgrades, from now on. Slip coated strikers have proven their worth.
NICE!!
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So what exactly does slip coating the striker do?
I get that it slides more easily, just unsure of what the improvement is, more repeatability?
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So what exactly does slip coating the striker do?
I get that it slides more easily, just unsure of what the improvement is, more repeatability?
Yes. Although everything I've dropped them into gains some speed... the important things are consistency, reduced lock time, and it makes cocking these feel much smoother.
The oval tube came in... it's exactly what I hoped for!
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So what exactly does slip coating the striker do?
I get that it slides more easily, just unsure of what the improvement is, more repeatability?
Yes. Although everything I've dropped them into gains some speed... the important things are consistency, reduced lock time, and it makes cocking these feel much smoother.
The oval tube came in... it's exactly what I hoped for!
That oval tube is awesome!! And it looks like a side by side shotgun to boot!! LOL!!
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I put a TKO muzzle brake on my 1st gen .22 and I love to shoot it. Need to adjust for more shots, but waiting on a chrony. Awesome little gun shooting clovers at 35 yds 18-20 shots before it starts to string shots. My brother hinted that he'd love to have it. Gotta love this $100 gun! I like the new fill that you put on yours.
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Mike, it sure does. If I put a rib on it, it would look like a bolt action, tube magazine, double barrel. :o Confuse everyone...
Busta, thanks. It's the set up shown in post #43, but I put a shorter Ninja fitting in as deep as possible, shortened the threaded area to need only a couple turns, and shortened the cap. A whole lotta work to lose a tiny bit of length, but I like the look. Not the most cost effective mod. :)
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Guys, RMM's test of the speed difference between a probe style bolt, and a short flow thru with a little contouring, mimicked my results here... There wasn't enough difference to be significant.
I will be cutting the "G" slot into customs on request (holds even the longest probe bolt back for quick mag loading, and makes a great safety), but the flow thru bolt clears the mag slot if the trigger group is set right.
Something to think about, if a repeater is in your future.
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Time frame?
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Not sure yet... hope to do a run soon, you'll know it's done when I post a pic of a pile of them.
It should be noted that both my and RMM's tests were done on air. The stubby flow thru is a bit faster, but that may not effectively apply 1 iota to CO2. The fact that the increase was minor (for the cost) at the pressure and other factors present, doesn't mean that the extra work to contour and fit the noses of the bolts was wasted.... but, it sure didn't prove cost effective under these conditions (free flowing .22s @ <2K). Unless otherwise requested, repeaters will continue to be shipped with a stout probe.
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Time frame?
As Stalwart said we were using air. Fill was 1600 and I shot down to #1 velocity then stopped recording. As you'll note in my graphs, LOL!!, I made sure I was repeating everything to obtain as accurate results as possible. Please field questions and I will answer as best I can, but please be gentle because I'm a virgin air gunner. <GBG>
P.S. Please note on all tests the bstaley (3 - #113 70D o-rings) was installed including the WO test (It was not noted as a constant)
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What would be involved to turn the repeater into a 9oz CO2 tank bulk filled gun? I don't need HPA as I don't shoot in the winter, and I can't afford it anyway. I have a 9oz on my AS2250XT and I love it.
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I have 2 first gen 60c's and would like to try converting one to a repeater. I have read thru all 20 pages here and have not been able to find a "how to" section for this mod. I also noticed some mention of using a Prod mag instead. I know it's a little different than the Mrod but is there some reason it's better for the 60c? Any help would be appreciated.....By the way I never did convert either one to HP air cuz they are just too much fun and plenty of power for backyard on co2...
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George, there is still no better way than that shown beginning on post #104. Still not cheap, but proven.
Gmman, the "how to" situation is answered in post #154. I have a considerable investment here... you'd be surprised.
I have been looking into ways to set the shrouds up to keep the weight as low as possible. Did some research on casting the barrels into the tube... looks encouraging. Resins that can take the temps of curing the powder coat are not cheap, but are readily available. They would make for a very stiff set up, that is quite durable.
The proto shows the finished weight will be at or below that of a stock barrel... which makes me very happy. The addition of a full length air tube pulled the balance point forward about an inch... still quite nimble, but I hope to avoid shifting it further forward.
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Is anyone making that pellet loader for a disco?
Tommy
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BNM make a repeater breech for the Disco that accepts MRod magazines.... well over $100....
Bob
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While supplies last, Umarex Fusion and Gen2 60C conversion customers will have the option of purchasing all metal, sweetened trigger groups. I will be squaring the sears, and giving them a polish. I will cut these to customer's choice of where in the arc the sear's release point is, and mod to eliminate the "2 Stage" if desired.
Combined with the G slot option, you'll have the best possible safety and the best trigger.
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While supplies last, Umarex Fusion and Gen2 60C conversion customers will have the option of purchasing all metal, sweetened trigger groups. I will be squaring the sears, and giving them a polish. I will cut these to customer's choice of where in the arc the sear's release point is, and mod to eliminate the "2 Stage" if desired.
Combined with the G slot option, you'll have the best possible safety and the best trigger.
And the hits just keepon comin. Do you ever sleep?? ;D
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Excellent
More caffeine!
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Mike, I do have periodic episodes of unconsciousness that interfere significantly with my work. It's a bad habit I'm trying to break... with zero success. >:(
Yarp, brew it up! I'm always ready for more.
;) ;D
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Coffee.... The drug of choice for voluntary insomniacs the world over.
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Guys, what would you think of a 60 that had the punch of a .25, but could also run 14.3gr CPHPs (and other fat ones) for plinking or pesting?
I've built quite a few guns with Marlin Micro Groove rimfire barrels, and they shoot well. I want to try one with bullets like these: http://northamericanarms.com/accessories/cb-accessories/cb-parts/cbb250.html (http://northamericanarms.com/accessories/cb-accessories/cb-parts/cbb250.html) , and I'm looking into other options. The NAA bullets will fit in a PRod mag, no problem.
I went straight to the Math Guy, and got this: "950 fps is 61 FPE, so at decent efficiency (boresize ports) that’s 61 CI of air per shot.... The FD-PCP tube is 7 CI x 69 bar = 483 / 61 = 8 shots.... I think there is a good chance to get 1 full PRod clip from 3000 psi down to 2000.... and you’d have something nobody else does.... a 60 FPE .22 cal bullet shooting repeater..."
I have had good luck with Duplicolor bed liner, shot thick and at low pressure for a nice texture, but it only comes in black. I just tried Rustoleum's tan, and got decent results. Here's a pic (including a trace of my mortal enemy...lol... bastid.) before I screw it all up with a local terrain camo job.
I'll post a pic of the finished job, if I don't embarrass myself too much.
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formidable
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Eric,
I've found that if you do a thick base coat of bedliner and then cover with a nice, even top coat of whatever color paint you choose, a lot of the texture remains.
Good Luck.
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This is really cool, it took me forever to read those wonderful 21 pages in this thread. How much is it for the cheapest repeater?
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formidable
Well put.
Eric,
I've found that if you do a thick base coat of bedliner and then cover with a nice, even top coat of whatever color paint you choose, a lot of the texture remains.
Good Luck.
Thanks... I think I'm going to need it... ;D Yours looks great.
This is really cool, it took me forever to read those wonderful 21 pages in this thread. How much is it to just mill the magazine slot and shorten the bolt?
YGPM
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As the MG barrels will be longer, there can be an added 1.3CI to the tube. Yay!
I have no experience with this yet, so I'm wondering if I put the adjustable port bolt in these, will they be a decent tune in both modes.... or, will they have to be tuned either for the pellets or bullets, and the off tune mode's efficiency lived with? After all, it's only air... unless you're the one pumping... ;D Any guesses?
If needed, I could go MG in the adjustable single, and find out... right after I finish a pistol run and a few rifles. Give me some time.
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As the MG barrels will be longer, there can be an added 1.3CI to the tube. Yay!
I have no experience with this yet, so I'm wondering if I put the adjustable port bolt in these, will they be a decent tune in both modes.... or, will they have to be tuned either for the pellets or bullets, and the off tune mode's efficiency lived with? After all, it's only air... unless you're the one pumping... ;D Any guesses?
If needed, I could go MG in the adjustable single, and find out... right after I finish a pistol run and a few rifles. Give me some time.
When you presented an 8 shot monster .22 I was also wondering about a tune for each pellet. I'm still in the experimental stage and learning as much as possible about PCPs and airgunning in general but my first thought would be tuning for a bell curve for one pellet, that curve will not work for another pellet of smaller or greater weight, an assumption mind you. I'm hoping myself one of our forum experts can field this question in layman terms.
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OK, guys, here is the deal.... In an unregulated PCP, making a drastic change to the pellet weight (like from an 18 gr. pellet to a 30 gr. bullet) will shift the curve.... If you tune it for the pellet, the fill, peak, and refill pressures for the bullet will all be lower (and the power down compared to what could be achieved), as the dwell will be way too short for the much heavier slug.... If you tune for the bullet, which takes a LOT more hammer strike, then when you use the pellet you will start off with the first shot the fastest (probably supersonic) and the rest declining.... The only possibility I can see, without a drastic hammer spring preload (or maybe spring) change would be to tune for the bullet, and then restrict the airflow (like with stalwart's bolt restrictor) to drop the power for the pellet.... I'm not sure exactly what the shot string would look like with the pellets, it might be basically flat for a few shots and then drop off gradually, but it should at least be usable.... I have the ability to do this on my Disco Double, but have never used the bolt port restrictor in that way.... It might work just fine.... Hmmmmmmmmmmmmm....
Bob
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OK, guys, here is the deal.... In an unregulated PCP, making a drastic change to the pellet weight (like from an 18 gr. pellet to a 30 gr. bullet) will shift the curve.... If you tune it for the pellet, the fill, peak, and refill pressures for the bullet will all be lower (and the power down compared to what could be achieved), as the dwell will be way too short for the much heavier slug.... If you tune for the bullet, which takes a LOT more hammer strike, then when you use the pellet you will start off with the first shot the fastest (probably supersonic) and the rest declining.... The only possibility I can see, without a drastic hammer spring preload (or maybe spring) change would be to tune for the bullet, and then restrict the airflow (like with stalwart's bolt restrictor) to drop the power for the pellet.... I'm not sure exactly what the shot string would look like with the pellets, it might be basically flat for a few shots and then drop off gradually, but it should at least be usable.... I have the ability to do this on my Disco Double, but have never used the bolt port restrictor in that way.... It might work just fine.... Hmmmmmmmmmmmmm....
Bob
Thanks a million Bob and I think part of my problem was porting (restricting and or increasing) a given air charge (valve dwell) but as I see it now it's just slowing down the charge when it can't be done with dwell to get the pellet down and out the barrel efficiently and effectively. Corrections are definitely in order.
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A heavier pellet, working at the same valve dwell and reservoir pressure as a lighter one, will not have moved as far down the barrel at the instant the valve closes.... The air between the valve and the pellet will therefore be occupying less volume but at a slightly higher pressure (moreso if the plenum volume is small).... This adds to the efficiency, allowing greater FPE to be developed by the same amount of air.... There are a bunch of interrelated things happening, and if you go wayyyyyyyyyyy too heavy the FPE will drop, not increase.... but understanding that will help you understand why a heavy pellet needs more dwell to take advantage of a given barrel length.... If you increase the hammer strike to get that dwell, you gain even more FPE, but then the gun is no longer tuned to work properly with a lighter pellet....
Bob
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A heavier pellet, working at the same valve dwell and reservoir pressure as a lighter one, will not have moved as far down the barrel at the instant the valve closes.... The air between the valve and the pellet will therefore be occupying less volume but at a slightly higher pressure (moreso if the plenum volume is small).... This adds to the efficiency, allowing greater FPE to be developed by the same amount of air.... There are a bunch of interrelated things happening, and if you go wayyyyyyyyyyy too heavy the FPE will drop, not increase.... but understanding that will help you understand why a heavy pellet needs more dwell to take advantage of a given barrel length.... If you increase the hammer strike to get that dwell, you gain even more FPE, but then the gun is no longer tuned to work properly with a lighter pellet....
Bob
Got ya. I will now go back and tune my Bobcat for JSB Exacts 18.13 and use the CPHPs 14.3 for another plinker project. While I got ya on the phone :D what's a good starting velocity for the 18.13s??
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I guess it depends on your port sizes.... but as long as you keep the 18.1's under about 960 fps they'll hit what you aim at, even at 100 yards.... That's probably a little ambitious for a Bobcat, so whatever gives you a decent shot string at the pressure you are using.... Remember, my Bobcat is tuned as a Grouse Gun.... 18.1's @ 710 fps (20 FPE) using a bstaley setup to get 16 shots.... The best string I got with those pellets was 7 shots averaging 900 fps (32 FPE) with some port work done.... All my strings use a 4% ES....
Bob
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OK, further to my comments of June 24, above, I pulled out my .25 cal Disco Double tonight, adjusted it for a decent curve with my 50.6 gr. Bob's Boattails, starting from 3000 psi, and peaking after 5-6 shots at 900 fps (90 FPE).... I then tried a 25.4 gr. JSB King and blasted it through the Chrony at 1190 fps.... I screwed in the bolt stop all the way, got a shot at 830 fps, backed it off a turn, filled back to 3000 psi, and the first shot was 999 fps.... I shot an 8 shot string, which ended at 960 fps (4% ES in a linear down trend) that used about 500 psi of air (so about 0.8 FPE/CI).... In other words, first shot fastest, and not very efficient....
I think this pretty much proves to me that you can't just set a PCP up for heavy bullets and then detune it properly for pellets that are half the weight by just restricting the ports.... You need to also back down the hammer strike to dial back the dwell or you will have poor efficiency and a falling shot string with the pellets.... It may, however, be quite possible to have a two cocking positions for the hammer, one for bullets and one for pellets, to obtain two useful tunes....
Bob
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Bob, I can't thank you enough.
Readers of this thread who have done R&D know how much time and energy Bob has saved me on all this. If you ever see me washing Bob's car, you'll know why I'm doing it so cheerfully. ;D
Ok... The Trans-ammo idea is on hold. Indefinitely. I'll build an MG single for testing, asap... and will be trying the 2 stage striker, once everything else is set in stone.
johninthecamper sent me a bullet sampler, and I'm very impressed. Quality is Top Shelf. We will not lack for good ammo, and the options he can give us are virtually unlimited.
Some numbers I got backstage... I'm getting excited about the .22 Wolverine: "BTW, just ran some numbers.... The 30 gr. NAA bullet should retain 70% of its FPE at 100 yards instead of 50% for a pellet like the JSB Heavy.... and have less than HALF the wind drift (5” vs 12”).... Interesting thread on Wind Drift in the PCP gate.... The NAA bullet can be pushed to 1050 fps (75 FPE) without gaining too much drift.... so whatever we can drive it to will work great, assuming it stays accurate...."
It's gonna be a fun summer!
;D
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Just remember Bob likes 2 coats of wax! ;D I have been following this thread closely and have needed plenty of aspirin to keep up with Bob (failed miserably )
Brian
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Not a problem. Whitewalls, wire wheels, whatever... I'll be whistling while I work.
I tried to get pics, but I'll need some sun to get good relief... I slugged a couple of John's bullets through a MG barrel with stunning results. His dies are true. To quote Brock Samson: "It's freakin' GORGEOUS!".
Edit: Got one.
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Not a problem. Whitewalls, wire wheels, whatever... I'll be whistling while I work.
I tried to get pics, but I'll need some sun to get good relief... I slugged a couple of John's bullets through a MG barrel with stunning results. His dies are true. To quote Brock Samson: "It's freakin' GORGEOUS!".
Edit: Got one.
It looks like you've got a good "skirt" engraved by the rifling. How close of a tolerance is there between the forward part and the lands? There doesn't seem to be any contact at all, no marks along the shaft. This would seem to indicate that the skirt does all the work of centering the bullet in the bore as well as imparting spin and sealing the air in back of it. So I'm curious as to how precise the "bore riding" section fits the bore. Personally I'd like to see just a smidgin of contact to ensure that it rides true and is not cocked a bit to one side or another. Of course, the proof is in the pudding, uh, er, in the shooting and grouping. We'll stand by for the range reports. :)
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The range reports are a ways off...lol. Got to build a gun.
This pic sorta shows what I can see, but cannot seem to photograph. There is enough contact to scrape some felt tip marker off.
Sorry about the bad pics. I'm taking these under a magnifying lamp. I don't know what I'm doing with a camera... I shoot til I get lucky.
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Okeydoke - that looks much better! :) Yeah, details like getting a gun built before shooting the bullets are a drag... ;-) :-D
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Is this the same gun with the oval shroud?
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Okeydoke - that looks much better! :) Yeah, details like getting a gun built before shooting the bullets are a drag... ;-) :-D
These are samples made to give me an idea what I need to change, if anything. The band is .224, and the area scored is .217-.218. I don't think it would hurt to go .220 in the front, but this may fly as is.
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Is this the same gun with the oval shroud?
No, this is a Marlin .22 rimfire barrel I'm going to built into a bullet shooter.
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You sure have lots of stuff going on.
I somehow missed the PB barrel thing. That is pretty impressive work.
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I'm impressed with the appearance of the bullets.... it will be interesting to see if they shoot as good as they look.... What is the weight of the sample in the photo?....
A two-stage cocking hammer may be problematic if you stay with bolt-cocking.... may need a rear cocking design.... not great on a repeater....
Bob
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They are 31 grain.
LOL... I hadn't even thought about cocking the thing as a repeater. End up with a gun that's harder to operate than a backhoe... ;D
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Is the MG going to be PCP or HPA??
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The terms are somewhat interchangeable.... I assume by PCP you mean with a tube, while with HPA you mean using a tank (bottle).... Since either can be regulated (or not) that really isn't a distinction.... I don't know which stalwart is planning (or both), but I assume initially it will use a tube, but constructed for 3000 psi, running right through the receiver....
Bob
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The terms are somewhat interchangeable.... I assume by PCP you mean with a tube, while with HPA you mean using a tank (bottle).... Since either can be regulated (or not) that really isn't a distinction.... I don't know which stalwart is planning (or both), but I assume initially it will use a tube, but constructed for 3000 psi, running right through the receiver....
Bob
Yes I was wondering if it would be tube or bottle and I would say you are correct with the tube Bob. Learning something new everyday,such as, it's all in the terminology. ;)
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Yup... 3K tube. I like the idea of packing the weight of the reserve, off the gun. 8 rapid shots is enough for a hunting gun, around here. Never hunted grouse, but if they'll stick around for more than 8.... I'd definitely gear up for them!
Eventually, I'll build something so hungry it needs an affixed tank. Maybe this winter...
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Yup... 3K tube. I like the idea of packing the weight of the reserve, off the gun. 8 rapid shots is enough for a hunting gun, around here. Never hunted grouse, but if they'll stick around for more than 8.... I'd definitely gear up for them!
Eventually, I'll build something so hungry it needs an affixed tank. Maybe this winter...
Tanks for fulfilling my query. :D
I've been trying to wrap my head around the OEM Chinese springs and their compression rate efficiency and ES. I had a set main spring in one of my 60s, the set was arched, which Mike sent me two more with my 3rd 60 purchase (after all the 60s are experimental and a big thanks to Mike). But I was wondering if custom springs would tighten up the ES along with eliminating as much friction as possible in the chain of moving parts (stalwart's Teflon coated striker). Can anyone, Bob :D, please satisfy my curiosity again??
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There are those who are trying to figure that out. ;)
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A spring guide may help.... I don't know if you will find any more consistency with a spring change, however....
Bob
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There are those who are trying to figure that out. ;)
A spring guide may help.... I don't know if you will find any more consistency with a spring change, however....
Bob
This is a good thing because it shows I'm not the only one thinking about springs. ;)
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Frankly, I'm surprised some enterprising fella hasn't made up a high quality spring and screw kit. Some homework, and a couple hundred bucks... and you'd be in bidness.
If someone hasn't done this by the time I get through R&D here... I will. There are RC guys who pay for a lot of bad habits, and save folks a lot of time, doing just that.
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Mike, I do have periodic episodes of unconsciousness that interfere significantly with my work. It's a bad habit I'm trying to break... with zero success. >:(
Yarp, brew it up! I'm always ready for more.
;) ;D
I swear by grinding beans daily just before brewing, and have a regular Amazon order of
5lb every 2 months of dark roast Celebes Kalossi beans - best in the world- about $45-$50.
(= 6 cents a cup - take THAT, Starbuck's!)
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All repeaters will be shipped with these 2 upgrades, from now on. Slip coated strikers have proven their worth.
SWEET!
-you've got mail...
-Rod
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Frankly, I'm surprised some enterprising fella hasn't made up a high quality spring and screw kit. Some homework, and a couple hundred bucks... and you'd be in bidness.
If someone hasn't done this by the time I get through R&D here... I will. There are RC guys who pay for a lot of bad habits, and save folks a lot of time, doing just that.
Your a good man Eric. Thanks for springing on the wants of others. ;D ;D ;D
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Your a good man Eric. Thanks for springing on the wants of others. ;D ;D ;D
Arrrgh.... Cornball.
;D
Been playing around with strikers, and got a few mm of extra stroke without cutting into the receiver... and about double the weight. Really smacks home, hard.
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Excellent news.... keep up the good work !!!.... We'll need all we can get, eventually, at 3000 psi....
Bob
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Bob, I'm wringing every ounce of energy I can out of this system.
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Nice !
Bob
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It will take a modded F trigger frame mount to clear the striker, but we are in at 30mm stroke, and 90+g of striker.
Double the pleasure... double the fun!
8)
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I like the shortened up valve / striker block idea.... but how are you sealing the back side of the exhaust port?....
Bob
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I'm going to epoxy these together, and put a 016 ring in like the later Bobcats. Given that the DOM tube is far more precise, and will be polished internally, I don't think this is going to require a fat ring. I have to put the (2) 1/4 x 28 backup screws in, then I'll glue, true, and size the combo.
What kind of FPE numbers can we get from this setup?
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I was just looking at the location of the two screw heads.... They are so close together that the tubing wall separating them will effectively have no bearing ability for the front screw, right?.... Imagine if you will the front screw moving back and bending the thin web between as it stays in contact with the rear screw head.... I realize that the shear load from a tear-out point of view is, in theory, lined up with the ODs of the screws, and that is just over one head diameter.... but I can envisage the web between the screws bending to the rear because the only part resisting the valve moving back is the cradle behind the rear screw.... Even if the tube doesn't shear, I can see the valve setting back under load.... Also, where is the O-ring going to seal, there are now 3 holes in the tube?.... (or is that only in the receiver?)
As far as FPE numbers, that will depend more on port sizes, caliber, and bullet weight.... What you are trying to achieve with the striker is enough hammer energy and momentum to allow as much dwell as you need at 3000 psi to develop that....
Bob
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The 2 screws are going to be left with all their inherent slop. They will settle under pressure, as they do stock... but it will be into the (2) 1/4 x 28 screws fully set through the sides of the tube, into the block. Those will have 4.25" of solid tube behind them. This leaves the stock screws to serve as mounting (as well as the 2 back CS screws) for the tube. That's (4) 5mm screws... when I said you could mount a bayonet, I wasn't kidding.
As the entire power plant will be self contained, in the full length tube, I don't have to worry about any extra holes... could swiss cheese the receiver... and as an ex go fast guy, I'm quite tempted to do so, just to see how much weight I can lose. Someday.
Please tell me I have this right: We have all the oomph to do anything that can be done with 3K?
I was just looking at the location of the two screw heads.... They are so close together that the tubing wall separating them will effectively have no bearing ability for the front screw, right?.... Imagine if you will the front screw moving back and bending the thin web between as it stays in contact with the rear screw head.... I realize that the shear load from a tear-out point of view is, in theory, lined up with the ODs of the screws, and that is just over one head diameter.... but I can envisage the web between the screws bending to the rear because the only part resisting the valve moving back is the cradle behind the rear screw.... Even if the tube doesn't shear, I can see the valve setting back under load.... Also, where is the O-ring going to seal, there are now 3 holes in the tube?.... (or is that only in the receiver?)
As far as FPE numbers, that will depend more on port sizes, caliber, and bullet weight.... What you are trying to achieve with the striker is enough hammer energy and momentum to allow as much dwell as you need at 3000 psi to develop that....
Bob
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Ahhhhhhhhhh, yes.... side screws to do the heavy lifting.... I didn't want anyone viewing the thread to think that just those two screws, as located, were good for 3000 psi....
Please tell me I have this right: We have all the oomph to do anything that can be done with 3K?
Well knowing what you (we) have in mind, yes, I think we'll be just fine up to a .30 cal.... Slinging 150 gr. .357 cal bullets at 300 FPE ain't gonna happen with that hammer setup, though.... My Hayabusa .308/.357 uses a 145 gr. hammer with 1.45" of travel.... and the .410/.457 uses a 250 gr. hammer with 2" of travel.... There are two limiting factors that require more hammer strike.... The first is the pressure, the second is the diameter of the valve seating surface.... The force required to open the valve is the product of the two (pressure x area = force).... The 82 gr. hammer with 3/4" of travel I have in my Disco Double will handle 3000 psi and a 1/4" throat or a bit more now that I've gone to PEEK, and bullets up to about 70 gr.... On the other hand a 145 gr. gram hammer with 1.45" of travel is maxed out with 150 gr. bullets and a 5/16" throat in the Hayabusa....
Bob
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Thanks, Bob. For the near future, we are "fat and happy". There is no more stroke possible, without stretching... but the weight can be increased quite a bit ( I made a lot of room). I'll get into that more when we run out of punch... could be a while.
We are just a tiny change (CrMoly + 1 more 1/4" x 28) from 4.5K, right? The 3rd block screw could be converted from 5mm to 1/4" and the block floated... the pin slot needs to be elongated in the receiver only, that 3rd screw could be left with 40mm of backup in the tube itself. Got plans for the Winter of '15? ;D
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As we have far more energy than needed to make the .25s hum, I'm going to limit their stroke to 20mm (and eliminate the need to customize the trigger frame mount) and use the extra room to try an adjustable striker. There is a possibility that I can make one adjustable through the floor of the mag slot. Remains to be seen...
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4.5K?.... I think you need to slow down and get things working at 3K first.... Every change you make causes 2 problems (then 4, 8, etc), and pretty soon you can't find solutions fast enough....
Bob
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I'm almost crying with joy.
I've been so busy with work that I haven't checked any gates for close to two months. I knew I had to come here, first chance I got.
This thread always makes me happy. I love seeing people come together to make magic.
Now for the negative: You punks are making me want a new rifle... >:(
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I'm not going to 4.5 for a while... but it makes no sense to develop a part number, just to add another later. I'm going to set up the tube design to take 4.5 in CrMoly, or whatever comes along... and continue to work with steel at 3K pressures. It's cheap insurance, and allows me to cut a bunch, if I want... and not be sitting on a pile of an early version when the time comes to go big.
IIRC, (3) 1/4 x 28 screws, riding on their heads, will hold 4.5K. No?
Negative? I thought it was written into Law here, that "Ye shall enable, at every opportunity, despite the lamentations of friend and foe..." Or, something like that. Just playing by the rules....punk!
;D
Wondered where you were...
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Ya know.... sometimes just reading is funner than modding or shooting or machining or developing or whatever the heck you magicians are doing.
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You're pushing it.... Safety margins are 2.4:1 to yield on the tube and 2.3:1 on the bearing area.... but yeah I think it'll live.... but only because the SM to burst on the tube is well over 3:1.... I was more referring to what would be required to knock open a valve against 4.5K of pressure.... Even with 1/4" ports and a slim seat, you are talking 277 lbs. force just to crack the valve.... Got room in there for a balanced valve design?.... and the time to machine it?....
Bob
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Those answers remain to be seen, but we sure have a high ceiling to work under.
What would the longest useful range of travel be, for an adjustable striker?
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Ya know.... sometimes just reading is funner than modding or shooting or machining or developing or whatever the heck you magicians are doing.
You're right... and I do a ton of it here. Just wish more would stick in my withered bean.
;)
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IMO there is no need for an adjustable travel except to tune a bstaley setup.... Since the #113 O-rings are 0.103" thick, then about 0.10" is all the travel you need.... Since you can get "backer rings" which are half thickness, you really only need half that.... and since you have the option of using a #016 (which is 0.070") and some #113s, in various combinations, you might get away with even less.... A more important question is how much room do you have for the O-ring buffer with the longer striker?....
I will never build an adjustable striker again unless it's to tune a bstaley setup.... Every time you reduce the striker travel you just have to wind in more preload, so why bother?.... Set the gun up with the striker weight and travel to do the job you want with a reasonable spring and use the preload for all your tuning.... KISS....
Bob
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I have 10mm more to work with. The Wolverines (.25 and .22 bullet) will be limited to 20mm stroke. We don't need more, and why increase the lock time? I have room for far more weight than they'll ever need.
I think I can make this happen.
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A three x #113 O-ring stack (0.31") is all you need, or two plus a backer ring (total of ~1/4").... maybe 1/8" travel on the striker to be able to easily tune it.... For the Wolverines I can't imagine you will ever want to decrease the power by going bstaley, but sounds like you have the option....
Bob
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Well. I'm sure the more sadistic among you will be pleased - I've officially gone over to the dark side.
After a long talk with the VERY accommodating Mr. Mike, I have ordered what I like to call a 'fakie' Gen 1 - a .22 GenII (unfortunately still not for $100) with no plastic anywhere, and a Power tune. And a pump of course (I'm already engineering a steampunkish way to power-automate the thing - just in case. WAY cheaper than a shoebox if you can weld and have lots of gokart parts and sources. ;)
Eric, we'll be talking next month about that repeater - if I can let it out of my hands that soon ;)
I just may have to wait until I can also afford a bottle and we can do the 24"(+?) bbl, extended tube thing.
(depending of course on how this bbl is..)
Then there's a chrony, fill tank, and a huge monthly *heavy* pellet bill....and the new decision between pellet and bullet!
CURSE this thread and its oh, so generous members with the info & experience....
(and wait'll "Hq" -the wife- sees the Brown Santa stopping here with gun-sized boxes..)
Hope it comes before my spine surgery date, whenever that will be.
I needed an incentive to wake up after that, and pumping the Benji after surgery wouldn't have cut it.
I get flack, from both her and this now 5 weeks of 24/7 debilitating back pain, whenever I try it now.
(In my boredom I even bought a sick little CO2 toy dbl action T4 - a $35 daily deal refurb, which I have to say works surprisingly well for what it is. It's about good for DENTING cans.. and squandering gobs of .177 H&N eco-lights. Groups well at 3 yards.)
It looks like this thread really is my new Bible, and a VERY enjoyable one at that.
Seriously, THANKS guys!
That hospital "dang" better have WiFi.
(huh? ~NANNY~ s/w? 4shame, GTA. Have you SEEN 2000's public TV?)
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Rod, you are in for some real fun now! Velcome to zee Dark Side!
Guys, I figured out how to get a striker force equal to Bob's Hayabusa's. I'm going to get ~36mm stroke, and a boatload of weight out of a mod that's been bouncing around in my head for a while. It will take some real work, but it's in there.
These guns have the potential to get really nasty... and I couldn't be happier. ;D
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Would it be possible for you to share where you got that oval shroud material?
Or just an update on that project, if there is one.
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I got some resin to test the casting idea... give me a little time, and we'll know if it works.
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Got some stuff roughed in tonight. Looks like my estimates will be pretty close. The striker may weigh a bit more.
Looking at these springs... any suggestions for good replacements for a +20mm stroke? http://www.mcmaster.com/#9657k427/=ssd72s (http://www.mcmaster.com/#9657k427/=ssd72s)
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Just measured it out, and it wouldn't be hard to extend the tube's "tail" and bore into the stock far enough to expose a decent preload adjuster, just above your hand.
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Love the preload adjuster idea.... persue that.... It will also give more room for a spring.... Springs to try that will fit in a 3/8" hole:
Stock QB 7X: 0.33 x 2.34 x 0.047
McM-C # 9657K427: 0.36 x 3 x 0.051 (the one you found)
Bob
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I'm on it.
We aren't limited to that diameter... if there is any reason giving up some weight would be worth it, now would be the time to discuss it. I could make bigger bolt handles, if we want more spring.
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That spring, and an 80 gr. hammer, should be capable of handling anything up to .30 cal, maybe even .35 cal with a heavier hammer.... If you are going to cock it with the bolt, you don't want anything heavier, believe me.... even that spring at max will be mighty hard to cock.... The only suitable spring I have that is larger is the McM-C # 9657K218.... 0.50" x 4.5" x 0.072".... but I was looking for more than a 2" travel.... I'm sure they have others that are stiffer than the 0.36" OD and can handle travels of ~ 1.5".... However, you would need to make the gun a rear cocker, side cocker, or convert it to a side-lever bolt, IMO.... I do have some Trakar springs, made in Canada, but McM-C have a good selection....
Once again, you need to try some of these things and see the results, before getting carried away.... BTW, increasing the diameter of the spring requires a larger wire, just to get back to the same spring rate....
Bob
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But.... but.... if I can't get carried away, what's the point?
;D
I'm just looking for an idea of the max this design can handle. As to weight and springs.... if I build one with the "tail" 12" long (with a butt plate), I can fit about 5# of striker in it...lol. If I make one with a separate cocking lever, a 2.5" stroke is possible. Or, I can make it a reservoir by tapping a micro line in and running it to the front. How about a rear mounted tank?
R&D is my passion. When you talk about "problems"... I see challenges. For me, this is the fun part.
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Maby you should get a block of 7075 and do a rear bottle bullpup! :D No need for a line.
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I'm thinking that finding one of these in a time capsule 100 years from now would be mind boggling.....lol
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Well, the beast has arrived - no pump yet, but it gives me time to build a chrony
and do some barrel cleaning.. polish the hammer, or Eric's teflon thing?
Any suggestions for a FDPCP-specific how2, on hammer polishing & spring source?
How about FDPCP (GEN1) Valve power mods-
(20 degree hole? Port matching? May have to wait until I can afford
the minimal bottle setup, next month...low pressure open valve lock,
with no tank to clear it, would not so good.)
Two questions- ok, three:
1. What's the current state of the art for FDPCP RAW POWER mods
- you know, valve, hammer spring etc.
What's the absolute highest POWER that modders have reached with this gun
(.22, GenII but with no plastic, "power tuned")
I mean, FPE with accuracy over 50Yds and the HEAVIEST pellet available
- screw the shot count for now.
2. Who will build me a turnaround block with a TUBE READING gauge fitting?
(again, for those reading my posts, I want to wrap a 22ci -ie, 14" reg. incl.- tank,
back toward the trigger or the front edge of the action block,
eventually sinking that tank -possibly at a slant following the forestock-
into a customized AR2079 or B51 style thumbhole stock)
3. As I also want a repeater mod, I guess I'm talking to Eric here...
I'm now also wondering if I can find a match(choked, LW?) barrel even LONGER than 24"-
Reading about the first airguns has me thinking Kentucky long rifle... STUPID long range!
(And the obviusly suggested much longer tube, with an extension between the tank and
the reverse block to get the weight back AFAP toward the CG...)
Think 'LR sniper,' rather than a lightweight trail trekking hunter.
Oh - and no one here in WV cares about sound!
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Your question about maximum power with accuracy will vary barrel to barrel, unfortunately.... I have never found anything heavier than the 18 gr. JSB Exact Heavy that shoots accurately at 50+ yards in ANY of my guns, so that limits you to about 36-37 FPE (950-960 fps with an 18 gr. pellet).... You can probably get a bit more power than that in .22 cal, but if you can't hit anything, does it really matter?....
LW barrels are 23.8" long, although you can custom order longer.... If you get a .217 cal airgun barrel from Mike at TJ's you can order whatever length you want, but as you can get 40 FPE without going longer than 24" in .22 cal with pretty much any PCP I don't know why you would bother, other than appearance (and a bit of efficiency).... I don't know if you can get Mike's barrels in larger than 1/2" OD in .217....
Bob
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I'm thinking that finding one of these in a time capsule 100 years from now would be mind boggling.....lol
If things keep going the way they have, the capsule would need a stocker so you can tell what it used to be...lol. I can see versions of this thing that will be unrecognizable as a 60.
Guys, with the stock only bored deep enough to just hide the tube (and allow a small hole, if needed, for an adjuster to be reached)... you can have a 40mm tail. In this context, that's a ton of room.
I found a good way to strip the receivers. I wish I had tried this before wasting a bunch of stripper... Soaking in cheap lacquer thinner lets you easily scrub the coating off with a scuff pad. From now on, any conversions sent need to be stripped... or I need to charge to do so. I highly recommend that 1.5K rigs be internally polished in both the bolt and striker bores. All conversions get the slip coated strikers... it's impressive how well they work in a polished bore.
I will eventually be offering strikers in custom weights, and with strokes ranging from 15mm up... including an adjustable option. Give me time to refine the system, and I'll offer something that can be "Lego-ed" into a wide range of outputs, using only different barrels, bolt noses, and strikers.
All prices I have quoted to date will be valid until Aug 1. I'm trying to drive some costs (mostly machine time) down here, now that I have a better look at them... and, some (not surprisingly) are resisting all attempts to do so.
Rod, you might want to build your gun so it can eventually evolve into a bullet shooter. With this platform, you can pass pellet's capabilities pretty easily.
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I really like the concept of boring a hole 40mm deep into the wrist of the stock, with a smaller hole for an allen key to adjust the preload.... I'm thinking the end plug with a plastic crossplug insert to act as a brake to prevent it from self-adjusting.... should be able to slide the allen key in from the back of the wrist OK.... I assume the rear of the trigger group can mount into a tapped hole in the rear plug?.... How much of an extended tail on the tube do you need for a 1" travel on the striker and 80 grams or so?.... or would you just go 40mm on all of them and change the length of the rear plug?....
Bob
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I have a couple ideas for preventing torsion on the screw which would also keep the head of the screw at the back, so you wouldn't have to reach into the bowels of the tube to crank it all the way up. One incorporates the trigger and stock mount screws. I have to cut protos to prove them, but neither constitutes Rocket Science.... I'm just looking more for the least expensive way to get things done on a production basis.
I have found that if a device ends up successful, every dime spent to avoid excess part numbers will be re-payed tenfold (or more).... so, I'm close to just going for a version with the 40mm tail, and calling that the standard. It's plenty of room, so if you ever see me with a 60 with the tube protruding through the stock... cover your ears! ;D
1" x 80g is nearly the limit for a tail-less rig, but it will fit nicely. The only reasons for a tail at those power levels, or below, are to get a clean adjuster and less part #s.... and the future option of stupid amounts of energy (my kind of foolishness... ;D).
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Eric, per your request, here is the graph about recommended hammer weight for a given FPE level.... I usually try for hammer weights along the "typical" line or just under.... I know that Motorhead uses the "light-fast" line, but that is primarily for low-medium powered, regulated guns, where he is striving for efficiency over power.... PEEK poppets can get away with lighter hammers than Delrin, because they are easier to crack, leaving more energy and momentum to create lift and dwell....
(http://i378.photobucket.com/albums/oo221/rsterne/Important/HammerWeightvsFPE_zps8745ccb1.jpg) (http://s378.photobucket.com/user/rsterne/media/Important/HammerWeightvsFPE_zps8745ccb1.jpg.html)
Note that since I made that graph I have decided that most hammers will lie between the lower two lines, it isn't necessary to have hammer's heavier than the "typical" case.... In a really powerful gun the "light-fast" hammers will require either extremely long travel or a spring that will make the gun very difficult to cock.... Values in between the blue and red lines will require progressively more travel / spring as the hammer is lighter.... For the same spring force and travel, the energy (and therefore the lift) is a constant, but a heavier hammer will have more momentum (and therefore create more dwell), which is necessary for driving heavy pellets/bullets.... hence the relationship between hammer weight and FPE....
Bob
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Thank you, Bob.
Guys, the 40mm tail allows a striker of around 150g. As the graph shows, some truly nasty guns can be built around that. It's going to be a fun winter around here.
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I would suggest you concentrate on the area around the red line (ie 250 FPE @ 150 gr.) as much more likely, unless you have some way of coming up with a couple of inches of hammer travel and a REALLY beefy spring.... Still, that's lots of potential.... My Hayabusa can get in that power range with a 145 gr. hammer and 1.45" of travel, using a spring that takes about 25 lbs. of force to cock, and therefore uses a separate side lever to pull back the hammer itself.... You won't do that with a bolt cocker, but maybe with a side-lever breech....
Bob
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The longest stroke we can have, with the bolt as the cocking lever, is about 35mm... with a separate lever, we can have 62mm... or by moving the valve forward, up to 130mm or so. I don't see the latter happening.
I plan to work with the 30-35mm set up for now, to get a feel for all this. The "through" tube design is pure potential. More than we can ever use.
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So the distance from the sear to the back of the valve stem is about 62mm?....
Bob
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Your question about maximum power with accuracy will vary barrel to barrel, unfortunately.... I have never found anything heavier than the 18 gr. JSB Exact Heavy that shoots accurately at 50+ yards in ANY of my guns, so that limits you to about 36-37 FPE (950-960 fps with an 18 gr. pellet).... You can probably get a bit more power than that in .22 cal, but if you can't hit anything, does it really matter?....
LW barrels are 23.8" long, although you can custom order longer....
Bob
For perspective, I've read about 1700's and 1800's' airguns used in European (and even American) militaries, to kill (i.e. "effective") at 100 yards using only 800 psi charges (in interchangeable charging "flasks" that doubled as the stock and curiously had the outline -though revolved into both planes- of the PB stocks used even today.) They shot .462" lead ball ammo, traveling at 500f/s, and had 4' long barrels- and this "Girardoni" gun (supposedly used by Lewis & Clarke) had a shot count of 80 (the size of their primitive gravity magazine/loaders) per charge flask! Hence, I guess, my fascination with much longer barrels.
(http://www.defensemedianetwork.com/stories/the-girandoni-air-rifle/ (http://www.defensemedianetwork.com/stories/the-girandoni-air-rifle/)
&
http://military.answers.com/military-weapons/the-girandoni-air-rifle-and-the-lewis-clark-expedition (http://military.answers.com/military-weapons/the-girandoni-air-rifle-and-the-lewis-clark-expedition))
Especially a later Japanese version reportedly accomplished similar feats using a huge external hammer spring and mechanically extended the valve's dwell with a sort of lever/cam arrangement along the leg of a long (actual) hammer. From the pics it looked much like a flntlock PB.
The point being that modern technology should at least be able to duplicate that efficiency and power usable on larger game. And we can make 3000psi and more. But they had only 800, .462cal. and 4' barrels.
Is there some possible (non electronic) independent control over valve dwell that we might explore?
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Your question about maximum power with accuracy will vary barrel to barrel, unfortunately.... I have never found anything heavier than the 18 gr. JSB Exact Heavy that shoots accurately at 50+ yards in ANY of my guns, so that limits you to about 36-37 FPE (950-960 fps with an 18 gr. pellet).... You can probably get a bit more power than that in .22 cal, but if you can't hit anything, does it really matter?....
LW barrels are 23.8" long, although you can custom order longer....
Bob
For perspective, I've read about 1700's and 1800's' airguns used in European (and even American) militaries, to kill (i.e. "effective") at 100 yards using only 800 psi charges (in interchangeable charging "flasks" that doubled as the stock and curiously had the outline -though revolved into both planes- of the PB stocks used even today.) They shot .462" lead ball ammo, traveling at 500f/s, and had 4' long barrels- and this "Girandoni" gun (supposedly used by Lewis & Clarke) had a shot count of 80 (but the size of their primitive gravity magazine/loaders was only 22 rounds) per charge flask! Hence my fascination with much longer barrels.
(http://www.defensemedianetwork.com/stories/the-girandoni-air-rifle/ (http://www.defensemedianetwork.com/stories/the-girandoni-air-rifle/)
&
http://military.answers.com/military-weapons/the-girandoni-air-rifle-and-the-lewis-clark-expedition (http://military.answers.com/military-weapons/the-girandoni-air-rifle-and-the-lewis-clark-expedition))
Especially a later Japanese version reportedly accomplished similar feats using a huge external hammer spring and mechanically extended the valve's dwell with a sort of lever/cam arrangement along the leg of a long (actual) hammer. From the pics it looked much like a flntlock PB.
The point being that modern technology should at least be able to duplicate that efficiency and power usable on larger game. And we can make 3000psi and more. But they had only 800, .462cal. and 4' barrels.
Is there some possible (non electronic) independent control over valve dwell that we might explore?
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The Girardoni was one of the most hyped, overrated airguns in history.... The results they claimed are NOT possible, even with modern technology, using the fill pressures and volumes of the day, or even with increasing those as in the modern replicas.... Here is one example.... http://www.gatewaytoairguns.org/GTA/index.php?topic=49656.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49656.0)
The "lock" mechanism they used was a rotating cam which had no provision for feedback based on the reservoir pressure, giving basically a timed release of air which of course meant less air with every shot as the pressure dropped, just as seen in that modern replica.... The Lewis and Clark gun no doubt impressed the Indians with it's ability to provide killing power for a few shots on a fresh charge, but as a long range infantry weapon it was a lot of hype....
Once again, if it sounds too good to be true, it probably is.... Any attempt at using a (constant) timed or measured (by volume) release of air from a reservoir that is dropping in pressure, without some sort of feedback (self-regulating) mechanism that changes the dwell inversely to the pressure, will produce the first shot the most powerful and then decreasing power after that as the pressure drops.... The common solutions to this problem are currently the "strike open" self-regulating valve, a regulator before the valve so that it sees constant operating pressure, or electronic control over the dwell as used in the Crosman Rogue....
It is commonly suggested to use a "dump valve" to release a precisely measured amount of air, much as is done in MSPs, but that is a terribly inefficient method as much of the air released is wasted after "Elvis has left the building".... With your engineering background, you would probably enjoy wading through what we refer to as the "Geek Gate".... http://www.gatewaytoairguns.org/GTA/index.php?board=164.0 (http://www.gatewaytoairguns.org/GTA/index.php?board=164.0) .... There are many threads there with huge amounts of data and discussion that you may find very enlightening.... and in which you are welcome to partake....
Bob
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So the distance from the sear to the back of the valve stem is about 62mm?....
Bob
From the sear (trigger group back on Gen1) to the face of the block... roughly 2.5".
What's the most length we want the stem to protrude?
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It depends a bit on the caliber (and bullet weight), but about half the throat diameter is roughly the maximum usable lift.... at the low pressure end of the shot string.... I have a 0.160" limit on my quarterbore Disco, and the only time it gets there is with what is basically a dump shot.... If you allow 0.200" maximum you should be fine for up to .30 cal, you might want a bit more for a .357 with boresize porting.... However, running such high lift REALLY wastes air....
Bob
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Given that I can provide access through the mag slot floor, what is keeping us from putting an adjustable valve stem in these?
What could you accomplish with only that and a quality pre-load adjuster?
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Not sure what benefit an adjustable valve stem is, unless you are doing a bstaley mod, on an unregulated PCP.... If you limit the travel to reduce the power, then on the low power settings you end up with a "start fast, reducing velocity" shot string as the pressure drops.... Self-regulating valves depend on increasing lift and dwell to counteract the dropping pressure to produce the usual "bell-curve" shot string....
In a regulated PCP, then you could use variable lift to change the power instead of doing it with preload.... I have a feeling that for low power settings you wouldn't get the increase in velocity below the setpoint that you get using preload, the velocity should drop immediately below the setpoint if you were limiting the lift.... On the other hand, that would mean you couldn't tune to get a few extra shots below the setpoint like you can with the preload set on the "knee" of the curve....
Bob
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The single shot, big bore, proto receiver. 30mm stroke, 40mm tail.
I'm going to bond the receiver to the tube. There is nothing to be gained by keeping them separate, and with the valve bonded to the block, this eliminates 3 screws... which allows retention of quite a bit of striker weight. It'll be stout.
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Anything besides glue holding the receiver to the tube?.... I'm just thinking of recoil working it loose....
Bob
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Between having plenty of surface area, and the fact that any loads would be pure shear... I'm confident it will hold. Before I put any of this up for sale, I'll dupe the surface area in a defective receiver, and sledge hammer it to destruction. If I see anything I don't like, I can always resort to a press fit.
The R trigger group mount/stock mount would act as a block, too.... but I seriously doubt it could come to that.
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Have you given any thought as to how you are going to mount the stock once you cut it off even with the front of the receiver for a bottle?....
Bob
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Yes, but have not decided on anything. I left a wide band around the tube at the front to use, if I need it.
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.....I have never found anything heavier than the 18 gr. JSB Exact Heavy that shoots accurately at 50+ yards in ANY of my guns, so that limits you to about 36-37 FPE (950-960 fps with an 18 gr. pellet).... You can probably get a bit more power than that in .22 cal, but if you can't hit anything, does it really matter?....
Bob
I keep coming back to that statement and wondering (honest curiosity, not facetiously or antagonistically at all) how it is that .22 pb's are accurate at well over 50yards - and the big airguns reach out with 200 ballpark FPE at at 100-200 yards. Seems like we should be able to get distance accuracy with enough power and heavy pellets.
Aero? Most of the heavy pellets are shaped more like bullets anyway.
Power? We're pretty much there too. The .40-.50 cal airguns don't use any more than 3K (-4.5K?) psi, do they? We can make big valves, and the multiple ports thing in the FD PCP Gen II(which I just realized , never having seen it mentioned, in finallly getting around to stripping my new gun) shows great promise by defeating the "pellet size" limitation of just one big port. What happens if we make those just a *little* bigger (there;s abut a cm betwee them,) and feed it with more valve and rec'v'r. exhaust size...we could even thin the barrel -again, a *little*, increasing the channel that feeds them around the barrel. But first I have to get rid of the plastic that seems to have sneaked its way into my gen II. I'm not going to get the explosive hammer impact or the valve dwell increase I want, with any plastic absorbing impact, decreasing the stroke (why is that spacer there?) or defeating inertia components. Again, I very much like the way Eric's going with the heavier hammer (striker) and longer stroke. What I want is an "air hog," whose "waste" I can then use to make power and distance (and accuracy) with a much longer barrel and really heavy pellets. "Big Bore" is the next "Dark Side" ;) (Now let's make IT affordable too,) And those two little extra barrel ports remind me of what Rotax did with their kart racing rotary valve 2-strokes in the early 80's. The limitation of exhaust port widths that the piston rings could fall into, was a direct analogy to our airguns' pellet caliber (barrel diameter) port size limit.
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I've never found those radial port worth it, they were used in the RWS 850 and the gun worked better with just one large lower port.... Same for the Hatsan valve, it works better if you plug 5 of the 6 holes to get rid of the wasted volume and enlarge the remaining single port.... I've never seen a Gen 2, but I assume that's what you're talking about.... The problem is the wasted volume around the barrel as a "collector", and all the multiple corners.... Any volume between the valve seat and the pellet drops the initial pulse of pressure and wastes power....
If somebody comes up with a pellet in the 25 gr. range that is ACCURATE then .22's will take a big jump in power.... I have my Hayabusa .224 shooting a 41.5 gr. bullet at 100 FPE with good accuracy, and in Holland they are drilling 11mm groups with it at 100M (0.4 MOA @ 110 yds).... so yes, it can be done.... but the velocities are still limited to subsonic....
It all comes down to the limited power of airguns and transonic drag....
Bob
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I've been messing around with this idea: I'm calling it a "V port".
Plenty of plenum could be eliminated by cutting at just enough height to fully clear the bore, and by using a ball end mill... but you get the idea. Both ports are bore size in length (.177), and even wadcutters feed beautifully.
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With the right dia ball end bit, at the right angles and depth, you can achieve 2 slot shaped ports of extremely excessive size.... without the base of the port being any bigger than the red outline. I'll get the flow of this experimental cut, but have a stronger bridge that is still slim enough to impede flow as little as possible.
I'm looking at finding the biggest square exhaust port I can fit into a stock valve. That will determine the barrel port's base size maximum (potential), and I'll see how close I can get to a decent .357 port before resorting to a custom valve body (which would allow port slots as long as we want).
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With the right dia ball end bit, at the right angles and depth, you can achieve 2 slot shaped ports of extremely excessive size.... without the base of the port being any bigger than the red outline. I'll get the flow of this experimental cut, but have a stronger bridge that is still slim enough to impede flow as little as possible.
I'm looking at finding the boiggest square exhaust port I can fit into a stock valve. That will determine the barrel port's base size maximum (potential), and I'll see how close I can get to a decent .357 port before resorting to a custom valve body (which would allow port slots as long as we want).
Now that's what I'm talkim'bout....
If I had the spare parts, a mill and a lathe, I'd be trying this sort of thing.
I really like the way you think.
I'm just working on the more conservative ideas of others right now
until I can at least afford a second valve...... barrel.......receiver....striker..... LOL
Right now I just need to be able to air it up, with my bad back.
(And, I just thought of something -
They BETTER not put any ~plastic~ in there when they cut me open next month!)
.oO (get it in writing, Rod......how would you check?)
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I've been messing around with this idea: I'm calling it a "V port".
Plenty of plenum could be eliminated by cutting at just enough height to fully clear the bore, and by using a ball end mill... but you get the idea. Both ports are bore size in length (.177), and even wadcutters feed beautifully.
Beautiful...
I bet NOW the quality of those barrel O-rings is starting to matter...
What are your latest valves looking like? Two ports?
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I've been messing around with this idea: I'm calling it a "V port".
Plenty of plenum could be eliminated by cutting at just enough height to fully clear the bore, and by using a ball end mill... but you get the idea. Both ports are bore size in length (.177), and even wadcutters feed beautifully.
I just looked, and my GEN II .22 barrel is very different.
There's only one band of barrel isolation, not two;
and it's isolated by two, and not three O-rings.
All three ports are therefore in the same radial plane perpendicular to the barrel's axis.
Much less possibility (1/2 the real estate, in fact) for port expansion, and never could rival a GEN I, right?
As rsterne suggests, only the most trivial amounts of air could reach the aux ports, and they're essentially wasted on the GEN II. At least in comparison, its potential will always be less than the GEN I, and it's probably less inherently powerful out of the box, being unavoidably port-challenged in comparison.
The GEN I must have two valve exhaust ports,
and/or different (extra- branched?) transfer porting in the receiver, right?
It also makes me wonder how the probe can be long enough to get a pellet
beyond (what I call) the "aux" ports, and still clear the breech for pellet insertion.
I have measured this GEN II's ports by a go/no-go test , using a set of graduated Morse drill blanks, and measured the barrel with an admittedly cheap digital readout caliper.
The 0.585" barrel's od is thinned to 0.463" for that single isolated port "band," and has the (Morse #16= 0.1770"=) 4.49580mm main exhaust-fed port at 6 'clock,
and two, (Morse #43= 0.0890")= 0.22606mm each, ports at 10 o'clock and two o'clock,
or maybe even 9:30 and 2:00, they're not very precisely located.
If the aux ports, as I suspect, are separately isolated and fed on GEN I,
then I missed out on even more than I thought, and paid more for a lot less,
in not knowing about it until GEN I was long sold out.
I probably shouldn't have allowed all the enthusiasm for GEN I to cloud my judgement :(
The time was right for a PCP (even if the budget was not and would never be,)
but I might have done better with a B51 ( I would have been in for $300+ either way)
- except they're not (and weren't) available in the US in .22, and I'm not a paper puncher.
Like you, I'm a garden guarder and tinkerer, with some technical vision (however inexpertly supported by technical skills, equipment and experience for the genre, compared to you and most here.)
What has been your assessment of the RELATIVE (more extreme) power
possibilities for GEN I v GEN II?
Am I wasting my time on the less promising platform, as I suspect?
I get the impression, having it open, that it had been "improved" only from the POV
of those with very different, even opposing considerations to my own.
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MM has said he will have more GEN 1s available in .177. He might even have a couple of those left. You can always get a barrel and have it machined to fit. I am not sure what garden pest would stand up to a .177 making over 20ftlbs with a 16 grain pellet though.
If anyone can make a GEN2 into what you want it probably is stalwart though. I know he mentioned a while back a desire to turn a uramex fusion into something larger calibered. That is the same gun as your GEN 2.
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A few points to make here....
1. The Gen 1 only has ONE exhaust port in the valve, ONE transfer passage in the receiver, and ONE barrel port....
2. The PLENUM that we require to get the minimum pressure drop during the shot in a regulated gun is IN FRONT OF the valve seat.... The bigger it is, the less the pressure drop during any given shot....
3. Any excess volume between the valve seat and the base of the pellet (such as the "V" Port cavity) will DECREASE the pressure at the pellet because the pressure in the reservoir/plenum must expand to fill that space, and that pressure loss can never be recovered and will decrease the power of the shot....
4. All that is required to bring the barrel port up to the same area as the bore is to make the port LONGER (axially) than it is wide (ie oblong or oval in shape).... The only downside it that the pellet must be loaded slightly further forward....
Bob
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Thanks, rsterne - but I'm now even more confused.
If the second segmented section of the barrel (shown in a .177 what I assume is a GEN I
-as I think I remember the three barrel O-rings being a difference between the GEN I and GEN II)-
isn't addditional exhaust port area,
to provide added post-valve charge to behind the pellet,
then to what are it and its ports connected (if it had them,
before "V-porting" which I had assumed erroneously, it did?)
- and to what purpose ?
Additionally, why else would that separate barrel section even exist?
Is it just blank, to support the loose fitting barrel? In that case using it
by connecting to the valve's exhaust, say, by cutting away the separating wall, doesn't sound like a terible idea to try - as long as you have a way to push the inserted pellet past it..
There's no way for me to see the actual gun from all angles
(as I can the GEN II) so it's hard to picture.
I would have to see all sides of the removed barrel
Has anyone noticed and mentioned or discussed the two extra ports
in the GEN II (,22) and I just missed the posts/threads?
Seeing those ports was news to me.
How about the second isolated barrel section in the GEN I?
Or, is it specific instead to the .177 (Possibly even GEN II?)
-Rod
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Rod, when the repeater conversion is done, the first 2" of the barrel have to be removed, and it gets re-cut. You don't have to worry about any of the Gen1 vs Gen2 differences...
The V port will not have nearly as much extra volume as the stock Gen2 set up, and slightly more than the Gen1... but, it is only useful when the slight slot Bob mentions isn't enough. The V will not be of any use for smaller calibers.... it can only help when the port size needed can't be had with a single slot due to fit issues. The pic is not representative of actual sizes... I made those experimental cuts to see 2 things: How fine a bridge could be had without weakness, and to check how thin it could be while supporting the pellet for smooth feeding.
The idea was also to see if I could get enough port area for a bigger bore, in total, without moving the valve forward or making a longer valve body. I used a .177 barrel simply because it is going to be converted, and that section will be cut off anyway.
Bob, your point #4 is correct, but there is also the fact that the stock valve is not long enough to get a bore size port for .357, but a square exhaust can get it close (80% or so).
Guys, I'm all over the map here for good reason. I'm trying to standardize all the dimensions possible, in search of numbers that can allow the max number of upgrades (bores) for 1 part #. There are a couple more things to try, and I'll know what can be done using a stock valve body w/mods. A custom valve (as we can choose the port location, size, and shape) will allow all kinds of madness. ;D
My Gen2 was the first time I had seen multiple ports, and although it seemed to make sense, I couldn't figure out why the holes had to be so far apart... causing both excess volume (which I was taught is also called plenum... perhaps not), and a long twisted path. The V is an attempt to have our cake, and eat it too. One thing is for sure: There is no need to have multiple holes so far apart... a tiny bridge supports the pellet well. And, a V with 2 holes of a realistic area will be very small compared to the radial design that seems to work well enough to produce in mass numbers.
I picked the sweet spot on Bob's graph (200FPE) and did a bunch of homework. I concentrated on .32, 9mm (.356), and .357. I found that the most choices in bullet weight and size, and the most choices in molds... are had (hands down) in .357. Johninthecamper is tooling up to produce .357 in sizes as low as 80gr... and Lee makes molds as small as 105gr... so, I'm going to see if I can do a .357 that hits hard 3 times on a charge.
Wish me luck??
;D
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First of all, the only useful plenum is on the pressure side of the valve.... between the valve seat and the pellet any extra volume is wasted, in fact worse than that, it reduces the peak pressure seen by the pellet.... and that peak pressure is the most efficient part of the shot....
Secondly, I've never heard of anyone managing bore-sized porting in a .357, and certainly not in a 3/4" ID tube.... nor do you need it for 200 FPE, unless you want to do it at 2000 psi.... A 75% boresize, round barrel port is 0.267", and in fact running bullets you can go a bit larger to 0.281" (79%) and not have a loading problem.... That is what I'm using on my Hayabusa, and it's seen 257 FPE at 3000 psi, and will shoot a 9 shot string averaging 220 FPE from 3000 psi down to 2200 with 132 gr. bullets on 460 cc of air (22 CI tank plus 100 cc in the tube, unregulated).... That 856 - 876 - 856 fps over the 9 shots, just a 2.3% ES.... and the efficiency is 1.28 FPE/CI to boot....
No need to get fancy.... just stay with a single, round 9/32" port and you can get what you want easily.... Don't forget, to supply a 0.357" port you will need a valve throat of over 3/8", and that will require more hammer strike than I have in my Hayabusa (145 gr. @ 1.45") which only has a 5/16" throat.... I don't need to wish you luck, only convince you that you don't need to get greedy....
Bob
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You are full of good news today! The valve/block I showed earlier has just enough room for a .270 round hole. Can be done with a stinkin' drill. This is gonna happen.
I'll save some madness for later. 200 FPE is a good goal, and (I believe) will sell well locally.
Just loving these 60s... ;D
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Rod, when the repeater conversion is done, the first 2" of the barrel have to be removed, and it gets re-cut. You don't have to worry about any of the Gen1 vs Gen2 differences...
The V port will not have nearly as much extra volume as the stock Gen2 set up, and slightly more than the Gen1... but, it is only useful when the slight slot Bob mentions isn't enough. The V will not be of any use for smaller calibers.... it can only help when the port size needed can't be had with a single slot due to fit issues. The pic is not representative of actual sizes... I made those experimental cuts to see 2 things: How fine a bridge could be had without weakness, and to check how thin it could be while supporting the pellet for smooth feeding.
The idea was also to see if I could get enough port area for a bigger bore, in total, without moving the valve forward or making a longer valve body. I used a .177 barrel simply because it is going to be converted, and that section will be cut off anyway.
Bob, your point #4 is correct, but there is also the fact that the stock valve is not long enough to get a bore size port for .357, but a square exhaust can get it close (80% or so).
Guys, I'm all over the map here for good reason. I'm trying to standardize all the dimensions possible, in search of numbers that can allow the max number of upgrades (bores) for 1 part #. There are a couple more things to try, and I'll know what can be done using a stock valve body w/mods. A custom valve (as we can choose the port location, size, and shape) will allow all kinds of madness. ;D
My Gen2 was the first time I had seen multiple ports, and although it seemed to make sense, I couldn't figure out why the holes had to be so far apart... causing both excess volume (which I was taught is also called plenum... perhaps not), and a long twisted path. The V is an attempt to have our cake, and eat it too. One thing is for sure: There is no need to have multiple holes so far apart... a tiny bridge supports the pellet well. And, a V with 2 holes of a realistic area will be very small compared to the radial design that seems to work well enough to produce in mass numbers.
I picked the sweet spot on Bob's graph (200FPE) and did a bunch of homework. I concentrated on .32, 9mm (.356), and .357. I found that the most choices in bullet weight and size, and the most choices in molds... are had (hands down) in .357. Johninthecamper is tooling up to produce .357 in sizes as low as 80gr... and Lee makes molds as small as 105gr... so, I'm going to see if I can do a .357 that hits hard 3 times on a charge.
Wish me luck??
;D
I for one definitely do wish you luck - it;s never that simple, for any change. But let's talk about that 2" length loss (as well as the necessity to re-port.. It sounds like something would have to be done to recreate the (more complex than we -or at least I- knew) stock porting; and even increase it at least to compensate for the lost length. (You know my mania for barrel length.... and power. It's "do no harm," there. ;)
btw, I wasn't considering the increase in post-valve plenum significant, only the increase in port diameter over just considering the single large one, as I suddenly found I had to do in trying to analyze porting and i.d. the choke point.. This gun seems to do better stock than most of its size, price point, and air pressure, at least from what I've read from owners, not manufacturers or vendors,(and not having owning many guns myself.) But it would be a shame to lose ANY power in exchange for the repeater convenience. If that were the case I would not make that choice.
With the present gun, (if I can call what's currently a bucket o'parts a gun again,)a very tedious day of measuring ports and a little math, has brought me to the conclusion that the choke point is definitely the valve. Even not increasing the barrel porting to max. for the caliber (which it would be a shame not to do if you have to cut the ports off anyway,) the factory porting with the small auxiliaries MUST do something (or they definitely wouldn't bother) and losing that edge would also be a shame. So, by extension, would be neglecting to push those ports' sizes, and matching up the valve and even the receiver - measurements having shown the receiver porting is the largest of the three, stock.. Not having checked the matching I can't say whether that isn't just to correct for any expected mass production mismatch. I would increase even that to the new max, though.
But before being reminded of the loss of even stock ports, necessity to re-port any way, and losing 2" of barrel length, I'm starting to think I shouldn't have discarded the LW barrel idea. Sure beats having to cut the tube. Then again if you're buying a barrel, and having to redo porting, why not increase the caliber, &/or go to an even longer, or a PB barrel....and having to redo the valve....and.... .oO(&$*#&%@$ dark side....
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Rod, the 2" only brings the barrel more even with the tube... you should have no reason to have to cut the tube. Anyone using the stock F sight will have to mod it for clearance (continue MM's mod another 2").
Mike presented these guns as "tinkerer's guns". They certainly are, and I would have no interest if they weren't. I would go 1 step further, and classify them as "kits". To me, they represent the best possible value as raw material. Like a model kit, they allow any level of sophistication in assembly... and that alone keeps me interested.
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Yep.... KISS (keep it simple, stalwart)....
Bob
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(dupe- sorry)
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MM has said he will have more GEN 1s available in .177. He might even have a couple of those left. You can always get a barrel and have it machined to fit. I am not sure what garden pest would stand up to a .177 making over 20ftlbs with a 16 grain pellet though.
If anyone can make a GEN2 into what you want it probably is stalwart though. I know he mentioned a while back a desire to turn a uramex fusion into something larger calibered. That is the same gun as your GEN 2.
Thanks, and I understand your point -but I have other reasons as well, to stay with .22 for now.
My other rifle -a Benji- is a .22, and for economic as well as experimental control reasons, I prefer to stick with the one pellet caliber for rifles, and use .177 for pistols. The JSB Exact Jumbo Heavy domes are working well for both, and their Jumbo Monsters were even starting to work well with the FD before I decided the nice new gun was well past its deserved initial barrel cleaning, exam/documentation, and trigger polish. It's getting bottle fed next week, and I think the already powerful gun's valve will benefit from a few hundredths bigger drill and maybe a feed improvement (like moving the spring out of the flow.)
If it improves the way I expect, having already loved its power out of the box, once I put it back together I will not want to tear it down and do without it right away like this! So I wanted to do as much as I know I will be doing this first time. That may mean moving the valve spring to the rear and making a new shaft, and even poppet. I know I will be replacing the delrin(?) spacer (XS's "Plug," or what I call the "anvil";) with heavy wall 4130 tube - that's easy. And since a foot is their minimum purchase, I may experiment with different lengths, for minute improvements in safety on the front side (as Bob S. has astutely observed elsewhere,) and adjustments in striker *impact* behind the mounting screw.. I'd love to make that striker heavier for its size, and maybe more of a 'deadblow' type (birdshot-filled?) device.
Hopefully Eric can also help with the issues I'm having pulling the bolt (a medical issue with my back.
It actually hurts more to cock the gun than pumping up the air to 1600, which is shockingly easier than pumping the Benji!)
I really wouldn't mind a lever -but only if that can be done without adding an operation (cocking AND chambering.) And the lever can be almost a foot long, I don't care.
(Rack & Pinion/gear section operating the bolt, maybe?? Dunno how airgun levers work yet.) Left side is OK, I will always be using at least a bipod. And I will probably be changing this stock when I see what tank mounting choices I can devise for the 22ci. I may wish they made an even longer 2"d. tank. I may possibly get a reg extension to move it back AFAP toward the gun's CG.
A bipod, maybe as part of the metal barrel band it desperately needs, is definitely coming.
Rod
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Rod, the 2" only brings the barrel more even with the tube... you should have no reason to have to cut the tube. Anyone using the stock F sight will have to mod it for clearance (continue MM's mod another 2").
Mike presented these guns as "tinkerer's guns". They certainly are, and I would have no interest if they weren't. I would go 1 step further, and classify them as "kits". To me, they represent the best possible value as raw material. Like a model kit, they allow any level of sophistication in assembly... and that alone keeps me interested.
I love tinkering (especially $)((# polishing - ie tinkering with "the cheap stuff," been doing it all my life - not always by choice. it's a peculiar kind of bragging rights... )
and actually I never could resist it. Remember my first airgun was a P17...
I just really blew it this time, missing out on GEN I (.22 only please) and thinking I could fix it.
But it took being struck down as an invalid to get me away from more strenuous hobbies and back into airgunning and the fora.
It's just sometimes rough in retirement (fixed income) to remember no kit ever contains all the parts.
(*looks back @ post #1 of the thread...)
Anybody know where I can find XS60C parts? (The barrel band was once metal.)
Metal Triggerguard stop?
To those lucky ducks with GEN I's:
Was this part (trigger stop)ever metal?
I realize I'm assuming it was.
The "anvil" -valve/hammer "plug"- is easy, 3/4 id .133 wall 4130 tube...for a spring reversal valve mod, anyway.
And BTW I did finally get the front sight off. Only a few marks on the barrel where the visegrips bit right through the padding. (I did choose the spot where the band falls ;)
I *Thought* I posted the pic of GII parts (and shot count line target) as someone requested,
but can't seem to find it now.
-?-
(Two solid months of pain and sleep dep, waiting out the delay for surgery, does little good for one's disposition, or patience. For that, I apologize to all wherever it may have reared its ugly head..)
But I'm still determined to make gone the plastic.
Back to ordering metal parts to make a GEN II into a GEN I,
-and maybe a little psychotherapeutic break to shoot that toy T4
and contribute as much CO2 as I can to the WV atmosphere.
The plants love it....
(OK gimme a break - I did invest in lead-free.
The T4 likes tinfoil anyway,
H&N Field Target Trophy Greens are its favorite...
now get off my back! ;) oops, no pun intended...
If you want me tomorrow I'll be on my back porch
littering the lawn with tin from the T4
-8mags, no waiting-
(And on the phone buying the household's new resident FDPCP more metal gifts.)
I wound up making targets for T4 plinking today.
Rod
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Got some samples from John, for the MG .22. They fit perfectly... weigh 30gr.
Any suggestions for lube?
Rod, yes, the part behind the trigger group is metal on Gen1.
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Got some samples from John, for the MG .22. They fit perfectly... weigh 30gr.
Any suggestions for lube?
Rod, yes, the part behind the trigger group is metal on Gen1.
Those look nasty!! In a good way of course. I don't know if you're going to have to resize them but if you do I've used Alox with great results in .45 & .38 powder guns. I've also used dry moly, throw a teaspoon or more in a vibratory tumbler and let the bullets impregnate themselves by gently bouncing off of each other.
Erik you and your co-conspirators amaze the heck out of me, so please keep doing it.
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Here are the swaged bullets I intend to try in the MG .22 cal barrel....
(http://i378.photobucket.com/albums/oo221/rsterne/224%20Long%20Range%20PCP/IMG_4491_zpsc9e1a267.jpg) (http://s378.photobucket.com/user/rsterne/media/224%20Long%20Range%20PCP/IMG_4491_zpsc9e1a267.jpg.html)
They are NAA 30 gr. (actually weight 30.6 gr.).... and the price is certainly right at $8.00 for 250 bullets....
http://northamericanarms.com/accessories/cb-accessories/cb-parts/cbb250.html (http://northamericanarms.com/accessories/cb-accessories/cb-parts/cbb250.html)
If they prove to be accurate, that is less money than many .22 cal pellets....
Bob
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I'm going to try them, too. If they work, they'll make a heck of a deal. What is their OAL?
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They measure 0.366" LOA.... longer than a Baracuda/Kodiak 21 gr. but shorter than an EunJin Dome 28 gr.... They function perfectly in a .22 MRod magazine.... (and obvious no problem in a PRod mag.)....
Bob
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You are nothing but good news lately, Sunshine!!
;D
So many ways to play... almost can't wait for winter.
John's are .485". It's snug, but they fit in my adjustable 60's (Sean Pero reamer) chamber, and shoot nicely. I'll get chrony results, just for fun.
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Wow, that's long for a 30 gr.... My 41.5 gr RWS bullets from Holland are only 0.469" LOA.... Both are 0.224" diam, for a .22 rimfire barrel....
Bob
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its possible to increase or decrease the length,keeping the same weight.its also possible to keep the same weight and change the length.weight/length and shape can all be adjusted,by changing two variables, one can stay the same or two can stay the same with one change
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At this length, they fit perfectly in the stock loading tray.... and at this dia, they are snug, but not in a bad way. Have no idea how they fit in a stock chamber, but I'll sure find out asap. Got no legs right now, but they are on order...lol. ;D All in good time!
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fourth variable, dia.
that can be adjusted too
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Guys, I need input on a few things:
Is there any reason the valve's throat can't be offset toward the barrel? I can't see any, but that's no insurance.
My coating oven situation has worked out nicely, I'll be up soon. I'll be able to do seamless coatings on the fixed barrel Bobcats, and fit the 31" tubes/receivers that 25" barrel/40mm tail combos require. I will stock and offer Desert Tan (Mil) and Federal Matte Black, and was wondering what you guys thought of offering a super durable powder coated primer that could be nicely spray bomb camo-ed to taste. Worth stocking?
I've looked into making .22 barrels using liners and sleeves. I'm starting to wonder if there is any real benefit, to many, in spending the money to allow having a pellet + bullet gun. MG barrels aren't cheap, and I have to buy in lots to keep costs down. A 25" straight bullet barrel can be built for about the cost of an MG at 20 - 21". Is anyone drooling for a 60 MG... or should I stow that concept for a while?
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No reason I can see not to offset the throat, other than shrouding of the poppet on one side by the valve/tube ID, but that might not matter.... As you move closer to the exhaust port you need more angle on the port (or the further you have to move the seat back) to be able to "see" through the port/throat combo.... and IMO the better you can see through it the better the airflow....
I personally don't like painting guns, the typical spray-bomb paint is too easil scratched....
I was looking forward to a .22 cal MG barrel as I already have the bullets.... and I think at about 60 FPE it will fill a gap in available PCPs by making a .22 cal bullet shooter available that isn't trying to emulate a .22LR, which is pretty tough (and therefore expensive).... However, I would be unlikely to shoot pellets in it, so a 25" bullet only barrel would also work....
Bob
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We're thinking along the same lines. I'm not sure I would ever shoot pellets in a gun that can do bullets. These already need to be de-tuned to efficiently shoot pellets. An easy and repeatable adjustor would make a lot of sense in a dual projectile gun... and make the concept make more sense as well.
I have been pondering building a true survival rifle someday... maybe that is the best place to put in that kind of infrequently used versatility. We'll mess with it this winter, but I wouldn't be surprised if we are the only ones who end up doing so. 60fpe is a great level, I'd think it would find a lot of uses.
The powder primer will make the spray bomb stronger, but on it's own should keep scratches from being deep enough to cause rust. Touching up the paint (or changing the camo to match the season or conditions) would be easy and quick. I'm a little surprised that there aren't more threads on custom finished 60s... I was fully expecting to see some crazy **** by now. Maybe we need a contest to bring out some creativity? I've asked why GTA doesn't have contests... got crickets. I could put up some decent prizes, if someone got something going in that direction.
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We're thinking along the same lines. I'm not sure I would ever shoot pellets in a gun that can do bullets. These already need to be de-tuned to efficiently shoot pellets. An easy and repeatable adjustor would make a lot of sense in a dual projectile gun... and make the concept make more sense as well.
I have been pondering building a true survival rifle someday... maybe that is the best place to put in that kind of infrequently used versatility. We'll mess with it this winter, but I wouldn't be surprised if we are the only ones who end up doing so. 60fpe is a great level, I'd think it would find a lot of uses.
The powder primer will make the spray bomb stronger, but on it's own should keep scratches from being deep enough to cause rust. Touching up the paint (or changing the camo to match the season or conditions) would be easy and quick. I'm a little surprised that there aren't more threads on custom finished 60s... I was fully expecting to see some crazy **** by now. Maybe we need a contest to bring out some creativity? I've asked why GTA doesn't have contests... got crickets. I could put up some decent prizes, if someone got something going in that direction.
I'll be puttin a spray finish (Cerakote or such) on my Bobcats this fall or early winter. Shelf life of some of these coatings are short and I want fresh product when I spray plus I want to have two rifles ready when I start.
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The powder primer will make the spray bomb stronger, but on it's own should keep scratches from being deep enough to cause rust. Touching up the paint (or changing the camo to match the season or conditions) would be easy and quick. I'm a little surprised that there aren't more threads on custom finished 60s....
Actually what I think it needs desperately is a durable functional coating for INSIDE the receiver's bolt and valve tubes.
I'm looking for a way to fill those longitudinal production 'scratches' - grooves, really- that I found when trying to smooth those channels. And the galling in the bolt channel was even worse.
I hope my temporary measures (like adding side screws to the valve and its "backing plug,'' if that's what you call it) won't be a problem when I want the Bobcat/Slick and "through tube" mods.
What size tube do you put on (or in) there? I have a stick or two of 7/8-.065 4130. Do you replace the bottom half of the receiver and set the cut-away top half on it like a saddle, (best for a new, durable cocking slot, IMO, and the ID of the 7/8 is the familiar .745"...)- or do you sleeve it with something smaller?
What can I spray in that bolt channel in the meantime? (I have rattlecan DuPont "Teflon Silicone Lubricant" to try for temporary.)
To cut the "A%^&*-r" QB fill plug's TWO o-ring slots out for the Crosman 113's, it looks like I'll have to get out the "hillbilly lathe" (LARGE two-handed 1/2" drill, and even more huge 3/4" chuck...
need to find a 1/2"-20 bolt for a mandrel...)
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Rod, given that the plans you have to back up the valve won't use the same screws as my set up (and there's the difference in position), and the through tube (7/8 DOM... same as your shorter one) will negate most of your work... I'd suggest we start with a fresh receiver (I'm stocked).
If you manage to imbed silicone or Teflon into your receiver (and you will), there is no way later coatings will stick. Anyone who is contemplating eventual powder coatings should stick to lubes that can be flushed fully out of the metal's surface.
With my design, the striker and pin both ride in steel... and both are Teflon coated. With the bolt channel heavily Teflon coated (both slick and smaller 8) ) you'll be happy with it. I love the feel of mine.
I say keep going with what you're doing, and learn what you can in the process. When the time comes for a 3K or 4.5... we'll start from scratch.
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Rod, given that the plans you have to back up the valve won't use the same screws as my set up (and there's the difference in position), and the through tube (7/8 DOM... same as your shorter one) will negate most of your work... I'd suggest we start with a fresh receiver (I'm stocked).
If you manage to imbed silicone or Teflon into your receiver (and you will), there is no way later coatings will stick. Anyone who is contemplating eventual powder coatings should stick to lubes that can be flushed fully out of the metal's surface.
With my design, the striker and pin both ride in steel... and both are Teflon coated. With the bolt channel heavily Teflon coated (both slick and smaller 8) ) you'll be happy with it. I love the feel of mine.
I say keep going with what you're doing, and learn what you can in the process. When the time comes for a 3K or 4.5... we'll start from scratch.
LOL definitely "learning" -most of it bad, some tragic, - and glad you mentioned receivers,
I was about to try another (probably just as futile) attempt to get parts from Mike.
I'm seriously considering a raw oob parts G1 if he'll do it on the next round.
For our project I could contribute a fresh (paint-stripped) receiver AND 4' of 7/8" .65w 4130...
I find myself wondering how people who add side screws, to support the valve, avoid leaks.
An exhaust port o-ring seems to me the only way.
And there won't be an empty thread's depth in there to seal the screws, with the cap heads fitted into both valve and receiver (poorly, BTW-hand tools only-- more "learning.") [hmmm...black expoxy putty left over from bedding the P17... socket caps will be somewhat sunk into the receiver anyway...]
In retrospect it would have been FAR better to put the side screws in the "plug" ;(
(Making a new one anyway, this one's ~Plastic~ YUCK. Hammer strikes feel SO cheap...
and it's zero backup for the valve in a pressure "surprise," unless someone wants to get into those inserts the one stock screw uses.)
I'm still waiting for the back ordered HP fittings... now the gun won't be ready before Thursday (surgery,) which means a six week delay.
I think I have some CO2 carts for the T4,but they won't last six weeks (recovery).
The pain/sleepdep/painkillers-addled brain is starting to design lever options...
I always loved the W'73...thin billet levers up the sides could do it (even though exposed.)
If I could only steal the room for one pin through a nonpressurized part of the receiver
- and no more single-sided bolt activation.
Hey, how's that exposed power adjuster access coming? Abandoned?
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The adjuster is figured out... it'll happen. Eventually.
Time is short around here, for now. Lots of non AG related stuff going on right now, I'm looking forward to this winter, when I'll have more time to enjoy focusing on R&D for these.
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I think I have a way to salvage this receiver (but still need to get at least one parts gun to have a fresh receiver for Eric to do Bobcat/Slick/Through Sleeve, maybe bullet barrel, mods.)
Here's the plan:
Since I already have holes in the receiver to counterbore the heads into the (spare QB) valve, I can cut straight line grooves lengthwise across the top of the valve, one next to each side of the port, running from front O-ring(s) to the rear one(s.)
They sell linear O-ring material by the inch(ft.?) intended to be glued together for odd or impromptu emergency O-rings.
Then I just put a length of that into each of the two straight line grooves. That would essentially be a sealed port, @least more so than the stock arrangement, also eliminating a (not very...) possible slow; or (more probable) brief 'firing time' leak around the stock valve mounting screw, and of course, the two unacceptable ones I've created by drilling the receiver for the Allen screw heads. Much easier to retain when installing the valve than a round ring at the port, which I could never have retained through its insertion.
I just wish I had a mill, or there was a local machinist who could quickly and cheaply run those two 5/16" long grooves for me. It'll take a fine hand on the angle grinder or Dremel cutoff wheel... (maybe time for a $20 HF 2"-3" electric die grinder?)
Rod
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It's a unique idea. I'll be interested in seeing what happens.
Every single Gen1 I have handled has those grooves (to varying depths). As the receivers are extruded, and the lines are always full length, I'm convinced they are caused by the dies. Even the Gen2 have some traces of them. I sort receivers by these grooves... the bad ones get set aside for through tubes. That takes care of them.
I have considered boring one slightly to see if that would do it, but, I'm probably going to need all the receivers I can get, to upgrade.
Keep us informed?
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Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???
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Yup. I think the thread is in Mike's V gate.
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It's a unique idea. I'll be interested in seeing what happens.
Every single Gen1 I have handled has those grooves (to varying depths). As the receivers are extruded, and the lines are always full length, I'm convinced they are caused by the dies. Even the Gens 2 have some traces of them. I sort receivers by these grooves... the bad ones get set aside for through tubes. That takes care of them.
I have considered boring one slightly to see if that would do it, but, I'm probably going to need all the receivers I can get, to upgrade.
Keep us informed?
Will do. Funding on Sept03 - and working on a few other ideas, like visually steampunk-powering(actually electric and pulleys/gears) the FD pump -a health NECESSITY after my first back surgery last week.
-and lever cocking, possibly eventual Winchester '73 (or Daisy)style (ditto "necessity..."- surgery recovery, docs say "push, never pull...")
If(when) I do, it will of course have to be a double, two sided external linkage- no more trying to pull a galling bolt with a handle on only one side!
I STILL can't believe some enterprising semipro machinist(or amateur with a lathe, or even just someone with credit who wants to finance one quick; and a 1/8"npt tap) won't run off HPA fill plugs,
for regulated bottle-feeding the 60C/FDPCP, with two O-ring grooves (to bypass the tube threads!)
It would just need a collar ridge (and OD to the end, like the stock FD plug) on it so they can use their stock FD fill plug screw cap...no check valve needed for a regulated tank. No troublesome threading.
It'd sell like hotcakes at $45-48... It could ("shall?") have two npt holes, and be long enough for one axial(ie on the end) & one radial(on the side)... LOTS of flexibility there for the user. MUCH cheaper solution than a reversing block.
If I had an ounce of credit I'd already have done it.
And I'd buy one or two yesterday, if someone else just would.
Another nice product would be REALLY long ASA/Regulator extensions.. 4-12"
-to get the tank's weight back nearer the trigger, esp. with LONG barrels/tubes.
(Mine will eventually be four FEET)
CP's $20/inch doesn't cut it for those lengths.
Rod - now age 69.
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Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???
One poster said they used coats of nail polish...
I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.
Rod
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Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???
One poster said they used coats of nail polish...
I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.
Rod
My preferences in epoxies are Devcon and JB Weld for such fixes.
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Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???
One poster said they used coats of nail polish...
I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.
Rod
My preferences in epoxies are Devcon and JB Weld for such fixes.
I'm guessing it will have to "flow" a little more than that..
Viscosity will be everything.
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I feel pretty lucky, of the 3 I bought, 2 hold all their air indefinitely. The other holds for days then drops very slowly.
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Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???
One poster said they used coats of nail polish...
I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.
Rod
My preferences in epoxies are Devcon and JB Weld for such fixes.
I'm guessing it will have to "flow" a little more than that..
Viscosity will be everything.
I have found both to be self leveling as I have used both to bed rifles.
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I experimented with the nail polish on one receiver but got a better flat finish using Duplicolor high heat engine rattle can spray paint with ceramic. I like this paint because it dries well. I had masked the face of the hammer block then installed it then shot a heavy coat where the machine mark is then lied the receiver flat so the paint would even out to avoid runs. Applied another coat after first coat dried and must say it looked pretty good covering the machine marks. Forgot to mention I did mask of the threads for the air tube also.
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I experimented with the nail polish on one receiver but got a better flat finish using Duplicolor high heat engine rattle can spray paint with ceramic. I like this paint because it dries well. I had masked the face of the hammer block then installed it then shot a heavy coat where the machine mark is then lied the receiver flat so the paint would even out to avoid runs. Applied another coat after first coat dried and must say it looked pretty good covering the machine marks. Forgot to mention I did mask of the threads for the air tube also.
Thanks! -"with ceramic"- sounds promising, I'll be trying this first.
A perfect example of why I put up with a somewhat rocky misunderstanding-ridden start with GTA.
I now count this forum as one of my blessings.
(a daily process that doctors have prescribed as part of my surgery recovery..)
Rod
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I experimented with the nail polish on one receiver but got a better flat finish using Duplicolor high heat engine rattle can spray paint with ceramic. I like this paint because it dries well. I had masked the face of the hammer block then installed it then shot a heavy coat where the machine mark is then lied the receiver flat so the paint would even out to avoid runs. Applied another coat after first coat dried and must say it looked pretty good covering the machine marks. Forgot to mention I did mask of the threads for the air tube also.
I have used quite a bit of this on other things, and can vouch for it's ability to nicely fill. Good stuff... good idea.
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Guys, given that these make a good gun at only 1.5K... would it be worth it to produce a receiver that is sleeved as well as incorporates a back up lip for the screw in tube's seal?
Also, who makes a good pump action gun?
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Guys, given that these make a good gun at only 1.5K... would it be worth it to produce a receiver that is sleeved as well as incorporates a back up lip for the screw in tube's seal?
I vote "YES" - continuing a disturbingly complete agreement with the rest of your ideas!
We need to talk...
Rod
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Guys, given that these make a good gun at only 1.5K... would it be worth it to produce a receiver that is sleeved as well as incorporates a back up lip for the screw in tube's seal?
Also, who makes a good pump action gun?
I for one have seen the galling of the aluminum receiver and vote yes to a sleeve. Not only will the sleeve help in galling, when polished it will facilitate a better platform for the lubricity of your Teflon coated striker.
As far as the lip for the screw in sleeve I've seen not problem with the lip in my receiver.
Keep up the good work.
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I think what stalwart is referring to with the "lip" idea is to retain the tube seal which can pop out if the tube is overtightened.... I made an insert to try and cure that problem I mine.... The tube can be tightened much tighter without the seal popping out of place, but unfortunately the slow leak persists.... Once down to about 500 psi it basically stops....
Bob
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I think what stalwart is referring to with the "lip" idea is to retain the tube seal which can pop out if the tube is overtightened.... I made an insert to try and cure that problem I mine.... The tube can be tightened much tighter without the seal popping out of place, but unfortunately the slow leak persists.... Once down to about 500 psi it basically stops....
Bob
Now I see. Thanks.
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I think what stalwart is referring to with the "lip" idea is to retain the tube seal which can pop out if the tube is overtightened.... I made an insert to try and cure that problem I mine.... The tube can be tightened much tighter without the seal popping out of place, but unfortunately the slow leak persists.... Once down to about 500 psi it basically stops....
Bob
Have all of the usual indicators been tried - i.e., condom, talc, soap bubble?
Rod
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I think what stalwart is referring to with the "lip" idea is to retain the tube seal which can pop out if the tube is overtightened.... I made an insert to try and cure that problem I mine.... The tube can be tightened much tighter without the seal popping out of place, but unfortunately the slow leak persists.... Once down to about 500 psi it basically stops....
Bob
Have all of the usual indicators been tried - i.e., condom, talc, soap bubble?
Rod
For me? Only when it itches. ;D
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I finally got some GEN1 parts today!!
How many times do we need to say it, but Mike Melick is surely the best businessman in America- for his customer service alone! (then there's that tuning expertise....awesome.)
The G1 receiver really IS different, has a little ball bearing right where the GII's bolt galled unacceptably, and although I probably won't be touching it in order for Eric's magic to have a pristine platform, the arrival of the parts for the GENII receiver I butchered (but not TOO bad I hope) to go plastic-free, will be an inspiration to continue beyond sealing up the capscrew heads into the GII receiver and also finish the experimental QB valve I'm modding. An 8mm capscrew countersink is coming, to bury the back of the QB valve into the QB steel "anvil"- to cautiously get the spacing right for its mounting screw, and so it'll trap the valve body's back Oring(-s?.) Then I can bore out the 8mm (.315")pilot hole to 3/8(.375") for the rear-relocated return spring, cut off half the valve's front threads and most of the spurious Al piercer-and-(formerly front)spring mount, thread the valve stem for a nut/washer to hold the spring in back, and cut down a lot of the poppet's front sides into a blunt cone. I'll be making washers to hold the counterbored-in(FD style) valve stem's rear O-ring(another -tiny- counterbore to buy,) by slicing the GII's spurious plastic anvil. If I trust the tools will do it, I may try to cheat a little more intake area in the throat and on the stem. My measurements, and the history of others (loving some GTA,) show it's worth it, even in tiny amounts of flow added to the valve's throat, still the bottleneck. The next step would be to try a whole new (much bigger-flowing and simpler) valve cylinder with the inset thick washer-like PEEK seal, and steel(? I'd prefer titanium...) golf-tee(or 4stroke IC motor valve)-like poppet. That pretty much exhausts the new versions I've read about in these forums.
It'll be fun to compare their performance.
With an X-Y vise on its way, I may even try to run, "as is," the old Walker-Turner DP (I was meaning to recondition before my back went out,)cautiously using it as a mill, to get a straighter shot at those short axial O-ring-material grooves I'm putting on either side of the (valve's) exhaust port so the screw heads won't leak.
(shhhh.... don't tell the wife or the doctors... those WT parts are ALL heavy as ^&*().
I DO have a winch on an overhead track ;) one reason I lobbied heavily 7 years ago for this retirement house with the old welder's garage.
Think I'll give it a few more days weeks (saw the doc Friday) first though,
before I try to heft or even manipulate that heavy iron..
THREE doc visits this week produced disappointing results:
Newest assessment says "not even lawnmowing for another month, minimum." :(
Working on parts for the pump automation.
Rod
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Teflon bearing powder coat doesn't come in anything but high gloss... but I figured out how to give it a decent matte finish (2 step). Can now do choice of gloss, matte, or textured.
I really like the way this looks, and it shows no prints.
I'll get this all figured out... eventually.
;D
.
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Looks really nice....
Bob
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Thank you, sir!
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Teflon bearing powder coat doesn't come in anything but high gloss... but I figured out how to give it a decent matte finish (2 step). Can now do choice of gloss, matte, or textured.
I really like the way this looks, and it shows no prints.
I'll get this all figured out... eventually.
;D
.
That looks real good!
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Thanks, Mike.
I am pretty happy with this stuff now. Durable, practically sheds dirt, and within a few cycles... slick as it gets. Could end up SOP here.
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Now mike has to get more gen 1s, I need a spare to send off for this.
Looks amazing.
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Thanks, Mike.
I am pretty happy with this stuff now. Durable, practically sheds dirt, and within a few cycles... slick as it gets. Could end up SOP here.
You just keep raising that bar a little higher and higher don't ya Eric?
Looks awesome.
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Steve... I hope he gets a trainload of these things. If I was talented enough already to build the gun that I know these can be... I would, and it would be clearer why I am so committed here.
Thanks, Bill. I'm sure trying! Sometimes, it's like a ratchet in a tight space... as long as I can get a click or two, I'll keep twistin'.
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As I refine this little endeavor, some things have become clearer.
Many of the receivers I have been setting aside for through tube use, due to flaws near the valve o-ring, are actually quite fixable with a careful reaming. From now on, all 1.5K guns sent for work will be treated as needed... as well as having the tube threads chased with a good tap.
For the 1.5K single shot guys, I will be keeping a small pile of chased and reamed receivers in stock (for exchange or outright sale). If you love your gun, but the darn thing won't hold air at the valve ring... holler. We can deal with it. I ream only until that area at the ring is round and smooth... and will also powder coat to taste, if desired.
All prices quoted to date will be effective until Oct. 7.
What we in CA call "winter" is fast approaching, and I'm not only almost ready for it... I'm looking forward to it (thanks to you guys and GTA!) in ways I haven't since I was a kid waxing my sled runners. We're gonna have some fun... ;D
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UPS came today, brought me this:
http://www.homedepot.com/p/DuraVent-DVL-6-in-x-48-in-Double-Wall-Chimney-Stove-Pipe-in-Black-6DVL-48/202269780?quantity=1 (http://www.homedepot.com/p/DuraVent-DVL-6-in-x-48-in-Double-Wall-Chimney-Stove-Pipe-in-Black-6DVL-48/202269780?quantity=1)
I've been waiting nearly 2 months for my "new" oven. I finally gave up on the guy, and came up with this: I'm going to put a standard 6" burner (120V) in the bottom, on a decent base... fill the gap between the pipes with vermiculite... build a cradle for holding barrels and Bobcats that drops in.... and make a lid with the temp sensor in it. I already built the digital controller... plugs into my ovens, and works great.
The inner pipe is stainless... cost me $91 shipped. It will hold 3 Bobcats, or about 6 barrels. If I ever need more than 42" of length, I just add another pipe. Very energy efficient (no wasted space), and roughly $125 a copy.
Back on track here... I'll get this thing running asap, and have some drop-in stuff ready in time for Christmas. ;D
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UPS came today, brought me this:
http://www.homedepot.com/p/DuraVent-DVL-6-in-x-48-in-Double-Wall-Chimney-Stove-Pipe-in-Black-6DVL-48/202269780?quantity=1 (http://www.homedepot.com/p/DuraVent-DVL-6-in-x-48-in-Double-Wall-Chimney-Stove-Pipe-in-Black-6DVL-48/202269780?quantity=1)
I've been waiting nearly 2 months for my "new" oven. I finally gave up on the guy, and came up with this: I'm going to put a standard 6" burner (120V) in the bottom, on a decent base... fill the gap between the pipes with vermiculite... build a cradle for holding barrels and Bobcats that drops in.... and make a lid with the temp sensor in it. I already built the digital controller... plugs into my ovens, and works great.
The inner pipe is stainless... cost me $91 shipped. It will hold 3 Bobcats, or about 6 barrels. If I ever need more than 42" of length, I just add another pipe. Very energy efficient (no wasted space), and roughly $125 a copy.
Back on track here... I'll get this thing running asap, and have some drop-in stuff ready in time for Christmas. ;D
Is there any limit to your creativity?? I hope not.
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I honestly don't know, Mike. It looks like unless I can arrange 40 hr days, or get a crew of workshop elves (tiny hands... zero knowledge of Federal labor laws), I may never get a chance to find out. Meanwhile, my pile of amateurish drawings and scribbled spec sheets continues to grow.
;D
http://www.walmart.com/ip/Elite-Cuisine-Single-Burner-Hot-Plate/8467243 (http://www.walmart.com/ip/Elite-Cuisine-Single-Burner-Hot-Plate/8467243) Perfect sized, stout element and just enough high temp wire inside to get it done. 750 watt... more than enough power.
Got the element mounted, the base is next. Leaning toward molded concrete, to get the CoG down so I can keep the footprint smaller.
I'm delighted with the design, but quite disappointed with how long it took me to come up with it. This ain't Rocket Science...
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@least you're lucky with the form factor - think how hard an oven for kart frames is gonna be.
It can't even be flat and thin, b/c of seat and steering hoops.
But I think discarded electric stoves will be my friends as to heating coils.
I'm warming up by devising a rust electrolysis tank - which CAN be temporary and shallow,
as rust removal precedes welding on (usually, replacing) those hoops.
Airgun-wise, barrel hunting is a bear....
need .25cal (or even .300)choked match, about 36"+... for under $200.
I did manage to score a backup .22 (microgroove bullet, but only 21," chamber already removed)
for $20 -shipping included.
Rod
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I honestly don't know, Mike. It looks like unless I can arrange 40 hr days, or get a crew of workshop elves (tiny hands... zero knowledge of Federal labor laws), I may never get a chance to find out. Meanwhile, my pile of amateurish drawings and scribbled spec sheets continues to grow.
;D
http://www.walmart.com/ip/Elite-Cuisine-Single-Burner-Hot-Plate/8467243 (http://www.walmart.com/ip/Elite-Cuisine-Single-Burner-Hot-Plate/8467243) Perfect sized, stout element and just enough high temp wire inside to get it done. 750 watt... more than enough power.
Got the element mounted, the base is next. Leaning toward molded concrete, to get the CoG down so I can keep the footprint smaller.
I'm delighted with the design, but quite disappointed with how long it took me to come up with it. This ain't Rocket Science...
From past memory there are refractory materials (EPA approved) that mixes with water to pour or refractory material that can be carved to make a lid.. Price and availability I don't know but I'm a lot like you: "Necessity is the mother of invention."
Keep on scribblin an a drawin your doin GREAT!.
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Thanks, my friend!
I am working on molds for both the base, and lid. The lid will be cast from vermiculite and concrete at a 5:1 ratio. I changed my mind and will make it like a pot lid, and put the sensor in the body. To allow the oven to be easily extended, I have to have either the base or lid end left alone.. and it looks like the base end of the tube makes more sense to mod than the lid end.
Years ago, I experimented with soundproof concrete speaker boxes (low freq). It was a ton of fun, in a "mud pie" kind of way... I'm looking forward to this.
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For anyone thinking about building a coating system.... it's easy.
Ebayed in the relay (SSR), the controller and the sensor... the rest is salvage. The box is an old PC power supply, painted with the dregs left in 2 spray cans. The switch now defeats the 5VDC (old phone charger), which kills the relay and the fan... allowing passive monitoring.
Built this 2 yrs ago, and have been hammering it since... works great:
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If you need 5VDC why not get it from the PSU instead of a phone charger? Or did I misunderstand?
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I used a dead PSU for the box, fan and switch only. As I only needed 120VAC and +5VDC.. and nearly all the room inside.. I went for the smallest DC source I could come up with, out of the junk pile.
The brain runs pretty cool, but the SSR can get quite warm when asked to switch real amperage. It needs the fan, and some room to breath.
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Oh, that makes sense.
I thought you were using the PSU as is.
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Just pulled from the base mold. 3.5" thick, straight concrete with channel through bottom for wiring. Probably gained over 35#... quite steady now.
Poured a slug to test 5:1 ratio for strength, but (predictably) it's nowhere near set yet.
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Not sure you would want it, but if you have concerns about your SSR overheating I have access to plenty of heatsinks of various sizes.
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This rig runs cool enough (25A SSR), but I plan to build a controller next year for 240V. It will need 2 relays, and I intend to pump a lot more amps through it. It will need sinks... I'll holler. Thanks, Steve.
The 5:1 mix is still not anywhere near set. I'm wondering if I got bad advice on that ratio? I'm going to pour a few slugs from smaller ratios, if this thing doesn't hurry up. It's only an experiment for the lid... I may get tired of the messes, and go for something out of metal.
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Been turning everything in sight... and among the bits are these streamlined bulk caps. I'm mounting genuine Ninja fittings and valves, and will set them up for CO2 cartridges on request.
Next: custom caps with ports for gauges, etc...
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The customer wanted close fit of the retainer (with heavier ridge), 3 ports, and enough tail to put an o-ring past the threaded portion of the tube. This is what I came up with:
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Very nice.... Retained by the standard "nut"?
Bob
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Thanks, Bob! ;D
Yup... FDPCP.
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Had to check the fits..
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Just a one off?
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Had to check the fits..
Eric,
what is the purpose for the 3rd port?
maybe a bleeder valve?
Will you soon be offering these?
if so, what is the cost?
I'd like to get one, as well as a repeating receiver for my .22 gen 1
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Mainly flexibility and location of a much bulkier burst disc (with a holder at 1/4" available AT A PRICE, and interchangeable discs in 200psi increments from around 2k to 4-5k.) So bulky, you'd have to 'wrap' it back with a 90* fitting. Also contemplating a better gauge.
But the original driver was RSterne's similar plug's extra length (additional O-ring) into the tube, to eliminate pressurizing the thread area. It just looked like a good idea - and I also wanted to locate the 22ci bottle closer to the tube (and to the trigger,) mostly inside an AR78A match stock
- now I gotta learn, & tool for, woodworking?;)
I can aways plug an 'extra' npt. But look at the pic and envision choices of fittings to wrap back toward the stock, as far back as possible (maybe regulator extensions) for the bottle, with an inline on/off ASA instead of the 'normal' right angle one. I could come out the end or out one "side" npt. A gauge can likewise either go in the end or one side, with the third hosting either a common (but limited choice) 1/8" burst disc, or a less common 1/4" carrier arrangement.
Eric has a great approach to keeping the NPT's from adding the usual extra adapter length.
Obviously this gun (one of two initial FDPCP .22's, one Gen1 in progress and this Gen2) is not intended for carrying around through the woods. It's a windowsill gun.
Like hand pumping, those days are long gone thanks to a bad back and hip/knee joints.
I'm also working on automating the FD pump. Steel has arrived, and next week's predicted indian summer days look like my first shot at welding since the surgery and 8 week recovery. Almost six total months out of commission, even to mow the lawn.
A few incidentals, like dessicant, HallEffect sensors, relays, bearings and belts; will have to wait until the following week. I have a sequencer kit left over from a CD Mastering Studio I built and used to run in NYC, that may save me some work/expense. I'll experiment with magnet placement by manually triggering the multispeed blower motor's speed relays at first.
The idea is not to stress and wear out the pump. I don't want to keep replacing it.
The frame will have a space for a small preload compressor, dessicant, and air tank storage, probably something like a couple of Ninja 90/4500's.
I'll be pushing the FDPCP's close to their limits, going next to .25 unless a suitable .300 or larger (LOONG, mg) barrel presents itself cheaply. The ultimate goal is exceptionally long range at high fpe. As for shot count 9 tops is fine, but I suspect the bottle will do a little better, even with big bore, due to extreme barrel length and a corresponding new (long) tube.
Is anyone building higher flow, Mrod-style valves for the FD tube form factor yet?
You know, flat or dished(countersunk?) front; 4stroke IC-motor or golf-tee shaped, rear-springed poppet? You know, like this:
http://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=55930.0;attach=71861;image (http://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=55930.0;attach=71861;image)
(or is that yet another job for Eric? Any brass left? :)
Rod
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"But the original driver was RSterne's similar plug's extra length (additional O-ring) into the tube, to eliminate pressurizing the thread area. It just looked like a good idea..." Yeah, that RStearne guy is pretty handy to have around... :)
I plan to eventually offer these, in 2 port configs, as OTS parts... but for now, I'll be making a handful of them for sale to GTA members. It may be a while before I make more than that. At the end of this session with the lathe, I'm going to turn a part for a through tube fixture that is yet another attempt to speed up that process, and cut my (our) costs.
I'll have an exact price when I have a better idea of how much time they take to make. Looks like somewhere between $55-$65... but, don't quote me. They will be as shown, but with the retaining ridge 2mm rearward, and the gauge port recessed to allow a tighter fit to the gun.
Built as the mock up is, these weigh almost 5oz. I'm going to proto an aluminum version, with slip coating, to see what that weighs/costs.
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Eric,did you get the E-mail about the high power valve being made by the Cothran Machine shop?He said he took three years to perfect it and has achieved over 300 FP in .357 with a 27inch barrel.I sent you an Email direct but I never trust my skill with my evil computer so I post here also.
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I got a chance to look it over.... pretty slick. Says it fits 7/8 tube... do you know if that means OD? A couple ring grooves would adapt it to the 60s, if so.
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VERY interested...
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over 300 FP in .357 with a 27inch barrel
at what pressure?
Bob
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That's pretty good, my theoretical projection is 302 FPE using a 24" barrel at 3000 psi.... Several people are getting close, managing that with either a 27-30 " barrel or a bit more pressure....
Bob
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Is a Disco tube 7/8 ID?
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The Disco tube is 7/8" OD x 0.065" wall.... the same as what you are going to be using on the HP version of the FD-PCP.... It would be tough to get a 3/8" throat inside that, which would be required for full bore-sized porting in a .357.... I have a 5/16" throat in my Hayabusa .357 which uses a 1" OD x 0.065" tube and can go a bit bigger.... Going to a 3/8" throat in a 3/4" OD valve would require moving the screws away from the porting.... ie a much longer valve stem....
Bob
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With the valve mounted to the striker block, as my design does, there will be nothing in our way. ;D
The Cothran valve would eliminate the need for a tail on the thru tube, for the more extreme rifles. Not cheap, but gives us options to ponder.
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I'm thinking it (Cothran FR valve) also should allow a lighter striker spring and therefore lighter bolt cocking force- a real consideration for those with the health (and bolt galling) issues I've been through.
The Cothran valve definitely goes on the January parts 'buy list'...
Rod
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Not only that, but it may allow a combo of weights and springs that would significantly reduce lock time.
http://www.chuckhawks.com/locktime.htm (http://www.chuckhawks.com/locktime.htm)
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A Cothran valve is headed here, we will know a lot more soon. If it does the job, it may make the tail obsolete before it sees production. I hope so!
I added 1 sentence to my site tonight. Self explanatory, and apparently necessary: "Please note: Builders kits are for skilled builders only. If you saved the money we charge to reassemble, don't expect us to handle emails holding your hand during that process."
It only takes a few guys who don't know, or perhaps don't care, that there is a line between service and servitude... to cost everyone else money. I'm nipping this one in the bud.
:)
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That's pretty good, my theoretical projection is 302 FPE using a 24" barrel at 3000 psi.... Several people are getting close, managing that with either a 27-30 " barrel or a bit more pressure....
Bob
Where are they getting 30"(+) quarterbore barrels?
LW wants $400/ or make 10 pcs+, for .25c 36"
Rod
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TJ's sells barrels (liners) in any length you want, by the inch, although he charges a bit extra (50cents per inch) for 30" and over....
Bob
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TJ's sells barrels (liners) in any length you want, by the inch, although he charges a bit extra (50cents per inch) for 30" and over....
Bob
The liner thing never made sense to me.
You still need a -very- straight and strong barrel to put it in, so why the extra expense?
Seems to me, skimping on the outer barrel to save $$ just makes a 'whippy' or even weak/fragile barrel, (remember, I don't mind, and actually value, weight;) never mind the double (even triple) labor, markups and shipping.
And I've priced used barrels. "Worn out" (which no one ever admits anyway) is not substantially cheaper than one that works.
Rod
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You need to educate yourself in the use of "liners" and what they are from TJ's before making such a comment.... He sells a .25 cal in ODs of 7/16", 1/2", and 9/16", any of which can be used by themselves as airgun barrels.... If you want to REALLY stiffen one up, then get a Carbon Fibre sleeve with a 1/16" - 1/8" thick wall and glue it on....
It terms of the importance of a barrel being - very - straight or useless.... perhaps FWB need to learn this, as here is a photo of a target pistol they made for Dr. Beeman....
(http://i378.photobucket.com/albums/oo221/rsterne/Important/FWB2twist2.jpg) (http://s378.photobucket.com/user/rsterne/media/Important/FWB2twist2.jpg.html)
According to them, if the last inch at the muzzle is straight and the crown perfect, you're good to go....
Oh, and BTW.... You could get a "liner" from TJ's, a thick wall CF tube, and the necessary Epoxy for less than half the $400 for a LW barrel....
Bob
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You need to educate yourself in the use of "liners" and what they are from TJ's before making such a comment.... He sells a .25 cal in ODs of 7/16", 1/2", and 9/16", any of which can be used by themselves as airgun barrels.... If you want to REALLY stiffen one up, then get a Carbon Fibre sleeve with a 1/16" - 1/8" thick wall and glue it on....
It terms of the importance of a barrel being - very - straight or useless.... perhaps FWB need to learn this, as here is a photo of a target pistol they made for Dr. Beeman....
(http://i378.photobucket.com/albums/oo221/rsterne/Important/FWB2twist2.jpg) (http://s378.photobucket.com/user/rsterne/media/Important/FWB2twist2.jpg.html)
According to them, if the last inch at the muzzle is straight and the crown perfect, you're good to go....
Oh, and BTW.... You could get a "liner" from TJ's, a thick wall CF tube, and the necessary Epoxy for less than half the $400 for a LW barrel....
Bob
(I've seen it, of course.)
I'm just guessing - but also guessing there's a difference between a low FPE, low speed, low distance 10m match pellet pistol, and a high powered long distance hunter/sniper.
Anyway, doesn't this suggest a choke is essential for accuracy? I thought I read we had disproven that in the real world.
BTW there are plenty of muzzleloader barrels, new and used, on eBay for $150 or even less.
I'm afraid I will always believe weight (mass) = stability.
God knows mine can use all the help it can get.
(And I'm not known as a fan of plastic almost anywhere on a gun- or a vehicle; any machine, really. 0-rings, and valve poppet or seat -MAYBE- but that's it. Esthetically I abhor it. It's cheap and ephemeral.)
Rod
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No idea what the "choke" comment is about.... and while I agree that stiffness in a rifle barrel is critical, you won't convince me that straightness is....
If you are referring to Carbon Fibre as a "plastic" you are sadly mistaken.... only the glue that holds it together is a plastic.... CF is stronger and stiffer than steel, and a LOT lighter.... If a 9/16" steel barrel isn't heavy enough for you, then purchase a piece of steel tubing of that ID and as large as you can get OD and solder them together (since you don't like glue).... It's a great way to make a match quality barrel....
and, if you don't like my suggestions, then ignore them, I have no problem with that....
Bob
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Bob, if I didn't respect your opinions so much I wouldn't bother to discuss them.
It's really OK to disagree on one thing - especially esthetics.
And I have done considerable homework on this liner thing since Eric suggested it, as I do like (OK, need,) to save money ;) My opinion includes that, and even its adopters give a considerable nod to resonance issues but don't address concentricity (re: the entire process,) and I don't have affordable access to a lathe to correct or adjust that. So IMO I'm better off taking a shot for +/- (sometimes way less than)$100 at gettting lucky with a purpose built, one piece, heavy, final product barrel.
YMMV of course.
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Dissimilar materials in laminate can go a long way to damping harmonics.
I'm leaning toward aluminum bull barrels with the smallest OD liners possible, for the hunters. Coat-able, light, and stout.
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Dissimilar materials in laminate can go a long way to damping harmonics.
I'm leaning toward aluminum bull barrels with the smallest OD liners possible, for the hunters. Coat-able, light, and stout.
You may have something there with Aluminum... depending on the hardening,(or lack of,) its softness might help the resonance thing. Then there's brass to try....
I admit my assumptions always (but sometimes inappropriately)start with CrMO... I use so much of it for racing stuff. I'd still stay with the thickest liners though, personally.
Lots of fun (but expensive) experimentation possible.
(again just my airgun-inexperienced but educated engineer's guesses...having long abandoned the math of my BSEE through experience in the superiority of 60 pro yrs. of 'gut feelings,' which reality will so often inconveniently provide. The saviour there is accompanying artistic talent. ;)
And I was taught early on, (in 3rd grade English,) disclaimers on one's statements as opinion are NEVER necessary nor appropriate.
If anything one says or writes is NOT "(just) his opinion," and he didn't footnote or otherwise attribute it to the originator, he is a plagiarist.
To assume otherwise (by expecting his statements to include said apology) is therefore to accuse him of possible plagiarism. "JMO," is therefore redundant and never necessary.
Rod
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Dissimilar materials in laminate can go a long way to damping harmonics.
I'm leaning toward aluminum bull barrels with the smallest OD liners possible, for the hunters. Coat-able, light, and stout.
If you are still considering an oval shroud, would it be possible to use the smallest OD liner and support it only with some baffles?
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I would think that using a very small OD liner which is not continuously supported by bonding it into a larger, rigid barrel would be a recipe for additional nodal vibrations between the supporting baffles.... and the slimmer the liner the more pronounced the effect.... Tensioning the barrel by putting the shroud in compression with a threaded fitting at the muzzle will raise the resonant frequency of the vibrations, both primary and secondary, in a similar way to increasing the OD of the barrel....
Bob
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As it sits now, the shroud set up would be attached to a barrel that is just small enough to be forced into the oval, and it would be bonded full length, top and bottom. The baffles will be bonded in at the same time.
Time, and the cost of experimenting with high temp resins are what's holding that up. I have that, and a couple more ideas to try... as soon as the basics are covered.
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As it sits now, the shroud set up would be attached to a barrel that is just small enough to be forced into the oval, and it would be bonded full length, top and bottom. The baffles will be bonded in at the same time.
Time, and the cost of experimenting with high temp resins are what's holding that up. I have that, and a couple more ideas to try... as soon as the basics are covered.
Now that is a unique arrangement. Exciting stuff.
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No idea what the "choke" comment is about.... and while I agree that stiffness in a rifle barrel is critical, you won't convince me that straightness is....
If you are referring to Carbon Fibre as a "plastic" you are sadly mistaken.... only the glue that holds it together is a plastic.... CF is stronger and stiffer than steel, and a LOT lighter.... If a 9/16" steel barrel isn't heavy enough for you, then purchase a piece of steel tubing of that ID and as large as you can get OD and solder them together (since you don't like glue).... It's a great way to make a match quality barrel....
and, if you don't like my suggestions, then ignore them, I have no problem with that....
Bob
Trying to heat and solder all 360 degrees and the entire length of a 36-41" long tube at the same time , with home equipment (a torch, or torches) sounds pretty daunting... Doing (and cooling) it evenly, sounds impossible. They don't guarantee the wall thickness/ID tolerance of commercial, even aircraft, steel tube; to be all that uniform either... which is an issue whether you use glue or solder.
;)
Rod
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The typical procedure in bygone days for installing a .22 liner in a CF rifle barrel was to drill it out about 0.010" larger than the OD of the liner, tin the liner, tin the inside of the barrel, start the liner into the preheated barrel and heat the barrel with it vertical and watch the liner just slide down into place from gravity.... My Dad did one, I shot it for years.... He told me that skilled shooters used to make .22LR target rifles from worn out CF barrels that way all the time.... and they shot better than most purpose made .22LR target barrels....
Bob
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Wouldn't you have to be equipped as a barrel machine shop anyway to drill something 36-41" long accurately?
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Actually, my Dad brazed a 5/16" (or slightly bigger) twist drill to a piece of 1/4" steel rod about 24" long and used that to drill the barrel.... no lathe, either.... I didn't see him drill it, but we had the drill kicking around years later.... I think he started with a .303 British, so about all he had to do was clean out the rifling.... I know the liner was a very thin wall, I always got a kick out of looking at the muzzle and seeing the liner and barrel with a line of solder in between.... That barrel shot as good as any .22 LR I have ever shot....
Bob
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"dang" you Bob.
You actually have me thinking of trying it..
You are a very bad man.
(J/K - Rod.)
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& "nanny s/w" is incredibly lame here.
4shame.
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Sometimes things aren't as tough, or complicated as you think....
Bob
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You are a very bad man.
I have been trying to warn everybody about Bob, but no one will listen! ;D
Seriously, Rod... how proud would you be of a barrel you put together?
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LOL that would depend on whether I could hit the garage with it at 20 feet
Of course, if I make it long ENOUGH..... ;) (to throw like a spear)
BTW the plugs look GREAT!
(They came today.)
now to start watching eBay for rusted-out Muzzleloader bbls.
People tend to sell only the ones that look usable.
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Now, you're talkin'.
8)
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Now, you're talkin'.
8)
Woke up this morning envisioning a machined Al collar (if I had a lathe) with 3-4+ setscrews and drilled depressions in the breech end of a barrel (will get turned down eventually) - to hang it from... with heavy steel wire. (what if it melts first? OK, steel rod. Fireproof triangle rig? Gotta support the liner straight until it drops, too..)
Some things are NOT simpler than they sound....;)
Need a better description from Bob's memory (mining his dad's experience) obviously.
Rod
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Got some .30 cal mags in from Lloyd at Airgun Lab. Slick! Does anyone smell something cooking?
I promised this would be a fun winter! ;D
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Oh, and Rod... the guy who taught me to machine used to say "With every project, there comes a time when it's best to shoot the engineers, and go into production".
(J/K) ;D
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Got some .30 cal mags in from Lloyd at Airgun Lab. Slick! Does anyone smell something cooking?
I promised this would be a fun winter! ;D
Are you sayin' I should be thinking beyond .25?
(How to fit that much valve in an FD....never mind the extra barrel length
for the poor receiver to support. I was thinking 36" is enough for the .25)
Rod
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Yup.
If a 60 is cut to take an MRod .25 mag, it can be used for .22 (wheel change), .25, and with Lloyds' mags, .30 cal. With the impending single shot tray, we can keep going up, until the barrels are too thin to mount.
johninthecamper has .30 BTs that work well. I don't know the specifics, though.
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I will bet that Don C's valve, the new mags, and Bob's boolits along with your creativity are brewing up one butt-kicking .30 cal rifle! I am sure that you will love the valve from Don. I have had one for almost a year and haven't been able to get at building the rifle around it! I need a good butt-kicking myself!
Looking forward to the end result. I am sure it will be an eye opener. Keep the wheels turnin"!
Edit: This got posted after you had already confirmed Mike's boolits! Oops!
Tom
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Oh, and Rod... there comes a time when it's best to shoot the engineers, and go into production".
(J/K) ;D
*ACK* - and I'm not only an engineer but a piano player too!
(which is why I need to arm up, to defend myself -J/K-...
-even though professionally retired from both;)
Rod
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Yup.
If a 60 is cut to take an MRod .25 mag, it can be used for .22 (wheel change), .25, and with Lloyds' mags, .30 cal. With the impending single shot tray, we can keep going up, until the barrels are too thin to mount.
johninthecamper has .30 BTs that work well. I don't know the specifics, though.
But how many INCHES high does the scope have to be (for the MRod mag)?
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Brewing is an apt description. The yeast was added about the beginning of tourist season, for Bob. It's been bubbling ever faster since. We've been calling it "Grizzly", and many of it's design features (and production methods) will trickle down into the Wolverines.
The value of Mr. Sterne's input, in all aspects of the design, cannot be overstated.
Rod, you know the rules out West... just keep banging out the Ragtime, and you can ignore the gunfire...
The mags differ from .22 mags in length only.
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AHEM!.... There is also a 70 gr. BBT in .30 cal that just happens to fit the aforementioned MRod magazine.... Molds are available from Tom at Accurate, #30-070A.... I see someone has also added a 75 gr. stretched version, #30-075A, using the lengths of my .308 cal 79 gr.... I don't know if its stable in our 26" barrel, but it will fit the MRod mag. also....
The distance from the boreline to the top of the .25 cal magazine is 0.070" higher than with the PRod magazine.... only 0.030" taller than a .22 cal MRod mag....
Bob
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With a scope as low it will go, there's plenty of room.
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With a scope as low it will go, there's plenty of room.
YES !!
THanks...
Rod
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Rod, you know the rules out West... just keep banging out the Ragtime, and you can ignore the gunfire...
I play MUCH better ragtime on the guitar :)
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At Eric's request, I have run the numbers for the safety of the Fill Plug and Retaining Nut at 3000 psi.... Bear in mind I am NOT an engineer, but here is my take on it, complete with the math I used.... First of all, I assumed that the tube and nut are mild steel, with a tensile strength of 53K and a yield strength in tension and compression of 44K.... I used 6061-T6 aluminum for the end plug, with a tensile of 45K, a yield of 40K in tension, and a compressive strength of 56K.... If brass is used instead, the strengths are similar, depending on the grade selected.... I used the standard of 60% of yield strength for the shear strength....
The tube on the FD-PCP is 0.875" OD x 0.065" wall, giving an ID of 0.745" (the XS-60C has a 22 mm x 1.5 mm tube) and the threads are external, 22 mm x 1 mm pitch, with a minor diameter of 20.8 mm (0.819"), and a pitch diameter of 21.3 mm (0.838"), using standard Metric thread dimensions.... The end cap (retaining nut) has an ID of 21mm (0.827") and a hole through the end flange that measures 18.75 mm (0.738").... The flange on the end of the cap is 2.3 mm (0.090") thick.... I used a flange of 0.100" on the end plug to mate with that (I did not have that actual dimension).... The O-ring is positioned inboard of the threaded portion of the tube.... Here are the numbers:
Area of end plug: PI x (0.745^2) / 4 = 0.4357 sq.in....
End force at 3000 psi: 3000 x 0.4357= 1307 lbs....
Thickness of tube wall below the threads: (0.819 - 0.745) / 2 = 0.037"....
Area of tube wall below the threads in tension: PI x (0.745 + 0.819) x 0.037 / 2 = 0.0909 sq.in....
Yield point: 44,000 x 0.0909 = 3998 lbs.... Safety margin: 3998 / 1307 = 3.1:1
Shear area of threads for 1/4" engagement: PI x 0.838 x 0.25 / 2 = 0.329 sq.in....
Yield point: 44,000 x 0.6 x 0.329 = 8683 lbs.... Safety margin: 8683 / 1307 = 6.6:1
Shear area of plug flange: PI x 0.738 x 0.100 = 0.232 sq.in....
Yield point: 40,000 x 0.6 x 0.232 = 5568 lbs..... Safety margin: 5568 / 1307 = 4.3:1
Shear area of nut flange: PI x 0.827 x 0.090 = 0.234 sq.in....
Yield point: 44,000 x 0.6 x 0.234 = 6170 lbs.... Safety margin: 6170 / 1307 = 4.7:1
Width of flanges in compression: (0.827 - 0.738) / 2 = 0.044"....
Area of flanges in compression: PI x (0.827 + 0.738) x 0.044 / 2 = 0.108 sq.in....
Bearing limit: 44,000 x 0.108 = 4557 lbs.... Safety margin: 4557 / 1307 = 3.6:1
I have asked QVTom to double-check my math, and to do a Finite Element Analysis of the strength of the retaining nut in case the simple shear calculation I did is not complete enough.... I will ask Tom to add his comment to this thread when he has had the time to run the FEA.... However, based on the above, it would appear to me that the weak point is the remaining tubing wall below the threads in the tube itself.... It just barely makes the recommended 3:1 safety margin at 3000 psi, and this assumes that the threads are not cut deeper than spec.... If they are, the safety margin drops even more....
Bob
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At Eric's request, I have run the numbers for the safety of the Fill Plug and Retaining Nut at 3000 psi.... Bear in mind I am NOT an engineer, but here is my take on it, complete with the math I used.... First of all, I assumed that the tube and nut are mild steel, with a tensile strength of 53K and a yield strength in tension and compression of 44K.... I used 6061-T6 aluminum for the end plug, with a tensile of 45K, a yield of 40K in tension, and a compressive strength of 56K.... If brass is used instead, the strengths are similar, depending on the grade selected.... I used the standard of 60% of yield strength for the shear strength....
The tube on the FD-PCP is 0.875" OD x 0.065" wall, giving an ID of 0.745" (the XS-60C has a 22 mm x 1.5 mm tube) and the threads are external, 22 mm x 1 mm pitch, with a minor diameter of 20.8 mm (0.819"), and a pitch diameter of 21.3 mm (0.838"), using standard Metric thread dimensions.... The end cap (retaining nut) has an ID of 21mm (0.827") and a hole through the end flange that measures 18.75 mm (0.738").... The flange on the end of the cap is 2.3 mm (0.090") thick.... I used a flange of 0.100" on the end plug to mate with that (I did not have that actual dimension).... The O-ring is positioned inboard of the threaded portion of the tube.... Here are the numbers:
Area of end plug: PI x (0.745^2) / 4 = 0.4357 sq.in....
End force at 3000 psi: 3000 x 0.4357= 1307 lbs....
Thickness of tube wall below the threads: (0.819 - 0.745) / 2 = 0.037"....
Area of tube wall below the threads in tension: PI x (0.745 + 0.819) x 0.037 / 2 = 0.0909 sq.in....
Yield point: 44,000 x 0.0909 = 3998 lbs.... Safety margin: 3998 / 1307 = 3.1:1
Shear area of threads for 1/4" engagement: PI x 0.838 x 0.25 / 2 = 0.329 sq.in....
Yield point: 44,000 x 0.6 x 0.329 = 8683 lbs.... Safety margin: 8683 / 1307 = 6.6:1
Shear area of plug flange: PI x 0.738 x 0.100 = 0.232 sq.in....
Yield point: 40,000 x 0.6 x 0.232 = 5568 lbs..... Safety margin: 5568 / 1307 = 4.3:1
Shear area of nut flange: PI x 0.827 x 0.090 = 0.234 sq.in....
Yield point: 44,000 x 0.6 x 0.234 = 6170 lbs.... Safety margin: 6170 / 1307 = 4.7:1
Width of flanges in compression: (0.827 - 0.738) / 2 = 0.044"....
Area of flanges in compression: PI x (0.827 + 0.738) x 0.044 / 2 = 0.108 sq.in....
Bearing limit: 44,000 x 0.108 = 4557 lbs.... Safety margin: 4557 / 1307 = 3.6:1
I have asked QVTom to double-check my math, and to do a Finite Element Analysis of the strength of the retaining nut in case the simple shear calculation I did is not complete enough.... I will ask Tom to add his comment to this thread when he has had the time to run the FEA.... However, based on the above, it would appear to me that the weak point is the remaining tubing wall below the threads in the tube itself.... It just barely makes the recommended 3:1 safety margin at 3000 psi, and this assumes that the threads are not cut deeper than spec.... If they are, the safety margin drops even more....
Bob
I notice you didn't mention receiver to tube thread so will your preliminary calcs @ 3000 psi be used with the threaded tube to receiver?? (I'm assuming the aluminum 60 receiver metallurgy would have to be known to do the proper calcs. I would also assume that if the receiver metallurgy was known the thread fit would have to be tight.)
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Thank you, Bob.
Guys, if we can use this arrangement, it will not only allow someone to use their custom cap when upgrading to 3k... but, it will allow the side port(s) to be turned to any angle.
Just trying to make this design as adaptable as possible, as well as keeping the amount of part #s as low as I can.
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I purposely did NOT address the strength of the threaded portion of the tube, as I got my knuckles rapped for doing so previously.... I asked repeatedly for the material the tube was made from and was told that information was proprietary.... I did the calculations assuming mild steel, as above, and got a pressure to yield of the threaded portion of 4370 psi and to burst of 5264 psi, which works out to a safety margin at 1500 psi of 2.9:1 to yield.... Using normalized 4130 CrMoly, with a tensile of 97K and a yield of 68K, and bumping the pressure to 2000 psi, I got 6258 psi to yield (3.1:1).... The threads in the receiver do not really concern me (assuming they are machined properly) as the thread depth is such that the shear area is huge.... It is to address the issue of pressurizing the threaded portion that Eric is looking at doing a "through tube" installation without threading to weaken the tube....
Bob
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The tube on the FD-PCP is 0.875" OD x 0.065" wall, giving an ID of 0.745" ........
Thickness of tube wall below the threads: (0.819 - 0.745) / 2 = 0.037"....
Area of tube wall below the threads in tension: PI x (0.745 + 0.819) x 0.037 / 2 = 0.0909 sq.in....
Yield point: 44,000 x 0.0909 = 3998 lbs.... Safety margin: 3998 / 1307 = 3.1:1
Bob
Bob, where did you get the 0.819" above?
Rod
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I purposely did NOT address the strength of the threaded portion of the tube, as I got my knuckles rapped for doing so previously.... I asked repeatedly for the material the tube was made from and was told that information was proprietary.... I did the calculations assuming mild steel, as above, and got a pressure to yield of the threaded portion of 4370 psi and to burst of 5264 psi, which works out to a safety margin at 1500 psi of 2.9:1 to yield.... Using normalized 4130 CrMoly, with a tensile of 97K and a yield of 68K, and bumping the pressure to 2000 psi, I got 6258 psi to yield (3.1:1).... The threads in the receiver do not really concern me (assuming they are machined properly) as the thread depth is such that the shear area is huge.... It is to address the issue of pressurizing the threaded portion that Eric is looking at doing a "through tube" installation without threading to weaken the tube....
Bob
Thanks Bob, and the through tube is the best way to go to attain a higher safety margin with higher pressures..
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Couple questions, quite likely rather uninformed on the topic, but that is why I am asking the experts.
Could the assumed weak section be lined to strengthen it? Is that what through tube basically does, by not stopping at the receiver?
Is there any concern of galvanic corrosion between the aluminum receiver and ferrous airtube?
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Thank you, Bob.
Guys, if we can use this arrangement, it will not only allow someone to use their custom cap when upgrading to 3k... but, it will allow the side port(s) to be turned to any angle.
Just trying to make this design as adaptable as possible, as well as keeping the amount of part #s as low as I can.
There are a few advantages of the custom plugs you made me, that many may not realize (and may not be accounted for in the calculations for a stock plug.)
I mean in addition to the plugs' extra(2nd) O-ring deeper in the tube, which eliminates the threaded area as a radial stress point... the original safety idea suggested and orginally demonstrated by Bob.
One such feature is significantly reduced capture tolerance (between the machined plug ring and cap 'hole,') resulting in a larger contact surface and stronger retention by the (screw) cap before failure. This adds to the plug seal's resistance to axial stress.
The caps are still completely removable, but they're tighter - except of course if the customer wants the fatter plug end, to merge visually with a 1" gauge.
I forewent the fatter plug in favor of the removable (interchangeable, but still stronger) caps; and because I wanted a larger, USA gauge, bottom (not rear) mount, readable from the side (or even the rear, as an experimental choice,) rather than at the end - which I agree is neater, but makes me a little nervous.. especially with my bad eyesight at close range. And remember (one of these two) is a windowsill (bench) gun, not a carry gun..
(Not to waste the extra stock and receiver, I've decided to make a .22 "quick" plinker/varminter carry gun also. Eric, if you can, please save me a trigger group ;)
Rod
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I had trouble finding the minimum diameter for a 22 mm x 1 mm thread, but if you look at the other diameters that have a 1 mm pitch, the thread depth is 0.6 mm, and that is the standard for Metric threads.... I therefore used 22 - (0.6 x 2) = 20.8 mm = 0.819" as the diameter at the bottom of the threads.... If you have better information, I will gladly use it.... Like any threads, there is a tolerance involved, and I did note that if the threads are cut deeper, then the safety margin is less....
I just found this table.... http://www.newmantools.com/tech/threadmf.htm (http://www.newmantools.com/tech/threadmf.htm) .... It gives the minor diameter on a 22 mm x 1 mm Male thread as 20.77 mm (0.818") .... That drops the safety margin on the tube wall in tension to 3.0:1....
Bob
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I therefore used 22 - (0.6 x 2) = 20.8 mm = 0.819" as the diameter at the bottom of the threads...
Bob
Ah - I didn't know you were still using the threaded area.
Eric's plugs -and the one(-s?)you made earlier- bypass that area for radial stress, no?
(And wouldn't axial stress be distributed across all threads -combined with the outer, mating threads, as well?)
Just trying to understand why Mike's experience varied from this calculated risk.
Rod
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The threaded portion is NOT pressurized and sees no radial forces.... That calculation was for the TENSION load in the thinner portion that is threaded, between where the thread is engaged and the full diameter section of the tube.... It is something people often forget to calculate....
I will not discuss what other's have done, only what Eric has asked me to assess....
Bob
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Yup.
If a 60 is cut to take an MRod .25 mag, it can be used for .22 (wheel change), .25, and with Lloyds' mags, .30 cal. With the impending single shot tray, we can keep going up, until the barrels are too thin to mount.
johninthecamper has .30 BTs that work well. I don't know the specifics, though.
I took some out to qvtom's,shot a few,not the steadiest of benchrest,but did quite well.one hole @25 yds& hit the spinner@84 yds,windy day.this was toms custom r.s.II,with t.j. barrel at bobs spec.,67 gr@140 ft lbs flew nicely
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The threaded portion is NOT pressurized and sees no radial forces.... That calculation was for the TENSION load in the thinner portion that is threaded, between where the thread is engaged and the full diameter section of the tube.... It is something people often forget to calculate....
I will not discuss what other's have done, only what Eric has asked me to assess....
Bob
Thanks - I get it now. I should look at it on the gun.
So what you're saying is, we should use (longer) .083" 4130? (I agree.)
But you know me. I put zero store in "rightsizing," preferring brute force overdesign.
It just doesn't cost that much more, doing it yourself as a one-off.
Rod
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If you increase the wall thickness, you will have to turn down the valve, backer block, hammer, and fill plug.... You would have to ask QVTom if making the hole in the retaining nut flange smaller and moving the point where the force is applied further in from the thread causes more stress on the corner from leverage.... The smaller diameter would decrease the area and increase the stress on the shear planes in the nut and the plug as well, but not by a lot (~5%)....
Just changing to 4130 on the 0.065" wall would increase the yield strength from the 44K I used to 68K, which would increase the safety margin on "stretching" that thin portion of the tube wall axially from 3:1 to 4.6:1, making it no longer the weak link.... It would also increase the yield and burst pressure of the tubing by the same margin.... Here are the calculated yield and burst pressures of a couple of materials for the tube, and the safety margin at 3000 psi, using 0.875" OD x 0.065" wall tubing.... Note that the original XS-60C uses 22 mm x 1.5 mm tubing, which isn't as strong....
Mild Steel (1010) - Tensile 53K, Yield 44K:
Pressure at yield: 7678 psi.... Safety margin 2.6:1....
Pressure at burst: 9248 psi.... Safety margin 3.1:1....
Low Carbon Steel (1021) - Tensile 70K, Yield 52K:
Pressure at yield: 9074 psi.... Safety margin 3.0:1....
Pressure at burst: 12215 psi.... Safety margin 4.1:1....
Normalized CrMoly (4130) - Tensile 97K, Yield 68K:
Pressure at yield: 11866 psi.... Safety Margin 4.0:1....
Pressure at burst: 16926 psi.... Safety Margin 5.6:1....
Note if the tube is threaded and that threaded portion is exposed to the pressure, these numbers do not apply as the wall thickness is reduced to only 0.0365".... That is why Eric is planning on using a through tube on his 3K conversions, with the only portions exposed to pressure the full 0.065" wall thickness....
Bob
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If you increase the wall thickness, you will have to turn down the valve, backer block, hammer, and fill plug.... You would have to ask QVTom if making the hole in the retaining nut flange smaller and moving the point where the force is applied further in from the thread causes more stress on the corner from leverage.... The smaller diameter would decrease the area and increase the stress on the shear planes in the nut and the plug as well, but not by a lot (~5%)....
Just changing to 4130 on the 0.065" wall would increase the yield strength from the 44K I used to 68K, which would increase the safety margin on "stretching" that thin portion of the tube wall axially from 3:1 to 4.6:1, making it no longer the weak link.... It would also increase the yield and burst pressure of the tubing by the same margin.... Here are the calculated yield and burst pressures of a couple of materials for the tube, and the safety margin at 3000 psi, using 0.875" OD x 0.065" wall tubing.... Note that the original XS-60C uses 22 mm x 1.5 mm tubing, which isn't as strong....
Mild Steel (1010) - Tensile 53K, Yield 44K:
Pressure at yield: 7678 psi.... Safety margin 2.6:1....
Pressure at burst: 9248 psi.... Safety margin 3.1:1....
Low Carbon Steel (1021) - Tensile 70K, Yield 52K:
Pressure at yield: 9074 psi.... Safety margin 3.0:1....
Pressure at burst: 12215 psi.... Safety margin 4.1:1....
Normalized CrMoly (4130) - Tensile 97K, Yield 68K:
Pressure at yield: 11866 psi.... Safety Margin 4.0:1....
Pressure at burst: 16926 psi.... Safety Margin 5.6:1....
Note if the tube is threaded and that threaded portion is exposed to the pressure, these numbers do not apply as the wall thickness is reduced to only 0.0365".... That is why Eric is planning on using a through tube on his 3K conversions, with the only portions exposed to pressure the full 0.065" wall thickness....
Bob
Tempting, as I just happen to have a bundle of 4' 7/8" .065 4130N...
I may have one or two left after making the hoops for my 1960 Evans Spl (kart) resto, and for my 1981 IKS Banzai Laydown NOS frame...
Maybe he'll tell us what he's planning to do at the other (plug) end.
I was thinking that area of the tube just past the cap threads this whole time.
Rod
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I thought I covered that.... The O-rings on the fill plug end are inside the threaded portion where the wall is full 0.065" thick.... There is no radial load on the front threads, only an axial load.... Using CrMoly, that axial load has a safety factor of 4.6:1 to yield at 3000 psi.... plenty for me....
Bob
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As I mentioned, I have asked QVTom to run a Finite Element Anaysis of the retaining flange on the plug and the retaining nut for it.... We're still hashing out the details, but it appears that there is a stress concentration in the inside corner of the nut, where the flange that retains the plug meets the outer sleeve portion of the nut.... In order to have a sufficient safety margin that may limit the pressures to maximum CO2 pressures (~1800 psi?).... I'm sure Tom will post when he has completed his FEA simulations.... and hopefully we can find a solution to provide a 3:1 safety margin at 3000 psi....
Bob
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I'm not finding an affordable source for an M22x1 RH Die...
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Look for a 7/8" with very fine thread.... maybe 28 tpi?.... The finer the thread the more tubing wall is left.... You might get away with 24 tpi, finer would be better, there is also 27, 28, and 32.... http://www.efunda.com/designstandards/screws/unified.cfm?start=148&finish=227 (http://www.efunda.com/designstandards/screws/unified.cfm?start=148&finish=227)
minor diameter of male thread:
24 tpi = 0.8242"
27 tpi = 0.8297"
28 tpi = 0.8312 - 0.8324"
32 tpi = 0.8367 - 0.8378"
Any of those are larger than the minor diameter of a 22 mm x 1 mm thread (0.818").... If you have to make your own retaining nut for a 7/8" tube, forget the Metric and go 7/8", IMO....
Alternately, you could use 13/16" x 28 tpi internal thread like Crosman do.... and use a Crosman fill plug.... The remaining wall is 0.031" on the outside of the tube....
Bob
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I want to remain FD standard except for the alloy- for obvious reasons.
(For one, I now have four perfectly good plugs...and am not tooled up to make my own
nuts - which I call 'caps,' it's a cap with a hole in it.)
Could a machinist cut threads (on the tubes) for cheaper than the Brits wanting about $200 for a die?
(OK then, any suggestions for one(or 2)-off machining, maybe in OH, PA, or east?)
The local machinist went bust shortly after we retired here.
(btw my first bottle/reg is only 3k/1600, so this is spec which I might as well do now)
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You will likely have to turn down the outside of the tube slightly to start a 22 mm (0.866") die on a 7/8" (0.875") tube.... but not having tried it I'm not sure.... The thread you use on the outside won't have any bearing on the diameter of the plug you use on the inside, of course.... but you couldn't use an FD nut, you would have to make one to match the thread you use.... To use the FD nut you must stay with 22 mm x 1 mm threads....
Threads can be single-pointed on a lathe, but it's VERY easy to cut the threads too deep, both ending up with loose threads and a thinner tube wall below them.... A properly cut thread is square or rounded on the bottom of the cut, not a sharp "Vee" which is often the way threading tools are made (or sharpened).... so beware of cheap quotes on such an important dimension.... I believe Eric may actually have a tap or die, or both....
Bob
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Just as an aside.... I looked up the tap drill size for a 13/16-16 tpi thread and it looks like 19mm or 3/4".... Shouldn't that start right into a 7/8" OD x 0.065" wall tube (0.745" ID).... The OD is still 0.8125 regardless of the pitch, so why couldn't you use a thread that coarse on an end plug?.... Anybody?.... The minor diameter of that thread is 0.745"....
Bob
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My question is can a tank block be used like the Mrod mod? If the receiver was to be drilled or machined out from the front short of the hammer striker block. Can the tube be expoxied in? Being that the valve fits into the tube. Predrilling for valve screw and transfer port would be also necessary. Anyways its was something rattling in my head.
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All this talk of threads has got me more and more wanting to single point new threads into some 7/8" x .065 CroMoly I bought for fixing my botched (I botched it) FDPCP 60 tube. Heck I bought the threading attachment and a bullnose live center for my Sherline lathe so why not? I can answer that. I've never single pointed in my life but I also didn't know what an elephant looked like till I saw my first one. ;D
Anyway I'll practice on my botched tube until I'm comfortable enough to thread the CroMoly for tighter tolerance male threads to the female threads in the 60 receiver.
I like these little guns so much I have commissioned Eric for 'another' Bobcat to compliment the already ordered Wolverine. His work is impeccable.
You guys make this oh so much fun.
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Just as an aside.... I looked up the tap drill size for a 13/16-16 tpi thread and it looks like 19mm or 3/4".... Shouldn't that start right into a 7/8" OD x 0.065" wall tube (0.745" ID).... The OD is still 0.8125 regardless of the pitch, so why couldn't you use a thread that coarse on an end plug?.... Anybody?.... The minor diameter of that thread is 0.745"....
Bob
Wouldn't you have to use a 4130 plug too, for thread strength?
Not being tooled (nor skilled) as a machinist myself, I wonder how hard that stuff is to machine?
I know it cuts and welds ok... and makes a fast-reacting kart frame when new.
Rod
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The threads aren't the problem for strength, even a 1/4" engagement of the existing threads has over a 6:1 safety margin at 3000 psi with mild steel....Check my original calculations on the end plug nut on the preceding page.... Threads have an extremely high shear area of half the total engagement overlap, measured at the pitch diameter.... half on the female and half on the male part.... If the engagement is 1/4" the area in shear is effectively 1/8" on either side.... so you calculate the strength based on the weaker material....
Bob
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Just as an aside.... I looked up the tap drill size for a 13/16-16 tpi thread and it looks like 19mm or 3/4".... Shouldn't that start right into a 7/8" OD x 0.065" wall tube (0.745" ID).... The OD is still 0.8125 regardless of the pitch, so why couldn't you use a thread that coarse on an end plug?.... Anybody?.... The minor diameter of that thread is 0.745"....
Bob
This scenario is why I asked about the plug being 4130.
When I read this I naturally envision plugs being brass - not MS.
Those are the 'threads' to which I referred in questioning their strength.
Another solution comes to mind:
How about 24mm tube, with 3mm wall, drilled out to .745"?
(Titanium even - but NOT Chinese... that can be weaker than MS, no matter the unregulated "grade.")
As long as we're making our own caps, and chucking all our custom plugs,
at least we can keep our expensive Cothran valves, etc.
J/K (well, maybe half...)
Rod
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I don't know why you are worried about the threads, be the material brass, aluminum, steel, or 4130.... with 1/4" engagement or more they are the strongest part of the plug.... and IIRC, the engagement is more like 3/8"....
Now you are suggesting a 3mm wall?.... with a burst pressure of over 17,300 psi in mild steel?.... Oh, right, I keep forgetting you want to add more weight.... I'm not interested in continuing to run numbers that have nothing to do with the project Eric and I are working on.... I'm sure you know how to do that yourself....
Bob
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I don't know why you are worried about the threads, be the material brass, aluminum, steel, or 4130.... with 1/4" engagement or more they are the strongest part of the plug.... and IIRC, the engagement is more like 3/8"....
Now you are suggesting a 3mm wall?.... with a burst pressure of over 17,300 psi in mild steel?.... Oh, right, I keep forgetting you want to add more weight.... I'm not interested in continuing to run numbers that have nothing to do with the project Eric and I are working on.... I'm sure you know how to do that yourself....
Bob
Drilled out to 0.100" wall.
I don't consider a <50%, .035" tube wall increase unreasonable, at less than 8 oz. increase, especially for what's essentially a cannon, whose caliber -and max psi- haven't even been decided yet.
Sorry you misunderstood - I wasn't asking you to run the numbers (I did that,)
just -suggesting- the alternatives to waste I have to address
(most recently plugs, and contemplating so much more.)
And I'm not really that "worried" about the threads, just got caught up in this whole overthink for a minute. MY bad.
It's a public discussion thread, and I post with that in mind. I presume to 'task' no one.
This (24mm tube)suggestion was driven by availability and convenience, not to split hairs creating more irreplaceable unobtainium just to save a few (<8)ounces of weight. But hey, for you machinists there's always that Ti. (I remember safety-drilling the Ti pittman bolts on my kart was NOT easy...)
And yes, I thoroughly admit my default approach is material overdesign - especially since materials are so very much cheaper than having to have someone remake what I already have invested in (paid)labor, though I am considering buying certain tools - like a honkin' thread die.. Size: still in question (hence the 24mm musing. Still visualizing how to make my own -naturally overdesigned- cap, without a lathe, or a $100 tap. Sounds doable though.)
The threaded area of the 24mm might even be turned down and threaded to use stock caps (if that's needed) without unacceptable safety loss, always assuming (USA)4130. And it would give some leeway to play with the really tiny -imo too hard for Heisenberg to measure, or certainly to reproduce IRL- differences in thread depth, i.e. root profile, we're considering already. Still can't find THAT die... I may try painstakingly filing one down the few(?) thou.
After all, whoever guessed a decade ago that .25cal would become the new .22,
we'd be making .30-.50cal's with 3Kpsi assumed and even surpassed,
and that 100+ Fpe would be the new 20? It has happened and could become a goal.
If I bother to make something it has to last forever and be cheaply upgradeable. I can't buy one every year OR every decade, especially now those decades are all fixed sub FPL income, and I don't even know whether I have another full decade left.. but I'm planning for the gun(-s) to well outlive the likes of me, (and die with it still working "in my cold dead hands?" ;)
and without having to "fix" it -except for its unavoidably plastic seals of course..
(hey, is there an O-ring thread? I have questions...)
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Couple questions, quite likely rather uninformed on the topic, but that is why I am asking the experts.
Could the assumed weak section be lined to strengthen it? Is that what through tube basically does, by not stopping at the receiver?
Is there any concern of galvanic corrosion between the aluminum receiver and ferrous airtube?
A liner could be made, and soldered or brazed in... but would require resizing valves, blocks, etc. Thru-tube will be easier. Galvanic reaction would be no more than stock, and the bonding agent may even reduce it.
My question is can a tank block be used like the Mrod mod? If the receiver was to be drilled or machined out from the front short of the hammer striker block. Can the tube be expoxied in? Being that the valve fits into the tube. Predrilling for valve screw and transfer port would be also necessary. Anyways its was something rattling in my head.
That makes 2 of us with that rattling sound. Been doing mock-ups... this winter will reveal the best ways (I hope).
Guys, I am proto-ing with steel, but any 3Ks that see the street will have Chro-Moly tubes. Wide safety margin, and 4.5K upgrades won't be out of the question. I will respond to the upcoming cap analysis in 3D asap... either way.
T's Cothran valve will be here soon... ;D
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Couple questions, quite likely rather uninformed on the topic, but that is why I am asking the experts.
Could the assumed weak section be lined to strengthen it? Is that what through tube basically does, by not stopping at the receiver?
Is there any concern of galvanic corrosion between the aluminum receiver and ferrous airtube?
A liner could be made, and soldered or brazed in... but would require resizing valves, blocks, etc. Thru-tube will be easier. Galvanic reaction would be no more than stock, and the bonding agent may even reduce it.
My question is can a tank block be used like the Mrod mod? If the receiver was to be drilled or machined out from the front short of the hammer striker block. Can the tube be expoxied in? Being that the valve fits into the tube. Predrilling for valve screw and transfer port would be also necessary. Anyways its was something rattling in my head.
That makes 2 of us with that rattling sound. Been doing mock-ups... this winter will reveal the best ways (I hope).
Guys, I am proto-ing with steel, but any 3Ks that see the street will have Chro-Moly tubes. Wide safety margin, and 4.5K upgrades won't be out of the question. I will respond to the upcoming cap analysis in 3D asap... either way.
T's Cothran valve will be here soon... ;D
Sorry, I was unclear. I was referring to the stock setup when I asked about galvanic corrosion. I have seen steel and aluminum decide to weld themselves together when left touching for a long time.
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In case you guys haven't seen it, Tim @ Mac1 Airguns just won the Extreme Bench Rest contest with his new .30 cal USFT, with the best score ever recorded at 75 yards, 239 - 8X.... Why might this interest the followers of this thread?.... The barrel he used is the one that Sean and I designed, made by Mike at TJ's, which just happens to be the one we will be using on the Grizzly repeater.... Tim added a 1/8" thick CF sleeve to his to stiffen it, but I have one that is only 1/2" OD and it plunks the 45 gr. JSBs into dime-sized groups at 50 yards.... The barrel on the Grizzly is 0.590" OD.... Oh, and BTW, an MRod with one of our barrels placed 2nd in the Sportsman class at 75 yards.... That barrel is GOLD !!!
Bob
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Bob,
yeah it's pretty cool news, and how cool does it feel to know you were an integral part of it ? ? ? ;) ;D
I haven't even got my FDPCP sent off to Eric yet,.... and now I'm envisioning one of my Mrods wearing one of those barrels.
Dear Santa Clause,
.. I've been a good boy all year long,...
...and all I want is a Red Rider with compass in the stock and that thing that tells time ,... err, I mean,...
... one of RSterne's barrels on my Mrod
prettyprettyprettypleeeeeeease !
(and I promise not to shoot my eye out)
So whats the price tag one one of those beauties anyway ?
(I'm quite sure I'll need to be saving my pennies for quite a while :'( )
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Congrats on the successful engineering.
If you go commercial with those barrels, you'll have a long line.
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I got the pleasure of sharing my design with you guys, and seeing Tim beat the bejebers out of all the FXs.... *grin*.... The barrels are available from Mike at TJs, sold by the inch.... Ask for the .300 cal Airgun barrel by Sean and Bob.... It is 0.300" groove, 0.294" land, 26" twist, and available in either 1/2" or 0.590" OD.... The 1/2" will slide right into the .25 cal MRod breech, machine in the port, chamber and leade, cut in an O-ring groove, crown it, and make a new nose for the bolt.... get a new 7-shot mag. or two from Lloyd at AirGunLab, and you've got a .30 cal MRod.... Of course hogging out the valve or getting a hot one is in order to fling those 45-50 gr. slugs at a decent velocity....
OR, save up your pennies for a .30 cal Grizzly, that's our winter project.... 22 CI bottle, regulated, repeater.... I can't wait to get started on developing it.... *grin*....
Bob
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Hi Bob, is the Grizzly going to be based on a XS60C?
very interesting project as usual.
thank you
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Yep, stalwart is the guy, I'm just helping with ideas, development, and tuning (once I get the parts).... This project has been on the back burner all summer because neither of us had the time to work on it.... With winter here, it's "clear the decks, full speed ahead".... I hope....
Bob
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got it thank you
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Yep, stalwart is the guy, I'm just helping with ideas, development, and tuning (once I get the parts).... This project has been on the back burner all summer because neither of us had the time to work on it.... With winter here, it's "clear the decks, full speed ahead".... I hope....
Bob
I can't promise "clear decks" here, but I'm making a real effort to clear enough deck to get this done in a somewhat timely fashion.
Guys, let's be blunt. Bob doesn't need me for anything here. I have a lot to learn, and that process will be shared here. We'll all know a bunch more by the time Bob gets his head above the snow, and starts shooting.... I hope...
;D
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Quick question here, stalwart -
Can a 15/16" OD (available in 4130) through tube be fitted into an FDPCP receiver?
(i.e. can we steal another 0.03125" from the receiver walls
without having to turn down the through tube's OD?)
- It (the tube) would still have to be bored out from .720" nom. ID to .745,
but would buy us an .096" wall tube....
Just wondering-
Rod
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Even if it did fit, you would be losing precious room for the magazine to clear the tube, particularly on the MRod mags (the PRod might still fit, only avail. in .22 cal).... Boring out a sufficient length for the valve and hammer might be a bit tricky, no?.... or would you not bother and just make all the internals 0.720" (would be easier).... The remaining wall on the sides of the receiver would be 0.040", I didn't check the bottom, and in fact they may not be consistent?....
Bob
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.... or would you not bother and just make all the internals 0.720" (would be easier)....
Bob
I wonder if all I'd really need to get bored out wouldn't be the receiver end (about 7-11/16" nom.) and plug end (about 11/16".) With the lengths I'm planning, and the far rearward tank location (by 1/4"npt long nipple,) it seems to me there'll be plenty of added (unregulated) plenum length not to begin worrying about the rest of the tube bore being .020" undersize.
Rod
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Even if it did fit, you would be losing precious room for the magazine to clear the tube, particularly on the MRod mags .....The remaining wall on the sides of the receiver would be 0.040", I didn't check the bottom, and in fact they may not be consistent?....
Bob
So, it might limit the mag size and so larger bores?
I guess it also depends on the strength of the through tube's attachment.
Maybe the first attempt would be limited to .25cal...?
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The .25 cal mag. is deeper than the PRod mag, you have to use an MRod mag.... stalwart would know if there is enough depth above a 15/16" diameter tube, I don't.... IMO a 0.040" wall on the receiver is pretty thin, I personally wouldn't do it, but your choice.... No idea why you insist on such heavy wall thicknesses, if you want weight, just bolt a chunk of lead on the gun....
Bob
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No idea why you insist on such heavy wall thicknesses....
Bob
I blame you :)
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Normalized CrMoly (4130) - Tensile 97K, Yield 68K:
Pressure at yield: 11866 psi.... Safety Margin 4.0:1....
Pressure at burst: 16926 psi.... Safety Margin 5.6:1....
That is for 7/8" x 0.065 wall without threads at 3000 psi.... Why would you blame me?.... Sorry, I don't get it....
Bob
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Normalized CrMoly (4130) - Tensile 97K, Yield 68K:
Pressure at yield: 11866 psi.... Safety Margin 4.0:1....
Pressure at burst: 16926 psi.... Safety Margin 5.6:1....
That is for 7/8" x 0.065 wall without threads at 3000 psi.... Why would you blame me?.... Sorry, I don't get it....
Bob
The end-of threaded area, axial strength thing -keeping threads, and standard parts, as possible. Still waiting about the cap, but I will build if I have to.
and who said I want to limit it to 3K psi? ;) If we're bothering with all this....
(and for you weight watchers, I did save .00738" of OD by going from 24mm to 15/16"
-discovering it was available.)
Hey, have you seen the ".38 special" Mr. hollowpoint youtubes? Nice gun... 6' OAL
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I meant this...
the thinner portion that is threaded, between where the thread is engaged and the full diameter section of the tube....
That is for 7/8" x 0.065 wall without threads at 3000 psi.... Why would you blame me?.... Sorry, I don't get it....
Bob
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OK, so at 4K, the safety factor is 3:1 to yield, 4.2:1 at burst.... At 4500 psi it's 2.6 to yield and 3.8:1 at burst.... I still don't see a problem.... You don't need to use threads for the end cap, you can use screws or shear pins.... lot of options....
Just sayin'.... the only reason to use a thicker wall, IMO, is for weight.... or if you want to argue?.... Anyway, I'm not interested in arguing the point any more, just don't blame your decisions on me, they're YOUR decisions....
Bob
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I think I've got the thu-tube tooling covered... finally. Took me long enough! Boring these takes forever (have to go easy to pass slots and holes)... this takes 1/2 as long.
Unless a tail is needed, they will be cut to this depth. There is no reason to go past the striker, and have to deal with re-drilling the mounting holes. This gives us the steel pin slot, and striker channel.
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Looks good....
Bob
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Glad you like it! Yours is pictured.
I found a way to speed these up a bit more: I was reversing to clear chips, often, to get a pretty finish. Pretty dumb... considering that that finish will never be seen, and it will get a roughening up to aid in bonding.
I'm hogging them now. Yours and T's are done, and Mike's is in the lathe. I'm pretty tickled with the new set up... it wasn't cheap, but it will pay for itself soon.
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I think I've got the thu-tube tooling covered... finally. Took me long enough! Boring these takes forever (have to go easy to pass slots and holes)... this takes 1/2 as long.
Unless a tail is needed, they will be cut to this depth. There is no reason to go past the striker, and have to deal with re-drilling the mounting holes. This gives us the steel pin slot, and striker channel.
Very nice Eric. Very nice indeed.
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Thank you sir!
Does this look vaguely familiar?
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How much hammer travel can you get without boring for a through tube?.... Will it still be possible to fit a longer spring and RVA that is externally adjustable?....
Bob
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Glad you like it! Yours (Bob's) is pictured.
I must be misunderstanding the "through tube' thing - isn't it a one piece pressure tube that extends back through the receiver? In that case wouldn't the picture show a (nom.) 25" long tube?
Or is the idea to retain modular replaceability of the stock FD tube?
I guess this is just the receiver to show how it's hogged out....never mind :)
How is the through tube 'fixed?' That epoxy they use for barrels?
Looking forward to the earliest I can send you my GenI receiver. It's just sitting here....
January 3, I order a Cothran valve and some 4130 (7/8", .065) - and will hopefully have found a barrel.
Rod
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Thank you sir!
Does this look vaguely familiar?
Heh, heh, heh Yes it do, and it's looking gooooood tooooo!!!
Was messing with my Bobcat, setting up for JSB 18.13's (permanently), today and shot dead my chrony. I was jut breaking that chrony in!! No wake, she's for sure dead, but funeral will be tomorrow in the A.M.. LOL!! On my "Notes to myself list" I added shoot a target after removing stuff from rifle before throwing lead over the chrony.. Front scope ring wasn't seated in dovetail (the rear one was) so scope was high and barrel shot low.
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How much hammer travel can you get without boring for a through tube?.... Will it still be possible to fit a longer spring and RVA that is externally adjustable?....
Bob
You mean a tail? Without a tail, we can roughly double the stroke, and the weight. IIRC, 25mm is easy.
Both are possible with a custom striker. The adjuster design for tail-less will fit stock rifles, too. I'm really hoping the Cothran lives up to it's promises... it would pay for itself in labor alone, over a tail.
Thank you sir!
Does this look vaguely familiar?
Heh, heh, heh Yes it do, and it's looking gooooood tooooo!!!
Was messing with my Bobcat, setting up for JSB 18.13's (permanently), today and shot dead my chrony. I was jut breaking that chrony in!! No wake, she's for sure dead, but funeral will be tomorrow in the A.M.. LOL!! On my "Notes to myself list" I added shoot a target after removing stuff from rifle before throwing lead over the chrony.. Front scope ring wasn't seated in dovetail (the rear one was) so scope was high and barrel shot low.
I've only hit mine with a P17... chewed up the sticker real good...lol. Seems everyone does it, eventually. :)
I'm always open to suggestions on adhesives. They get better every year.
1/2 way through a thru-tube installation, you get a great base for a lined 1.5K. This one had good threads, but a deep scratch. I'll put the lip in as discussed earlier. I did Mike's from the back, as the order was made after the barrel had been bonded
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Even hogged, the bores need roughing. A quick twist of 80 grit, on a cordless drill, will put teeth in them.
Second from the bottom,right, is one with the seal cut made so non-concentric, I'd bet lunch it wasn't ever going to seal.
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How much room is left above the top of the tube for a Crosman MRod.25 cal magazine?.... When you machine the notch does it hit the tube?.... What about the PRod mag?....
Bob
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None.
I plan to make a mag well floor that can be changed to a single shot tray, that attaches to the top of the block. I had planned to make inserts for the different mags, but I like your idea of changing the mag wheels a lot more.
A PRod mag well will come pretty close to the tube, if not touch it.
How much room is left above the top of the tube for a Crosman MRod.25 cal magazine?.... When you machine the notch does it hit the tube?.... What about the PRod mag?....
Bob
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So the tube ends up milled across the top for an MRod mag?....
Bob
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Yes.
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Is there any reason I can't powder coat (400F, 10mins) the tanks? I have an armor coating (rubberized) that would make a decent foregrip and "clank" remover.
I will have to play with textures, but could compliment the bedliner stocks nicely, I'm guessing.
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I can't think of any reason.... Take the regulator off first, of course, and protect the threads and O-ring seat well....
Bob
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The Cothran valve came, and I'm encouraged! There is enough brass in the right places to convert it to a 60. I may have to make a longer stem, but we'll see.
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Eric,, I looked at my Cothran valve and had the same thought about a longer valve stem. Being hollow and that tiny hole makes it a bit of an issue to machine a new stem. My thought is to use a two piece stem, like the firing pin that the lever action Marlin rifles use. The second stem would be mounted in the valve backer block. My thought on the subject.
Tom
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Tom, I hadn't noticed that tiny hole until you mentioned it. I bet you're right.
Sure is nicely made. What did you plan for yours?
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Never seen one, but how about machining off the back of the valve body to increase the available lift IF you think that is an issue for a big-bore?.... From lift measurements I have done, the lift is about 1/4 the throat diameter at the high pressure end of the fill range, and about double that at the low pressure end (and shouldn't be).... If the throat is 1/2", your lift range will start at about 1/8" and go up to 1/4".... In a regulated gun, properly tuned for efficiency, the lift will never exceed 1/3 of the throat diameter (and more likely about 1/4).... Of course I have no idea if those lift measurements apply to the Cothran valve....
Bob
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The hollow valve stem and that tiny hole is how that valve operates the piston. Perhaps you haven't taken the valve apart, but it is TOTALLY different than any other valve in the way it functions.
I have had my valve for almost a year and haven't decided what to build. Being partially disabled I don't get out to shoot much anymore as living in this stupid city means I have to drive a fair distance to do so. I wanted to build a .308 boolit shooter but am unsure about that. I may just sell the valve to someone that could really use it as I could build the rifle, but have no where to shoot/test it!
I think you will find a heck of a lot of power in that valve. Best wishes for a kick-butt rifle! Build a .30 first!
Tom
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More pressure to build a .30...
I guess the .50 cal will have to wait. ;)
Some cool parts will be here soon. Ninja...
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More pressure to build a .30...
I guess the .50 cal will have to wait. ;)
Some cool parts will be here soon. Ninja...
Add my pressure on that .30...
Rod
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Just as an aside.... I looked up the tap drill size for a 13/16-16 tpi thread and it looks like 19mm or 3/4".... Shouldn't that start right into a 7/8" OD x 0.065" wall tube (0.745" ID).... The OD is still 0.8125 regardless of the pitch, so why couldn't you use a thread that coarse on an end plug?.... Anybody?.... The minor diameter of that thread is 0.745"....
Bob
I've considered all options, and I'm thinking this is a good one for my Grizzly. I want max plenum. How far would I have to go in?
Guys, Bob is going for a nice reverse set up, and I'm trying for more of a "brush gun". Bob has his figured out... I do not. Comedy ensues...
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Without doing the math, 3 threads is probably enough but I'd never do that.... certainly 1/2" of engagement would be plenty.... The weak point will be the threaded assembly trying to pull the tube apart right at the end of the threads where the wall thickness is the tube thickness minus the thread depth.... Since the tube is 0.875" OD and the 13/16" threads are 0.813" OD, the remaining wall is 0.031" thick, so the area is PI x (0.813+0.875)/2 x 0.031 = 0.082 sq.in..... If the tensile strength of the tube is 70K and the yield point is 52K (1021 steel) the yield point is 4264 lbs.... At 3000 psi on a 0.745" plug the end force is 1307 lbs. so the safety margin to yield is 3.26:1.... If you use CrMoly with a yield strength of 63K, that increases to nearly 4:1.... The safety margin to failure is greater, of course....
Bob
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Cool. Thanks, man.
I'm sure I'm not the only one here who appreciates how completely you answer questions.
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That is the absolute truth! Bob's posts are not only thorough, his designs brilliant, but his explanations make you realize that perhaps a builder is not putting enough thought into the safety of a design. Designing a project is great when everything fits and functions as you envisioned it should, but is that design as safe as you can possibly make it? I think (myself included, until now) safety is too easily overlooked in the "rush to create" the newest coolest and best rifle/pistol/gizmo ever. I cannot thank him enough for making me realize this important fact.
Thank you Sir! You are greatly appreciated!
Tom
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Look what Tim (Mac1) sent! Regged to 2K.
Based on Bob's calcs, we are going to end up with a couple .30 repeaters with enough shots per fill to mean it.
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SWEET !!!
I'm gettin' antsy.... *grin*....
Bob
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I've been plagued with a leak in my sons's FD-PCP since new.... I tried everything to get it to seal to no avail.... One serious problem was a deep lengthwise scratch in the receiver, and when I found that I was sure that was the problem.... I sanded out the inside of the receiver where the O-ring sits, leaving the paint in the scratch, but it still leaked.... I wasn't happy with the OEM seal on the end of the threaded tube which is a rather hard, proprietary item that is pinched between the end of the tube and the front of the valve, and "maybe" expanded outwards to seal, or maybe not.... If you tighten the tube too much, it pops inwards and you can't even fill the gun it leaks so badly.... I had tried O-rings, 70D, 90D, square in cross section, quad-seals, but they all popped out on installation....
I came up with the idea of making a thin insert that I could put inside the tube, with a shoulder to keep the OEM seal from collapsing inwards, and that at least allowed me to tighten the tube in as tight as I could by hand without it popping inside the tube.... It STILL wouldn't seal.... Then this morning I awoke with the idea of using the seal holder insert with a standard 90D #115 O-ring.... I reasoned that the insert would keep the O-ring from popping inwards, and when I tightened the tube against it, it would have to expand outward to seal that all important gap between the receiver and the outside of the tube, where the threads are.... FINALLY, I got a seal.... Here are the parts....
Seal holder with O-ring
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/IMG_4688_zpsf1ec50a4.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/IMG_4688_zpsf1ec50a4.jpg.html)
Seal holder with OEM seal in place (didn't work for me, might for you)
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/IMG_4690_zps7e61cb07.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/IMG_4690_zps7e61cb07.jpg.html)
The installation that FINALLY sealed up....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/IMG_4692_zps8632cdb2.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/IMG_4692_zps8632cdb2.jpg.html)
The tube shown isn't the threaded one from the FD-PCP, but is the same ID and OD.... The brass insert is glued into the end of the tube with a drop of crazy glue.... There is no load on it, you just don't want it to slide out of the way.... The shoulder on the insert is flush with the end of the tube, and the part that fits into the O-ring is 0.080" long and 11/16" OD.... The insert is 5/8" ID and the OD is a slide fit inside the tube, about 0.740" works fine, then glued in with the 11/16" portion proud of the end of the threaded tube.... After installing the valve, you slide the lubed O-ring down to sit against the shoulder in the receiver.... Thread the tube in, and the short, 11/16" OD part of the insert goes inside the O-ring and the end of the tube tightens against the O-ring.... It can't pop inwards because the insert prevents that.... so it expands outwards against the receiver, pinched between the end of the tube and the receiver....
One other thing, make sure that the end of the tube is smooth and square.... You don't want it to slice up the O-ring.... HAND TIGHT IS ALL YOU NEED....
Bob
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Well done, Bob. Thanks for putting it here.
For all... a teaser:
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You two, Bob and Eric, never cease to amaze me.
I've got not much farther than this but Stalwart 2K .30, meet Mike's 1.5K .22.
P.S. Mine is just going to be a brush gun. ;)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3721_zps5c2e00e0.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3721_zps5c2e00e0.jpg.html)
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OOoooooooooooo.... getting closer.... *grin*.... I really like the looks of that with the 22CI tank, looks MEAN.... like a Grizzly....
Bob
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It's going to be a fun little rig, Mike. You going for shot count, or zip?
OOoooooooooooo.... getting closer.... *grin*.... I really like the looks of that with the 22CI tank, looks MEAN.... like a Grizzly....
Bob
Very close, actually... and headed North, soon.
;D I love this place...
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It's going to be a fun little rig, Mike. You going for shot count, or zip?
;D I love this place...
I'm seeing the importance of FPE for hunting , with accuracy of course, so zip it is. I'm still in the novice mode, you and Bob are light years ahead of me, but I'm having a ball with this stuff, including my mistakes.
;D I love this place also...
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I'm using an rsterene Maxi valve in my Bobcat and it can be removed out the rear of the receiver so does anyone see any reason the tube to receiver threads can't be permanently epoxied or red Loctited?
Or let's go one step further and leave out the flat o-ring and let the epoxy or red Locktite be the seal??
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Other than that you are pulling the valve O-rings out past slots, which tend to be hard on them, I see no reason.... There is actually a purple Loctite made, I believe, for sealing Hydraulic fittings that might be just the ticket.... JB Weld should work as well, of course.... Mind you, if you get a leak, you'll never get it apart to fix it, either....
Bob
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Thanks Bob and I'm still putting some thought to the permanent tube to receiver idea, it was your tube leak problem that got me thinking. I'm just playing with my Bobcat and If I decide to just screw in the tube I will be doing your 0-ring trick, oh and thanks by the way.
My other two 60's will be Stalwart 3Ks so I'm setup just right with those. ;)
Still having fun in IL
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Hey Eric, anything new going on with the project? Did everyone go to the Bahama's?
And Bob, thanks for sending all that Canadian below zero weather down here for us Minnesota people to enjoy! LOL!
Tom
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Waiting for parts to arrive here.... from two sources....
Bob
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Hi. Does anyone knows how to calculate the tube's tensile strength having allen screws in shear like the US FT PCP airgun front plug?
I had observed that the screws here are not in the same axis - i think 3 screws are in the front and maybe 2 screws somewhat at the back.
Based on the looks of it, the tube strength is increased. Am I right?
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Providing the plug in the tube is a relatively close fit compared to it's length, and the screws are far enough apart, it doesn't matter whether the screws are evenly spaced around the tube or not, or whether you have 1, 2, or 3 (of course if 3 you have 3 times the strength of 1).... However, if the screws are of different sizes, or the holes in the tube not accurate, one can fail first, leading to a "zipper" failure because the others are then under more stress.... Proper design would have a safety margin of at least 3:1 to failure, better is 3:1 to yield....
Beyond that, all the details are needed to do such a calculation....
Bob
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Stalwart
Its been quite awhile since I have been on here but I am wondering if you have all the details for the mods to the 60C to use the Marauder magazines I it and if so what is the cost for you to do so on a 22 caliber 60C. I had issues with my valve stem seal being cut early on after getting my 60c but since have modified the crosman 22xx and 13xx series old brass valves to work with a delrin seat in the 60c by pressing the stem out of the crosman valve head and pressing in a new longer stem that is also a much tighter fit in the valve end so there is less loss of air past the stem when shooting.
The stock 60C stem is .118' in diameter with the hole in the valve body being right at .125" and the stem that I pressed into the crosman valve head is .123' so it just right for a smooth but tight fit.
If you have the Mrod mag fitment and production worked out I am interested in the costs to have it done.
Buldawg76
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Stalwart
What kind of progress have you made in getting these into the production stage as you were saying in the beginning of this thread. it has been awhile since I have been on the site but was wondering iof you are making the mad in a production run that can be purchased by the members of the forum and if so what is the cost of the breech and barrel mods and do you have exchanges or do you do the parts as they are sent to you.
Any further info on your progress would be welcomed
BD.
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Hi rsterne, thanks for the response. I really appreciate your great help for us – airgun enthusiasts.
Way back to my inquiry, your answer is pointing to the strength of the screws that are in shear stress.
This is the way I understand your reply ofcourse. I think what you are pointing is the same like the
FIRST SITUATION shown in the picture here?
What I’m referring is the tensile strength of the tube/cylinder in relation to the way the screws are
placed –SECOND SITUATION.
(http://i1209.photobucket.com/albums/cc390/smile241/A4_zps2d9a8161.jpg)
For Details, let’s assume these:
Tube: 2024-T3
Yield Strength: 50 ksi
Ultimate Tensile Strength: 70 ksi
Tube I.D.: 25mm
Tube O.D: 30mm
Thickness: 2.5mm
Allen head screw’s Yield strength: 120 ksi
Allen head O.D: 8mm
Pressure inside the tube: 3000 psi
FIRST SITUATION: All four pieces allen screws are placed on the same plane; 10 mm from the tip of the tube (as shown in the picture).
SECOND SITUATION: Two allen screws are on the same plane; 10mm from the tip of the tube
Another two allen screws on the other stress plane; 28mm from the tip of the tube
Question: Does the tube in the SECOND SITUATION has more strength than the FIRST SITUATION?
Does placing the screws like the one in the SECOND SITUATION gives higher safety factor for the tube?
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I am not an engineer, but my gut reaction is this.... The loading on the screw heads and the tube wall is exactly the same in both cases, so in terms of the shear strength of the screw heads and the yield strength of the pockets in the tube wall there would be no difference.... I assume that the O-ring sealing the tube from the air pressure is at the front end of the valve, so there is no radial load on the tube near the screws....
The only difference, IMO, would be the strength of the remaining tubing wall between the four holes in terms of the tensile load applied.... and the tearout strength of the holes due to their distance from the end of the tube.... A quick back-of-the-napkin calculation:
Area of end of valve = 25^2 x PI/4 = 491 sq.mm. = 0.760 sq.in. x 3000 psi = 2281 lb. end force @ 3000 psi....
Tube circumference (inner) = 25 x PI = 78.5 mm (using outer diameter increases safety margin)
Minus holes = 4 x 8 mm = 32 mm.... so remaining total "width" between the holes is 78.5 - 32 = 46.5 mm
Tube thickness = 2.5 mm, so the cross-sectional area between the holes is 46.5 x 2.5 = 116.25 sq.mm..... which is 0.180 sq.in....
Maximum tensile load on the portion of the tube between the holes is 70,000 x 0.180 = 12,613 lbs.... Safety margin is 5.53:1 based on tensile strength....
Using yield strength.... 50,000 x 0.180 = 9000 lbs.... Safety margin is 3.95:1 based on yield strength.... The strength of the 2nd situation would be greater because there is more area to provide tensile strength between the holes....
The area of the pockets subject to the bearing load is.... 8 mm x 2.5 mm x 4 = 80 sq.mm. = 0.124 sq.in. x 50,000 = 6,200 lbs.... Safety Margin of the bearing load is 2.72:1 based on yield strength....
The "tearout" (shear) area between the pockets and the end of the tube is.... 10 mm x 2 x 2.5 mm x 4 = 200 sq.mm. = 0.310sq.in. x 70,000 x 60% = 13020 lbs.... Safety Margin is 5.7:1 based on shear strength.... The strength of the 2nd situation would be greater because two of the screws are further from the end of the tube....
Since the lowest safety margin is the load on the pockets, IMO there is no practical difference between the strengths of the two situations.... Please remember, I am NOT an engineer, just a guy trying to understand the safety aspects involved.... I am not approving or suggesting any design....
Bob
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rsterne, thanks for the time in sharing your numbers here.
I assume that the O-ring sealing the tube from the air pressure is at the front end of the valve, so there is no radial load on the tube near the screws....
Yes, you're right. I'm thinking the same way.
The "tearout" (shear) area between the pockets and the end of the tube is.... 10 mm x 2 x 2.5 mm x 4 = 200 sq.mm. = 0.310sq.in. x 70,000 x 60% = 13020 lbs....
Is it not 10mm x 8mm(diameter of the hole) x 4(number of holes)= 320 sq. mm =0.496 sq. in. ( Based from the FIRST SITUATION)?
Regards. ;)
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The calculation for tearout strength, as I understand it, is based on the two shear planes in the direction of force from the edges of the holes to the end of the tube.... I used the distance from the center of the hole to the end of the tube (10mm) instead of 14mm, for increased safety (in case it doesn't tear straight from the edge of the hole).... The way you are suggesting is to use all the area between those two shear planes, which is not my understanding of the way the calculation is done.... and you neglected the thickness of the tube (2.5mm)....
The bearing area is, however, the width of the hole times the thickness of the tube, times the number of holes, and THAT is the limiting factor, and in fact it usually is....
Bob
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Hey Eric, anything new going on with the project? Did everyone go to the Bahama's?
The Bahamas sound pretty good right now...
Just real busy with non-AG life right now. All good, but hectic. The planned production will happen, but I have customs and lots of R&D to do before that. I'll let everyone know what the schedule will be... as soon as I do. I'm looking for some competent help... no luck yet.
I've been running into some pretty non-concentric barrels lately. That can decide whether or not I can make them removable... fixed barrels are no problem. I'm looking into solving that with custom barrels. If I can, I'd like to come up with something at a good price. Any suggestions are welcome...
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Hey Eric, anything new going on with the project? Did everyone go to the Bahama's?
The Bahamas sound pretty good right now...
Just real busy with non-AG life right now. All good, but hectic. The planned production will happen, but I have customs and lots of R&D to do before that. I'll let everyone know what the schedule will be... as soon as I do. I'm looking for some competent help... no luck yet.
I've been running into some pretty non-concentric barrels lately. That can decide whether or not I can make them removable... fixed barrels are no problem. I'm looking into solving that with custom barrels. If I can, I'd like to come up with something at a good price. Any suggestions are welcome...
Darn right the Bahamas sound good! 8) -14F here this morning. :o Heck, your neck of the woods sounds pretty good to me right now. ;D
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Hey Eric, anything new going on with the project? Did everyone go to the Bahama's?
The Bahamas sound pretty good right now...
Just real busy with non-AG life right now. All good, but hectic. The planned production will happen, but I have customs and lots of R&D to do before that. I'll let everyone know what the schedule will be... as soon as I do. I'm looking for some competent help... no luck yet.
I've been running into some pretty non-concentric barrels lately. That can decide whether or not I can make them removable... fixed barrels are no problem. I'm looking into solving that with custom barrels. If I can, I'd like to come up with something at a good price. Any suggestions are welcome...
-14 F outside this morning, 50 F in the house, furnace repair man here right now... Bahamas sound real real good right now.
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I used the distance from the center of the hole to the end of the tube (10mm) instead of 14mm,..
You're right, and that's actually the only way.
The way you are suggesting is to use all the area between those two shear planes, which is not my understanding of the way the calculation is done.... and you neglected the thickness of the tube (2.5mm)....
Based from the FIRST SITUATION, using thickness (2.5mm) is already 'perpendicular' to the direction of the force. Tearing (shear) of the tube actually rsterne should be 'parallel' to the direction of the force. That's why I used 10mm(tearing distance) x 8mm(hole diameter for screw) cause its the only dimensions that are parallel to the direction of the force.
BTW, from my first post, I was just asking if the strength of the tube is strengthened if the holes for screws are fashioned like the one in the SECOND SITUATION of my drawing. And your calculations add up to the way i see them. Honestly, thanks.
As for the tear ( shear), and bearing strength, this is just what I've learned. Peace.
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If the 2.5mm tube thickness makes no difference to the tearing strength, then I don't understand what is going on.... good thing I'm not an engineer, eh?.... I was taught that the thickness of the tube was paramount in the tearout calculations....
As I see it, the 8mm width of the hole is perpendicular to the force, just as much as the tube thickness is.... only the 10mm length is parallel to it.... To develop a force in lbs. required for failure requires a pressure (lb/sq.in) times an area (sq.in), just look at the units.... One of those dimensions it the length of the area being sheared (the 10 mm, agree on that).... That leaves only two other possibilities for calculating the area, the width of the hole or the thickness of the tube (x 2).... It we reduce the width of the hole to zero (a point load) then there is only one shear plane, and the area being sheared is the length (10mm) times the tube thickness (2.5 mm).... This is just the same as shearing a bolt, where the area of the bolt is used in the calculation.... Double the tube thickness, double the area, double the force to shear it....
When we make the hole wider, we develop two shear planes, one at either edge of the hole.... Think about using a square peg in a square hole, that is 8mm wide.... The center of the peg is being supported by the bearing load of the tube, and the shearing stress is concentrated at the corners, developing two shear planes, 8mm apart.... If we double the thickness of the tube, we double the area to be sheared, but either way, the area to be sheared is the length (10 mm) times the tube thickness (2.5 mm) times 2.... Doubling the width of the square bolt only moves the shear planes further apart.... At least that is what I was taught....
I think perhaps if the distance between the hole and the end of the tube is large enough (and I don't know how large, maybe 10 times the hole diameter?) then the situation approaches the idea of a point load, with only one (wide) shear plane, but the thickness of the tube still must a governing factor in the strength.... Basically the tube cannot tearout, because the failure mode becomes the bearing load exceeding the tensile strength of the tube.... Surely at that point, we are dealing with a bearing load failure, not a tearout failure, and of course the bearing load calculation uses the width of the bolt hole and the thickness of the tube....
The fact remains that in nearly every case in a PCP, the bearing load is the one that fails first, unless the holes are WAY too close to the end of the tube.... In our example, that doesn't occur until the edge of the hole is less than 5mm from the end of the tube.... at which point tearout becomes the likely failure mode instead of (or combined with) a bearing yield failure....
Bob
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good thing I'm not an engineer, eh?....
It doesn't matter whether you are an Engineer or not. What is important is that we come up with the right analysis for our safety purposes right? ;) You actually think and see things like an engineer.
As I see it, the 8mm width of the hole is perpendicular to the force, just as much as the tube thickness is.... only the 10mm length is parallel to it....
You're right, 8mm width of the hole looks like perpendicular same as 2mm thickness. But, only if you look at it like a line. What I'm referring here is the plane area that is in stress. Please see my drawing below so that we can picture it out;
(http://i1209.photobucket.com/albums/cc390/smile241/A5_zps6fe3feb3.jpg)
Now you may say that it's the same as 2mm thickness right? because you projected the area same as like that. Though it may seem like that, 2mm (which is the thickness) is already perpendicular with respect to the force. Let's see the next drwaing:
(http://i1209.photobucket.com/albums/cc390/smile241/A6_zps4b7d2c3f.jpg)
The upper drawing is what I'm talking about. The stress area (Side view of the tube) is the shaded one cause by screw to the tube. If you will see it from the 'Force A' to 'Force B' direction, the area that is under stress is in parallel to the direction of the force.
The Lower drawing is what I understood with respect to your calculations " 10mm(tearout/shear distance) x 2( two planes) x 2.5mm (thickness) ". Again, as you can see, 2mm thickness is already in perpendicular plane. Moreover, you have missed the area between the two planes.
Same principles is applicable to the bolt in shear.
Though your calculation is safe, imagine if you're in a project calculating huge area. You will surely spend more, ;)
Peace.
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So you are arguing that the tube thickness is irrelevant?.... I still don't get it....
In your upper diagram, while the entire shaded area is under compression, only the two thin bands in my diagram are in shear.... IMO....
Bob
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Tube thickness is relevant only in determining how much pressure the tube can contain ( Barlow's principle) . And then followed by tensile, then tear/shear stress.
For the tear/shear, yes it is irrelevant. I'm not arguing bro. It just so happen that i happen to see how you calculate, that's why I asked and got curious. Peace.
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Tube thickness is relevant only in determining how much pressure the tube can contain ( Barlow's principle).
For the tear/shear, yes it is irrelevant
OK, if you say so.... I guess you have the qualifications to back it up.... I just got my methods from guys who do it for a living in the oil patch, like I said, I'm not an engineer.... So the tube thickness is irrelevant for the bearing load of the screw head on the tube wall, too, I guess?.... It could be 1" thick , or 0.001" and still support the same load?.... for the tearout too?.... Wow !
Bob
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I would welcome your friends' methods with my open heart. If somewhere I missed something, I would admit it.
Remember, we where talking about 'shear' that can contain by the tube with 10 mm tear distance. You would not design a pressure vessel with 0.001" thickness, 1 inch ID and pressurize it with 3000 psi. It will surely burst.
As I said, the way I see it, how much pressure the tube can contain is the first thing to be calculated before proceeding to the tensile, and shear cause by the plug. If it's safe, that's the time you will proceed with the tensile and shear.
As for the 1 inch thick or more, if you are familiar with the principle of punching stress, you will know what I mean.
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P.S.
This discussion is for educational purpose only.
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The methodology is either valid or not, the tube does not have to be a pressure vessel, it could simply be a vertical tube, supporting a weight vertically, hanging from the plug that is bolted into the tube by the four 8mm screw heads, as per your diagrams.... Somehow I don't think a 0.001" thick tube wall could support 2281 lbs. but I'm darn sure a 2.5 mm one could.... I am certain that the wall thickness is a vital part of the calculation, but as I say, I'm not an engineer, I just use what I was taught, and common sense....
Bob
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(http://i1209.photobucket.com/albums/cc390/smile241/A6_zps4b7d2c3f.jpg)
The upper drawing is what I'm talking about. The stress area (Side view of the tube) is the shaded one cause by screw to the tube. If you will see it from the 'Force A' to 'Force B' direction, the area that is under stress is in parallel to the direction of the force.
The Lower drawing is what I understood with respect to your calculations " 10mm(tearout/shear distance) x 2( two planes) x 2.5mm (thickness) ". Again, as you can see, 2mm thickness is already in perpendicular plane. Moreover, you have missed the area between the two planes.
(http://i1209.photobucket.com/albums/cc390/smile241/A6_zps4b7d2c3f.jpg)
I agree 100% with Bob. His analysis of the tear out and bearing load of the screw heads on the tube was spot on.
Tear out is calculated using the areas in the second picture. Two lines that are tangent to the hole and parallel to the load are the tube thickness x the length from the tangent point to the end of the tube.
I don't understand how the area in the fist picture is of any value calculating tear out.
Tom
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Tom, thanks for the confirmation.... I guess I'm being conservative by using the distance from the center of the hole to the end of the tube, nice to know....
Bob
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Man I love these kinds of threads.
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This is what we had discussed so far right?
(http://i1209.photobucket.com/albums/cc390/smile241/A10_zpsdc51d644.jpg)
This is what I understood about what we talked about with Bob. With the 'screw head' pass the OD of the aluminum tube, the shear area (accordingly) is the plane area of 'L-2' and 'L-3', that is,
A2= L-2 x 10mm = 2.5mm(thickness) x 10mm(tearing distance) PLUS
A3= L-3 x 10mm = 2.5mm(thickness) x 10mm (tearing distance)
A (overall) =0.0775 sq. in. x 4(number of screws)
A (overall..Bob) = 0.310 sq. in. (Bob's calculation), punching shear principle same as 'square peg' that you've described.
But how about if like this,
(http://i1209.photobucket.com/albums/cc390/smile241/A11_zpsd270f5b9.jpg)
In the picture here, i moved the screw inside the tube and fashion it in a curve style so that it is just 1.25mm attached inside the tube. So now, there are already 3 plane areas that are in shear right? 'L-4', 'L-5', and 'L-6', hence we have,
A4 = L-4 x 10mm = 8mm( hole diameter) x 10mm( tearing distance) PLUS
A5 = L-5 x 10mm = 1.25mm (thickness) x 10mm (tearing distance PLUS
A6 = L-6 x 10mm = 1.25 mm (thickness) x 10mm (tearing distance)
A (overall) =0.16275 sq. in. x 4(number of holes)
A (overall) =0.6510 sq. in , this is how I see by applying how you calculate it. Isn't the overall value (0.6510 sq.in) greater than the original calculation you've got (0.310 sq.in) ?
Maybe I missed something.
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This is what we had discussed so far right?
(http://i1209.photobucket.com/albums/cc390/smile241/A10_zpsdc51d644.jpg)
This is what I understood about what we talked about with Bob. With the 'screw head' pass the OD of the aluminum tube, the shear area (accordingly) is the plane area of 'L-2' and 'L-3', that is,
A2= L-2 x 10mm = 2.5mm(thickness) x 10mm(tearing distance) PLUS
A3= L-3 x 10mm = 2.5mm(thickness) x 10mm (tearing distance)
A (overall) =0.0775 sq. in. x 4(number of screws)
A (overall..Bob) = 0.310 sq. in. (Bob's calculation), punching shear principle same as 'square peg' that you've described.
But how about if like this,
(http://i1209.photobucket.com/albums/cc390/smile241/A11_zpsd270f5b9.jpg)
In the picture here, i moved the screw inside the tube and fashion it in a curve style so that it is just 1.25mm attached inside the tube. So now, there are already 3 plane areas that are in shear right? 'L-4', 'L-5', and 'L-6', hence we have,
A4 = L-4 x 10mm = 8mm( hole diameter) x 10mm( tearing distance) PLUS
A5 = L-5 x 10mm = 1.25mm (thickness) x 10mm (tearing distance PLUS
A6 = L-6 x 10mm = 1.25 mm (thickness) x 10mm (tearing distance)
A (overall) =0.16275 sq. in. x 4(number of holes)
A (overall) =0.6510 sq. in , this is how I see by applying how you calculate it. Isn't the overall value (0.6510 sq.in) greater than the original calculation you've got (0.310 sq.in) ?
Maybe I missed something.
Your second illustration... Is this a blind hole? If so there isn't much point in the design as the parts can't be assembled. If it is a thru hole the same tear out criteria applies, but you have reduced the bearing surface of the hole and it is likely that the tube material would yield in compression. Which occurs first is dependent on the bolt head diameter and hole placement from the end of the tube. Both modes of failure can potentially kill so it is best to get it right or copy a design (exactly) that is already proven safe.
Tom
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I can't see a practical use for that setup, but it seems you may be correct for the shear area.... HOWEVER, you have now reduced the BEARING area of the screw head by 50%, so instead of a 2.7:1 safety margin you are about 1.35:1.... That is low enough (under 2:1) to be subject to fatigue, so WILL eventually fail.... In addition, there is an increased possibility of the tube stretching outward over the head of the screw (ramping outward), and failing in hoop strength (tensile)....
Overall, I see no point in continuing along that line, sorry....Beyond that, I agree with Tom, you can't assemble it....
Bob
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It's a true hole Tom. How can I place the screw if it's a blind hole, :)
Ah yes, the bearing load. Good day.
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QVTom, have you figured out how much pressure the XS60 bulk cap retainer can handle? Would love to know... ;D
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Your bearing area calculation for the thread is incorrect, you only used the contact area of ONE thread, you have to use the full engagement depth, the same as you do for the shearing force on the threads.... Your calculation for the thread shear is also incorrect, you used the major diameter, you need to use the pitch diameter....
Your comment about bearing load not being important is just plain UNSAFE.... A soldered connection relies on the shear strength of the solder, there IS no bearing area....
Plus, your previous diagram showing the crowned head on the screw is wrong as well, because when you rotate the screw to install it, the head must be a body of rotation, so the contact point with the pocket in the tube would not follow the top of the profile, but the edge.... The edge is very close to the ID of the tube at the center of the hole, drastically increasing the possibility that the tube would stretch and slide up over it.... a VERY dangerous situation....
If you are an engineer, I respectfully suggest you need to go back to school, because the designs you are suggesting, and your understanding of them, leaves a lot to be desired, IMO.... I'm not trying to insult you, but I will no longer discuss this stuff with you, I have better things to do with my time....
Bob
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Ali, you seem to be hunting for examples to support your position on tear-out and bearing surface calculations then MISS-APPLYING them. Like Bob I'm not trying to insult you but you really need to learn to accept the advise of the more qualified. This forum is a great resource for members of all disciplines and skill levels but it not a debating club. You have been offered lots of good advise, I suggest you play it safe and follow that advise even if you believe it leads you to over build your designs. Just think about a larger screw engagement vs the alternative.
Tom
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QVTom, have you figured out how much pressure the XS60 bulk cap retainer can handle? Would love to know... ;D
Still waiting on me? LOL Could you please PM me the last drawing with all the dimensions and I'll give it a go.
Tom
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For dissimilar metals threaded together, you do the shear strength calculation using the pitch diameter, and using 60% of the tensile strength of the weaker material.... or 60% of the yield strength for a greater safety margin.... You must derated the area by 50% because through that plane (cylinder of pitch diameter) half the shear plane area is on each part (male and female)....
I assume since you haven't stated any qualifications, that like me, you are self-taught with the help of input from people in the field who know what they are talking about and have taken the time to share.... Its a great way to learn, provided you listen carefully....
Bob
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So this little guy right here. The XS60C. It accepts MRod magazines with some mods? Hmmm...would anyone be willing to cut my receiver and barrel if I order one? I have plenty of MRod mags from my 22xx and this seems like a better version of a Disco as far as bang for your buck goes.
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So this little guy right here. The XS60C. It accepts MRod magazines with some mods? Hmmm...would anyone be willing to cut my receiver and barrel if I order one? I have plenty of MRod mags from my 22xx and this seems like a better version of a Disco as far as bang for your buck goes.
stalwart is the guy to contact about this. He's been tweaking on these rifles and newing and improving them for quite a while - and has many satisfied customers.
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So this little guy right here. The XS60C. It accepts MRod magazines with some mods? Hmmm...would anyone be willing to cut my receiver and barrel if I order one? I have plenty of MRod mags from my 22xx and this seems like a better version of a Disco as far as bang for your buck goes.
stalwartarms.com
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QVTom, have you figured out how much pressure the XS60 bulk cap retainer can handle? Would love to know... ;D
Still waiting on me? LOL Could you please PM me the last drawing with all the dimensions and I'll give it a go.
Tom
Ok, this is the nut as I understand it. The transition from the internal thread to the front face is suspect......... So if you can verify all these dimensions and post a picture that would be great.
(http://i1147.photobucket.com/albums/o553/QVTOM/fd-nut_zpsbcdb3288.jpg)
Tom
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They vary in most dimensions, by quite a bit, and even the shapes vary. I had 2 at hand... the dimensions not exampled are within .002.
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The one I had here was 0.738" ID and 0.945" OD, the dimensions I gave Tom.... I don't think I specified an overall length, it won't matter anyway....
Bob
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Stalwart,
Are you willing to make new nuts to achieve your 3k0 fill goal? If so the logical path would be to make two changes. 1) use a material like 1144 for its strength and ease of machining. 2) Increase the OD to give more wall thickness in the threaded area. Is the room in between the nut and barrel to add diameter? If so, how much?
Tom
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Tom, the existing nut touches the barrel now, unless you put a spacer under the barrel in the barrel band to shim it slightly, then it just misses.... The OD of the existing nut is knurled with lengthwise grooves.... One thing, though, isn't the OD of a 22mm thread 0.866" instead of 0.878".... or is the larger number you used the Max. D of the female thread?....
Bob
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Stalwart,
Are you willing to make new nuts to achieve your 3k0 fill goal? If so the logical path would be to make two changes. 1) use a material like 1144 for its strength and ease of machining. 2) Increase the OD to give more wall thickness in the threaded area. Is the room in between the nut and barrel to add diameter? If so, how much?
Tom
Tom, I had hoped to both give the guys who already own my caps the option of upgrading their rifles in the future to 3 or 4.5K, without needing a different set up... and also to allow me to stock less part#s. Given the machine time needed to make a nut, and a cap... I don't see that making sense. The guys buying the 3Ks would be paying more than necessary.
Looks like I'm going to go with an internal thread in the tube. I sure appreciate the effort you made (guys, he did a second sim with thicker ridge... got the same results).
It looks like I will be eventually offering screw in 1.5K tubes with the internal set up, so a 3-4.5K upgrade would not need a new cap. I'll keep the standard style available for guys who have FDPCPs, and are happy at lower pressures. I think I can make the internal style look pretty clean.
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Tom, the existing nut touches the barrel now, unless you put a spacer under the barrel in the barrel band to shim it slightly, then it just misses.... The OD of the existing nut is knurled with lengthwise grooves.... One thing, though, isn't the OD of a 22mm thread 0.866" instead of 0.878".... or is the larger number you used the Max. D of the female thread?....
Bob
Yes the larger number was used (max for m22x1). With the large variation in tolerances of the few examples best error on safety. An enterprising air gunner could do a hydro test on the FD setup to see where it actually at. My guess you wouldn't need more that 4k0 test pressure to pop it unless that nut is some special material which I doubt.
FD-PCP tinkerers PLEASE be careful and DON'T EXCEED CO2 on a hot day (1k5 psi) pressures with a stock setup.
Tom
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Stalwart,
Are you willing to make new nuts to achieve your 3k0 fill goal? If so the logical path would be to make two changes. 1) use a material like 1144 for its strength and ease of machining. 2) Increase the OD to give more wall thickness in the threaded area. Is the room in between the nut and barrel to add diameter? If so, how much?
Tom
Tom, I had hoped to both give the guys who already own my caps the option of upgrading their rifles in the future to 3 or 4.5K, without needing a different set up... and also to allow me to stock less part#s. Given the machine time needed to make a nut, and a cap... I don't see that making sense. The guys buying the 3Ks would be paying more than necessary.
Looks like I'm going to go with an internal thread in the tube. I sure appreciate the effort you made (guys, he did a second sim with thicker ridge... got the same results).
It looks like I will be eventually offering screw in 1.5K tubes with the internal set up, so a 3-4.5K upgrade would not need a new cap. I'll keep the standard style available for guys who have FDPCPs, and are happy at lower pressures. I think I can make the internal style look pretty clean.
I like the idea of internal threads, my favorite method by far.
Tom
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I agree, and in CrMoly a huge safety margin....
Bob
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Tom, the existing nut touches the barrel now, unless you put a spacer under the barrel in the barrel band to shim it slightly, then it just misses.... The OD of the existing nut is knurled with lengthwise grooves.... One thing, though, isn't the OD of a 22mm thread 0.866" instead of 0.878".... or is the larger number you used the Max. D of the female thread?....
Bob
Yes the larger number was used (max for m22x1). With the large variation in tolerances of the few examples best error on safety. An enterprising air gunner could do a hydro test on the FD setup to see where it actually at. My guess you wouldn't need more that 4k0 test pressure to pop it unless that nut is some special material which I doubt.
FD-PCP tinkerers PLEASE be careful and DON'T EXCEED CO2 on a hot day (1k5 psi) pressures with a stock setup.
Tom
Amen.
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Regarding the safety issue stated above.
Would someone take the time to explain the term, 1K5? Until seeing this repeated I assumed this to be a typo for 1.5K which seemed to be a good estimate of the pressure in a carbon dioxide cylinder stored in a car trunk in my part of the world.
Also, as per the graph below, the temperature pressure relationship varies significantly with the percent of a CO2 cylinder's "rated" fill. The curve between 80% and 100% for temperatures of 90 degrees and 120 degrees F is astounding. There seems to be a good deal more uncertainty here than I anticipated and I'm wondering if some of us might "chip in" for a pressure test. I'm definitely game.
Thank You.
(http://www.warpig.com/paintball/technical/gasses/co2pv.gif)
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David, 1k5 is shorthand for 1500. The k being 1000.
I believe the max accepted working pressure for CO2 1800 (1k8)psi. I'm sure Bob can add more information.
Tom
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David, 1k5 is shorthand for 1500. The k being 1000.
I believe the max accepted working pressure for CO2 1800 (1k8)psi. I'm sure Bob can add more information.
Tom
1k5 would be 1005. If I understand this correctly. 1.5k would be 1500.
Or is this some odd notation style I have never seen before?
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1K5 means 1.5K or 1500 psi.... 1005 psi would be 1K005, the K replaces the decimal point in that type of notation.... The maximum safe working pressure for CO2 is that found stamped on CO2 tanks, 1800 psi.... A properly filled (to 100% of rated capacity by weight) CO2 tank is about 1900 psi at 120*K, which is the maximum temperature marked right on most CO2 cartridges....
My concerns with many of the Chinese made CO2 guns, including the QB79, are that I think (no proof) that they used 850 psi for their MSWP in their calculations, or they didn't do any.... The screws holding the tank block on a QB79 are WAYYYYYY too close to the end of the tube, and if you take the stock off and put it in a car on a hot day, filled with CO2, and then examine those screw holes afterwards, you will find that the end of the tube is no longer flat, that the tube has distorted from the force of the screws.... This doesn't seem to happen if the two stock screws are in place, from what I have seen and heard, but to me it indicates just how close they are running to disaster.... I know of one QB79 that was converted to HPA that had a regulator leak and the tank and tank block assembly blew off the end of the gun during filling at 2600 psi.... The screws sheared, and the holes in the tube partially tore as well.... The tank assembly went spinning across the shop floor, the gun went flying the other way, but fortunately, nobody was hurt.... There were two problems there that contributed to the failure, besides the design.... One, the stock was not inletted for the tank block, so the block was not supported by those two extra screws (a very common thing for modded QB78s) and Two, the regulator only had one burst disc, a 3K to protect the tank, and nothing to protect the downstream side from going over 1800 psi (good paintball regulators have a 1.8K burst disc fitted, this cheaper design didn't).... The same thing could have happened if the 1.8K disc was replaced by a 3K, which is common practice when guys mod the HPA regulator over 1500 psi.... With a 3:1 or greater safety margin recommended for (every part of) the strength of HPA systems, that failure at 2600 psi means the MSWP of the QB79 action, when removed from the stock, is 867 psi....
I questioned a few of the things about the FD-PCP and got my fingers wrapped, so I will not comment further.... It is interesting to see this data, however, as the safety of the fill fitting retaining nut is something I never even looked at....
Bob
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Many thanks for the education.
It would be interesting to test a few of these cylinders to failure. Would it be better to discuss this possibility on another thread?
Addendum:
It should be understood that this is not intended to express concern for the integrity of cylinders in unmodified PCPs.
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I would prefer having that discussion right here, David. In fact... Please?
Quite a while ago, I offered to chip in a gun for testing, as airgunwarriors said he had access to facilities. It never gelled. If you want to set it up, I'd be thrilled to see the numbers... either way.
I have considered trying something here, using a Porta-Power type set up. I trust Bob's math implicitly, and would love to see just how high we'd have to go to blow a 3K up.
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Lloyd has done quite a bit of destructive testing, using air over oil hydraulics (no air in the test part, only to pressurize the oil).... However, I really like the idea of using a Porta-Power, making SURE the entire system is air-free, using a good pressure gauge (ideally with tell-tale), and working behind a suitable safety shield.... The thing to remember is that whatever the pressure at failure, the MSWP should be a third of that or less.... The only exception to that, for me, (and I'm not recommending this, it's just my opinion) is things like settling in of screw heads into the pockets in a tube to equalize the loads, which I actually view as desireable, and will accept on my personal guns at about a 2:1 margin (using yield strength) above what I use for an MSWP....
I can tell you that Crosman 22XX tubes have been tested to 10,000 psi without failure, but we don't know the grade of the tubing, even though they are also 7/8" OD x 0.065" wall.... tested at full wall thickness, of course....
Bob
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1K5 means 1.5K or 1500 psi.... 1005 psi would be 1K005, the K replaces the decimal point in that type of notation....
Interesting. Where does this style of notation come from?
I am used to placing the units at the end. Like 4.5GiB, 4.6Kg, or 5l. That is SI style notation. Commonly used in Scientific and IT realms.
I assume 1k5 means 1451psi-1549psi? Or is there another way to determine significant digits? Or does this notation assume a margin of error instead?
I love minutiae like this.
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I don't think it's designed to be used to indicate significant digits, but yes, I would round the results as per your example.... I have no idea where it comes from, but seems quite common in engineering circles.... The units, if specified, would still be placed at the end.... as in 1K5 (psi)....
Bob
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I would prefer having that discussion right here, David. In fact... Please?
Quite a while ago, I offered to chip in a gun for testing, as airgunwarriors said he had access to facilities. It never gelled. If you want to set it up, I'd be thrilled to see the numbers... either way.
I have considered trying something here, using a Porta-Power type set up. I trust Bob's math implicitly, and would love to see just how high we'd have to go to blow a 3K up.
I'll poll my two relevant contacts. The best bet is a former employer up north. The other is a testing lab a few miles down the road. What's your estimate of the minimum meaningful test pressure?
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Since we are interested in 3000 psi fills on stalwart's 3K gun, the gun should be tested to at least 10,000 psi.... If it stands that and nothing happens, no changes are needed for a 3K fill.... The way the FD-PCP was originally sold, as a 1500 psi gun, the test equipment should be capable of at least 5,000 psi, with 4500 psi being required for a 3:1 safety factor.... Since the vendor has said more than once in his gate not to fill the gun above 2,000 psi without undertaking precautions (ie safety mods), that implies a 6,600 psi minimum test pressure, with anything over 6,000 psi supporting a 2K MSWP....
I personally think that if would be great if both stock and 3K versions are tested to failure.... If the failure occurs at a lower pressure than 3:1, but in a non-catastrophic manner (eg. an O-ring leaking, or the screws deforming the supporting structure (but not tearing or rupturing it), then that may or may not be OK.... However, if the failure is sudden and catastrophic, then the 3:1 rule over MSWP pressure should be applied, IMO.... ie record the failure pressure, and take one third of that as the safe maximum.... No failure should be allowed below a safety factor of 2:1, again IMO....
When you consider that 4500 psi filling equipment is now relatively easy to obtain, it could be argued that any gun or tank filled with HPA should be safe for repeated fills to that pressure without danger of sudden and catastrophic failure, and I know I am not alone in that opinion.... If you fill from such equipment, there is always the possibility of that happening, even when using a regulator (they can fail).... I would note that these comments apply to all brands of PCPs, and to "self-builds" as well.... This does NOT mean that 4500 psi is the MSWP, but an acceptable test level unless you ONLY fill from equipment not capable of that pressure (eg. a hand pump)....
Bob
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Regarding the safety issue stated above.
Would someone take the time to explain the term, 1K5? Thank You.
(having been explained above) I would just like to add, I've seen it in many non-airgun places, most quite technical and some professional. (retired BSEE here;)
I believe it is, at the least, one de facto standard (of many.)
HTH,
Rod
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After months of thinking and waiting for winter to get here and ordering parts, I finally got my box of goodies to build the Grizzly prototype yesterday.... In case you don't know, the Grizzly is a .30 cal repeater with a 22CI 3000 psi tank, regulated to 2000 psi, with the receiver bored out for a through tube to eliminate the threads in the receiver.... The rest of the details will fall into place as Eric and I proceed with this build.... The purpose of these posts will be to let you see what goes into this gun, and follow the progress....
I got right into modding the Grizzly today, the first thing I tackled was the valve to see how big I could make it.... The good news is that I first drilled the throat to 17/64” (0.266”) and then I managed to use a 7/32” (0.219”) mill on a 20* angle to bore out the exhaust port.... I then used a 1/2” mill to bore out the rear of the valve, and completely removed the raised portion of the seat and drilled the hole for the stem to 1/8” and dropped in an MRod poppet.... Between the smaller poppet OD and the larger valve ID, there is lots of room for airflow.... I drilled the front of the valve to 3/8” instead of milling the slots bigger, and will use a tapered spring.... More on that when they come in....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Valve%20Porting_zpsiwpo7zoo_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Valve%20Porting_zpsiwpo7zoo_1.jpg.html)
The stem of the MRod poppet is a lot shorter, as below, but we have a solution for that.... Note the HUGE port, 75% of the bore diameter for the .30 cal....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/MRod%20Poppet%20Length_zpstwi3jmfq_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/MRod%20Poppet%20Length_zpstwi3jmfq_1.jpg.html)
The striker on the hammer can be extended, into the hole in the steel backing block, so that is not an issue.... What IS a problem is going to be getting a signficant increase in the travel.... As I see it, the lug that catches the sear will hit the front trigger mounting lug leaving only 0.8” maximum travel, including the valve lift.... This photo shows the cocked position....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Cocked%20Position_zpsowbtyz6i_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Cocked%20Position_zpsowbtyz6i_1.jpg.html)
and this photo shows the sear lug on the hammer where it would run into the front mounting lug for the trigger, which is inside the tube....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Travel%20Limit%20Including%20Lift_zpsflac7jpp_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Travel%20Limit%20Including%20Lift_zpsflac7jpp_1.jpg.html)
All the rest of the stuff on the hammer is not a big deal, from what I can see.... The striker portion can be longer and thinner to fit through the backing block.... The entire hammer should be able to be 0.74” diameter, except for a flat machined on the bottom in front of and behind the lug that catches the sear.... Therefore, we can certainly make the hammer a lot heavier.... Eric has an idea on how to avoid the interference with the trigger mounting lug to get more travel, which would be nice.... More info to follow as it develops....
Bob
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Cutting the square hole in the steel tube, for that insert, big enough to allow it to rest on aluminum again, and cutting a relief for it in the trigger housing will let it drop out of the way.
If a safety isn't going to be used, and the fore and aft adjustment of the trigger group, for properly setting the safety's relationship with the sear, isn't used...that hole can be made just long enough, and positioned so the trigger housing is positively indexed to the rear. This will allow max stroke of the striker.
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Watching with great interest!
I've been thinking along these lines, with the addition of a longer barrel.
Had either of you considered the Cothran valve for this project?
-Rod
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I've never seen the Cothran valve, but it seems like a good product.... I am confident we can achieve what we want without a problem, at signfcantly lower cost than a Cothran setup....
I now understand about setting the front trigger mounting lug down into the tube to increase hammer travel.... now pondering the other details to increase the hammer travel as much as reasonably possible....
Bob
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I spent the morning measuring and working on the valve and hammer.... Eric machines the back of the valve to fit inside the backing block to shorten the assembly, and because of the short MRod poppet, I did the same thing with the hammer.... I machined the front of the block for a #016 O-ring....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Modified%20Parts_zpslpaq0hmp_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Modified%20Parts_zpslpaq0hmp_1.jpg.html)
The stub on the valve is a slide fit into the block, and will be glued or soldered to it to seal it so that the air can't leak below the O-ring on firing.... The nose of the hammer was turned down smaller, so that it won't hit the block and can drive the stem of the poppet below flush.... Here is why....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/MRod%20Poppet%20Position_zpswmuttbna_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/MRod%20Poppet%20Position_zpswmuttbna_1.jpg.html)
With the valve and block assembled, the MRod poppet just protrudes behind the block, which is moved forward over 0.20".... The nose on the hammer currently is stock length, and when the flange on the hammer hits the back of the block, the valve will be open 0.25", which is more than we need.... I will likely shorten the nose on the hammer about 1/16" to gain a bit more hammer travel as we don't need 1/4" of lift.... Here are the parts slid together....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Valve%20and%20Hammer_zpsttflslby_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Valve%20and%20Hammer_zpsttflslby_1.jpg.html)
The hammer, in this position, is about 7/16" further forward than where it used to stop when it hit the back of the block in it's original location.... This, of course means that the cocking pin would hit the front of the slot in the breech, so I then lengthened that as below....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Cockng%20Slot_zpsfkogwgqp_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Cockng%20Slot_zpsfkogwgqp_1.jpg.html)
When the hammer face hits the back of the block (in its new location), the cocking pin would also hit the cocking flange on the bolt, so I ended the slot in the same location as the back of that flange with the bolt fully forward and the handle down.... There is no more travel possible for the cocking pin, I was able to get everything there was....
Bob
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Lookin' good!
Rod, the Cothran is best suited for either big bore, or a target rifle (very light striker, short stroke... for minimum lock time). It's just not cost effective in the .30 Grizzly. As Bob indicated... there are no real benefits. The one pictured earlier is going into a single shot MRod barreled .25, set up to take bigger bore liners on demand. In .25, it will be very easy to cock!
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I spent half the afternoon building a new backing block for the valve to accept two 1/4"-28 screws in the sides, got it all finished, and decided I didn't like it.... There wasn't enough room, IMO, between the O-ring and the side of the screw head, plus it didn't give me a good way to mount the stock.... So, I decided to use the original block, solder it onto the valve so that I could hang onto it, and drilled and tapped two more holes to 5mm x 0.8mm (the same as the current valve and block threads), plus spot faced all three holes.... I had some HoloKrome 5mm low profile SHCSs, which were perfect for the job.... The head is a fraction larger and thicker than a 10-32 low profile screw, but they are still far enough from the O-ring groove.... An alternate method would be to make a new block, using three 10-32 SHCSs with a full thickness head.... The head would then just protrude from the receiver, whereas these are just below flush.... Both are thicker than the tube, however, which is where all the load is taken anyway....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Valve%20and%20Screws_zpsfocnxx33_1.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Valve%20and%20Screws_zpsfocnxx33_1.jpg.html)
The nice thing about this arrangement is that I can use the original valve mounting hole to accept the pan head stock mounting screw.... Since the front of the stock has been cut off to allow for the tank, it had to be replaced, and this will do a nice job.... This setup has over a 3:1 safety margin in the tube, and the screws are over 4:1 in shear, at 3000 psi, so it's built to laugh at a regulator failure....
Bob
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More progress this morning.... After much careful measuring (measure
twice 10 times, cut drill once! ), I drilled the holes in the receiver to allow access to the valve screws.... While they are not really structural (the load is taken on the walls of the tube inside), if you get them in the wrong place it will look horrible.... I first centered the breech on the forward valve screw hole, and drilled it and the port hole, directly above it, out to 1/4".... The hole in the top of the valve is only 7/32", but I plan on making the barrel port 3/16" x 1/4", so this seemed like a good way to transition from round to oblong, where the air passes through the wall of the receiver between the tube and the barrel.... I then carefully measured the distance between the two bottom bolt holes (on the valve and the block), which ended up being 0.520" (I would suggest stalwart machine the parts to make this exactly 1/2"), moved the cross-slide holding the breech that far back, and drilled out and milled the lower hole for the valve screw.... I double checked that for position, turned the breech 90* in the vice (it had an end stop to index it back in the same fore-and-aft location), measured down to where the center of the tube will be, and drilled a 5/16" hole through both sides of the receiver.... Using a size "Q" drill, which is a perfect fit on the heads of the Metric screws, I enlarged the hole, crossed my fingers, and took the breech out of the milling vice.... When I tried the valve inside, centered by the tube, it fit perfectly....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Drilled%20Receiver_zps47reedct.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Drilled%20Receiver_zps47reedct.jpg.html)
You will notice that the bottom screw hole broke through into the original rear block screw location, but that doesn't matter, because only the hole for the screw head will be drilled through the steel tube inside.... The screw heads will be a bit deeper once tightened against the flats on the valve, but will still catch in the receiver to locate everything.... Notice the location of the new stock mounting screw.... I'm getting pretty close to being able to drill and slot the tube.... WOO HOO !!!
Bob
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GREAT STUFF BOB!!
Thanks for posting... I am trying to absorb!! ;D ;D
CW
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It took me all afternoon to drill and slot the tube and modify the trigger housing to fit.... Here is the bottom of the tube, with the valve installed....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Tube%20Bottom_zpsb5oac6au.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Tube%20Bottom_zpsb5oac6au.jpg.html)
You will note that the part of the slot where the front trigger mount goes is shorter and wider than the slot in the receiver.... It is wider to allow the "T" nut to drop down out of the way of the hammer, which will allow the hammer to move the extra distance we have made possible by moving the block forward and modding the nose of the hammer.... The slot is shorter to index the trigger to the fully aft position, to maximize the hammer travel.... Here is the top of the tube....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Tube%20Top_zpsjheslhxp.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Tube%20Top_zpsjheslhxp.jpg.html)
The cocking slot is longer at the front to allow for the extra hammer travel as well.... When cocking the gun, you will feel the bolt engage the hammer much further forward and have a longer cocking stroke.... You can see the massive port in the valve.... I used a small ball shaped Dremel burr to smooth and fair the top of the port to the 1/4" hole in the tube to minimize turbulence at that point.... Below is the modified trigger housing and "T" nut....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Trigger%20Mods_zpsvct6gr1d.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Trigger%20Mods_zpsvct6gr1d.jpg.html)
The wider notch in the tube means that the ears on the "T" nut only catch on the sides of the receiver slot, so it projects below the bottom of the receiver.... I therefore had to remove the same amount of material (1/16") from the middle portion of the pad where the front screw goes through the trigger housing to allow clearance for the nut.... When I tested the clearance for the hammer, I found that the center portion of the "T" nut still interfered with the hammer, so I had to file a shallow, curved notch in it to insure clearance for the hammer.... When the trigger is bolted into place, the upper surface of the nut is now about 0.010" below the ID of the tube, so the hammer no longer hits it.... The trigger screw is JUST flush with the top of the nut, and therefore clear of the hammer as well.... but with production tolerances between parts, that is not guaranteed, so the length of that screw must be checked to make sure it won't hit the hammer....
I put everything together briefly and tried cocking the gun, and it cocks smoothly, with a much longer cocking action than previously.... The sear on these triggers has to rotate a long way aft of it's cocked position to cock, nearly 1/4", and that resetting of the sear occurs when the bolt handle is just 1mm (less than 1/16") from the back of the bolt slot.... I have achieved the maximum hammer travel without lengthening the bolt slot....
Bob
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I know the thought of increasing the hammer stroke was brought up way back in this thread. I also don't want to clutter it up with useless posts like this one. But I just have to say I am always impressed by your solutions to any problem that comes up. Thanks for taking the time to show us the progress to this one and any others that you have done.
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Paul, I can only speak for myself here, but, I have never seen a post of yours that contained "clutter".
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I can't take credit for the solution to the hammer stroke, it was stalwart who figured out to slot the tube wider and let the "T" nut drop down out of the way.... He didn't warn me that the center of it would still hit the hammer, though.... The first time I dry fired it, the hammer came to a screeching halt, causing one of *those* moments.... *LOL*.... Production tolerances at work, maybe?.... Easy solution was a few minutes work with a round file....
The gun is currently sitting on my bench, all the parts bolted together and fitting nicely.... I have a QC issue on the rear adjusting / trigger mount bracket to deal with, one of the holes in it or the receiver is drilled about 1/16" out of whack and has to be moved over.... I'll fix that tomorrow, and mount the action in the stock.... then probably machine the slot for the magazine.... Next week comes the fun of building the reverse tank block.... LOTS of chips to make there....
Bob
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I can't take credit for the solution to the hammer stroke, it was stalwart who figured out to slot the tube wider
Good job stalwart :) ;)
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Thanks, Paul.
You can also get the t-nut to settle in more if you internally bevel the slot with a flat file, to match the nut. Either way, it's a quick fix.
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This morning I machined the notch for the magazine.... Man, there sure isn't much room to work with.... Anyone tackling this on their own, blind, the first time, had better be very good, very lucky, or be prepared to buy a second receiver and/or tube.... Here is a photo of the finished notch....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Magazine%20Notch_zps5x7rznm3.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Magazine%20Notch_zps5x7rznm3.jpg.html)
Note that when you machine deep enough for the .25 / .30 cal MRod magazine not only do you machine through the receiver, but the tube as well, and may even tickle the top of the valve.... Here is what the tube looks like at this stage, and the magazine sitting in the receiver....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Magazine%20Installation_zpsow1ljzkg.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Magazine%20Installation_zpsow1ljzkg.jpg.html)
The nose of the bolt protrudes into the magazine notch when closed, so a new shorter bolt is required.... This will lose some of our hard-earned hammer travel, but cannot be avoided to allow the use of the magazine....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Bolt%20Nose_zpsbqgnvsqu.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Bolt%20Nose_zpsbqgnvsqu.jpg.html)
Next job is to make that new bolt.... More later....
Bob
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What wall thickness tubing are you using?
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.065"
Guys, 3Ks produced for sale here will be skeletonized. This will cut down on machine time (your $), and will be covered by the stock.
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Yeah, yeah, yeah.... He expected me to remember that!.... Oh, well, spending a half day machine two matching sets of holes in the receiver and tube was good practice for me.... *LOL*....
Anyway, I spent the afternoon making a new bolt....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/New%20Bolt_zpsr4huiarh.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/New%20Bolt_zpsr4huiarh.jpg.html)
It's a flow through nose design (with the feed hole in the side not yet drilled) because that style is a lot shorter overall and won't have to be held back against the hammer spring to get the magazine in and out.... It functions flawlessly, popping pellets out of the magazine one after the other....
Now, on to the next problem.... The cocking pin on the hammer now hits the flange on the front of the bolt, not good for either the bolt or pin.... If anything is going to come to a crashing halt, I want it to be the face of the hammer hitting the back of the backing block.... So, now we need a new hammer, with the cocking pin further back relative to the nose.... I was hoping to do some testing with the stock hammer weight, even though I didn't think it would produce enough dwell, but since I have to make a new one, I'm going to maximize the weight, so it will be a straight cylinder, with only flats where needed to clear things and provide a place for the sear to catch....
Bob
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"Oh, well, spending a half day machine two matching sets of holes in the receiver and tube was good practice for me.... " And it sure turned out pretty!
Nice bolt... getting to the meat and potatoes here...
8)
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Guys, I remember seeing snap in single shot trays for MRods... who makes those?
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They are made by Crosman, and snap into place the same way as the magazine.... I have a modified .25 cal tray for my .30 cal Disco Double, works just fine.... Only problem is, they are nearly as expensive as a mag....
Bob
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Got some time in on the Cothran valved rig. Cut the bolt's slot as far forward as possible, cut the receiver's pin and bolt handle slots as long as would fit. Got 36mm of bolt travel. The poppet stem protrudes 4.35mm, and I'll find out what we lose rolling the sear into place, when I get that set up. We'll get somewhere around 28mm... stock was 13mm (IIRC). This little thing is gonna be nasty.
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Since I have to make a new hammer, I figure I may as well go for broke and extend the bolt slot (and the pin slot) to the rear as well.... 36mm looks right.... I'll make the hammer so that it touches the cocking block when forward and the pin just misses the bolt lug.... and the rear of the hammer just touches the new adjusting block when the bolt is at the back of the slot.... Then I'll machine the sear slot so that the sear resets with about 1mm of bolt travel left under load and see how much effective stroke we can get.... I figure about 27mm with 5mm of valve lift, so we are looking at the same numbers, which is comforting.... In reality, an inch of travel (25mm) is pleanty for the Grizzly as I can get the hammer well over 100 grams (stock is 48).... That works out to double the energy and 4 times the momentum in the hammer....
Bob
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I was away part of the day today, so I only got the new hammer spring preload adjuster done....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Preload%20Adjuster_zpst0acfqme.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Preload%20Adjuster_zpst0acfqme.jpg.html)
The casting that came with my gun was pretty much useless.... It was drilled in the wrong places, and it was machined crooked and the adjusting screw hit the hammer instead of entering into it.... I decided to completely change the design and fabricate one out of aluminum bar stock.... The boss is round, and a proper fit in the back of the receiver, and mounts with the two original screws.... It has a lug on the back the same length as the original, drilled and tapped 5mm to accept the original mounting screws for the rear of the trigger and the rear stock mount.... However, it is drilled and tapped 7/16"-20 NF, so that if the adjusting screw is removed you can swap out the hammer spring without having to completely pull apart the back of the gun.... The adjusting screw is made from a 1.5" long bolt which I softened by heating to cherry red and allowing to cool slowly.... Grade 8 bolts are very hard to machine, especially to drill, and I drilled the bolt to allow a piece of 7/32" diameter drill rod to slide easily through it to act as a full length spring guide, a design that I really like and use on all my builds now.... That rod will have a head on the front which will be captured between the spring and the hammer, and travel with the hammer, adding weight.... Since it can stick out the back, I can slide on an O-ring (shown) which will give me a way to directly measure valve lift, to insure that the hammer isn't impacting the backing block when the gun is properly tuned.... The original head of the bolt was turned down to 7/16", and then machined square to accept a 5/16" wrench for adjusting it.... To prevent the screw from self-adjusting, there is a 6-32 set screw pressing a brass pin against the side of the adjuster to act as a brake.... You can see it in the flange that sits against the back of the receiver.... I have a total of well over an inch of adjustment, plenty for the new hammer spring, which is 3" long made from 0.051" wire.... you can see it in the photo.... Tomorrow I plan on making the new hammer....
Bob
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Elegant.
I really like the ability to change springs with ease. These guns have a lot of potential, and anything that makes tuning easier is going to pay for itself.
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Here's a tip for getting rid of those extra holes:
JB high temp epoxy putty. After about an hour it can be filed and sanded smooth. It gets rock hard overnight. It can be painted... and as it is high temp, I am going for powder coating.
Those holes bug me. The plastic plugs you can get look somewhat better, but this will disappear them for good.
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Here's a tip for getting rid of those extra holes:
JB high temp epoxy putty. After about an hour it can be filed and sanded smooth. It gets rock hard overnight. It can be painted... and as it is high temp, I am going for powder coating.
Those holes bug me. The plastic plugs you can get look somewhat better, but this will disappear them for good.
Great idea and thanks.
What's going to happen to the ball detent contraption in the upper right of the receiver??
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Today I lengthened the cocking slot towards the rear in the receiver and tube, and lengthened the bolt slot at the back by 1/8".... That gave me extra bolt and hammer travel, and allowed me to determine how far to extend the nose of the new hammer and how far forward to move the sear lug.... I then made the new cylindrical hammer, and on first trial found I couldn't close the bolt once the gun was cocked, because with the cocking pin aft the milled flat in the bolt wasn't long enough, so that had to be extended to the rear as well.... Here is the new hammer assembly.... The hammer weighs 84 grams, and the spring guide another 22, so the total weight is 106 grams....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Hammer%20and%20Adjuster_zpsykrvnosa.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Hammer%20and%20Adjuster_zpsykrvnosa.jpg.html)
While checking clearance at both ends of the hammer travel, I found that in order to be able to preload the spring to coil bind I had to allow the 7/16" D adjusting screw to move into the hammer, so I drilled a 1/4" deep recess in the back of the hammer for that.... Then I found out that the adjusting screw I made yesterday was too long.... it projected too far aft and would hit the stock when backed off.... so I had to make another one from a 1" bolt.... In the position in the photo above it is set for no preload with the hammer sitting against the back of the valve (backing block), which I had shortened slightly.... I also ground almost 1/16" off the end of the MRod poppet so that it is flush with the back of the block when closed.... The nose of the hammer extends 0.200", so that is the limit to the valve lift, more than it will ever need.... Here is the finished spring guide, the new 3" spring, and the original 2.3" spring....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Springs%20and%20Guide_zpsvbkmblob.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Springs%20and%20Guide_zpsvbkmblob.jpg.html)
After looking after a few other small details, it was time to assemble the action and measure the hammer stroke.... In the photo below the gun is uncocked, the preload adjuster is set where it would be to have no preload on the spring with the hammer just touching the valve stem, and the distance between it and the O-ring is the maximum lift available before the hammer face hits the backing block.... When the adjuster is wound in to coil bind, it is about 1 thread from fully in....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Uncocked%20no%20Preload%20Showing%20Lift_zpsmvchmo0i.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Uncocked%20no%20Preload%20Showing%20Lift_zpsmvchmo0i.jpg.html)
In the photo below, the gun is cocked.... You can see how far back the spring guide is projecting (it will be shortened after testing to not hit the stock), the O-ring indicates the available hammer travel, including the valve lift.... That measured out to 30.4 mm, and the lift is 5 mm, so I ended up with exactly 1" of hammer stroke to valve contact.... The bolt handle actually moves 36mm total, and the gun cocks less than 1mm from the back of the slot, so you can see how much the rolling sear has to rotate aft to reset, over 4mm.... You will also note that the front of the bolt is retracted clear of the magazine slot, you don't have to pull the bolt back past the cocking position to change magazines, a really nice feature....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Cocked%20Showing%20Travel_zpskmrqxzu7.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Cocked%20Showing%20Travel_zpskmrqxzu7.jpg.html)
This day emphacized how many things change when you start modding an airgun.... A day that started as "I think I'll make the hammer" turned into a full day in the shop, solving one problem, which created two, and those created four, etc.etc., and pretty soon it was dinner time.... Now don't get me wrong, I enjoy this kind of project.... but it sure shows how much work goes into doing this kind of a conversion.... and the huge number of hours you have to be prepared to spend to figure everything out.... Tomorrow I plan to fit the stock, and tidy up a few small jobs and then take a break to contemplate the next step in this conversion....
Bob
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Very nice...as always! 8)
Would there be anything to gained by making the bolt's nose (the lift) adjustable?
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Here's a tip for getting rid of those extra holes:
JB high temp epoxy putty. After about an hour it can be filed and sanded smooth. It gets rock hard overnight. It can be painted... and as it is high temp, I am going for powder coating.
Those holes bug me. The plastic plugs you can get look somewhat better, but this will disappear them for good.
Great idea and thanks.
What's going to happen to the ball detent contraption in the upper right of the receiver??
With the slot lengthened, it will actually work to hold the bolt back during mag changes. Stock, not so much.
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It just occurred to me that if the stock is relieved as I do for the tails, a removable set of weights could be attached to a longer version of Bob's spring guide... all the way at the back. It would eliminate the need for a tail, as it would function identically...
Yes? No?
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Heck... thread that end of the rod, make 2 thin knurled nuts (think quill stop)... and just stack washers between them.
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If you put a short tail on it, and that rod came out the back and had a t-handle at the end... and was threaded into the hammer... you could lose the pin, and get all the stroke you would need by cocking it separately. The longer the tail, the farther you could push the port/mag forward... there's enough room for an absurd amount of stroke.
You wouldn't have to use a t-handle... there has to be a few clever ways to cock the thing. I want a pump. I asked, a while back, who made a good pump action... got crickets. Maybe we should?
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... You wouldn't have to use a t-handle... there has to be a few clever ways to cock the thing. I want a pump. I asked, a while back, who made a good pump action... got crickets. Maybe we should?
A lever would be best for me- or maybe even an underlever(with a necessarily external mechanism, fine.)
I definitely need some M.A. over straight bolt action, so a T-handle is also out of the question..
-and the spine surgeon says, in general, (of house, shop & yard work etc.) "always PUSH - never pull."
I notice (unmentionable) has a QB Lever kit - but it looks like pressed sheet metal, flimsier than what I'd want - I always prefer billet.
Annyway... it's barrel ordering day.
Can't decide between .300 and .308 though. Probably that (26?) twist 300, depending on what's developed since, and of course, price..
Going for 43" (being generous, usable outer barrel is about 37")
(shoot. Mike's away. Eric, any advice on the barrel, please email or call!)
Rod
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Got some time in on the Cothran valved rig. .... This little thing is gonna be nasty.
The Cothran valve will fit in the through tube, yes?
Rod
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Yes you could add weight to the end of the spring guide, but the percentage gain would be small.... In addition, when the action is installed into the stock with the spring guide the length it is in the photos above (let alone longer with an added weight), you can't cock the gun because as soon as you pull the bolt back 1/4" the end of the spring guide hits the stock.... Yes, you could drill a small hole to clear it, but I don't think you want one big enough for a weight.... Although the action would fit into the stock easily with the new adjuster on the back (it slides into the large recess there), once I put the trigger in place, no way.... I had to open up the top front of the recess as in the photo below so that the adjusting screw and the top shoulder on the adjusting block would clear when the action is on an angle as dictated by the trigger group on installation.... You can't see where it is ground out after the action is in place.... You can also see the new hole for the front stock mounting screw.,,,
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Inletting_zps5cuxyalj.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Inletting_zps5cuxyalj.jpg.html)
Here is a photo of the bottom of the stock, showing the location of the new front screw.... I didn't have a blued one, only a plated one.... It screws into the existing 5mm threaded hole in the bottom of the brass valve which is no longer used to hold the valve from moving back, that is done by the three high-tensile screws in the backing block....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Front%20Stock%20Mount_zpswkoica5r.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Front%20Stock%20Mount_zpswkoica5r.jpg.html)
Once both screws are in place, the action and stock are mounted together very solidly.... You will notice that the front of the stock has been cut off to clear the back of the tank, which will serve as the foregrip.... I checked the location of where a rear cocking rod would come out, and it should be possible to have about 2" of stroke for a "T-handle", but I have no idea how you would install it.... The spring guide has to be threaded into the hammer to draw it back, not just sitting in the spring pocket, which means alignment with the hole in the adjusting screw is critical to avoid hammer drag.... In addition, the cocking handle could now drag in the hole in the stock, it would be so long it would be prone to bending, and you would have to have a slot in the top of the stock to drop it into place.... I don't think it is really practical on this design without a lot of thought and work.... I would likely go to a side cocking knob screwed into the side of the hammer right at the front and working through a slot in the tube and receiver.... There is just shy of 2" of room between the magazine slot and the vertical bolt slot, so with enough room at the ends of the slot plus the 1/4" diameter of the handle you could get about 1.5" of hammer travel (about 38mm).... Unfortuately, that includes the valve lift (5mm) and the sear rotation (4mm), so the gain would only be about 2mm of stroke, not worth it just for that.... However, it would allow using a much stiffer spring once you are pulling directly on the hammer, the handle has weight, and by using a longer tail in the tube the hammer could be longer and heavier as well.... Certainly not something I am considering for this build, but a possibility if you want to persue a gun in the 200+ FPE range and the Cothran valve doesn't allow that with the existing hammer....
Here are photos of two cocking arrangements I have used on other projects.... "T-handle" rear cocker on my Disco Double....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg.html)
and the side-cocking arrangement on my Hayabusa....
(http://i378.photobucket.com/albums/oo221/rsterne/Hayabusa%20PCP/Hayabusa410Shotgun_zpsfb2626a8.jpg) (http://s378.photobucket.com/user/rsterne/media/Hayabusa%20PCP/Hayabusa410Shotgun_zpsfb2626a8.jpg.html)
I find the T-handle awkward, as I have to move my head out of the way to get my hand behind the handle to pull straight back with two fingers.... The side cocker doesn't require you to move your head, but if the cocking effort gets up over 20 lbs. you may have to drop the gun down from your shoulder to get a better grip and better leverage on it to overcome the high effort required.... Bottom line is that increasing the cocking effort too far makes the gun unpleasant to shoot.... None of this is an immediate consideration for this build, we should have tons of hammer energy and momentum.... they are just food for thought for any future stalwart star-wars projects....
Bob
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Got some time in on the Cothran valved rig. .... This little thing is gonna be nasty.
The Cothran valve will fit in the through tube, yes?
Rod
Yup.
Bob, the orbiting ring of airguns wasn't supposed to be announced until next week. Please check with someone in the PR/Media dept, next time, before leaking any hints? They get edgy about that kind of thing...
;D
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OOPS!.... ME BAD !!!.... :-[
Bob
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Here are photos of two cocking arrangements I have used on other projects.... "T-handle" rear cocker on my Disco Double....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg.html)
LOVE the stock!!
My Disco has a nice "for a disco" stock. But I fancy swapping to something like yours.
CW
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Norm at Disco R Us inlets the Blaster (above in Forest Camo) for the Disco and MRod.... You could probably get him to inlet it for the XS-60c if a few guys lined up.... just a thought (not me, BTW, haven't got the cash).... I laid my project gun up against the stock above, and the back of the trigger mounting lug (stock or my new one, but a cylindrical one would look better) comes level with the back of the breech in the photo above.... and the main tube needs to be set about 1/4" deeper than the upper tube in the Disco to have the trigger group sit in the right place.... OR the stock at the trigger location could be cut thinner to expose the XS-60c trigger with the tube set the same depth as the upper tube in the Disco.... Using the same tube depth would allow a twin-tube setup within the Blaster stock with an XS-60c.... Either way, it could be done....
Bob
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The second option could be made very pretty. The trigger housing is tall anyway, cutting just enough to properly reveal it... would look pretty hot.
Not asking anyone to quote Norm's work, but roughly how much does a stock like it hurt?
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$210 unfinished, $250 finished.... Boyd's just had a HUGE price increase....
Bob
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$210 unfinished, $250 finished.... Boyd's just had a HUGE price increase....
Bob
Huge increase. The nice lady who runs Richard's said that a big manufacturer picked up the burned factory and is now in the process of refurbing the plant. Pretty sure she meant Boyd's but wouldn't or couldn't be more specific. Explains the huge increase.
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Just took my first close look at the Disco Double... pondering doubling up a 60. Liked everything I saw, thought I'd see if it was cheap enough to talk me out of trying to make myself one. Took a look at the price...
I am just 1 tap away from mounting those parts to a 60... and I can't build myself one for what he gets for a well finished, complete product. I don't have the time to work for free, even for myself. ;)
Also looked at Blasters for the first time. I really like the "pepper", but the "coyote" would strike a chord in these parts. If anyone wants to get distinctive, I could color match the actions to the accent colors in the stocks... in high quality powder coating.
I know what I want for my birthday... ;D
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Anyone know, offhand, how long DD tubes are?
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REVISED:
They are 18.05" long, including the rear plug, measured from the front of the Disco tube.... In addition, the two front plugs (including fill covers) add 1.25" to the length of both tubes at the front.... They will fit any tube with internal 13/16"-28 threads on the front.... It would be worth talking to Norm about an XS-60c version of the Blaster, and a Double tube version of it.... He is doing the stocks for the new Millennium Pumper, so I know he works on stuff other than Crosman....
Coyote?.... Is that a desert Nutmeg?....
Bob
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Yes, stacked with what they call "natural"... 2 very common colors in the summer here.
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Today I started on the reversed tank blocks.... I have two to make for myself, and one for stalwart.... so as this is a run of three units I decided it would be a good thing to keep track of the time.... This does NOT include the hours of design time, prototyping, design changes, etc.etc. which took place while developing this design to fit the 22XX/Disco/QB tubes which it will also fit.... The first step was to cut a length of 3" x 1" 6061-T6 bar stock into three pieces, and then cut those to the appropriate height, using a horizontal metal bandsaw.... Then I squared one edge (the front) to the one remaining untouched side of the original material (the top) using the milling attachment on my lathe.... Then I cut out the material from the notch formed by the tube insert and the back face where the tank will mount, again using the bandsaw.... Here is a photo at this stage....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Tank%20Block%20Material_zps9i7gap6n.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Tank%20Block%20Material_zps9i7gap6n.jpg.html)
I admit I'm not very speedy when it comes to machine shop work, I spend too much time measuring and thinking, so that hopefully I don't make any mistakes, and do things in the best order to not cause myself more work later because I worked myself into a corner.... at this point I have a total of 3 hours invested, of which 2.25 hrs. is machine time, the rest measuring and pondering what to do next....
I like the Coyote, didn't see it on their website....
Bob
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I already stock powder in Mil spec "Desert Tan"... If my monitor is accurate, it's a very close match to the "natural" in the stocks. I think it would make a pretty rifle, with serious overtones.
So many shiny objects... so little time... :)
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Indeed.... and my afternoon was spent making chips and smaller shiny objects out of larger ones....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Rear%20Face%20and%20Stub_zpsqubmdl51.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Rear%20Face%20and%20Stub_zpsqubmdl51.jpg.html)
I mounted the pieces above in the four-jaw chuck in my lathe, and spent quite a while getting the first one in the correct position and centered, so that the tube that slides over the stub will be flush with the top of the block, and centered side to side.... The result is that the stubs are completed, including the O-ring grooves, and the rear of the blocks are faced off flat as well.... As usual, the first one of anything takes twice as long as the next one, and true to form the first one took nearly two hours, but to finish all three "only" took me 3.75 hours.... so the total time now on the three tank blocks is 6 hours (2 hours each)....
I've had enough for today, any more and I'd probably start making mistakes.... More tomorrow....
Bob
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Not only do you deserve a break, Bob... you obviously know the smart times to take them.
Nicely done.
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While rsterne and stalwart are off on their mothership fabricating out this world air gun stuff I stayed back on earth awhittlin onna bobcat.
I’m also working on a 1.5K to 2K reverse tanker Bobcat, very slowly, and thought I’d share plus get some ideas on the rear tank attachment I fabricated.
As you can see in this first pic it appears the tank is just floating in air suspended by the upfront tank reverse adapter but it’s not
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3745rearairtankmount3_zpsf13c5fc2.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3745rearairtankmount3_zpsf13c5fc2.jpg.html)
I whittled (routed) out the stock to receive a fabricated (bent) and angle made out of.125 x .500 aluminum (6010) with a circular attachment piece (.250 thick, 6010) for the plastic bottle holder (left over part from a vacuum cleaner hose extension kit). I have a polyethylene glue kit to fasten the plastic tube to the circular aluminum so I can dismiss mechanical fasteners. ( I saved some of polyethylene cuttings to test)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3758rearairtankmount3_zps74e5c376.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3758rearairtankmount3_zps74e5c376.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3757-croprearairtankmount2_zpse4b5cc06.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3757-croprearairtankmount2_zpse4b5cc06.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3755-croprearairtankmount1_zps2f410750.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3755-croprearairtankmount1_zps2f410750.jpg.html)
I cut the circular piece with a hole saw then turned it down on a lathe to fit the plastic tube. I attached the angle to the circle by cutting a keyway to fit then machined a stepped plug to fit in the hole left by the drill bit in hole saw which was drilled and tapped to fasten the angle. I'm to the point right now I'm not sure if I want counterbore the stock, fab a couple of ferrules for the counter bores, for a couple of flat head SHCS to fasten the drilled and tapped angle to the stock or just plain epoxy the angle to the stock.
As far as the fastening the stock to the receiver I plan on making a new backing block, using a couple of extra flat head SHCS for safety then use the OEM hole as a fastening point for the stock with a ferrule in the stock for the bolt to pass through and to keep from compressing the wood (the ferrule will be compress a flat spot on the backing block).
I found great pleasure in shooting the stock Bobcat but I'll take greater pleasure in having more time to shoot without multiple refills with the 13ci bottle.
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Well done!
I knew when I shipped that 'cat, it was going to a good home... 8)
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Today was the job I hate, because it is soooooooooooo easy to make a mistake and ruin the part, or end up with a leak.... Fortunately, that didn't happen, and I ended up with three usable tank blocks (at least so far) that hold 3000 psi just fine.... You can see the fitting I used to test them.... Here are the parts....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Regulator%20Attachments_zpsml1yz3l0.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Regulator%20Attachments_zpsml1yz3l0.jpg.html)
The 1/4" hole at the bottom of the fitting is the air passage, and there will be a 1/8" pin protruding from that to open the pin valve on the regulator.... You have to remove the gauge and Foster from the regulator to rotate it under the stub for the air tube on assembly.... The threads are 1/2"-NPS, and were done in two stages, with a plug tap, run by hand in the lathe as per the photo below, and then finished with a bottoming tap that I had to grind flat from a second plug tap.... This is the setup I use for accurate and square threading, using my lathe....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Lathe%20Setup%20for%20Hand%20Threading_zpszgxpse4w.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Lathe%20Setup%20for%20Hand%20Threading_zpszgxpse4w.jpg.html)
There is a lot to see in that photo.... On the left is a hand crank, inserted into the hole in the spindle, and secured with a split/tapered nut the same way the seat post on a bicycle works.... You slide it in from the left, and reach inside the spindle with a socket wrench to tighten it in place.... This allows you to turn the chuck by hand, with good leverage.... The tap is in the chuck.... The tank block is clamped in the milling attachment.... It sits against an end stop (against this end of it), back against the vertical part of the milling vice, and clamped down, so that it can be removed and replaced at will and will always go back in the same place, allowing all three parts to be made without altering the vertical (Z) or crossfeed (Y) settings, they are locked in place once the correct location for drilling and tapping the hole is determined.... The carriage moves left and right (X), to drill the holes, and you can see a dial indicator on the ways that tells me how far in I have drilled or tapped.... When tapping, I run the part up against the tap, zero the dial gauge, push the carriage to the left by hand to load the part against the tap, and start cranking the chuck by hand.... Once it gets a good bite, the carriage just follows left and right as the tap screws in and out of the part, and the dial indicator tells me how far in the tap has advanced.... When making these tank blocks you have to be careful not to damage the straight bored portion below the threads.... I finish the job in a bench vice, using the bottoming tap by hand....
Anyway, that's how I made the ASA fittings in the tank blocks, and today was a very successful day.... I did a practice version in a piece of scrap that took an hour, but I didn't count that as part of the time (probably should have).... The total time for drilling and tapping the three blocks, and machining off the bottom of the blocks to the proper depth, was 3 hours.... so the running total is now 9 hours, 3 hours per tank block....
Bob
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Bob, I'm following your build with great interest and thank you for the in depth detail you provide.
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Bob, this is another great example of your willingness to share information on your projects. I especially appreciate the pictures of your machine setup and covering some of the ways you overcome a problem. That hand crank setup is brilliant! I have never used a milling vise like you have but would assume that it is not very easy to hold close tolerances with a setup like that. It sure doesn't look very solid. I would think that it would invite quite a bit of vibration?
Thanks again!
Tom
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It's not the greatest, but when you don't have a Mill, you don't have any choice.... The vice jaw is only 1" deep x 2.5" wide and opens just over 2", Vertical travel is only 3", and crossfeed is only 6", so all those limit you as well....
That hand crank setup is compliments of Lloyd Sikes, he uses it for single point threading, particularly up against a shoulder.... No more worries about crashing the work, and you can leave the half-nut engaged all the time....
Bob
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You asked about the rigidity of the Milling Attachment above, and I didn't mention one of the major drawbacks.... With the lack of rigidity in the tower, you can only take light cuts.... I usually use 0.020" in aluminum (sometimes 0.030") for roughing, and 0.010" or less when finishing.... That is one of the reasons everything takes me so long.... Today's project was to cut the 3-slot Picatinny Rails in the bottom of the tank blocks.... Here is what they look like now....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Picatinny%20Rails_zpszmyrmyd3.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Picatinny%20Rails_zpszmyrmyd3.jpg.html)
The were four major steps involved, and four milling cutters.... First I had to narrow up the rail (5 cuts per side), then cut the undercut (8 cuts per side), then the bevel (4 cuts per side), and lastly the slots (8 cuts per slot).... The total time was 3.75 hrs. for the three blocks, so the total time is now 12.75 hrs. (4.25 per block).... BTW, that works out to 174 passes through the mill, plus deburring and finishing afterwards....
I still have to machine the recess in the top front corner to mount the barrel band and drill and tap the mounts for that, machine the mounts for the three screws to mount it to the tube, drill the air passages, and fit the plug for the air passage in the bottom.... I really enjoy working at this pace, doing a specific job each day, and a run of three isn't too terribly boring.... I can't imagine having to sit down and do ten (or a hundred) of anything anymore, I had enough of that when I was working....
Bob
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Beautiful work, Bob.
It's encouraging to see there are those who still understand it takes real time to do something right.
Rod
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I'm working on the first 3K Bobcat, and had to show this to you guys. The PRod mags require the shallowest slots, and they don't go through the tube (hence won't require an extended and relieved block to cover the gap), and in fact leave enough steel to make a very stout "dust cover".
The 3k 'cats will use the standard configuration (with backup screws), but will get the recessed trigger guard mounting so you can mess with custom hammer weights without interference.
This will be a simple, clean and cost effective little rifle... with a real sting.
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Got my .300 cal. Barrel, Carbon Fibre sleeve, Loctite 638 to glue them together, tapered valve spring, assorted hammer springs, taps and O-rings today.... so I think I have all the parts now to complete my build.... Hopefully back in the shop tomorrow....
Bob
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Got my .300 cal. Barrel, Carbon Fibre sleeve, Loctite 638 to glue them together, tapered valve spring, assorted hammer springs, taps and O-rings today.... so I think I have all the parts now to complete my build.... Hopefully back in the shop tomorrow....
Bob
Woo Hoo!
Finished the tube's slots and holes tonight. Reamed it from the block back, to fit stock parts... cut the least labor intensive slot at the bottom. It will allow loading the valve from the back, if desired, while presenting the o-rings with the least amount of challenges.
This one is set to index the trigger housing to the back, you can see the little ears protruding back into the mounting slot. This will be SOP, unless a customer wants a safety.
The pin's slot is a bit narrower than stock, and it now rides on steel only.
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Got my .300 cal. Barrel, Carbon Fibre sleeve, Loctite 638 to glue them together, tapered valve spring, assorted hammer springs, taps and O-rings today.... so I think I have all the parts now to complete my build.... Hopefully back in the shop tomorrow....
Bob
Woo Hoo!
Finished the tube's slots and holes tonight. Reamed it from the block back, to fit stock parts... cut the least labor intensive slot at the bottom. It will allow loading the valve from the back, if desired, while presenting the o-rings with the least amount of challenges.
This one is set to index the trigger housing to the back, you can see the little ears protruding back into the mounting slot. This will be SOP, unless a customer wants a safety.
The pin's slot is a bit narrower than stock, and it now rides on steel only.
This looks much stronger than cutting away the bottoms of the receivers.
Rod
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I'm sure it is, but the force required to demonstrate that would have to be both very specific and in an absurd quantity.
With that steel backbone, I could lighten the receiver into lace, and unless it was used as a splitting maul, you would never miss that metal. Considering that many rifles are held together with 2 small screws, in the same place these still have solid metal... I firmly believe that a bayonet could be effectively used with these, if not an entrenching tool.
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Got my .300 cal. Barrel, Carbon Fibre sleeve, Loctite 638 to glue them together, tapered valve spring, assorted hammer springs, taps and O-rings today.... so I think I have all the parts now to complete my build.... Hopefully back in the shop tomorrow....
Bob
Woo Hoo!
Finished the tube's slots and holes tonight. Reamed it from the block back, to fit stock parts... cut the least labor intensive slot at the bottom. It will allow loading the valve from the back, if desired, while presenting the o-rings with the least amount of challenges.
This one is set to index the trigger housing to the back, you can see the little ears protruding back into the mounting slot. This will be SOP, unless a customer wants a safety.
The pin's slot is a bit narrower than stock, and it now rides on steel only.
Stalwart, I'm honored to have this build in my stable, thanks.
If it wasn't for you and Bob, and there are more, whom have helped me with your willingness to share I wouldn't have challenged myself to do some of things I've been doing, but I still have a lot to learn so please keep sharing, teach this man to fish.
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I'm sure it is, but the force required to demonstrate that would have to be both very specific and in an absurd quantity.
With that steel backbone, I could lighten the receiver into lace, and unless it was used as a splitting maul, you would never miss that metal. Considering that many rifles are held together with 2 small screws, in the same place these still have solid metal... I firmly believe that a bayonet could be effectively used with these, if not an entrenching tool.
Will you be putting prices for bayonet mounts on your website or should we email you?
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:D
Are you sure you wouldn't rather have a battle axe? Grappling hook?
Seriously? I have been pondering a stone cold survival rifle for a very long time.
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I'm sure it is, but the force required to demonstrate that would have to be both very specific and in an absurd quantity.
With that steel backbone, I could lighten the receiver into lace, and unless it was used as a splitting maul, you would never miss that metal. Considering that many rifles are held together with 2 small screws, in the same place these still have solid metal... I firmly believe that a bayonet could be effectively used with these, if not an entrenching tool.
That's great news - for the ~45" long 1"steel octagon-handled 20 pound splitting maul I'm building ;)
You never know what might come through the door out here, and when the air runs out... LOL
But serially folks, I have to admit I'm just an overdesign/overbuild kind of guy.
There's going to be a lot of stuff hanging off that tube-
& a barrel already trying desperately to droop from extreme weight and length.
I was up all night thinking tooling scenarios for shaving it down to clear the tube. Everything from feeding it under a fixed grinder, to a sort of router and fences with a side mill cutter, to handheld whatever....using a worn (7/8") cutting wheel... Dremel stone??
HF portaband, mounted with a table and fence?
I'll just have to see what cuts it with the least tool bearing load.. Good thing I also got a shorter barrel to practice on.
Monster Barrel Liner is ordered as of yesterday - and I can't wait!
Need the actual dimension to know how much to grind away.
....Even though it's still 10 degrees outside, and nowhere near metalworking (even gluing) season, here in darndest WV - YET
(4' of 4130 arrives today. Shoulda ordered more, the shipping is what hurts.
It's always as much as the steel -But Shapiro guarantees no Chinese steel.)
3/4" Brass heavy wall tube also coming to experiment with sealing a stock tube better
(rsterne's oring support bushing.)
Call it machining practice now I guess. Or maybe I can try building a valve some day.
Rod
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"Stalwart, I'm honored to have this build in my stable, thanks.
If it wasn't for you and Bob, and there are more, whom have helped me with your willingness to share I wouldn't have challenged myself to do some of things I've been doing, but I still have a lot to learn so please keep sharing, teach this man to fish."
Mike, thank you for the support you've given... takes guts to order a gun that has never been built before.
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:D
Are you sure you wouldn't rather have a battle axe? Grappling hook?
Seriously? I have been pondering a stone cold survival rifle for a very long time.
I was mostly kidding, but that survival rifle idea has some merit for sure. Not really my style though. Now a straight pull, like a K31, would sure get my attention.
I have always wondered why that is not more popular in pellet guns. We don't need a strong caming force, which it lacks and that makes the design limited in the powder burner world. Probably just adds expense and not that much upside for the average joe.
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After a couple of days of running around, I got back in the shop today and drilled and tapped the three mounting holes in each Tank Block, plus the upper air passage....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Screw%20Holes%20Drilled_zps9syi3sum.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Screw%20Holes%20Drilled_zps9syi3sum.jpg.html)
These things are really taking shape now.... This step took 1.5 hrs., total now 14.25 hrs. (4.75 hrs. per block).... hopefully more progress after lunch....
Bob
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I got the bottom air passage drilled, tapped for the plug, and the safety bleed hole drilled....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Bottom%20Passages_zpsjwid98lx.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Bottom%20Passages_zpsjwid98lx.jpg.html)
This was another hour, for a total of 15.25 hours to this point, so let's call it 5 hours per block.... The only thing left is to make a short 1/8" pin to activate the pin valve in the regulator (or, that can be removed).... On my own blocks I am going to machine a mount for a barrel band on the top front corner, and dress them up a little bit with a groove around the middle, just for appearance.... However, stalwart's is ready to go.... I hope you all have enjoyed seeing what goes into making a reversed tank block.... It's not too surprising that JDS Airman charges $70.00 - $85.00 for his conventional tank blocks without a Picatinny Rail.... Here is a photo of the first assembly to the tank and block to the Grizzly....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/First%20Assembly_zpsfj12ihxo.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/First%20Assembly_zpsfj12ihxo.jpg.html)
I'm really pleased with the results so far....
Bob
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I got the bottom air passage drilled, tapped for the plug, and the safety bleed hole drilled....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Bottom%20Passages_zpsjwid98lx.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Bottom%20Passages_zpsjwid98lx.jpg.html)
This was another hour, for a total of 15.25 hours to this point, so let's call it 5 hours per block.... The only thing left is to make a short 1/8" pin to activate the pin valve in the regulator (or, that can be removed).... On my own blocks I am going to machine a mount for a barrel band on the top front corner, and dress them up a little bit with a groove around the middle, just for appearance.... However, stalwart's is ready to go.... I hope you all have enjoyed seeing what goes into making a reversed tank block.... It's not too surprising that JDS Airman charges $70.00 - $85.00 for his conventional tank blocks without a Picatinny Rail.... Here is a photo of the first assembly to the tank and block to the Grizzly....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/First%20Assembly_zpsfj12ihxo.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/First%20Assembly_zpsfj12ihxo.jpg.html)
I'm really pleased with the results so far....
Bob
I for one have enjoyed your build and I hope to be able to machine a reverse block some day, but I have a lot to learn before that happens. Thanks
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I finished off my own blocks this afternoon, made the barrel band mounts and made a cutout between the tube and regulator just to get rid of the "blocky" appearance....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Barrel%20Band%20Mount%20and%20Cutout_zpsqlgu3w1w.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Barrel%20Band%20Mount%20and%20Cutout_zpsqlgu3w1w.jpg.html)
The total time for blocks to this stage works out to 6 hours each.... That could be reduced by larger runs.... a more competent machinist.... or a CNC, of course....
Bob
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As the front trigger mount nut is more of a "Y" than a "T", I ran a dovetail cutter in the receiver's slot, and got plenty of clearance for the hammer. The screw needs to be shortened slightly, or a washer placed under it, to clear, but there is plenty of room now.
Does anyone know the hammer weight and stroke of the Discovery and the Crosman 22xx guns?
Bob, how much space is between the tank and the tube?
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Stock Disco hammer is 58 grams (22XX is 60 gr.) and the stroke is 0.58".... Very easy to increase the stroke to 0.65" by shortening the valve stem (no change to lift as stock the valve spring goes coil bound).... Increasing the stroke further requires lengthening the breech and tube slots, shortening the back of the valve and drilling the front of the hammer, shortening the back of the bolt and/or moving the hammer pin back, in other words similar problems to the XS-60c.... If you do everything you can get about 1.15" total travel, including the valve lift, so with 0.200" lift that is 0.95" stroke.... Maximum hammer weight, including a 7/32" guide, is about 80 grams, unless you add a weighted cocking knob.... You can get more hammer weight and stroke in the XS-60c....
About 0.010" max.... basically they touch.... Remember I asked you if you wanted enough for a 9 oz. CO2 and you declined.... I like it up snug, it can't stress anything if you drop/fall on the gun....
Bob
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Bob, in your reverse tank block design is your pin valve an on/off?? If not do you fell there's a need for an on/off?
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Nope, no On-Off feature.... If your gun doesn't leak, there is no need for one.... You have to remove the gauge and fill fitting to rotate the regulator anyway, so really no way to keep air in the tank if you have to remove it.... It would be quite easy to modify the tank block to have a screw operated pin to depress the valve in the regulator in this design, in fact I did one a couple years ago that was like that.... You have to seal the pin with an O-ring, of course, and make it so that removing the screw doesn't launch any parts under pressure.... The only advantage is that if you want to get into the gun you can turn off the regulator, drain the reservoir on the gun and remove the tank block from the front of the tube, without draining the tank....
Bob
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I got my new tapered valve springs the other day, and today I installed one in the valve.... It turns out that to get the same preload on the spring the valve has to be shortened 1/2", which means tapping the 16 mm x 1.5 mm threads deeper.... I also opened up the slide slots in the valve and streamlined the end of then for better flow.... There is a TON of room to get air to the poppet now.... You can see that the original raised seat for the poppet is gone, and the back of the valve is now 1/2" ID.... I saw no reason to shorten the male threads, as the entire tube is part of the valve with the front being opened up so much.... Note that the front of the valve is also drilled out to 3/8" ID....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Glue%20Test%20and%20Valve%20Parts_zpsllh6bzgd.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Glue%20Test%20and%20Valve%20Parts_zpsllh6bzgd.jpg.html)
The piece above the valve is a test piece for finding out how the Loctite 638 cures when gluing Carbon Fiber to Steel.... It consists of a 3" long piece of 1/2" OD steel rod, and two 1.5" long pieces of 1/2" ID CF tubing I had.... I wrapped 1" wide masking tape around the middle of the rod so that the two pieces of tubing would have a 1" long overlap.... On one piece I used Loctite 638 (green) Slip Fit Retaining Compound, cured at 100*F for 3 hours and then post-cured at 175*F for 3 more hours.... After that, I then glued on the other end (same Loctite), but just a 24 hour cure at room temperature.... I had been told that some plastics/composites don't cure properly without baking them, so I thought I would find out.... The plan is to put the piece in a vice and compress the ends of the tubes inwards until something fails.... The tubing is a thinner wall than my barrel sleeve, and I expect the tube to break long before the glue, but this afternoon I'll find out and report back....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Glue%20Test%20and%20Valve_zps4bxzjz15.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Glue%20Test%20and%20Valve_zps4bxzjz15.jpg.html)
Bob
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Here are the test results for the Loctite 638.... First, the method.... Pressure applied until failure of both sides....
(http://i378.photobucket.com/albums/oo221/rsterne/Parts%20for%20Sale/Glue%20Test_zpsysv6hqfy.jpg) (http://s378.photobucket.com/user/rsterne/media/Parts%20for%20Sale/Glue%20Test_zpsysv6hqfy.jpg.html)
Now the parts after testing.... You can see where the parts were overlapped before they were clamped in the vice.... 1" overlap on each end.... The vice is just snug, there is enough pressure that the parts didn't fall out of the vice and I could take the first photo....
(http://i378.photobucket.com/albums/oo221/rsterne/Parts%20for%20Sale/Loctite%20638%20Test_zps32zif4fh.jpg) (http://s378.photobucket.com/user/rsterne/media/Parts%20for%20Sale/Loctite%20638%20Test_zps32zif4fh.jpg.html)
The left side failed without a lot of pressure, I turned the handle on the vice about 1/8th turn from snug.... There was increasing resistance and then you could feel the joint yield on the side that had been cured for 24 hours at room temperature.... I wound the vice in until the steel rod contacted the vice on that end, and then started applying more pressure until the oven-baked side failed.... It took many times the force, and failed with a BANG!.... I then took the test piece out of the vice, split the tubes and slid them off the end....
The 24 hr. room temperature cured side (left) was mostly cured, but the glue line sheared.... The Loctite felt slightly soft, and there was a trace of liquid at the outer end, you can see the shiny line of it at the very left end inside the tube, and there is no corresponding cured residue on the steel on the outermost 1/4" of the overlap.... I assume that more time would have cured that material....
The side that was cured at 100*F, and then post-cured for 3 hours at 175*F was completely cured.... The residue on the steel, and inside the tube, was uniform and completely hard.... I have no doubt that with the amount of force required to break the joint that using this method to glue a carbon fibre sleeve to a barrel would work perfectly.... It is quite possible that a room temperature cure would eventually reach the same strength, but it might well take a week or more.... However, I think that even with a room temperature cure, that the Loctite 638 would work just fine for this purpose....
Bob
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I have used the green on spun bearings in hubs, and it holds up amazingly well. On an air rifle it would last nearly forever.
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About 0.010" max.... basically they touch.... Remember I asked you if you wanted enough for a 9 oz. CO2 and you declined.... I like it up snug, it can't stress anything if you drop/fall on the gun....
Bob
Perfect.
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Here are the test results for the Loctite 638....
......cured for 24 hours at room temperature....
.........cured at 100*F, and then post-cured for 3 hours at 175*F .... However, I think that even with a room temperature cure, that the Loctite 638 would work just fine for this purpose....
Bob
The work left for a few weeks to cure indoors, would be as strong as that cured in an oven
- just not ready to use as soon, right?
Good news - I didn't know where I would find an oven for a 43" barrel ;)
What's the offgassing like at room temp.?
Rod
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Yes, I think if you left it for a week at room temp. you wouldn't notice any difference.... the warmer the better, of course.... If you are metal to metal, you should have 100% cure in 24 - 48 hours depending on temp.... the post cure was for plastic/composite on one side....
I couldn't smell anything.... It is, after all, an Anerobic cure.... There was a slight smell while I was cleaning up the excess, but once I threw the paper towel away, nothing....
I plan to weigh the bottle before and after I do my barrel.... that should give a good indication how much I used (and wasted!)....
Bob
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I machined the barrel today.... cut the threads at the muzzle, chambered it using a reamer from Sean Pero, cut the three O-ring grooves, cut the CF sleeve to length, determined which way the curve was (it will be installed with the muzzle "up"), sanded and cleaned the parts, and glued the sleeve on with Loctite 638.... It's hanging to dry, I'll take photos in the morning.... I weighed the bottle of Loctite before and after, and I used 3.25 grams (about 3 ml), so you could probably do three barrels with a 10 ml bottle.... Yeah, I paid over $60 for a 50 ml, the good news is I've heard it stores well (Sean has had his 10 years)....
The sleeve was a snugish slide fit when I started.... I sanded the OD of the barrel and the ID of the sleeve with 100 grit in a spiral pattern to give it some "tooth" and a fresh surface.... I then cleaned the inside of the tube with a cleaning rod, with patches soaked in Acetone until clean and blew it out with compressed air.... I also wiped the barrel OD 3 times with Acetone after building up a collar of tape as a stop at the breech end and plugging the muzzle with a driven in piece of (snug) wooden dowel.... The fit was now loose enough that the barrel would slide out from it's own weight if you held the assembly vertical by the shroud, but the shroud would not slide off if you held it vertically by the barrel.... I think that is an excellent criteria to remember for the fit if you're using Loctite 638, at least it certainly worked well for me....
I squeezed some Loctite into one end of the sleeve and swabbed it down the inside of the tube with a patch saturated in 638, the did the same thing from the other end.... I then put three longitudinal lines of 638 (about 1/16" wide, equally spaced) the entire length of the barrel.... I then put a "collar" of Loctite around the barrel and inside the tube at the leading ends (first parts to go together) and slide them together, twisting as I went to wipe the lines of 638 around the barrel for full coverage.... The sleeve pushed a collar of 638 ahead of it, and by the time I got to the end (where the tape stop was) it was about 1/8" high and dripping off onto the floor (so don't do this where it matters).... The amount of effort it took to slide it together increased as the overlap increased, so I didn't dare stop.... It probably took 3-4 lbs. force by the end, but there was certainly no problem getting it together.... I mopped up the excess Loctite with paper towels and then hung the barrel by the threads at the muzzle from a string, it will stay there, at room temperature, for 18 hours until tomorrow morning.... At that time I will do a 3 hr post cure at 175*F....
I am VERY pleased with how this assembly went together.... Although this particular sleeve isn't that thick, it will add some stiffness, and it looks killer....
Bob
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I machined the barrel today.... cut the threads at the muzzle, chambered it using a reamer from Sean Pero, cut the three O-ring grooves, cut the CF sleeve to length, determined which way the curve was (it will be installed with the muzzle "up"), sanded and cleaned the parts, and glued the sleeve on with Loctite 638.... It's hanging to dry, I'll take photos in the morning.... I weighed the bottle of Loctite before and after, and I used 3.25 grams (about 3 ml), so you could probably do three barrels with a 10 ml bottle.... Yeah, I paid over $60 for a 50 ml, the good news is I've heard it stores well (Sean has had his 10 years)....
The sleeve was a snugish slide fit when I started.... I sanded the OD of the barrel and the ID of the sleeve with 100 grit in a spiral pattern to give it some "tooth" and a fresh surface.... I then cleaned the inside of the tube with a cleaning rod, with patches soaked in Acetone until clean and blew it out with compressed air.... I also wiped the barrel OD 3 times with Acetone after building up a collar of tape as a stop at the breech end and plugging the muzzle with a driven in piece of (snug) wooden dowel.... The fit was now loose enough that the barrel would slide out from it's own weight if you held the assembly vertical by the shroud, but the shroud would not slide off if you held it vertically by the barrel.... I think that is an excellent criteria to remember for the fit if you're using Loctite 638, at least it certainly worked well for me....
I squeezed some Loctite into one end of the sleeve and swabbed it down the inside of the tube with a patch saturated in 638, the did the same thing from the other end.... I then put three longitudinal lines of 638 (about 1/16" wide, equally spaced) the entire length of the barrel.... I then put a "collar" of Loctite around the barrel and inside the tube at the leading ends (first parts to go together) and slide them together, twisting as I went to wipe the lines of 638 around the barrel for full coverage.... The sleeve pushed a collar of 638 ahead of it, and by the time I got to the end (where the tape stop was) it was about 1/8" high and dripping off onto the floor (so don't do this where it matters).... The amount of effort it took to slide it together increased as the overlap increased, so I didn't dare stop.... It probably took 3-4 lbs. force by the end, but there was certainly no problem getting it together.... I mopped up the excess Loctite with paper towels and then hung the barrel by the threads at the muzzle from a string, it will stay there, at room temperature, for 18 hours until tomorrow morning.... At that time I will do a 3 hr post cure at 175*F....
I am VERY pleased with how this assembly went together.... Although this particular sleeve isn't that thick, it will add some stiffness, and it looks killer....
Bob
As always Bob, THANKS for the detail!
(especially the good news on the 10ml being enough!)
It will be very helpful when the time comes.
Rod
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What are the advantages of Loctite over something like Acraglas?
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I only used Acraglas once, many years ago when bedding a rifle, and it was a messy experience.... Of all the epoxies I have used over the years, it is the thinnest (runniest, least viscous), and the only one that I would trust to get into the very tiny gap (0.010" or less on the diameter) between the barrel and the shroud.... Some people have said there is a West Systems product that is thin enough, but it must be one I've never worked with, or they are thinning it with Acetone, and that is really a no-no on epoxy in a closed space.... If the Acetone can't get out of the epoxy before it cures, it remains trapped, the epoxy never cures properly, and that is exactly what should happen in this case.... Like any Epoxy, Acraglas is a 2-part system (resin and hardener) that requires fairly accurate mixing, it is sticky, and requires cleanup using Acetone.... If you DO use epoxy, stick to one that it thin enough to get into the joint on assembly.... Do a test piece like I did, let it cure, destroy it, and see if you had 100% coverage in the joint.... With the Loctite 638, even though it was the thickest of the three Loctite 600s I looked at, I got 100% coverage in the joint....
Loctite make a dozen "Retaining Compounds", mostly in the 600 Series, half of them green in colour.... They are an "Anerobic" material, which means they are a single component (no mixing) that cures in the ABSENCE of air.... The bottle is only half full when you buy it for that reason, the air keeps it from curing.... You can spread it out on a surface in the air and it just sits there, and since it has very little solvent, doesn't set, similar to Crazy Glue, to which it is closely related.... Put it in a narrow gap, sealing it off from the air, and it hardens.... Some are thick, some thin, some high temperature, some fast or slow cure, etc.etc.... The thinnest ones (eg. 609) are for close fitting parts (eg. press fits).... as they get thicker they can stand a bigger gap (slip fit).... The 638 I chose is the thickest of the "normal temperature, fast cure" Loctites (about like syrup), and the strongest.... Post cure on steel it is 4500 psi shear strength, which is superior to most epoxies.... Since it is thick, it is the most suited to "slip fits" with gaps up to 0.010" on the diameter, which I thought sounded perfect for our application.... It has a 4-10 minute assembly time before it gets too thick to move (the closer the fit, the less time) and takes 24 hours to cure (steel to steel) at room temperatures.... Heat accelerates the cure rate, it will fully cure in just 4 hours at 40*C (104*F), which is barely warm to the touch.... It was never designed for gluing plastics or composites, but the manufacturer has a work-around for that, by using a post-cure at elevated temperatures (they recommend 3 hrs. at 175*F) to fully cure the product....
The criteria for gluing a CF (or steel) sleeve to a barrel are pretty simple, really.... It has to fill the gap completely and cure to a reasonable strength.... It has to give you long enough to assemble and position the parts, and then cure within a reasonable length of time.... If the product you use meets those criteria, it should work just fine.... I chose Loctite 638 because it would fill the largest gap, and it had the highest shear strength.... I think that 609 or the new 648 (both designed for a 0.006" diametrical gap) would work as well, the 609 is the thinnest and slowest curing, and would therefore be the easiest to use, but it is only half the strength (still fine, though, at 2300 psi minimum).... I have never used the newer 648, which is in between in viscosity, the fastest set (3 min.), and nearly as strong as the 638.... There is also 640, nearly identical to the 648 in properties, but it is a slow cure product, with a 1 hr. assembly time, but it is only designed for a 0.004" gap, which may be too tight for easy assembly over the long length of a barrel, IMO....
Bob
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It looks like I'll need 620... I'll need the high heat resistance for powder coating aluminum sleeves.
I don't mind making a mess, but for 1 barrel at a time? Zoro.com has the 600s for $12.21 (10ml).
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I've done more whittlin. ;D
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3762anglebracketepoxiedtoreceiver_zpsc2c5788f.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3762anglebracketepoxiedtoreceiver_zpsc2c5788f.jpg.html)
I decided to epoxy the reverse tank bottle holder to the receiver as I couldn't figure out a mechanical fastener. I voided the idea of epoxying the bottle retention assembly into the stock as I felt that would have been a fatal flaw for the stock if dropping the gun. I roughed up the angle and receiver with 80 grit, cleaned with a stainless steel brush and acetone (no degassing) then air dried, once dry (a minute max) I immediately buttered with JB Weld so flash oxidation wouldn't spoil the bond. As far as shear strength I'm not sure but we'll find out here shortly plus she aint' aesthetically pretty but then again all will be hidden by wood. ;)
The plenum/tube is chromoly which I single pointed threads on both ends, after much much practicing as this is my first. Although the threads have a much better engagement than the FDPCP plenum/tube threads I resign to keep the Bobcat a 1.5K shooter, the reason being I should have paid closer attention to details afforded me by the wisdom of this group and should not have used a sharp V threading tool. Live and learn.
I've already pressure tested @ 1.5K with no leaks so I felt I was close enough to completion I ordered Cerakote to make my whittlin pretty.
I have to poke a hole (whittlin talk) in the stock for fore stock retention and I still think I'll use the backing block as it will have deeper threads. As far as staining and or painting the stock I've talked with stalwart about bedliner and bedliner it will be.
As always constructive critique is always welcome.
More to come.
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620 is pretty thick, about the consistency of honey.... but the good thing is it's slow enough to let you pull it apart and inspect it for 100% coverage and then reassemble.... Otherwise the specs look similar.... I'd check into the Activators, there may be one that will eliminate the need for the post cure?.... I have no idea what the temperature capability of Acraglas is.... If you get the CF sleeve too hot, the resin may come unglued (literally) anyway, something else to look at....
Bob
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It looks like I'll need 620... I'll need the high heat resistance for powder coating aluminum sleeves.
I don't mind making a mess, but for 1 barrel at a time? Zoro.com has the 600s for $12.21 (10ml).
I've used the RC620 for years. I never considered steel to CF before. Sometimes I room temp cure but for high temp apps I go for 25*F higher than the expected operating temp.
Tom
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The 620 needs a cure at 356*F, to activate it's 450* max working temp. .015 gap max.
I'll find out if the 10mins at 400* (coating cure) works. It'll only see heat once... maybe twice
Per barrel, considering the cost of many other adhesives (my head hurts...lol) and the time to clean them up, it is dirt cheap. 50ml only costs $33 and change.
Tom, I'm looking into aluminum sleeves, powder coated... so they can be beaten, and re-coated if needed. Thanks, your info is quite reassuring... 8)
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I've done more whittlin. ;D
As always constructive critique is always welcome.
More to come.
Not much to criticize, Mike... looks like a ton of fun already! You'll love the bedliner, it takes a real beating, and will take paint (camo?) well. Play with distance and ambient temp, and you can do some nice textures. When I use a spraycan, I put it in a 140* water bath (10 mins), and stand back a bit... it shoots spiderwebs that turn into a fine texture... grippy without retaining a lot of crud. Wipes right off.
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The 620 needs a cure at 356*F, to activate it's 450* max working temp. .015 gap max.
I'll find out if the 10mins at 400* (coating cure) works. It'll only see heat once... maybe twice
Per barrel, considering the cost of many other adhesives (my head hurts...lol) and the time to clean them up, it is dirt cheap. 50ml only costs $33 and change.
Tom, I'm looking into aluminum sleeves, powder coated... so they can be beaten, and re-coated if needed. Thanks, your info is quite reassuring... 8)
I assure you 620 will cure at room temp just fine. It will be slow and never reach its high temp properties until its post cured at temp though. Room temp cure and letting the final post cure occur during the powder coat will work just fine.
Tom
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This morning I post-cured the Loctite 638 that I used to glue the CF sleeve onto the barrel, and while that was baking I did some bluing on the main tube, valve backing block, hammer and spring guide.... After the barrel had baked, I machined the port and the pockets for the set screws, machined the flow-through side port in the bolt, and modified a Hatsan Air Stripper to fit he muzzle and then blued the bolt and the ends of the barrel.... I used Van's Gun Blue, and I'm pretty pleased with the results as you can see in the photo below....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Parts%20Blued_zpsrbzdbtyf.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Parts%20Blued_zpsrbzdbtyf.jpg.html)
Hatsan Air Stripper and threaded muzzle....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Air%20Stripper_zpsibfy4v6f.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Air%20Stripper_zpsibfy4v6f.jpg.html)
Bolt and Barrel Stub, showing ports.....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Bolt%20and%20Ports_zpsnlxafrqr.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Bolt%20and%20Ports_zpsnlxafrqr.jpg.html)
Hammer, Valve, Adjuster and Spring Guide....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Hammer%20Valve%20and%20Adjuster_zpstttzgzv5.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Hammer%20Valve%20and%20Adjuster_zpstttzgzv5.jpg.html)
With a little luck I'll assemble the gun far enough tonight to do a pressure test overnight....
Bob
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Looking good Bob, I'm amazed at the work you do with a milling attachment on your lathe. I used to have the exact same Atlas (branded Craftsman Commercial) lathe for years before I bought my first CNC. From about 1990 to 2013 when I finally gave it away to make room for a 16" Taiwanese Mori known as the Cadillac. I still miss the Atlas because every thing was so easy to setup and that little machine had nice clearances and travels where nothing would bump into itself during operation. I did some of my best work on that lathe. So you see, I get warn and fuzzy when reading about your projects on your Atlas.
Tom
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I'd be lost without that milling attachment, and one thing is does easier/better than a mill is working on an angle to the mill/chuck.... super easy to set up for that....
Ahem!!.... stalwart !!!! .... I have a bone to pick with you !!!!!!!
I ran a pressure test on my regulator today, and promptly blew the 3K burst disc.... Figured it was a dud, so I replaced it and blew that one too !!! .... Remember when you installed the 3K disc instead of the 7.5K ?.... You were supposed to move the 5K from the output side to the input side where the 7.5K was and install the 3K on the output side.... With it on the input side, it blows as soon as you get the tank to pressure.... FORTUNATELY I only had a 1 CI tank on the regulator, not the 22 CI.... My regulator is set at 1950 psi according to a pretty good gauge, so close enough....
Sooooooooooooooo .... you better check your regulator to make sure you have the 5K on the inlet side and the 3K on the outlet side or you'll do the same thing.... *LOL*.... The output side disc is further from the tank by about 1/8"....
Good news is that the main tube / valve / receiver / tank block is assembled and it's sitting with 3,000 psi in it for an overnight pressure test.... So far, so good....
Bob
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They were supplied with (2) 5ks installed. I have never worked with tanks/regs before.
Sorry.
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Absolutely no problem, buddy.... just giving you a hard time.... If Tim had caught it before he shipped them it wouldn't have been an issue.... and I should have looked when I popped the first disc, after all, this isn't my first Rodeo.... *LOL*.... Ultimately it's Ninja that have stopped using the 3K discs, they only have 1.8K, 5K and 7.5K, which is pretty dumb, IMO....
The gun is holding 3K so far, no drop at all in a few hours, so it looks like it's good to go.... I think I'll tether it at 1800 psi to start, simply because I have a regulator set up for that.... I may also give it a try at 2900 psi to see if we have enough hammer strike to handle that amount of pressure.... With a little luck, tomorrow should be an interesting day....
Bob
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Well, I'm embarrassed. :-[
Although this is my first rodeo, I was trying to pay close attention. Until now, I would have bet anything that I got it right. After deciphering what had to be done (3K farthest from the tank), and setting up to do the swap... I found the battery in my torque wrench was dead. Apparently, by the time I sent someone out for a new battery, and got back to it... brain fade had set in (happens to me daily, the trick is to see it coming).
Won't happen again... except when it does.
:)
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Don't beat yourself up.... I wasn't trying to.... *grin*....
Bob
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.
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It's 1/2"-20 NF.... standard muzzle threading.... I had to drill out the stripping cone, that stripper was a .22 cal, you can get then in .177, .22, and .25 cal.... The cone is adjustable fore-and-aft.... I positioned the CF sleeve so that the stripper tightens against it when the muzzle is about 1/16" proud of the shoulder in the back of the hole in the stripper.... The Hatsan barrels have an O-ring groove where the threads end to provide some friction to hold it on.... Not enough room on a .30 cal barrel, IMO, the groove would be pretty deep....
Bob
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.
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Don't beat yourself up.... I wasn't trying to.... *grin*....
Bob
Well, somebody's got to do it... and, it's not like it pays well enough to attract quality applicants. ;D
Why would Ninja ship with 5Ks at both ends? What do they make that needs 7.5K discs?
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I'd be lost without that milling attachment, and one thing is does easier/better than a mill is working on an angle to the mill/chuck.... super easy to set up for that....
Bob
and... you just reminded me to plan the $$ for a HEAVY right angle block to mount my new slide vise on. Then all I need is an equally heavy spindle and mount (eBay lathe head if I get lucky, super heavywall 4130 trued up by a local for a spindle, if not) and some sort of table/fence.
(and no, it wouldn't be cheaper to ship -and unload- even a FREE lathe, if that were even available any more.) Lathe parts always turn up on eBay. Retirement budgets dictate 'a little at a time' is the only choice.
Gotta find out what they did with all those rails when they stripped the old coal line (from the last "boom") to make the local cross-state "rails for trails" hiking trail that crosses down the street from us.
I've been coveting a RR rail for years... two 4-6' lengths make a fabulous welding table for kart frames.
I'm also loathe to cannibalize the old W-T bench DP I bought ($50) to clean up, a few years ago (and haven't yet ;) It'll still be the most useful as intended.
SO many builds and resto's - so little time in workable weather.... (and now health)
Rod
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The 7.5K disc is standard equipment for the regulator we received from Tim, which is 4500 psi input (x 5/3 = 7.5K).... By the same Hydrotest ratio (5/3), a 3000 psi vessel uses a 5K disc on the input side, and CO2 (which is 1800 psi MSWP) uses a 3K.... Paintball markers use the 1.8K, of course, on the output side.... With the 3K being common for CO2 I have NO idea why Ninja don't supply them any more, but they don't use them at all....
Bob
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I assembled the prototype Grizzly this morning, and conducted some tethered tests at 1800 and 2900 psi.... Here is what the gun looked like during this testing....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Tethered%20Test_zpsyo8jpznw.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Tethered%20Test_zpsyo8jpznw.jpg.html)
Good news: There is plenty of hammer strike, even for the 70 gr. bullets at 2900 psi.... and yet I can dial it down below what is necessary with pellets at 1800 psi....
Bad news: I didn't seal the tube to the receiver at the transfer port, so it blows a big slug of air out the slot in the bottom on firing.... This was expected....
Maximum achieved at 1800 psi:
44.8 gr. JSB - 936 fps - 87.2 FPE
49.4 gr. Daystate - 910 fps - 90.9 FPE
69.8 gr. BBT - 806 fps - 100.7 FPE
Maximum achieved at 2900 psi:
44.8 gr. - 1075 fps - 115 FPE
49.4 gr. - 1046 fps - 120 FPE
69.8 gr. - 945 fps - 138 FPE
These are virtually the identical results I achieved with my Disco Double at the same pressure, not really surprising as I copied all the port sizes for this build.... Still, it is very satisfying to accomplish them, I couldn't be more pleased.... When I fix the leak and the tank is installed, the 1800 psi numbers at maximum should be achievable with decent efficiency, since the regulator output is 1950 psi.... I did one short string, filling the tube to 2000 psi and dialing the hammer strike back to achieve four shots within a 4% ES with the 44.8 gr. JSBs of 906-913-894-879 fps, ending at 1300 psi.... This was only out of curiousity, as the tube is only 6 CI in volume (98 cc) and was dropping in pressure, whereas once the tank is installed it will be operating at a constant 1950 psi, with the air supplied from a 22CI tank.... However, the 4 shots averaged 898 fps (80.2 FPE) for a total of 321 FPE from 700 psi of air (48 bar x 6 CI) = 290 CI for an efficiency of 1.11 FPE/CI.... and that was with a severe air leak.... I don't think there is any doubt that the final result will be a couple of hard hitting 7-shot magazines....
I'm pumped.... Now to put all the information into my spreadsheet and I'll be back later with more details....
Bob
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I was away part of the day today, so I only got the new hammer spring preload adjuster done....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Preload%20Adjuster_zpst0acfqme.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Preload%20Adjuster_zpst0acfqme.jpg.html)
..... the new hammer spring, which is 3" long made from 0.051" wire.... you can see it in the photo.... Tomorrow I plan on making the new hammer....
Bob
Is the hammer spring you eventually used, a regular Century item, or do you have to make them?
-Rod
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I used a spring from McMaster Carr, # 9657K427.... However, there is an identical spring available from Century, # 71237.... Both springs are 0.36" OD x 0.051" wire x 3.0" long, and 15 lb./in spring rate.... Century have them available in smaller and larger wire sizes as well.... The gun is not difficult to cock, even set up for 3000 psi.... So here is all the data on how the Grizzly responded to preload changes at both pressures, and with all three pellets tested....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20Hammer%20Preload_zpsgcucivpj.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20Hammer%20Preload_zpsgcucivpj.jpg.html)
At 2900 psi, even with the 70 gr. Bob's Boattail cast bullet, the last two turns of preload did nothing, the gun could still be maxed out, so that is proof that a stronger hammer spring, or more hammer weight or travel, is not necessary.... In fact, the "knee" of the curve is where it says "Flush" on the graph, which is the point at which the end of the adjusting screw is flush with the inside of the rear plug on the inside.... At 1800 psi, the knee of the curve with the 70 gr. BBTs is right about where there is no preload on the hammer spring.... where it says "Zero" on the graph (which is -5T from Flush).... and for the pellets about 1 turn out from there.... In other words, the spring is rattling around lose when uncocked, although only by about 0.050".... This tends to be a fairly efficient setup, as hammer bounce is rarely an issue, so I have hopes that when I put on the tank, which is regulated at 1950 psi, it will be similar.... It appears from the graph that each 200 psi of pressure takes about a turn more on the preload to get back to the knee of the curve, which is a handy thing to know.... and the bullets need about a turn more preload than the pellets, which is typical....
All in all, I'm VERY pleased with these preliminary numbers.... It gives me great confidence that the completed gun will be both powerful and efficient.... and one in which you can tailor the performance to your requirements by simply selecting the regulator pressure between, say, 1600 - 2200 psi.... If a more powerful bullet shooter is required, then using a full length tube (or twin tubes) and running a 3000 psi fill will do the job with the 70 gr. BBTs.... This makes the Grizzly a very flexible platform....
Bob
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So, what is the intended target? Looking good!
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I used a spring from McMaster Carr, # 9657K427.... However, there is an identical spring available from Century, # 71237.... Both springs are 0.36" OD x 0.051" wire x 3.0" long, and 15 lb./in spring rate.... Century have them available in smaller and larger wire sizes as well.... The gun is not difficult to cock, even set up for 3000 psi.... So here is all the data on how the Grizzly responded to preload changes at both pressures, and with all three pellets tested....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20Hammer%20Preload_zpsgcucivpj.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20Hammer%20Preload_zpsgcucivpj.jpg.html)
At 2900 psi, even with the 70 gr. Bob's Boattail cast bullet, the last two turns of preload did nothing, the gun could still be maxed out, so that is proof that a stronger hammer spring, or more hammer weight or travel, is not necessary.... In fact, the "knee" of the curve is where it says "Flush" on the graph, which is the point at which the end of the adjusting screw is flush with the inside of the rear plug on the inside.... At 1800 psi, the knee of the curve with the 70 gr. BBTs is right about where there is no preload on the hammer spring.... where it says "Zero" on the graph (which is -5T from Flush).... and for the pellets about 1 turn out from there.... In other words, the spring is rattling around lose when uncocked, although only by about 0.050".... This tends to be a fairly efficient setup, as hammer bounce is rarely an issue, so I have hopes that when I put on the tank, which is regulated at 1950 psi, it will be similar.... It appears from the graph that each 200 psi of pressure takes about a turn more on the preload to get back to the knee of the curve, which is a handy thing to know.... and the bullets need about a turn more preload than the pellets, which is typical....
All in all, I'm VERY pleased with these preliminary numbers.... It gives me great confidence that the completed gun will be both powerful and efficient.... and one in which you can tailor the performance to your requirements by simply selecting the regulator pressure between, say, 1600 - 2200 psi.... If a more powerful bullet shooter is required, then using a full length tube (or twin tubes) and running a 3000 psi fill will do the job with the 70 gr. BBTs.... This makes the Grizzly a very flexible platform....
Bob
Fantastic! "Very flexible" were exactly the words that sprang to my mind in reading this.
Congratulations!
Rod
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I could not be happier!
It will surprise no one to know that these numbers are precisely what Bob predicted, way back... and what I was praying for.
A .22 LR equivalent will sell, easily, here on my turf.
Kudos, Bob!
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I have mounted the tank, and I'm doing a pressure test.... I removed the pin valve from the regulator, which will increase the setpoint slightly (typically 50-100 psi).... That is because the spring on the pin valve pushes against the piston, in the opposite direction to the Bellevilles.... ie in the same direction as the air pressure on the output side.... Therefore, to close the seat in the regulator (and stop the flow, limiting the pressure), once you remove the pin valve, you have to have slightly higher output pressure.... I will therefore be at or just on the high side of 2000 psi (which is what we ordered) rather than on the low side.... favouring slightly more power and maybe one shot less per fill.... As long as I get two full magazines (14 shots), I can live with that....
The next set of tests will be as the gun is intended to be used (at least for me).... regulated at 2000 psi.... I'm after a pellet shooter, with as much power as I can get for 14 shots.... What is does with the BBT's is, for me, a bonus.... Stay tuned, it's getting exciting....
Bob
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Stay tuned??
If anyone tries to pull me away from this screen... I'll scratch their eyeth out.
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Bob,
Nice build, those numbers sure tell the story that's for sure.
Congratulations and I wish you the best when you get your tank on and start testing again!
I'm all tuned in, cant wait ;D
William
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I couldn't wait until tomorrow.... It was my night to make dinner, but after the dishes were done I went back out to the shop, took my best guess at the preload and shot a string with each pellet.... Here are the results, starting from a 2900 psi fill using my regulator....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20Shot%20Strings_zpsrrsdgdi0.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20Shot%20Strings_zpsrrsdgdi0.jpg.html)
The first string, with the 45 gr. JSBs, was with the hammer preload at zero.... It was a pretty good guess, as the string extended down to 1700 psi, 300 psi below the setpoint, before it tanked.... That means I'm right on the knee of the curve.... 21 shots at 84 FPE, and an ES that doesn't matter.... I then shifted to the 70 gr. Bob's Boattails, added 1 turn of preload, and got 16 shots at 99 FPE, also ending at 1700 psi.... I then backed the preload out a half turn and tried the 50 gr. Daystates, and got 17 shots at 89 FPE.... That was a bit too much preload for best efficiency, but I wanted to reduce the number of shots and see what the energy was on that string.... If I tuned it for 14 shots, it would be over 90 FPE with those pellets, over 85 with the 45 gr. and over 100 with the 70 gr.... Those numbers were bang on what I was hoping for.... I'm getting a little bit of a "burrppp" from the gun at this preload, and the efficiencies are just under 1.0 FPE/CI because of the hammer bounce.... Running right at zero, or near zero, preload is always a bit of a problem, I think a different hammer spring (either lighter with more preload, or heavier rattling around loose) would reduce the hammer bounce and increase the efficiency.... However, even the way it is, it's a pretty stellar performer.... It certainly has the new Hatsan Carnivore beat....
Bob
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The Carnivore weighs 9.3#... what do you think the Grizzly will top out at?
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The Carnivore weighs 9.3#... what do you think the Grizzly will top out at?
My guess is 7lbs. 9oz.
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congratulations Bob, excellent results
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Congradulations. The fact that this all starts from a $100 PCP is just amazing. Not that there is anything wrong with the FDPCP, love mine, just stunning to see it turned into this.
I am guessing cost is why the Carnivore is not as good? Or is hatsan simply not paying attention?
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The Carnivore weighs 9.3#... what do you think the Grizzly will top out at?
My guess is 7lbs. 9oz.
Nope, too heavy.... It weighs.... *drum roll please*.... 6 lbs. 14 oz.
Bob
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Dumb question Bob, but how much more drop would a .30 pellet have than a .25 bullet of similar weight? At say 100 yds.
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Starting with equal velocity, and talking pellets, not bullets (eg. .25 cal JSB King to .30 cal JSB), the larger caliber has a better BC, and hence less wind drift and slightly flatter trajectory.... That is why they are winning events like the Extreme Bench Rest, which was won with the .30 cal barrel we are using in the Grizzly....
Comparing pellets of equal weight in different calibers is a muggs game, because you can't achieve the same velocity in the smaller caliber in an equal gun.... However, to answer your question, if you started two pellets of the same weight, at the same velocity, the smaller caliber would have the better ballistics.... It would just take some combination of longer barrel, more pressure, or more air used, to get it there in the first place....
Bob
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This repeater project has been a wild journey. Thanks to you and Eric I have learned a lot. By they way is that 6lbs 14oz with the stock? :)
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Yup, complete but no sights.... just weighed it to answer your query....
Bob
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I am sure it is some where in this 46 pages, but I can't seem to find how long the .30 barrel is?
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Yup, complete but no sights.... just weighed it to answer your query....
Bob
Light and powerful that is awesome.
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Yup, complete but no sights.... just weighed it to answer your query....
Bob
Light and powerful that is awesome.
Not to mention agile, and stout.
These results have confirmed, to me, that these rifles are deserving of even more development. This is something I have believed for a long time... we are nowhere near done yet.
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I assembled the prototype Grizzly this morning, and conducted some tethered tests at 1800 and 2900 psi.... Here is what the gun looked like during this testing....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Tethered%20Test_zpsyo8jpznw.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Tethered%20Test_zpsyo8jpznw.jpg.html)
I didn't seal the tube to the receiver at the transfer port, so it blows a big slug of air out the slot in the bottom on firing.... This was expected....
Bob
Did you mean "tube" - or valve?
i.e., was the through tube just inserted without glue, or what?
Just trying to understand...
Rod
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The .30 cal barrel is 25" long, plus about 3" for the Hatsan Air Stripper....
I checked the maximum velocity with the regulated setup this morning, and after a bit of head scratching, combined with yesterday's results, I decided that the setpoint was more like about 1900 psi, and the performance was a little less than I wanted, with more shots than I needed.... Soooooooooooo I drained the tank, pulled the regulator apart and added a 0.010" shim, which should add about 300 psi, bringing the setpoint up to ~ 2200.... I then reassembled the gun and ran through the preload settings to chart out the maximum velocity with the three pellets, and what preload settings were required.... While I was doing this, I also measured the valve lift by using an O-ring on the end of the spring guide as I mentioned earlier.... Here are the results....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20Preload%20and%20Lift%202200%20psi_zps5fpyblzo.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20Preload%20and%20Lift%202200%20psi_zps5fpyblzo.jpg.html)
Notice that the extra pressure moves the position of the "knee" of the curve up about 2 turns compared to the 1800 psi graph published earlier.... pretty much the 200 psi per turn I predicted earlier.... Next, take a good look at the Lift curve.... I'm sure you will be surprised at how little the valve really opens.... I allowed 0.200" of room when I built the Grizzly, knowing that I have never seen a PCP require that much lift when operating efficiently.... Sure enough, with pellets, any lift about 0.090" doesn't increase the velocity but just wastes air.... For the bullets, that occurs at about 0.100".... The throat in this valve is 0.266" in diameter, and a third of that is 0.089", so once again, you certainly don't need to allow more than half the throat diameter for maximum valve lift.... Maximum power levels at 2200 psi were 102 FPE for the 44.8 gr. JSBs, 107 FPE for the 49.4 gr. Daystates, and 121 FPE for the 6.8 gr. Bob's Boattails.... The Grizzly is solidly in the 100 FPE class at 2200 psi, even with pellets.... 8)
Based on the above data, I filled the tank to 3000 psi, topped it up after a few minutes of cooling, and set the preload to 2 turns in from zero.... I shot a string with each pellet, and the pellets were shooting a bit hot (the Daystates were right at 100 FPE for 12 shots) and not very efficient, but the bullets were virtually perfect.... I then repeated the strings with the pellets with the preload reduced by a turn, to just 1 turn of preload, and plotted the three strings on the graph below....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20Strings%202200%20psi_zpssz6lzqmi.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20Strings%202200%20psi_zpssz6lzqmi.jpg.html)
All three pellets produced usable strings (2% ES) over two magazines.... The 70 gr. BBT bullets averaged 110 FPE over 14 shots, ending at 1880 psi, for 0.90 FPE/CI.... The 50 gr. Daystate pellets averaged 94 FPE over 18 shots, ending at 1960 1900 psi, for 1.07 1.01 FPE/CI.... and the 44.8 gr. JSBs averaged 92 FPE over 17 shots, ending at 1950 psi, for 0.98 FPE/CI.... Note there is a slight bump in the velocity with the 70 gr. and 50 gr. just below 2200 psi, which indicates that they are operating right on the knee of the curve, and the strings extend about 200 psi below the setpoint, with the last usable shot taken at right about 2000 psi.... The pressure graph shown was using the 50 gr. Daystates.... It would be an easy matter to tune whatever pellets ended up being the most accurate in your gun for slightly higher or lower velocity with the corresponding change in shot count.... ie more power, fewer shots, and vice versa.... Overall, I think that having a regulator setpoint of 2200 psi suits my goal for the gun better than 2000, although using the lower pressure you can tune down a bit and get three magazines with the pellets.... Don't forget, I still haven't sealed the tube to the receiver at the transfer port, so I'm getting a pretty large blast of air out from under the magazine with every shot.... In addition, I haven't experimented with different hammer springs.... so I'm sure there is more efficiency lurking in the Grizzly, yet to be found....
Rod, the tube is just inserted into the receiver, no glue, at the moment.... Leaks were expected on firing.... but I might have had to make changes, so delayed gluing it....
Bob
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Here are the results, starting from a 2900 psi fill using my regulator....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20Shot%20Strings_zpsrrsdgdi0.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20Shot%20Strings_zpsrrsdgdi0.jpg.html)
.... If I tuned it for 14 shots, it would be over 90 FPE with those pellets, over 85 with the 45 gr. and over 100 with the 70 gr.... Those numbers were bang on what I was hoping for.... I'm getting a little bit of a "burrppp" from the gun at this preload, and the efficiencies are just under 1.0 FPE/CI because of the hammer bounce.... Running right at zero, or near zero, preload is always a bit of a problem, I think a different hammer spring (either lighter with more preload, or heavier rattling around loose) would reduce the hammer bounce and increase the efficiency.... However, even the way it is, it's a pretty stellar performer.... It certainly has the new Hatsan Carnivore beat....
Bob
It just gets more and more impressive, Bob!
What would it take to get the BBT's up to 900(+?) fps -
bigger ports, more air (bigger tube,) longer barrel, more hammer travel (lift?) higher reg pressure?
Which do you think would matter the most?
- Rod
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That would make a LARGE hole in a varmint.
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I love these EUREKA moments. Great job gentlemen.
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The 70 gr. BBT hit 900 fps at 2900 psi with the 25" barrel operating at the knee of the curve (ie relatively efficiently).... and 940 WFO.... so it's already within the capability of the Grizzly, not just in regulated form with the 25" barrel.... Barrel length and pressure are pretty much interchangeable, so in theory, a barrel length of (2900/2200) x 25" = 33" should be able to deliver ~ 900 fps relatively efficiently at 2200 psi.... *listen to that man singing*....
Porting and hammer changes will not be necessary for your build, although you will need a bit more preload to extend the dwell slightly to take advantage of the longer barrel.... There will be TONS of hammer strike available, IMO.... The air tube (plenum) being longer to support the greater FPE won't hurt, of course.... the one on the Grizzly is ideal at ~ 100 FPE....
Bob
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I took the gun apart to chase down the leaks I had this afternoon.... When I was fitting the tube to the receiver, I decided to mount the stock using the lower screw hole in the valve.... That meant drilling a hole through the inner tube at that location, and I didn't think about that being between the two O-rings either side of the exhaust port.... When the gun was fired, some of the air travelled down between the valve and tube and blasted out the bottom.... My solution was to drill and tap the bottom hole of the valve to 1/4"-28 and use a shortened 1/4" bolt fitted with an O-ring as a plug.... The receiver is drilled out to 3/8" for the OD of the O-ring, which flattens against the tube when the bolt is tightened against the bottom of the receiver.... I blind drilled and tapped the center of the plug for an 8-32 screw which will mount the stock.... I think stalwart has an alternative stock mount planned so that he doesn't drill the tube at the bottom between the O-rings.... One of the little things that prototyping teaches you....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Stock%20Mount_zpsuvhgk6pw.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Stock%20Mount_zpsuvhgk6pw.jpg.html)
I shortened the spring guide by an inch as well, so that when the gun is cocked it won't hit the stock.... I can no longer use it to measure valve lift, but that part of the research is done now, so the spring guide just serves it's main purpose, and acts as a cocking indicator when the gun is out of the stock.... It is now 4 grams lighter, so the total weight of the hammer plus guide is now 102 grams....
The last job for today was to clean and glue the tube into the receiver with some silicone sealer around the transfer port.... This shouldn't be too hard to remove if I need to take it apart, and hopefully will seal up the leak around the magazine.... I'll let it dry overnight.... and hopefully tomorrow I won't have air blasting out on every shot.... except out the barrel, of course....
Bob
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A month or more ago I was working with a 60 valve that had a bad valve stem seal. The pic shows how I fixed it with a -.006 o-ring. With the Delrin washer in place holding the o-ring the backer block keeps both from blowing out.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3769_zpse23ac466.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3769_zpse23ac466.jpg.html)
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The 70 gr. BBT hit 900 fps at 2900 psi with the 25" barrel operating at the knee of the curve (ie relatively efficiently).... and 940 WFO.... so it's already within the capability of the Grizzly, not just in regulated form with the 25" barrel.... Barrel length and pressure are pretty much interchangeable, so in theory, a barrel length of (2900/2200) x 25" = 33" should be able to deliver ~ 900 fps relatively efficiently at 2200 psi.... *listen to that man singing*....
Porting and hammer changes will not be necessary for your build, although you will need a bit more preload to extend the dwell slightly to take advantage of the longer barrel.... There will be TONS of hammer strike available, IMO.... The air tube (plenum) being longer to support the greater FPE won't hurt, of course.... the one on the Grizzly is ideal at ~ 100 FPE....
Bob
THANKS again!
Now, where can I get a PEEK Mrod poppet/stem?
;)
-Rod
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You don't need one.... PEEK is only needed when the combination of diameter and pressure exceeds the ability of the MRod poppet not to extrude through the throat of the valve.... We aren't there yet, nor do we need to be.... A PEEK valve is slightly easier to open because it is harder to compress.... but when used in an application that doesn't require it, it is more difficult to get to seal....
Bob
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I think stalwart has an alternative stock mount planned so that he doesn't drill the tube at the bottom between the O-rings.... One of the little things that prototyping teaches you....
I do. For the tankers, I'll be making a very similar set up (unsealed, of course), for the block. It will be shouldered, and act as a back up, as well as take the standard 5mm for stock mounting. I can't think of an easier option... and always try to avoid custom or rare hardware, when quality can be maintained... but the tanks give me no apparent options. Extended double tube set ups will use this, as a R tube mount. Single tubes will simply have a 3rd screw installed in that identical hole. This only generates 1 more part#, to cover all options in reservoirs.
I ordered a complete assortment of the screws, in bulk, of as high a grade as they sell. I'll be including full kits with any rifles done from now on. This included the 6mm long trigger group mount screws to allow stroking (recessing the F mount nut), without taking that mm or so off the end of a stocker, for clearance.
What are our options in a larger dia lower tube? I keep thinking that a fat 4.5K lower, with an inline reg to 3K max supplying the full length plenum, would really make these breath. A long time ago, I came across a thread discussing inlines... what's state of the art now?
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No idea, I'm not a fan of inline regulators, because of the plenum problem for any kind of real power.... Once you talk about running one reservoir, then a regulator, feeding a large plenum, you're talking my language.... The simplest way is to use the piston from a Ninja regulator and build a housing for it.... it can be in one of the tubes, or in the vertical portion of my tank block, take your pick.... As far as the commercially available inline regs., I know nothing about them....
If you use a lower tube that is larger than the upper, inletting the stock becomes problematic.... and in fact housing both tubes IN a stock ultimately becomes an issue.... Fat 4.5K tubes require significant engineering for the end caps.... and pretty soon you're looking at Titanium for the tube to save weight as they get heavy in a hurry.... I can't help but wonder how far it makes sense to go in that direction.... I becomes a matter of clearly defining a goal first, IMO.... for you, a marketable and profitable one....
Bob
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I'm just in awe trying to follow and keep up with what you guys are doing in this thread.
I keep telling myself that one of these days, I'm going to need to go back and read it all over from the beginning. Then I'll try to pick and choose what level I may eventually want to take mine to... but with the constant development you guys are doing, I keep waiting for the "end goal" to come.
I think this thread needs to get re-named as a parody to the movie "How to Train Your Dragon (part 10)" LOL!
Keep up the fantastic work guys !
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Keep up the fantastic work guys !
Thanks! Bet on it, Ron.
No idea, I'm not a fan of inline regulators, because of the plenum problem for any kind of real power.... Once you talk about running one reservoir, then a regulator, feeding a large plenum, you're talking my language.... The simplest way is to use the piston from a Ninja regulator and build a housing for it.... it can be in one of the tubes, or in the vertical portion of my tank block, take your pick.... As far as the commercially available inline regs., I know nothing about them....
If you use a lower tube that is larger than the upper, inletting the stock becomes problematic.... and in fact housing both tubes IN a stock ultimately becomes an issue.... Fat 4.5K tubes require significant engineering for the end caps.... and pretty soon you're looking at Titanium for the tube to save weight as they get heavy in a hurry.... I can't help but wonder how far it makes sense to go in that direction.... I becomes a matter of clearly defining a goal first, IMO.... for you, a marketable and profitable one....
Bob
The stock is no problem. A lot more familiar area for me. I've worked out a design I think you'll really like. ;D
As you have known for a long time, a true .22LR equivalent was my goal all along (they'll sell here, close=no cigar.), and I want to go 9mm for the next step. I think a big double is the way to go. Hanging that tank, reversed, at the end of a longer plenum is not an option. It would finish off the damage we have already done to the gun's (beloved, at least here) balance.
It's gotta happen, Bob.
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What if you were to combine the double tube with the tank? So there would be two shorter tubes stacked with a three way connection. Like a wye connection. Having the regulator and tank in front of the double tubes. This way the tank can sit higher and would be able to fit a stock. Or would there to much restriction of flow from one tube to the other? Anyways its just a thought.
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It's good thinking. Anything to pull some weight back. Bob can answer best, but I believe the transfer wye would have to be pretty large, to act as a plenum. Be nice if it doesn't! I'd love to get a look at Xisico's double tube (side by side) 60, apart.
I'm thinking of extending the lower tube all the way back to the block screw, and mounting it there. A 27" steel tube, 7/8" dia, weighs 3oz more than a bare 22ci tank. Figure in internal reg vs. reverse block... 1" tube (1-1/4?)... and it should be, at least somewhat, better balanced and better protected (reg). We're not done yet! ;D
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Made this a while back... turns nickle plated grommets into a nice way to keep screws from digging into the stock.
Every hardware kit will get one of these.
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Just looked into titanium tube... Will the same dimensions work with the pressures?
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.22LR replacement? As in 100ftlbs for the subsonics?
(http://i.imgur.com/Jj5117j.jpg)
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Yup.
;D
Bob figures 118 with a 7/8" double @ 3K, with no other changes. A full mag.
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I've got it covered, with the Windowsill Cannon's (and its tube's) extreme length - thus standard (7/8") OD throughtube receiver, plugs etc.
Now I'm just concerned with adding enough valve dwell to fill half that long barrel, without having it too hard to cock (hence the PEEK musing.)
Rod
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PEEK is .... more difficult to get to seal....
Bob
Wouldn't lapping it fix that?
Rod
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BTW - has anyone sourced a 4K3(-5) psi 2" bottle yet?
stalwart, I'm also wondering what is the difference between a 3K and a 4.5K throughtube...
(and no answering, "1.5K..." ;)
Rod
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ChroMoly tube, (3) 1/4"-28 backing screws. Everything else the same... Production 3Ks will probably just be 4.5Ks too. Less part #s.
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Don't forget, the pellet doesn't spend much time going from the 12" point to the 20" point in a (40") barrel, so the increase in the required dwell is no where near in proportion to the barrel length increase.... In fact, according to Lloyd's spreadsheet, if you put a 40" barrel on my Grizzly, with no change in dwell, those 70 gr. BBT's would move up from 840 fps to 934 fps (136 FPE).... NO OTHER CHANGES EXCEPT BARREL LENGTH.... Increasing the dwell to the 50% point of that 40" barrel should give 980 fps (150 FPE), and that only requires a 30% increase in dwell.... I can already achieve more dwell than that with my existing hammer and spring....
I think you could make a decent 9mm by using a full length upper tube as a plenum at 3K, regardless of how you feed it to give it more volume.... regulated or not.... 28" barrel would help the numbers....
Bob
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Well pulling the gun apart to chase leaks was worth it.... For the most part I've found them, although I still have one slight puff of air that I think is mostly blow-by from the valve stem.... When I fitted the MRod poppet it was a little loose.... Anyway, I got the gun back together and duplicated yesterday's tests, and there isn't enough difference to even bother changing the graph.... I picked up a few fps per shot on the 45 gr. JSBs, so the efficiency is about 1% better, although I did make a mistake on the ending pressure on the original string with the Daystates, that 1960 psi was after 17 shots, not the full 18, so the efficiency on that string is 1.01 FPE/CI.... I'm actually quite surprised how little difference getting rid of the leaks made to the numbers.... I did gain about 15 fps with all three pellets when I maxed the hammer preload, so the plateau is no longer quite flat, and that was consistent over all the weights.... I'm not sure why that is, but it doesn't matter anyway, because you can't run that much dwell, you are just wasting huge amounts of air.... The interesting thing is that once you tune back to the knee of the curve, the velocity gain with the leaks fixed was only about 5 fps or so.... No idea why the leaks are more siginificant when you are pouring huge amounts of air through the gun, but it is what it is....
I plan to make the barrel band tomorrow.... Oh, I did one other test today, I tried the Daystate 50 gr. pellets with another 1/2 turn of preload.... I gained 20 fps (up from 923 to 943 average), to give me an average of 98 FPE, but lost 5 shots (18 down to 13), and the efficiency dropped from 1.01 FPE/CI down to just 0.82 FPE/CI.... You can sure see how critical it is for efficiency not to run too much hammer strike on a regulated PCP.... I might try a setting in between, that should yield about 96 FPE for 15 shots, with an efficiency of about 0.90 FPE/CI, which I could live with.... The final settings and pellet choice will depend on accuracy, of course.... Accuracy testing will have to wait until the snow around here melts and I can get out to my test range....
Bob
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Here is the finished result....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%2030%20cal%20Repeater_zpssrkehvkl.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%2030%20cal%20Repeater_zpssrkehvkl.jpg.html)
This has been a really fun and satisfying project, from conception nearly a year ago to being able to shoot it this week.... I'm delighted with the way it turned out....
Bob
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Me too...
What's next for it? Gonna get fancy with the finish?
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Thanks for taking the time to share every step of the process. Now I'm just waiting on Eric. :)
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Thanks for taking the time to share every step of the process. Now I'm just waiting on Eric. :)
Tick... tock...
;D
I haven't been taking deposits on new work, as I'm kinda buried in non-AG matters right now... and slowly moving SA into a bigger space.
This doesn't mean we can't start planning something... email me with your thoughts. I'm making progress here... there's a light at the end of the tunnel, I'm just hoping it isn't an oncoming headlight.
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Nah, I'm a boring kinda guy.... I haven't access to powdercoating or anodizing.... and I hate bedliner, much prefer wood.... The stock actually looks great, I matched the stain (walnut, wiped off at the right time).... I'll waterproof the modified areas with a bit of oil and it's good to go.... All my guns end up with unfinished aluminum bits on them, it's kinda my trademark.... Comes from being lazy and no other choice anyway.... *LOL*....
I'm topping up my tanks with the Shoebox today and tomorrow, when my air supply is back up I'll probably try some different hammer springs.... just to see if I can improve the efficiency.... Did you notice the barrel band is done?.... It uses a # 113 O-ring of 70D in a hole just over 3/4" and ends up real tight on the barrel.... Locates it well but allows the gun to move under it with temperature and pressure changes.... I like that system, and my tank blocks are made for it.... The Grizzly looks great on a BiPod, BTW....
Bob
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Thanks for taking the time to share every step of the process. Now I'm just waiting on Eric. :)
Tick... tock...
;D
I haven't been taking deposits on new work, as I'm kinda buried in non-AG matters right now... and slowly moving SA into a bigger space.
This doesn't mean we can't start planning something... email me with your thoughts. I'm making progress here... there's a light at the end of the tunnel, I'm just hoping it isn't an oncoming headlight.
By no means in a rush to see your finish product. Its just a hobby that should be enjoyed with no time lines. I just appreciate your folks for taking the time to share your projects. :)
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The bear is loose!
http://www.airgunhome.com/agforum/viewtopic.php?t=10278 (http://www.airgunhome.com/agforum/viewtopic.php?t=10278)
http://www.airgunforum.ca/forums/topic66732.html (http://www.airgunforum.ca/forums/topic66732.html)
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She's a beauty. My hat is off to the two of you..
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Here is the finished result....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%2030%20cal%20Repeater_zpssrkehvkl.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%2030%20cal%20Repeater_zpssrkehvkl.jpg.html)
This has been a really fun and satisfying project, from conception nearly a year ago to being able to shoot it this week.... I'm delighted with the way it turned out....
Bob
What did you use and how many to fasten your reverse block to the plenum??
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Three 10-32 low profile, high tensile screws with the heads taking the load in the tube.... similar to a Disco valve, but wayyyyy better screws.... Lloyd figures they are easily good for 3500 psi with a 4:1 safety margin, the tube would go bang by then.... When he tested the screws, they didn't shear, they peeled open the pockets in the tube.... Thread and Video in the PCP Gate a while back.... I use this system all the time, my Hayabusa uses it in a 1" CrMoly tube at 3000 psi.... I've tested it at 4000 psi in a 1.125" OD CrMoly tube and the pockets in the tube (and the screws) look like new.... although I wouldn't recommend pushing them that far, the safety margin on the tube pockets is just over 2:1.... just out of fatigue range....
Bob
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Three 10-32 low profile, high tensile screws with the heads taking the load in the tube.... similar to a Disco valve, but wayyyyy better screws.... Lloyd figures they are easily good for 3500 psi with a 4:1 safety margin, the tube would go bang by then.... When he tested the screws, they didn't shear, they peeled open the pockets in the tube.... Thread and Video in the PCP Gate a while back.... I use this system all the time, my Hayabusa uses it in a 1" CrMoly tube at 3000 psi.... I've tested it at 4000 psi in a 1.125" OD CrMoly tube and the pockets in the tube (and the screws) look like new.... although I wouldn't recommend pushing them that far, the safety margin on the tube pockets is just over 2:1.... just out of fatigue range....
Bob
Thanks Bob.
I've been having a ball machining and remachining parts (good practice for a newbie), design changes etal on my Bobcat and I'm throwing around the idea of going away from the 22mm X 1mm nut and going to your system of retention (I have everything needed). Seeings my barrel is fixed and above plenum TDC and the reverse tank is below tube BDC I can not install a screw @ TDC or BDC but can @ 90° from either then the other two screws 120° from there but I just may do that. But I find these decisions to be a great part of the fun.
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So screws at 1, 5, and 9 o-clock?.... perfect !!!.... If the 1 and 5 are too close to the barrel / tube, you can go with 1:30, 4:30 and 9 as well.... or even 4 screws at 90* to each other on the 45's.... Just make sure you have enough room for the 1/8" air passage inside the O-ring and missing all the screw holes with enough meat between everything....
Bob
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So screws at 1, 5, and 9 o-clock?.... perfect !!!.... If the 1 and 5 are too close to the barrel / tube, you can go with 1:30, 4:30 and 9 as well.... or even 4 screws at 90* to each other on the 45's.... Just make sure you have enough room for the 1/8" air passage inside the O-ring and missing all the screw holes with enough meat between everything....
Bob
Yes to 1, 5, and 9 but I'll also check screw accessibility with 4 screws. This will be another good project for practice.
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If 1 and 5 o-clock will work, 1:30 and 4:30 are obviously OK.... Check the room for the 1/8" air passage, you don't want a nasty surprise.... I don't think there is room with four #10 screws, buy maybe with #8s.... Three I have no idea....
Bob
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Guys, some good news... Lloyd (airgunlab) is willing to make up custom double tube kits for me, for the 60s. His barrel band will not fit them, but I have already figured out a nice R mount. It will be stout, and clean.
He does very nice work, and is easy to work with... I'll have something to show you all, very soon.
It just keeps getting better, no?
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Guys, some good news... Lloyd (airgunlab) is willing to make up custom double tube kits for me, for the 60s. His barrel band will not fit them, but I have already figured out a nice R mount. It will be stout, and clean.
He does very nice work, and is easy to work with... I'll have something to show you all, very soon.
It just keeps getting better, no?
YES!!!!
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Perfect setup for an unregulated XS-60c with lots of power that needs lots of air at 3000 psi.... If we assume about the same total volume as my Disco Double (250cc), and since we know that the valve in the Grizzly breathes just as well and we have enough hammer strike to handle it, we can expect similar performance to my DD.... Here are the "best" tunes with that gun, with pellets and bullets, in .25, .30, and .357 cal....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/DiscoDoubleTunes_zpsef65df88.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/DiscoDoubleTunes_zpsef65df88.jpg.html)
I see no reason that a double tube XS-60c with the Grizzly valve and hammer, running at 3000 psi, could not duplicate these strings....
Bob
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What does that Disco weigh?
I ask because the DD weighs in at 6lbs 3oz with the supplied stock, but the weight of the Blaster might be more help than hindrance. For hunting, the balance can sometimes be far more important than total weight, if within reason...
Where does your gun balance?
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The DD Repeater with the Blaster stock balances in the middle of the swell in the foregrip, I find that very comfortable.... It weighs exactly 8 lbs. as shown below....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg.html)
Bob
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Is there a reason 2, 1/4" screws can't be used, or is the loading on the tube the reason for more, smaller screws?
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Two 1/4" screws have plenty of shear strength, but slightly less area for bearing load in the tube than three 10-32s.... still enough, depending on the tube material and pressure, it just changes the safety margin....
I spend the last couple of days repairing my ShoeBox, one of the sprockets on the jackshaft had come loose and the setscrew wore the shaft so I had to make a new one, and then while I had it apart I replaced ALL the O-ring, something I have never done before (not all of them).... I figured it was time, it has over 500 hours on it.... Then I had to refill my tanks, and got back to testing today.... I tried a couple of hammer springs made from 0.055" wire instead of the 0.051", which meant that they went from a slight preload to negative preload (ie they were rattling around loose when uncocked).... This often improves the efficiency by reducing or eliminating hammer bounce, and I wasn't disappointed.... I tried a 3" one, and the adjuster was right at the outer end of it's travel, so I replaced it with an identical spring that was only 2.5" long, which put the adjuster back in the middle of it's travel.... It is quite possible that with that spring, at 3000 psi, I might run out of travel on the spring, but I didn't care as this gun will always be on the regulator from now on, it's 3000 psi testing days are over.... I didn't bother running a complete set of preload curves, as I knew from previous experience that the dwell, and hence the velocity, was the critical thing to find the knee of the curve, so I just played with the preload until I got close to the velocities I had with the original spring, and then fine tuned it to reduce the shot count and increase the power until I got a full two magazines from a 3000 psi fill with the Daystate 49.4 gr. pellets.... I actually ended up with 15 shots averaging 98 FPE, with an ES of only 11 fps, and a big increase in efficiency to 1.10 FPE/CI.... At that setting the 44.8g r. JSBs were a little too close to 1000 fps for my liking, and I only got 13 shots, so I backed the preload down 1/2 turn for those, and got 18 shots averaging 94 FPE at 1.16 FPE/CI.... I could get the 15ish shots I want at the 1/4 turn in between at about 95-96 FPE, but never bothered.... Here are the shot strings....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20New%20Spring_zpsnedk0zgo.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20New%20Spring_zpsnedk0zgo.jpg.html)
I then locked up the hammer spring preload, put the action in the stock, and shot it that way for the first time.... I did two 5-shot groups, as below....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly_zps1a9h4w4g.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly_zps1a9h4w4g.jpg.html)
Now this was only inside my shop at 20', but those are pellets sitting in the holes, and the top one (the Daystates) met the FWB test, you could hold the target vertically and the pellet wouldn't fall out of the hole.... Any time I have a gun that will do that, even at close range, for a 5-shot group, I know I've got a shooter on my hands....
Bob
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The DD Repeater with the Blaster stock balances in the middle of the swell in the foregrip, I find that very comfortable.... It weighs exactly 8 lbs. as shown below....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/IMG_3527_zpsc4058736.jpg.html)
Bob
I would too... that is precisely where I like it. Is the Carnivore (9.3lbs) considered porky, or is that a common weight range?
Would it be easy to space the DD tubes out 2mm? If so, I could fit nearly 3.5" more tube under a 60.
FWB, huh? Until I came to GTA, I would not have thought that possible... Kudos, Bob.
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IMO, the Carnivore is wayyyyyyyyyyyyyy too heavy, I dislike the BT-65 platform (which is all it is), that is why I own an AT-44S Long.... Even so, with a 6-18X scope, mounts, and a folding BiPod it tips the scales at 10 lbs., so it's only my bench gun....
I don't think that would be an issue at all, but it would require a longer front connector between the tubes from Lloyd, so you would have to ask him about that.... He could also program the CNC to make a barrel band with the correct spacing for all three holes, that should be a simple task.... can't hurt to ask.... On the other hand, a gauge under (or on the side of) the receiver might be a good place to mount it, IMO you really need one on the gun, be it regulated or not.... I'm not a fan of counting shots, and not knowing if my gun leaked down since the last time I used it or not.... You could incorporate a gauge block into a front valve half easy enough.... there is enough room for the conical valve spring, against a 1/2" shoulder, and then the forward section with a 3/8" ID stopping flush with the front of the receiver and the gauge mounted in that, either on the side or bottom.... Each valve front would have to be made for the valve rear to get the thread "clocking" right.... but on the other hand, you don't need to use compression of the valve O-ring to get it to seal, an O-ring in a loose groove works just as well.... I have forgotten to tighten the front valve half more than once without leaks, and I did a QB79 where I just used a ring of threads for a front valve half, glued on to form a conventional O-ring groove with no issues.... Or, you could use a separate gauge block and avoid the clocking issues, but that needs two more O-rings....
I never heard of the Feinwerkbau test until about 3 years ago, and I have only done it, inside, with a few guns.... This is the only time I have seen it with a .30 cal.... so I guess that CF sleeved 1/2" TJ's really does work the way Tim showed it could at the Extreme Bench Rest Contest.... I'm PUMPED !!!
Bob
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I can't wait to see this thing shoot at 50-100 yds.
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Out of curiosity I tried a stock hammer spring today.... The recess was not deep enough in the back of the hammer to get enough preload without a spacer on the spring (the spring was too short), but with a 1/4" spacer there was plenty of adjustment to get the gun over 100 FPE at 2200 psi.... I backed off the preload until the velocity was the same as what I had yesterday, and you could hear the brraaapppp of hammer bounce, and the shot count dropped to 12 shots from 15 with the Daystate pellets.... This was not unexpected, as the preload was right around zero, which seems to be the worst place to emphacize that.... So, the gun will work with a stock spring, but is much more efficient with a stiffer spring rattling around loose when uncocked.... When I get some longer, weaker springs in a couple of weeks, I will try those to see if there is any more efficiency hiding it there, as they make the gun easier to cock for the same hammer energy than a short stiff spring....
This fine tuning of a gun that is already working great is always fun, you learn sooooooooooooo much.... and it can help you cure a gun that isn't working the way you want at a later date....
Bob
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I realize that, for you, finding a sweet spot like this isn't voodoo, but it still has to tickle you almost as much as it does me.
A .30 that can be tuned for .22 short power and all the way to .22 LR is a thing of beauty to me. .22 mag is not far off....
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Yes, and when I started a few short years ago, it was a rare airgun that could achieve .22 CB Cap power.... I first did that with a modded Disco in .22 cal and was pretty proud of myself....
Bob
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More tools trickling in... got a reamer to finish fit the side screws in the 3K Bobcat. The screw shown is just pushed in backwards to show fit. Next is bonding, so got a few pics before I hide the work forever... :).
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Is there any real benefit to sleeving a liner with 2024 aluminum as opposed to 6061?
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The modulus of elasticity of 6061 is 10,000 ksi..... For 2024 it is 10,500 ksi.... so 5% stiffer in the same cross section / diameter.... The tensile strengths, however, are vastly different.... Carbon fibre Unidirectional laminate runs about 26,000 ksi, and steel about 29,000 ksi.... Typical carbon tubes are anywhere from 14,000-20,000 depending on the properties (thread direction and density) of the laminate.... Higher modulus carbon fibre is available, at about twice the price.... the pure fibres run 33,000 ksi (standard) to 55,000 ksi (high modulus)....
http://www.gatewaytoairguns.org/GTA/index.php?topic=83050.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=83050.0)
Bob
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More tools trickling in... got a reamer to finish fit the side screws in the 3K Bobcat. The screw shown is just pushed in backwards to show fit. Next is bonding, so got a few pics before I hide the work forever... :).
Lookin good Eric, lookin good.
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Glad you like it, Mike.
It should be a fun piece... I expect this won't (along with one I will be keeping) be the last I end up building.
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Glad you like it, Mike.
It should be a fun piece... I expect this won't (along with one I will be keeping) be the last I end up building.
This is just the beginning. I hope others see the potential that you and Bob pulled out of this $100 gun and belly up to the bar to purchase one, or many, of the various versions offered. I know I'm having a ball with my Bobcat, experimenting and excersing new skills perpetuated by the gusto and willingness to share you and Bob project. I'm lovin it.
P.S. You can keep the other one till it's finished, then please return it to ME. LOL!!!!
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Even though I see none of the experts fiddling with a reverse valve spring valve I whittle on. I am aware of the threaded spring guide and jam nut coming loose plus the forces exterted on the poppet (the poppet and valve stem are threaded) but there's just something intriguing about the design I wish to, well say, whittle on. With that said I ask for help.
The specific problem I'm running into is, things are not concentric and the Delrin spring guide nut and jam nut touch the non concentric I.D. of the OEM backer block. With that said I made a new backer block out of 6061 and the same interference is occuring. So heare comes my deduction. I need a sring of smaller O.D. with the same spring rate as the 60 spring. The 60 spring is .035 WD, 325 O.D., .826 L. With the pics I provide and my request for a smaller O.D. spring (a new threaded guide nut and jam nut) what do ya'll think? P.S. I'm not familiar with springs and or selecting them.
With the pics shown below and what I've written above with please disect and throw some engineering speak in layman terms at me.
Please note the jam nut was introduced after this pic. The valve is an rsterne Maxi Valve.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3684_zps83f5ddd5.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3684_zps83f5ddd5.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/IMG_3769_zpse23ac466.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/IMG_3769_zpse23ac466.jpg.html)
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Quite common in custom builds. I think the reason it is not seen as much when modding existing platforms is due to the possible infringement on hammer stroke which seems to be at a premium in most designs.
Tom
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Here is a Spring Calculator.... http://www.msdspring.com/SpringCalculator%5CDefault.asp (http://www.msdspring.com/SpringCalculator%5CDefault.asp)
Put in the specs on your spring and get the spring rate for it.... Then put in the smaller OD you want, and reduce with the wire size until you end up with the same spring rate.... Once you find a range of specifications that appear to meet your requirements, then put those into the Century Spring search tool at....
http://www.centuryspring.com/Products/compression.php (http://www.centuryspring.com/Products/compression.php)
See what common spring size from their catalogue might work for you, write down the dimensions, and take your calipers to the nearest hardward store and go looking.... Alternately, if you have a spring about the right stiffness (spring rate), put it, and your existing XS spring on a rod (to keep them lined up) and push them towards each other.... If they collapse at the same rate, they are the same stiffness.... Overall, a 20% change in rate either way probably won't matter....
Bob
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Quite common in custom builds. I think the reason it is not seen as much when modding existing platforms is due to the possible infringement on hammer stroke which seems to be at a premium in most designs.
Tom
Ahhhhh! Now I see. If I wish to increase hammer stroke the spring etal will be in the way. Thanks!!
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Thanks Bob. I'm going to the site immediately after this post. With what Tom pointed out is there enough stroke with my setup to throw some 25gr pellets??
P.S. I've been going back and rereading this thread (I'm up to pg 27) and setting me up a Words of Wisdom condensed tutorial, PCPs in general plus reference to the 60 mods. After a while I was finding things running together in my forever busy head and I thought it was time to get organized. I hope this works. LOL!!
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Depends on the caliber.... Are you going to lose stroke, or can you still drive the end of the stem to flush on the backing block (and is that point in the same place)?.... Does the end of the new stem sit further back from the backing block when the valve is closed?.... The former governs how far the valve opens, and the latter governs the hammer stroke before contact, which governs the hammer energy and momentum.... Have you done anything at the other end to increase the hammer stroke, like I did in the Grizzly?.... Lots of ways to ruin a good plan, like anything else every mods means (at least) two more, most of the time....
Bob
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Bob the air rifle is a Bobcat with a fixed .22 60 barrel (it's a good barrel). What I did today was get prepared for a possible possible increase in stroke. First it has to breath, I think.
I cut enough of the threaded end off the aluminum cylinder to leave enough threads for the valve body to tighten down the o-ring + 2 threads. Here's some dimensions, intake port = .203", exhaust port = .190", barrel port = .168", Delrin poppet = .307, valve throat = .438" and the stem protrusion above the baker block is .377 (backer block .630" length) so I have stem to cut to length. I had planned work on more stroke since this 60 is my platform to play with the knowledge shared by the GTA mentors, plus I'm learning about machining to boot. This stuff is addictive, thanks.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/Valve%201_zpsbyjvj34a.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/Valve%201_zpsbyjvj34a.jpg.html)
This distorted out of focus pic shows how I can't take pictures!! LOL!! What it's supposed to represent is how I beveled and polished the concave end of the slot all the way to the valve throat. I did lightly bevel the throat mouth but it could use a little more.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/bottom%20of%20valve%201_zpsxcikox5z.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/bottom%20of%20valve%201_zpsxcikox5z.jpg.html)
This pic is the valve tester I use. Screw the nut off the bottom of the tube, slip the bottom in first, stem sticking out, put the nut on and pump it up. I might add after lightly lapping the poppet on a lapping block I made this valve holds air.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/valve%20tester_zps7x1tzjdj.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/valve%20tester_zps7x1tzjdj.jpg.html)
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Your stem in the top photo sticks out further than normal, which reduces the hammer travel before impact.... It will allow more maximum lift before the hammer hits the backing block, but you are unlikely to need more than 1/8" anyway.... I only allowed 0.200" on the Grizzly, and it uses about 0.070-0.080" when properly tuned.... I would cut off half the protrusion of the valve stem, even then you are losing hammer stroke....
I don't see how you could drill the throat of the valve out to 0.438", or why you would, that just increases the sealing area and the force to drive it off the seat.... I note that you say the poppet is 0.307", so that makes no sense anyway....
Bob
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Yes the stem is way too long for a reason. The first stem I made was way to short! LOL!!
My plans were to cut it down to between .110" and .125". But a question arises for me with lift. Will the lift change with various pressures?
Terminology is the key, and I don't have the key, yet. The area the poppet rides on I called intake port and that area hasn't been changed so the hole is .203" and upon the seat rides the .307" poppet.
The area I called throat the threads reside on the otherside thus the .438", so please correct my terminology. I felt I shouldn't increase that area because of the tension of the spring. The only way I figured to increase that area without machining was to decrease the size of the poppet. I could probable machine a wee bit more off the poppet but I thought a larger ledge for the valve spring to ride on would be prudent.
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What you call the intake port is the throat.... The area surrounding the head of the poppet (0.438") is the ID of the valve body.... That area, minus the diameter (area) of the poppet head can restrict the flow but usually doesn't, it is more a matter of the two 90* bends it causes at the seat.... I enlarged that to 0.50" on the Grizzly, as well as using an MRod poppet which is 0.33" diameter to get as much flow as possible to the seat of the valve, but the main restriction is the throat and ports areas.... I like to see lots of area on the inlet side of the seat (into the valve, and around the poppet head) so that any calculations made on port areas on the exhaust side are accurate, and not influenced by the intake side....
I am confused by your photos and description.... Have you moved the spring to sit on the stem, or is it still inside the valve?.... If it is on the stem, you can eliminate all of the aluminum inlet side expect a couple of threads to locate the O-ring, and that doesn't need to be compressed, it can just sit in a groove.... Here is a QB79 valve I did like that....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3578_zps463d6db8.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3578_zps463d6db8.jpg.html) (http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3581_zps43eaa031.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3581_zps43eaa031.jpg.html)
The spring and mount shown in the 2nd photo mount on the tank block in the QB79, they would be missing if they were on the other end on the stem of the poppet, of course.... The threaded aluminum ring is glued in place on the brass valve body, with just clearance for the O-ring.... The pressure forces it to seal just fine....
The lift does indeed increase as the pressure decreases in an unregulated PCP.... However, when the hammer strike is properly adjusted for the pressure you are running at, the lift will almost certainly be less than 0.100".... In the Grizzly, at 100 FPE with a 0.266" throat, it is only 0.070" with pellets and 0.080" with bullets....
Bob
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If you'll look back in this thread I've made a reverse valve spring version of your maxi valve but found out it's not the best valve to use on a 60. I was having problems with the spring/ spring guide and jam nut touching the I.D. of the backer block tilting the valve face from the seat and causing an air leak. If I increased the backer block I.D. large enough to eliminate the interfernce the nose of the 60 striker would beat itself into the new I.D. changing lift and eventually jamming the nose into the blocker hole. This reverse valve spring design will work great with a flat face striker.
The light bulb of valve design change also came on when QVTom mentioned using the reverse spring valve and working with stroke. If I wish to effectively increase stroke, as you and stalwart have, in my Bobcat I had to use a valve with the spring on the intake side of the valve. Now if I need to increase stroke I'm ready, but I'll wait and see if the stock stroke works with this new valve. As mentioned I would like to drive .22 up to 25gr from this Bobcat eventually settling for a specific pellet and weight.
Thanks for the terminology correctiion(s) plus your tutorials I'm learning a lot. I didn't dare open up the I.D. of the valve body as I thought I might get too close to the threads. The O.D. of the poppet is the same size as the O.D. of the valve spring as I didn't want to loose too much poppet ledge (support for the spring) to support the spring under compression.
Thanks for the lift analogy, but I have another question. You have a conical spring in your Grizzly valve, another stroke of genius, does the spring mimic the 60 spring rate which comes to 20.43 lbs per http://www.msdspring.com/SpringCalculator%5CDefault.asp (http://www.msdspring.com/SpringCalculator%5CDefault.asp) . I would assume the valve spring rate is
a big factor in determining lift and dwell. I'm starting to put all the pieces together and feel I'm getting close to using math, maybe. :D
P.S. In addition the second pic is looking at the bottom of the first pic.
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I didn't worry about the spring rate too much, I adjusted the preload to get to about 7 lbs. of force on the seat, which is about what the stock 60c valve and the Disco valve use.... The spring force is a minor part of the closing force on the poppet, most of it comes from the air pressure pushing on the area of the valve stem, which penetrates the valve body.... When the valve is open, it has full air pressure on one side and only 15 psi on the other.... At 2000 psi, the closing force on a 1/8" stem is ~25 lbs.... There is also a small closing force from the drag of the air moving around the head of the poppet (creating a small pressure differential across it).... The spring will be less than 20% of the total closing force....
Bob
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Thanks Bob, this puts the know in knowledge. There's more to these airguns than just filling them with air and shooting pellets.
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Lloyd showed me how to put a gap between the DD tubes... giving us the option of running the lower tube to the end of the receiver (no gap), or all the way back to the trigger guard (2.5mm gap).
The latter will take much more stock work (or inletting a custom)... but will be good for another 4.5"+ of reservoir.
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I'd ask Norm if he can inlet the Blaster 2.5mm deeper without a custom inletting setup required....
Bob
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How sweet would that be?
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If you'll look back in this thread I've made a reverse valve spring version of your maxi valve but found out it's not the best valve to use on a 60. I was having problems with the spring/ spring guide and jam nut touching the I.D. of the backer block tilting the valve face from the seat and causing an air leak. If I increased the backer block I.D. large enough to eliminate the interfernce the nose of the 60 striker would beat itself into the new I.D. changing lift and eventually jamming the nose into the blocker hole. This reverse valve spring design will work great with a flat face striker.
I wonder if that's what the Cothran valve does? - somehow create a reduced-friction, channeled piston that provides ALIGNED valve return (and controlled dwell?) somewhere outside the pressurized air intake path?
Just wondering... controlled (but noninterfering) dwell would be sort of a holy grail, though it was implemented in the earliest airguns, to rumored great effect, as we've all read, by interfering with the hammer stroke..
Rod
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Rod, I'm not sure how it works. There was a theory posted on the Canadian forum, but it is just that.
Is anyone else getting sporadic results from the notification feature here?
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Guys, I just got a dealer inquiry from the UK... and I have never shipped anything there.
Are there any pitfalls I should look out for? Is there a shipper who is demonstrably better to use (or one I should avoid)? Any hints for making the process smoother?
TIA!
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Legal, would be at the top of my list.
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Under 12 FPE if the customer doesn't have an FAC, and under 6 FPE for pistols.... but that's likely the dealer's problem to sort out.... No suggestions as to method of shipping.... Air Mail may be the cheapest without taking 2 months.... I think most eBay from the UK comes that way....
Bob
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Likely USPS airmail is the cheapest. You will need to fill out a customs form.
Legal issues should not be a problem for you, but for the dealers. Assuming you fill out the customs forms accurately.
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I'm sorry to see this thread moved to the PCP Gate, as it will soon disappear from the front page and be lost.... I see no reason it couldn't have been left in the Chinese Gate.... JMO....
Bob
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Thanks for the input, guys! USPS is the easiest for me, so I'm glad to hear this.
Bob, I don't get why this was moved, either... after nearly 48K views. Will this affect the ability of non members to find it when searching?
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Objections duly noted.
We have been doing a lot of overdue house cleaning lately. This is a PCP thread and belongs in the PCP gate. I support our moderators for the move.
Yes, it has almost 48K views. That is fantastic. WHERE it resides on GTA should make no difference in a search. The results will follow the search.
And as far as being buried? Not if interest remains and folks post to it. The thread, just as any on this forum, will stay on the front page as long as it is posted to routinely.
We could sticky it if it warrants such an action. But sticky's are mainly pertaining to as subject of interest to ALL watchers of that particular gate. I don't see moving it to the Chinese Gate as doing any justice to this thread myself.
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Dave, I honestly don't know enough about how this all works to object to anything yet. I was curious... but, I did enjoy being able to find it quickly.
It has sat on top of google for a long time... and as I don't use images hosted by others, it requires anyone really interested to join GTA to get the full scoop. Again, I don't know for sure, but I thought that was a good thing.
Will this move effect the standing on google?
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WHERE it resides on GTA should make no difference in a search. The results will follow the search.
Until I can see differently.....this statement should have covered it. Certainly is no intent to "BURY" such a good topic. Just putting it where it belongs.
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Ok, so you meant an internet search, not just a GTA search. I wasn't sure.
As it is now clear that this belonged in the "Dark Side" all along, can I expect a shipment of cookies soon? I am lift gate ready here, and a dock is just around the corner.
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FYI
I just did a Google Search of XS60C Repeater. Top result was to Stalwart Arms. Second was THIS thread. I think we are good to go.
:)
https://www.google.com/search?q=XS60C+Repeater (https://www.google.com/search?q=XS60C+Repeater)
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LOL... and your post just pushed it back over SA.
It's a VERY small pond...
;D
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LOL
See...no harm no foul. But house cleaning accomplished too.
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To whoever put SA.com in the links section of my posts... thanks! It should have been there all along.
Alright! The house is clean! Call your friends... it's time for a party! BYOB, and no smoking inside...
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Eric, I did that. I was trying to find a way to display it without plastering it all over the place.
Think this works.
:)
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Works for me! ;D
Thanks, man.
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;D Thanks Dave I guess I shouldn't second guess myself
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And it's up to 51 pages and counting... that's a LOT of reading for anyone who wants to get caught up from the beginning and is just coming to the party! :)
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Time for a Cliff's Notes version?
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Funny.... I was just going to inquire about that. Maybe a "in a nutshell" update as to where the project started thru where you are today? And , if possible/available, some prices if someone wanted to buy a repeater upgrade for the XS60C in either caliber.
Thanks
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Bill, I think you're right. I've been thinking of upgrading my site (it needs it, badly), and doing a few in depth looks at some of my work. I'm sure something could be done that could also be placed here for people who need some info, or inspiration. I'd love to see this thread then revert to a more open and relaxed place guys can drop into and share ideas and gripes. I miss that, it has inspired some fun work here.
The issues are: Time, and my incompetence with both a camera and the English language as applied with a keyboard. As I have mentioned, typing is a slow process, and uncomfortable for me. I have thought about doing a few vids, but I have no experience in filming or editing... and have never tried recording myself.
I am not only open to suggestion here, I'm more than willing to compensate someone to further either goal. I have some things cooking, in both the rifles and the pistols, that I'm dying to get back to work on.... but, as the move to bigger digs had to be done long before I wanted to do it (the perfect space came up, and it came to signing a lease or watching it vanish), I am buried in tasks I had hoped to finish before tearing SA down. I planned for the disruption as soon as I saw it coming, and adjusted the work load accordingly, so this is not a problem that threatens anything... But, dang it... I have some fun stuff simmering, and want to turn up the gas on a bunch of it. ;D I am also working on a very high performance mobility device (for paras, and weebles like me) that has elicited that "why didn't I think of that" response from those who have seen the skeleton (I say that all the time, it's nice to hear it!). I have a customer for the first one who is becoming impatient ...me.
As to prices and product offerings, I have to be very careful here, as I'm not a Vendor yet... and the added responsibility of maintaining another informative thread and providing customer service in a public setting (while answering general questions from others that naturally arise in that setting) is something I cannot do properly atm. I'll go all Green V when I'm sure I can do it right. For the near future, everything will remain "Price On Request"... and, with the exception of some upgrade parts, will remain custom work.
Again, I'm open to ideas here... input is most appreciated. Couldn't have done any of this without GTA...
:)
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Eric;
I can appreciate all you just said. We recently made the "big move" ourselves. I'm sure it wasn't as involved as yours. I didn't have a business to move. Not sure if you are aware of or have posted but, Dave and the rest of the staff have revamped the classified gates. Essentially splitting them into three sections including one for (pardon the reference) Hobbyists. You might find it useful to get some of your stuff out there if you so desire. (hope I'm not peeing over the wrong waterfall) Just a suggestion. I completely failed to consider your website as a source of information. Anyhow, congrats on the move and thanks to you and the others that post this wealth of knowledge and understanding in threads like this one.
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Bill, I think you're right. I've been thinking of upgrading my site (it needs it, badly), and doing a few in depth looks at some of my work. I'm sure something could be done that could also be placed here for people who need some info, or inspiration. I'd love to see this thread then revert to a more open and relaxed place guys can drop into and share ideas and gripes. I miss that, it has inspired some fun work here.
The issues are: Time, and my incompetence with both a camera and the English language as applied with a keyboard. As I have mentioned, typing is a slow process, and uncomfortable for me. I have thought about doing a few vids, but I have no experience in filming or editing... and have never tried recording myself.
I am not only open to suggestion here, I'm more than willing to compensate someone to further either goal. I have some things cooking, in both the rifles and the pistols, that I'm dying to get back to work on.... but, as the move to bigger digs had to be done long before I wanted to do it (the perfect space came up, and it came to signing a lease or watching it vanish), I am buried in tasks I had hoped to finish before tearing SA down. I planned for the disruption as soon as I saw it coming, and adjusted the work load accordingly, so this is not a problem that threatens anything... But, dang it... I have some fun stuff simmering, and want to turn up the gas on a bunch of it. ;D I am also working on a very high performance mobility device (for paras, and weebles like me) that has elicited that "why didn't I think of that" response from those who have seen the skeleton (I say that all the time, it's nice to hear it!). I have a customer for the first one who is becoming impatient ...me.
As to prices and product offerings, I have to be very careful here, as I'm not a Vendor yet... and the added responsibility of maintaining another informative thread and providing customer service in a public setting (while answering general questions from others that naturally arise in that setting) is something I cannot do properly atm. I'll go all Green V when I'm sure I can do it right. For the near future, everything will remain "Price On Request"... and, with the exception of some upgrade parts, will remain custom work.
Again, I'm open to ideas here... input is most appreciated. Couldn't have done any of this without GTA...
:)
I am an IT guy by trade and education, perhaps we should talk :)
Fixing up your website sounds like fun to me, uh I meant very hard work that would have to be well compensated.
I type all day and shoot all night.
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It would be a
fun grueling task... ;D
Drop me a line, Steve.
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Eric;
I can appreciate all you just said. We recently made the "big move" ourselves. I'm sure it wasn't as involved as yours. I didn't have a business to move. Not sure if you are aware of or have posted but, Dave and the rest of the staff have revamped the classified gates. Essentially splitting them into three sections including one for (pardon the reference) Hobbyists. You might find it useful to get some of your stuff out there if you so desire. (hope I'm not peeing over the wrong waterfall) Just a suggestion. I completely failed to consider your website as a source of information. Anyhow, congrats on the move and thanks to you and the others that post this wealth of knowledge and understanding in threads like this one.
Great idea! Thanks, Bill. I was not aware of the changes, and am quite impressed with what the staff has done there.
Not only does the hobbyist gate fit me to a T, it will be the first place I look for stuff. It is also a great place to watch protos turn into bleeding edge product.
I submit GTA has no peers.
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Now that I have my Freedom 8 up and running, and have a source of air, I finally got around to testing the Grizzly with a longer, softer hammer spring.... It was no problem getting the same performance as with the previous setup, but you could hear the hammer bounce and the efficiency was a lot less, something like 10 shots instead of 14.... I still haven't found anything better than the 2.5" long x 0.055" wire spring set up with free play, so that when the gun is uncocked it is rattling around loose (no preload)....
Bob
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I finally got a chance to let the Grizzly stretch it's legs today.... It was one ragged hole to groups you could cover with a quarter at 50 yards with both types of pellets tried, and at 100 yards there was a noticeable difference between the Daystate 50 gr. and FX 45 gr. pellets, with the FX performing slightly better.... Here is a 5 shot group from the bench at 100 yards, 970 fps.... Small squares are 1/2", large black squares are 2"....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20FX%20100%20yd001_zpsstcgntfc.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20FX%20100%20yd001_zpsstcgntfc.jpg.html)
It measures 1.30" C-T-C, so I'm very pleased.... It has the same trajectory, and the same scope (Hawke 3-12 x 44 SF) as my 2260 and 2560 HPA Varmint rifles, and is sighted in the same, all three being zeroed at 35 yards.... The POI is about 1 MilDot low at 50 yards, 2.5 Dots low at 75 yards, and the aim point is the top of the post (5 Dots low) at 100 yards on all three rifles, at 12X.... so I will be able to switch between rifles depending on the size of the quarry.... I'm really looking forward to introducing the Grizzly to Mr. Marmot in the near future....
Bob
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Nice shooting!
This whole project has been a fun education for me... can't wait to see what Mr. Marmot learns from it.
:)
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I think Mr. Marmot is gonna have a headache,... (but only for a second)
looking good Bob !
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.30 cal Grizzly Meets Mr. Marmot....
http://www.gatewaytoairguns.org/GTA/index.php?topic=89969.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=89969.0)
Bob
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Bob, those pics say it all. Good work, good shooting, and good info. A good day all around!
how close is the i.d in that tube compared to the discos
Same ID as the disco.
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I unearthed this today. I bought it in a boneyard sale, quite a while ago, as a non-functioning airsoft gun.
It's ABS, and rather stout (especially for it's weight). There is enough room inside for all the lasers, lights, etc. anyone could ever want. In the butt, there is already a battery mount. The butt and cheek adjust.
Here's a look at where it's headed, when time permits:
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Ooooooh... I feel a new thread coming on...
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Ooooooh... I feel a new thread coming on...
This one will just be for our general amusement. I'm thinking CO2, and if the basic fit is decent, I'll start adding gadgets just for fun. Modeling plastic has been a pastime for me since the mid 60's... I had better be able to do a passable job. :)
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Well guys, it appears the Umarex Fusion is holding it's value in the market. Been out for quite a while, and hasn't seen a penny in discounts. They're selling. Good news for me... except for today.
Anyone feel like seeing what can be done to them? I do... so I just ordered one from Pyramyd.
As a Gen2, they have the trigger safety, and lack the Gen1's rear bolt retention device. This one will get a G1 metal trigger group, and rely on the G-slot mod for positive bolt retention and safety.
I have never done a trigger job on the G2s, but others have said it can't be made quite as nice as the G1. I prefer metal to plastic, so that's 2 strikes...
What do you think? Time for the Ultimate Fusion?
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Well guys, it appears the Umarex Fusion is holding it's value in the market. Been out for quite a while, and hasn't seen a penny in discounts. They're selling. Good news for me... except for today.
Anyone feel like seeing what can be done to them? I do... so I just ordered one from Pyramyd.
As a Gen2, they have the trigger safety, and lack the Gen1's rear bolt retention device. This one will get a G1 metal trigger group, and rely on the G-slot mod for positive bolt retention and safety.
I have never done a trigger job on the G2s, but others have said it can't be made quite as nice as the G1. I prefer metal to plastic, so that's 2 strikes...
What do you think? Time for the Ultimate Fusion?
I ordered my GENII XS/FD with 'no plastic' (and no safety) so I can't say for sure, but I thought I read the only plastic in the (FD) trigger group was the the cover and the little triangular backstop (the latter, an oversight which had to be retrofit on mine, but which was enthusiastically corrected by Mike. So he may be able to supply you with metal parts. He also upgraded my plastic GENII valve stop block with a steel one.)
There are people here with Fusions, and some with GENII FD's, so I'm sure you'll get a definite answer soon.
Rod
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I'm very interested in comparing tolerances. My first 60 is G2, and the bolt fit better, even before the Teflon coating.
I'll note, here, any differences I find.
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It's pretty clear (other threads) how much I like the G1's safety design (direct striker lock), and the ability to tune it to fine operation. This is the only thing I change about it, as I don't like auto safeties.
Cutting this tab off is all it takes:
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I thought the G1 safety was not safe? I heard Mike removed them since if you fired it with the safety on, it would go off as soon as the safety was disabled.
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I believe misunderstanding of the reason for the trigger group adjustability (fore and aft) may be responsible for the widely held belief that the designers messed up on the safety.
That adjustment is meant to allow adjusting the clearance on the sear to prevent the binding that causes the problems so many have with these.
If you look into the inspection port that shows the sear engagement, and adjust the fore and aft of the group, you will see that when the clearance is just enough for the safety to work properly, the striker does not have to travel far (a few thou) to engage the sear... and there is no loud (and HARD) click.
If you adjust this clearance properly, and then rely on preload adjustments, springs, or spacers to get the striker force you seek... you get to keep the safety. If too much slop is left, the trigger will transfer the striker to the safety's hook, too far for the sear to re-engage it. IT WILL THEN FIRE WHEN THE SAFETY IS DISENGAGED.
It is an unusual design, and frankly (IMO) a very clever one. It allows good critical function tolerances to be had, without critical machining tolerances (spelled $$$) being needed.
I set mine up with just enough clearance, and when my safety transfers the striker to the sear, I have a solid click... and nothing more... and the safety can be re-engaged (pulling the striker back off of the sear). There is a good reason the safety lever is stout, and thumb operated... it's so you can pull the striker back a few thou when engaging it while the gun is cocked. The Teflon striker mod makes that pull VERY smooth.
The .01" sear clearance (seen in the little window) is all that's needed to make sure pulling the trigger doesn't cause it to bind and stay in the pulled position, making the safety into a trigger.
If, with the safety on, you can pull the trigger, without the striker moving... and releasing it allows the sear to re-engage (watch in the window), your gun is performing as designed.
A maladjusted G1 is a danger to some... and I can understand why the striker locking type was abandoned. Properly fitted and adjusted, the safety is stout and positive.
BTW... I have come across guns that would need the R slot in the trigger housing elongated (forward) to get the proper clearance. A more involved option is to deepen the hook on the safety's pawl, or relieve the striker's engagement face... or both. I cheat, and reach into a parts bin to find stuff that fits. I submit it wasn't the designer's fault, but the production tolerances that made this design so hit and miss.
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Darn good analysis! As usual.
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Thank you, sir!
I plan to do a tutorial on all this, for the site. The G1s will eventually be left behind by the market... but never in my heart. ;)
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I should mention something I really like about removing the auto safety feature: When you cock a stocker with the safety on, it releases the safety, then immediately applies it again. With that tab gone, any time you cock the gun, it becomes ready to fire. As I use safeties only if interrupted (briefly) during the shooting cycle, I like the fact that I can't forget to take it off before firing off a quick one, from an uncocked state.
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That tutorial sounds like a great idea. Being able to set things up to work EXACTLY how YOU want them to is a pearl of great price!!!!! I have never been satisfied having what somebody else thinks I should. Part of the reason you'll NEVER find an iPhone in my pocket... 8)
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Prepping to offer drop in trigger jobs in the Hobbyist gate, and thought I'd show you guys the differences in L, M, and S setups. They correspond with glove sizes.
Those who don't like the floppy fake 2stage set up can go even more refined in fit, by ordering the next size up, and epoxying the trigger in place at their optimum point.
I shape the sears to size, square and true them (in the Sherline, with a touch of positive engagement angle), then kiss them with a fine stone. They respond well to the work.
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I guess we'll see how the Hobbyist Gate works. I got in a rhythm, and finished a nice little pile of triggers. There is a finite and dwindling supply of these things, so anyone who wants to send their stocker back to me gets $15 of shop credit.
I'm pretty proud of these. Anyone who has pulled my triggers knows I'm fussy about that kind of thing.
:)
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OOPs Had pics that did not load.
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This is showing a bit of tinkering of the first and second generation XS60C triggers. Its just a first stage stop so the second pull length can be made longer or shorter. Not having a trigger scale but just a pull scale the trigger pull should be under a lb. Heavier or lighter hammer tension may change this.
The first picture is the second generation trigger group. The screw for the first stage stop assembly was cut short to clear for rear housing mounting screw.
Second picture is the first generation trigger housing. The screw for the first stage stop assembly can be longer because the trigger housing rear mounting screw can be installed before action is put into stock.
Where as the second generation trigger housing needs to be installed after the action is put into the stock.
Next three pictures just shows the parts and some fabrication info.
Last picture shows how I kept the rivet aligned straight while the epoxy cured.
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That's a cool mod.
It brings up the perfect time to make a point about 2 stage triggers. This mod creates a TRUE 2 stage... the stocker is not. The difference: A true 2 stage uses the first stage to nearly defeat a generous (ultra safe) sear engagement, gives you a clear tactile indication that you are at the point of firing, then fires with a minimum of additional movement.
The stocker waits at the point of firing (single stage) and the trigger provides the input that you are about to reach it ... which I don't need (or, quite get... unless they want customers to think they have a Rekord equivalent).
Nice work, Paul.
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Not an XS trigger, it's from the QB, but they are alike in function as two peas in a pod....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_2003-1.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_2003-1.jpg.html)
Note the spring loaded plunger in place of the overtravel screw.... That, plus a lighter trigger spring (which provides the first stage) gives a true 2-stage trigger.... They are a commercial part that fits in a 6-32 threaded hole....
Bob
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Not an XS trigger, it's from the QB, but they are alike in function as two peas in a pod....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_2003-1.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_2003-1.jpg.html)
Note the spring loaded plunger in place of the overtravel screw.... That, plus a lighter trigger spring (which provides the first stage) gives a true 2-stage trigger.... They are a commercial part that fits in a 6-32 threaded hole....
Bob
A while back after making my first attempt of the two stage mod. I did remember seeing that two stage trigger mod and or the part being sold for the QBXX trigger. If there are more ways to skin a cat that mod may be way easier. I remember seeing the part only and duh didn't think of applying it to the XS60C.
There was a member who had just posted recently on the same trigger mod part that he had bought from Mcmaster Carr. I am quite sure it can be used on the XS60C triggers also.
http://www.gatewaytoairguns.org/GTA/index.php?topic=92286.msg864627#msg864627 (http://www.gatewaytoairguns.org/GTA/index.php?topic=92286.msg864627#msg864627)
Thanks for posting that pic Bob. Got to love living and learning with all the tinkering. Even if you start doing things the hard way.
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Paul, if you are ever on the mainland, and you're getting hungry... drop by. Anyone who doesn't mind doing things the hard way, in search of the easy way, has work waiting... right here.
You'd fit right in.
:)
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That's a great offer Eric. Even when doing things the hard way I may not realize it at the time but later on do find I have learned or pick up something on doing the next hard way project. :)
As for the trigger mod I think its worth doing no matter which method its done. JMO
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Whatever way you do it...hard or easy, it ALWAYS seems to lead to something else, doesn't it? ;D
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That's a great offer Eric. Even when doing things the hard way I may not realize it at the time but later on do find I have learned or pick up something on doing the next hard way project. :)
As for the trigger mod I think its worth doing no matter which method its done. JMO
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Whatever way you do it...hard or easy, it ALWAYS seems to lead to something else, doesn't it? ;D
Not an XS trigger, it's from the QB, but they are alike in function as two peas in a pod....
Note the spring loaded plunger in place of the overtravel screw.... That, plus a lighter trigger spring (which provides the first stage) gives a true 2-stage trigger.... They are a commercial part that fits in a 6-32 threaded hole....
Bob
Nearly every day, I get solid proof (like this) that I am hanging with the right crew. 8)
The Fusion will be here Tuesday. In anticipation, I've been pondering pics... and this one brings up something: It appears the stock is deep and wide enough to take a much larger tube (but, not enough to go double). It looks like a 1" ID tube will fit without leaving a paper thin forearm.
What are the specs (and the threads) on an MRod tube?
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I have a Fusion we could play with.
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I have a Fusion we could play with.
Around here, those are what's known as "famous last words"! LOL... stick around, it won't get boring...
If you would, I'd love a pic of the inside of the forearm, from above?
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Mrod tubes are 1" ID, and use 1 1/8" x 20TPI threads, according to the net.
What would be the material choices on this, for 3K?
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The MRod tube is 1.25" OD x 0.095" wall, so that is 1.050" ID.... no idea on the threads....
Bob
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Big Bore Bart saved the day... a long time ago. http://www.gatewaytoairguns.org/GTA/index.php?topic=68971.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=68971.0)
Are we stuck using steel for the tubes? What would the OD be on any alternatives (it appears we are close to max OD for the stock)?
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Would using a tiny gas ram, instead of a striker spring, reduce or eliminate bounce?
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I may be picturing the idea of a gas ram wrong. But wouldn't a gas ram hold the valve open?
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Yes and no. It would be a balance of mass of the ram piston and force. The other possibility is to use a gas ram to power a lightweight striker with some negative preload.
Tom
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http://www.mcmaster.com/#9417k1/=xxt6u3 (http://www.mcmaster.com/#9417k1/=xxt6u3)
With a 1" stroke, and 26mm available (with my mods) within the tailless design, I would be able to leave negative preload. These have a 4mm shaft, and it would only go into the striker a few mm, so a lot of striker weight would be left where the spring would normally go.
There are a lot of choices in force... how would I figure out which is best?
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I'm thinking the way to set this up for tuning would be to either make a striker with adjustable weight (and min neg preload)... or make a solid one, use an adjustment of the gas spring's location, and fire the striker over the tunable gap. Am I lost in space here?
Bob answered this long ago, but I can't figure out where... what is the max force a standard bolt handle can manage comfortably? How about a separate lever with a fat handle?
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Another possibility might be to make a striker with an adjustable stroke. Piece of cake to make... make the catch a threaded (and locked) ring. A striker set up for this would also be easy to make weights for.
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It depends on what you are building the striker for, high power, or lots of shots at low power.... If you are looking for lots of FPE, I would leave the stroke at maximum, use the heaviest hammer you can, the heaviest spring you can cock, with a bit of negative preload.... The same would apply to a gas ram, the difference being that the first part of the cocking stroke would be heavier, and the ram less likely to be recompressed by the hammer flying back.... Since the force on the hammer is more constant, for the same average force, you can reduce the maximum cocking effort, which seems like a good idea.... You would tune the preload by varying the gap between the hammer and the ram, meaning that for a given cocking stroke the ram would be compressed less as you increase the gap.... If you can find the right ram, it would seem to be an excellent thing to try, my Grizzly could use one.... I need something with about a 10 lb. force uncocked and at least 1" of travel.... My current setup uses a 24 lb/in spring with 1/8" negative preload and a 1" stroke, so it is compressed 7/8" to a maximum force of 20 lb., and an average force of 8 lb. over the hammer travel, producing 0.66 FPE of energy in the hammer.... A quick check of N-Forcer gam rams shows that to get a 1" stroke the overall length is 3.6" (2.6" compressed), and they are 19mm (3/4" ) OD....
Bob
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Thank you, Bob. As usual, you seem to be able to make sense of the stuff ricocheting around in my cranium (not a common skill). We're gonna run this thing down, and eat it alive.
The Fusion is here. I'm tickled. I really like the stock! It's hollowed out as much as possible (stash!), and the grip is solid. Those finger grooves are OK for my hand, but could be (and might be) taken off, or reduced, quite easily.
The forearm is narrower than I perceived it might be, by looking at the pic. 1.25 OD will be a tight fit, if it goes at all.
The fit and finish are quite good. IMO, the gun is worth the price.
I took it apart without charging and firing it (it's an illness), and dropped in one of my G1 trigger groups (the stocker is, not surprisingly, horrid). GTG.
When time permits, I'll light it up, and report on the moderator. Then I'll put the barrel and moderator up for sale... it's going bigger bore.
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Something WICKED this way comes... 8)
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Something WICKED this way comes... 8)
Indeed.
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It's pretty clear why G2 trigger jobs aren't as nice as G1s. The auto safety actuator requires a slot through the sear area, which means that 3X the overlap (creep) is needed to achieve the same sear contact area.
Fitting G1 sear parts eliminates the auto function, and give it as crisp a trigger as this design allows (pretty nice, actually... plenty of sear area to work with).
I smoothed the seams on the plastic housing of the Fusion. It's good plastic, and looks a LOT better with the flash gone. All set now.
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Finally shot the Fusion...
The gun is louder than the ad shows (silent there) and gives off no red ripples...lol.
https://www.youtube.com/watch?v=fumMM8eO68g (https://www.youtube.com/watch?v=fumMM8eO68g)
It goes a long way toward eliminating the sharp snap, though. If someone doesn't buy the barrel/moderator, I'm thinking of cutting it down into a custom P17 set up. At half the speed, it might really quiet the pistol.
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... what is the max force a standard bolt handle can manage comfortably? How about a separate lever with a fat handle?
and I'm trying to answer it a different way ( a double-ended 8mm through-pin each, for bolt and for hammer; external cocking plates for both sides.) I think the main problem of cocking effort is galling partly due to pulling the bolt from only one side.
I'm sure your slick coating will also help- on bolt, hammer, pins and receiver sliding slots. (Tube slots can be oversized, NP.) I might even want it on the inner surface of the external sliding plates.
- will have dimensioned receiver pics for you this month.
Trying to make clean drawings disturbs the design flow.
I made some (messy!) progress on the bolt retractor for the windowsill cannon today.
Still have to look up the Grizzly cocking and bolt throws to get a preliminary plate design dimensioned.
(The plates are the easy part compared to the retractor ;)
2 Mags coming from Lloyd this week to get the loading throw nailed down.
You're making me SO glad I insisted on the Gen1 trigger for my Gen2.
Need another pack though, for the other receiver.
Rod
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Ready when you are, Rod. LMK what length trigger job you want, and I'll set one set aside.
Been doing gas ram striker (GRS) homework... and, as usual, it looks like the best way is the most expensive. Although there are plenty of smaller (easier to mount, and cheaper) rams made, the N Forcer has something no one else does: It can be recharged to any pressure needed. All I need is a Nitrogen tank, regulator (for well over 400psi) and fittings. Ouch. I'm currently looking for a regulator system that goes high enough.
So far, the best price I've found for a regulator that will go over 500psi (over 40# spring force), is $400. I won't need it for GRS, but, it would allow me to recharge springer rams to custom pressures (at some point, all these tools have to pay for themselves).
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The gas rams you are talking about are,correct me if I'm wrong,much smaller than any PCP reservoir.You can probably charge them to whatever pressure you wish with very few strokes of any pcp hand pump with the proper adapter.Lots of used ones out there,some for less than 200.00.Not so much fun for charging air rifles but ok,I would think for gas rams.I used to have a Beeman pump for my RX1 and it was puny next to even a Marauder pump.Not much work to pump below 1K.Just a thought.
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Eric, did you really mean #4000psi and not #400psi? Something sounds wrong to me!
Glad to see you are keepin' on keepin' on!
Take care,
Tom
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Something to watch RE gas rams.... some of them have a maximum operating speed (ram speed).... I found one beautiful little miniature ram that looked great until I got to where it said maximum ram speed was 1.6 m/s (just over 5 fps).... The hammer in my Grizzly is travelling about 14 fps at impact, and depending on the hammer weight and stroke, you might need even higher ram speeds.... I don't know what the N-Forcer specs are in that regard.... but I can tell you that a 19mm OD unit with a 25mm (1") stroke is big and heavy....
I would agree, you can easily charge a gas ram with air from a PCP hand pump, but it would be air, not Nitrogen....
Bob
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Tom, the pressure needed to create 40# of force, in the MF19 N-Forcer, is 400psi. Yeah, still kickin' :)
Bob, I wrote CS about speed and price... we'll know soon. And, the MF19 will fit in precisely the same space as the 40mm tail set up... no stock mods needed.
We'll have a ton of striker weight, even without moving the mag forward (always an option).
The gas rams you are talking about are,correct me if I'm wrong,much smaller than any PCP reservoir.You can probably charge them to whatever pressure you wish with very few strokes of any pcp hand pump with the proper adapter.Lots of used ones out there,some for less than 200.00.Not so much fun for charging air rifles but ok,I would think for gas rams.I used to have a Beeman pump for my RX1 and it was puny next to even a Marauder pump.Not much work to pump below 1K.Just a thought.
I looked into the comparative compressibility of air and N, but started getting lost in the math right away. Found no simple charts or ratios.
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Air will work fine, Nitrogen is preferable because it is dry and doesn't leak through seals as easily as air.... All that means is that the oxygen in the air might leak out a bit over time and you might have to test the pressure and top it up.... after a few years?.... Nitrogen and air both act as ideal gasses (and essentially the same as each other) until you go above about 3000 psi, so not to worry....
Because you will only need about 10# of uncocked force on the ram, your pressure will be really low.... like 150 psi?.... The problem is that at really low pressures, the rate change with compression is higher (less constant force), more like a conventional wire spring....
Bob
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That's really good new$.
Between the fine and extremely wide adjustability of the system, and the reduced (or eliminated?) bounce, I'm intrigued. Given that anyone can supply the psi needed to go from mild to wild, I'm now thinking of a fixed position ram, with a fosters sticking out.
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Bob, how is the rate of compression higher at higher pressures? Is the ratio not fixed? Explanation below.
The force differential of a gas spring is based on the volume extended and the volume compressed. Fill pressure doesn't change the ratio. Typical gas spring has a piston rod ~20% of total volume.
One consideration as you reduce the fill pressure is the the seal drag becomes more prominent.
Tom
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You're right, Tom, not thinking clearly here.... The N-Forcer rams have a 30% increase in force between extended and compressed, so unless you get down to really low pressures where the difference between gauge and real pressures starts to be an issue, that ratio would be maintained.... At 0 psi gauge (and hence zero force extended), the ratio becomes infinite, however, providing the compressed force is enough to overcome the friction of the seals.... At 100 psi gauge, the change in percentage force would be from 1.3:1 to about 1.5:1, would it not?....
Bob
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I'm willing to cheerfully put up with a few more pounds of cocking force, to get past plenty of seal drag... as it is our bounce damper.
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You're right, Tom, not thinking clearly here.... The N-Forcer rams have a 30% increase in force between extended and compressed, so unless you get down to really low pressures where the difference between gauge and real pressures starts to be an issue, that ratio would be maintained.... At 0 psi gauge (and hence zero force extended), the ratio becomes infinite, however, providing the compressed force is enough to overcome the friction of the seals.... At 100 psi gauge, the change in percentage force would be from 1.3:1 to about 1.5:1, would it not?....
Bob
Bob, I have experience with the MF25 but not the 19. I believe the design is the same other than the diameters of the rod and housing. There is some dead space in the back of the housing where the valve is so the piston does not quite displace as much volume as expected. I'd say the 1.3 is a good estimate.
The breakaway force on the seal is quite stiff, maybe about 4 to 5 lbs unpressurized so I'd expect more under pressure.
Tom
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They got back to me right away. In it's entirety:
"Good Evening,
We test units for seal life at 140 strokes per minute. For a 2" stroke it's 1 million cycles for leakage. We do not test for speed!
1 piece MF19X25 is $43.75 we need to know the pressure to charge the cylinder too
We accept VISA and MASTER CARD
Please note: MF19X125 is $46.95
Thanks,
Lauren ".
So, it looks like we'll have to learn that ourselves.
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Ready when you are, Rod. LMK what length trigger job you want, and I'll set one set aside.
Short, please. I have small hands (yet played the piano, organ and guitar...go figure.)
Just had a nice talk with Lloyd. He had just one mag of the pair I ordered left (it's coming Mon.)
but is expecting more in 2 weeks or so. He's saving me two more after this, for next month.
I should be done with everything by the beginning of August and then we can start.
The bolt retractor is gonna work!-
I'm using the corkscrews' second (upper, on the gun) pinion gear (-just two teeth of it actually-)
which I was going to discard, and reversing it with a guide-captured push-link from (each of) the main handle(s) just before the 'home' end of their stroke. Simplest I could get it so far.
I have a 1.5" stroke for the bolt (before an 8-9mm retraction.) I want the mag here so I can see if that's enough. If it works with these sloppy tolerances I can think about duplicating the corkscrew's mechanism with much better tolerances, and tweak along the way for more stroke etc..
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They got back to me right away. In it's entirety:
"Good Evening,
We test units for seal life at 140 strokes per minute. For a 2" stroke it's 1 million cycles for leakage. We do not test for speed!
1 piece MF19X25 is $43.75 we need to know the pressure to charge the cylinder too
We accept VISA and MASTER CARD
Please note: MF19X125 is $46.95
Thanks,
Lauren ".
So, it looks like we'll have to learn that ourselves.
There is a German manufacturer of gas springs which the name escapes me at the moment. They have substantial tech data online and they do have a spec. for maximum rate of extension.
Tom
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I just had a ridiculously simple idea that might reduce, or even eliminate hammer bounce, while making a gun easier to cock.... emulate the forces of a gas ram with a simple coil spring....
Put a positive stop for the spring, possibly an internal one, that prevents it from extending fully.... and have that stop the spring 1/8" before the hammer hits the valve.... Instead of using a heavy spring that has zero preload and let's say 20 lbs. of force when cocked, use a longer spring with a lower rate (about half?) so that the spring when against the stop has, let's say, 5 lbs. of preload.... When cocked, the force, with the correct choice of spring, could be about 15 lbs. instead of 20 lbs.... but when the hammer rebounds to hit the spring and recompress it, instead of hitting a spring that has zero preload (and hence is easy to compress), it hits a spring that already has 5 lbs. of preload.... The hammer impact might not even be enough to recompress it, and if it does, not very far.... The average spring force available to accelerate the hammer is 10 lbs. either case.... Also, in either case, the hammer is being accelerated for 7/8" of travel (assuming it moves 1" from cocked to valve contact, with 1/8" of free play (negative preload).... In both cases, the hammer energy should be the same, or very close....
What do you think?.... With the heavy spring, rattling around, the cocking force starts at zero and increases over 7/8" of bolt travel to 20 lbs.... With the light spring, preloaded against a stop, the cocking force starts at 5 lbs, and increases over the same 7/8" of bolt travel to only 15 lbs.... The spring and stop would have to allow the hammer to move away from that assembly without drag, of course, so that is the technical problem to overcome.... but I think it should work just fine.... The same problem exists with a gas ram anyway, the hammer must not drag on the sides of the ram....
Bob
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Makes sense to me! Given that you already know the forces you are dealing with, your idea would be directed at bounce, therefore efficiency, the new shot count would tell you all you need to know... right? If I get the picture here, your idea would incorporate your existing adjuster?
The GRS setup would only contact the striker (solid slug) at the very tip of the ram. There is just enough room for the ram (in the original stock), before trigger placement becomes an issue... post #438 shows a 26mm set up, to give you an idea.
I'm first going for all the force I can generate with 1" of stroke, to find the limits of that, then that will tell me if we have to use any more of the 2.5" the design can allow us, to get to the .357 I have been pondering for nearly a year. I need to come up with a modular design, so anyone can go up or down in both caliber and power at will (without needing me... I've got work).
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There is a German manufacturer of gas springs which the name escapes me at the moment. They have substantial tech data online and they do have a spec. for maximum rate of extension.
Tom
If you think of it, please say something.
I'm going to proceed with the MF-19 for now. I have 1 of their 25s in a springer... really like it, and feeling that initial "stiction" is what gave me the idea to put it to use as a damper. My experience with anything like this is HP suspension... and that drag is something you fight to eliminate many times (MC forks especially).
I really need to know just how much weight we can sling around, under control.
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Yes, only the tip of the ram should contact the striker.... The gas ram still has the advantage of a relatively small ratio of force from extended to compressed, which would be very difficult to obtain with springs.... The N-Forcer is only 1.3:1, my example above was 3:1.... However, a stiff, short spring with negative preload has an infinite ratio of compressed to extended force, and is the hardest to cock of all possible solutions for a given hammer energy....
Bob
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The N-forcer has an M6 fill port. Aren't there "probe" style fillers available that fit these? If so, where would I find one? I like the idea of needing no wrenches to top these off.
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Eric and Bob, would it be correct to say, the XS60 factory bolt probe deposits a boolit (or a pellet, if the 'probe' was almost a caliber thick) about 5mm past the port, when fully extended?
At least that's what think I'm seeing on my stock gen1 receiver.
In other words, it could be 5mm shorter if it was being retracted to clear the port at the end of the loading stroke?
If it was 5mm shorter, would that be enough to clear the grizzly's mag?
Or would you still need to cut the bolt handle slot's back end a few (guessing about 3) mm?
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Set the length of the bolt so it barely pushes the bullet clear of the front of the port, and retracts just enough to clear the port. You don't want extra plenum there.
It will then clear the mag nicely when cocking.
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Set the length of the bolt so it barely pushes the bullet clear of the front of the port, and retracts just enough to clear the port. You don't want extra plenum there.
It will then clear the mag nicely when cocking.
I was hoping I could assume that - thanks!
I realize I'm in danger of hijacking your thread, so I just truncated this post,
and am relocating the extended discussion to the "FDPCP windowsill cannon" thread where it belongs.
Please do look at it when you have a chance.
ALL comments (especially yours and Bob's, as its heart is a Grizzly) are gratefully appreciated.
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Eric-
Did I see somewhere back, that you cut off the front of the receivers (starting with the "Bobcat")
I assume that was to get rid of the threaded portion for some reason.
-Do you still do that on the Grizzly?
(Save me some - I'll buy them off you, to use to make the many pieced barrel bands I'll be needing!)
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The N-forcer has an M6 fill port. Aren't there "probe" style fillers available that fit these? If so, where would I find one? I like the idea of needing no wrenches to top these off.
Automation Die & Mold, the N-forcer folks, sell a fill adapter as an accessory. I made my own and have a few extras, you can have one if you wish. I think they are 1/4 npt.
You can see the fitting in this picture.
(http://i1147.photobucket.com/albums/o553/QVTOM/Springer%20Project/373_zps876b2037.jpg)
Tom
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Thanks, man!
;D
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Eric-
Did I see somewhere back, that you cut off the front of the receivers (starting with the "Bobcat")
I assume that was to get rid of the threaded portion for some reason.
-Do you still do that on the Grizzly?
(Save me some - I'll buy them off you, to use to make the many pieced barrel bands I'll be needing!)
LOL... I'm saving them... I'll start a box for you.
The chopping is just for lightening and is done only to 3K guns.
Thanks for the detailing here! I am following your thread, pondering right along with you.
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Have I mentioned yet, today, how much I love GTA?
USPS is bringing me something I have been trying to find for a very long time... the only thing left between me and building the 60 I have always wanted.
The generosity of the members here is not news to many, but I'm running into some of the most unselfish people I have ever met.
Prepare for a pleasant surprise, and some gratitude from me that borders on mushy.
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Have I mentioned yet, today, how much I love GTA?
The generosity of the members here is not news to many, but I'm running into some of the most unselfish people I have ever met.
and you should include yourself in that ;)
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Rod, given that I'm getting badly needed support from guys so far above my pay grade they will never need a d**n thing from me... means that paying it forward is my only option.
I do it gratefully. I hope that shows...
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I got a chance today to make a limited travel spring guide for the Grizzly.... It looks like this....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Limited%20Stroke_zpskvdgiaqn.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Limited%20Stroke_zpskvdgiaqn.jpg.html)
The 7/32" OD spring guide is threaded both ends to 10-32.... On the front, the single nut is loctited and peened in place and turned down to 0.36" OD (same as the spring) to be a loose fit in the 3/8" hole in the hammer, and tapered to match the bottom of the drilled hole.... The space between that and the rear nuts is the length of the spring plus RVA screw, minus just over 1/2", which results in 7 lbs. of preload in the spring as installed in the photo above.... The two nuts at the back are installed against the shoulder on the rod and locked together.... When they hit the back of the adjusting screw, they stop the guide in its tracks, leaving the hammer to fly forward on its own to open the valve.... I had to drill the hole in the stock deeper to miss the nuts when the gun is cocked.... Moving the RVA screw forward reduces the space between the front of the guide and the hammer, which results in less distance for the hammer to coast before hitting the valve, and also results in compressing the spring further when the gun is cocked, storing more energy in the spring.... Therefore the RVA still works as intended....
The original plan was to use a 3" long, 11 lb/in. spring, with 5 lbs. preload and 15 lbs. force when cocked, but to get that to work I had to run it right up until it touched the hammer.... I ended up with a 13 lb/in. spring, with 7 lbs. of preload.... I think I needed more force because the guide is no longer part of the hammer weight, reducing the weight available to open the valve from 102 gr. to 84 gr.... The end of the guide misses the hammer by 0.12", meaning that the 1" cocking stroke compresses the spring an additional 0.88", giving about 18 lbs. force when cocked.... This is when adjusted for 971 fps average (94 FPE) with the 44.8 gr. JSB, the same as I had previously.... Although the maximum cocking force is only 3 lbs. less than with the previous short, stiff spring (2.5" long with a 24 lb/in. rate), the gun is much nicer to cock, with no tendency to not complete the cocking stroke.... I think this is because the force on the bolt handle is much more constant (7-18 lbs.) instead of increasing so rapidly as you pull the bolt back (0-21 lbs.).... With the sudden increase of force at the end of the bolt travel previously, you had a tendency to not complete cocking the gun, which could lead to double loading pellets....
So, how did it work?.... did it make the gun any more efficient?.... Yes, it did, and there is no longer any audible hammer bounce.... When I first assembled and tested the gun, I got 17 shots with the 44.8 gr. JSBs at just under 94 FPE.... However, with use and wear, the gun has developed an audible hammer bounce, and in addition a leak between the barrel and receiver at the transfer port, and was down to 13-14 shots per fill.... It still leaks, but you can no longer hear any hammer bounce (a very obvious difference in the sound), and the shot count is up to 15 shots before any velocity loss.... It is only down 10 fps at 17 shots, by which time it is down to 2000 psi (the setpoint is 2200).... Basically, by changing from a short, heavy spring (which gave me the previous best efficiency) to a lighter, longer spring with preload and a positive stop that holds it 1/8" clear of the hammer when uncocked, I gained at least a shot or two, putting me back over 2 complete magazines, even with the present leak.... I can say with confidence that using a preloaded spring that is not sitting against the hammer can reduce or eliminate hammer bounce.... We now have one more arrow in our quiver for tuning PCPs....
Bob
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Nicely done. Are you going to try it on your other beasts?
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I asked about rebuild kits for the MF-19s, for the guys who plan to do over 2 million cycles... here's the reply:
"HI Eric,
The price for MF19 repair kit is $75.00 each.
Thanks,
Kristen".
:o For a $45 part? Maybe Kristen hand delivers it? Is she really cute? Might be worth it...
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As time allows, and the gun can utilize it.... It will be a balance between room for the spring and hammer travel, and the necessary hammer strike.... Some guns may not have the room for a longer lighter spring with enough force.... I may seriously think about making future designs to allow for it, I really like the feel of the way it cocks.... much smoother, and feels a lot easier, even though it's only about 10% less peak force.... Any guns I have where I can hear a B-r-a-a-p will get the first attention....
Bob
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I asked about rebuild kits for the MF-19s, for the guys who plan to do over 2 million cycles... here's the reply:
"HI Eric,
The price for MF19 repair kit is $75.00 each.
Thanks,
Kristen".
:o For a $45 part? Maybe Kristen hand delivers it? Is she really cute? Might be worth it...
Eric, you might give some consideration to making your own ram for your application. First, the operating pressure for your application is considerably less than industrial gas spring applications. Second, you could uses the largest diameter casing with a smaller piston diameter allowing a higher fill pressure and a more constant force. The N-Forcer uses a lip seal but I bet you could get away with an o-ring.
If you haven't seen this thread........ http://www.gatewaytoairguns.org/GTA/index.php?topic=48062.msg452463#msg452463 (http://www.gatewaytoairguns.org/GTA/index.php?topic=48062.msg452463#msg452463) it will give you an idea of what's involved.
Tom
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Bob, I strongly suspect the next gun to burp at you will get it's guts ripped out, in short order. Please LMK when it happens, and the result? Sure is a clean setup.
Tom, excellent thread! I always thought there would be a check valve in there, too. Clever, elegant system.
An in-house ram is a really good idea. The case is already there, in a thru-tube set up... and, it could be made to be externally adjustable at just about any point on the gun, with a little tubing.
I've been looking for the smallest Foster nipple made, for a P-17 MSP project, and got this. It could be stuck anywhere on a 60.
Is it Wednesday yet?
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Guys, Tom just lit a fire under me.
Think about it... the ram would use the same o-rings, at the ends, as the valve does. No special seals... I could toss in a few rebuilds worth at shipping. The additional weight would be a significant fraction of the N-Forcer's. Any changes needed in the forces, while proto-ing, can be made right here...
Although $45 is cheap compared to my time, a production item could be turned out here at a competitive price, given enough quantity. There would be little, if any, cost penalty to the customer.
I gave some thought to the possibility that someone would hook a tank to the wrong Foster, and blow the thing up. I decided that rather than make the GRS 4.5K capable (everyone pays), if I made the rear cap take twice the pressure the front can, the front would shear its retaining screw... and the pressure would vent through the trigger and bolt slots (only the perp pays... a little).
I think I'll pass on my usual geezer nap today.... homework to do.
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A good pressure release could be made from a Foster coupler, with a thumbscrew and vent hole, no?
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What about a vented set screw? Most fosters have a poppet with a stem that may be able to be pressed in far enough to release some air.
(http://i1147.photobucket.com/albums/o553/QVTOM/foster2_zpsrjrcbeez.jpg)
The N-Forcer's valve look like this. The valve has been moved to piston from the end of the casing. Parts are still factory N-Forcer.
(http://i1147.photobucket.com/albums/o553/QVTOM/sears3_zps6wmkl3na.jpg)
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The Ninja fosters I stock have a valve stem that goes almost flush to the top of the nipple. A coupler with a standard plug installed that is tapped for said set screw (cheapest by far) or thumbscrew... Done.
NEXT!
;D
Any gut feelings about what kind of pressure would give us the best performance, so I can (try to) figure out piston sizes? This is ALL new to me.
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Just a teaser for the QB7x guys here... I love mine, too, and as soon as I can get this design working, I'll build a GRS setup, in an HPA tube for them.
I have a good feeling about this... we shall see.
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Just ramblings. Use the smallest piston possible that won't mushroom in use and doesn't require too much pressure. 3/16 would need ~715 psi for 20lbs of force.
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Just rambling, huh? Hmmm.... do you tend to "ramble" more after a couple drinks? I could set that up. ;D
On it.
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As I wait for the P.O. to open, thought I'd toss this in:
The GRS, made in house, will be able to do any length stroke, and have a piston of any length. This means that the adjustability can be used in anything from mild to wild, and that it can be used with anything from a slug style striker to a stocker.
I'm very interested in learning what it can do inside 13mm of stroke (stock 60). In a thru-tube, the stroke can be set to any length by spacing the caps the proper distance apart, and making a piston that ends a couple mm before it touches the striker, at rest. If target shooting is your thing, the consistency of this setup will reap good ESs.
Tick... tock...
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Guys, I have come to the conclusion that I can no longer sell the small stuff (caps, strikers, etc) as customs. The ratio of correspondence to actual sales is coming very close to making these parts an exercise in charity.
This does not apply to established customers, who already know what is available and what they need.
From now on, if it isn't in the Hobbyist's Gate... or, in the upcoming "In Stock" section of my site... it isn't available at the time.
Also, any prices I have quoted to date are good until August 1.
Thank you for your understanding! :)
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It's here. I have been looking for this since before it was ever made. It's a rare beast... 2 in the world, and Tom Costan (QVTom) gave me one of them. Can you believe that??
It's a Slayer mag, made before the finalized design went into production. It varies a tiny bit from the production piece, in ways that mean nothing to this project.
I can honestly say that my search for a mag for this project has lead me to trying to get a good look at every mag available in the US... at least until very recently. I have MANY hours into that search... it's over, and I'm as happy as I get, about that!
It's a thing of beauty. Perfectly made. I intend to do it justice, with everyone watching.
When I saw the Slayer, I immediately thought about trying to get one... and when Tom told me that there weren't going to be any production spares for a while, I figured I'd just be patient, and persistent. When I told him that it was for my personal project, he suggested that I would be fine with this one, if it fit. He sent a drawing to make sure I could set it up, and (as you will all see), it will be a piece of cake.
*
Tom, I don't know what else to say... I can't thank you enough. We are gonna have a TON of fun building the baddest Fusion on the planet, and it wouldn't be possible without your (un-returnable, unless you need a kidney?) generosity and support. Only thing I can think of is to do us all proud here. I can't tell you how tickled I am right now...
BTW, guys... I have owned watches with tolerances sloppier than those of the air fitting Tom sent with this. Impressive.
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What size screws should I use to hold the end caps, so that the fronts fail reliably at about 2K... and the rears never do? I'd like to use the min number of fasteners.
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Are you installing end caps at both ends of the piston?.... the front one the piston slides through and the rear one contains a male Foster?.... What is the ID of the tube you are installing the plugs in, the main tube (0.745") ?....
Bob
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Yup, yup, and the tube is the main tube, extended through the back.
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For the front screws, you might try two 6-32 cheesy quality screws.... At 2000 psi, the force on the front plug is 872 lb.f.... If the screws are Grade 2 (74K psi tensile), derated to 60% of that in shear (44K) they should have a shear strength of about 350 lb.f. each.... so "in theory" should fail at about 1600 psi.... Figuring out how to make them fail so that they don't damage the plug or the tube, and so that they, and the plug can be removed after failure, might be a bit tougher.... How about a 3/32" brass shear pin, that should fail at about 400 lb.f., or about 900 psi?.... but would give you a working pressure of only 300....
The rear screws should have a 3:1 safety margin on whatever pressure you could possibly put in there.... Any chance of somebody hooking a 4500 psi tank to the wrong Foster?.... How strong do you want to go?.... You know what you need for 3000-3500 psi, three low profile, high tensile 10-32's with the head in a pocket in the tube.... same as the valve....
Bob
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I'll be running (3) 1/4-28 screws as you suggested, in the valve/block combo for 4.5K use.
Isn't that overkill for the GRS, as the total pressure is meaningless if the F always fails before the R?
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Agreed.... You probably should have 3 times the strength in the rear, so that the working pressure at the back is the failure point at the front.... Either three 8-32 with the heads in pockets, like a Disco valve, or two 10-32s, will give you 3.0:1 safety margin at 2000 psi if the screws are 120K Tensile (Grade 5 equivalent)....
Bob
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That makes good sense. Build the R as if it's real job is to blow the F out... every day. I like that.
I got a pic of the Fusion before the mauling began. It's now completely apart. It's going to be a long time before it's 1 piece again.
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I got a chance today to make a limited travel spring guide for the Grizzly.... It looks like this....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Limited%20Stroke_zpskvdgiaqn.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Limited%20Stroke_zpskvdgiaqn.jpg.html)
The 7/32" OD spring guide is threaded both ends to 10-32.... On the front, the single nut is loctited and peened in place and turned down to 0.36" OD (same as the spring) to be a loose fit in the 3/8" hole in the hammer, and tapered to match the bottom of the drilled hole.... The space between that and the rear nuts is the length of the spring plus RVA screw, minus just over 1/2", which results in 7 lbs. of preload in the spring as installed in the photo above....
The original plan was to use a 3" long, 11 lb/in. spring, with 5 lbs. preload and 15 lbs. force when cocked, but to get that to work I had to run it right up until it touched the hammer.... I ended up with a 13 lb/in. spring, with 7 lbs. of preload....
Bob
Is that a standard McMaster spring, or did you have to make it?
-Rod
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Just a quick pic to show everyone why seeing Tom's drawings got me so enthused.
It shows that the bolt slot is just long enough to clear the barrel seal and the mag. If the horizontal slot is extended far enough to push the bullet past the port, the bolt can be probe-less for the best flow.
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Just a quick pic to show everyone why seeing Tom's drawings got me so enthused.
It shows that the bolt slot is just long enough to clear the barrel seal and the mag. If the horizontal slot is extended far enough to push the bullet past the port, the bolt can be probe-less for the best flow.
;)
-Rod
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That is a Century Spring, 3" long x 0.36" OD x 0.049" wire.... with a rate of 13 lb/in.... if my notes are correct # 71215....
Bob
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That is a Century Spring, 3" long x 0.36" OD x 0.049" wire.... with a rate of 13 lb/in.... if my notes are correct # 71215....
Bob
They are - and THANKS!
BTW: aircraftspruceDotcom/catalog/hapages/an3.php
OR: (also ACS -) NAS464P3A48
(see gen-aircraft-hardwareDotcom/images/pdf/nashhb.pdf for NAS specs)
OR (for longer thread) ..? NAS66P03A48C (10-32, 3" chrome 'grip')
Then all you have to do is turn down the head... just sayin', if stalwart's mass producing..
-Rod
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The stripped stock weighs 785grams, about 100 less than the wood 60 stocks.
There's room in the forearm for quite a bit... but, not a double.
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Guys, I'm authorized to share the story of the very special custom bullet shown in the mag pic... by it's designer, manufacturer, and only tester. John Cripe (johninthecamper... http://pelletgarden.com/ (http://pelletgarden.com/) ) is the man behind the world's first Boat Tail Wadcutter.
He invented it in seconds. By inserting a Slayer mag in backwards (this kind of thing takes real genius!). As a result of it's poor feeding in the new gun (a last round partial feed resulting in a partial investigative teardown of the gun, rather than forcing it in) , the manufacturer of the Slayer came up with a good way to prevent more innovation of this kind. My mag was made before the change, and is one of (it turns out) 5 ever made capable of allowing this kind of out of the box research.
It's gonna be worth a LOT of money some day!
;D
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John just contacted me, and pointed out something I didn't realize:
He has a number of these bullets designed to give the shooter "field ready options". They're easy to use... just before loading, turn the mag or gun 180*. Clean holes in paper... no extra charge.
These guys on GTA... they're always thinking.
Seriously... this points out something important. The value of (end user) field testing cannot be overstated. Tom, having seen that mag in his head long before it ever saw 3D, isn't very likely to put it in backwards. John, faced with multiple jack rabbits, carrying a gun he was unfamiliar with... did what any of us might in a hurry... and improved the breed before Tom had to learn the hard way (we've all had that customer).
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Can't stop laughing... ;D
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Very funny post,had to read a few times to get full effect! Lol I totally agree from a manufacturers standpoint field testing is worth it's weight in gold as to finding out just what can go wrong. Luckily this problem of loading mag backwards happen at the end of the day.That Slayer is proven in my mind to be one tough piece of engineering. 8) I think John is in love with it too!! (http://i1276.photobucket.com/albums/y468/danawebbs/Mobile%20Uploads/image_zpsfhkytvxo.jpg) (http://s1276.photobucket.com/user/danawebbs/media/Mobile%20Uploads/image_zpsfhkytvxo.jpg.html)
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Can't stop laughing... ;D
I had to share. ;D
I think John is in love with it too!!
Who wouldn't be? I've shown the mag around to my shop neighbors (PB guys), and sight unseen they all want the gun that goes under it.
He speaks very highly of it, and he knows a good tool when he sees one.
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Jack and John ;D
(http://i1147.photobucket.com/albums/o553/QVTOM/jack%20and%20john_zpsaxdwqkrh.jpg)
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Jack and John ;D
(http://i1147.photobucket.com/albums/o553/QVTOM/jack%20and%20john_zpsaxdwqkrh.jpg)
you can get real close to those guys and not even know they are there
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Boy, no kidding! The first few times I looked at that pic, I didn't see any... and there is one very nearly at your throat!
I'm shaking, just thinking about what could have happened...
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What are the OD choices in TJ's .357 liners?
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1/2" and 5/8" to the best of my knowledge....
Bob
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Sweet. 5/8" is perfect... take a hair off, going into the receiver, and it's done.
Thanks. 8)
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.500 and .590 for 357
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Interesting.... I thought Mike's larger size tubing ended up 0.563" on a .25 cal, 0.590" on a .30 cal and 0.625" on a .357 cal.... I must have the wrong information.... I know you can also order special OD's, I think he centerless grinds them to size.... Of course if 0.590" is the largest he makes, that wouldn't apply here....
Bob
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Either way, I'm the proverbial "Happy Camper".
Both ODs would let a bit of light between them and the tube... but not much else.
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On the GRS, I'm considering making and stocking multiples of a standard piston "head" (actually a guide/stop), and MIG welding 3/16" drill blanks to them (quick custom lengths). If I choose very hard blanks for the quality polishing they would take, then allow that weld to cool slowly, wouldn't that make certain the hammering wouldn't fracture the rod?
http://www.mcmaster.com/#4347t37/=y4dhc0 (http://www.mcmaster.com/#4347t37/=y4dhc0)
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Guys, I just got this email, from a domain registration company (they say):
"Dear CEO,
(If you are not the person who is in charge of this, please forward this to your CEO, because this is urgent, Thanks)
We are a Network Service Company which is the domain name registration center in Shanghai, China.
We received an application from Huayi Ltd on July 13, 2015. They want to register " stalwartarms " as their Internet Keyword and " stalwartarms .cn "、" stalwartarms .com.cn " 、" stalwartarms .net.cn "、" stalwartarms .org.cn " 、" stalwartarms .asia " domain names etc.., they are in China and Asia domain names. But after checking it, we find " stalwartarms " conflicts with your company. In order to deal with this matter better, so we send you email and confirm whether this company is your distributor or business partner in China or not?
Best Regards, ..."
What should I do?
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Seems they want you .com domain or just more internet BS. You have 3 choices that come to mind. 1) Ignore it. 2) Buy up all the stalwart.X domains. 3) See if they are serious about buying your .com.
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http://www.cnwebregistry.org.cn/ (http://www.cnwebregistry.org.cn/) Seems legit. I told them I was not affiliated with Huayi Ltd, and they have no permission to use the name.
Hmmm... kind of resembles a situation that happened to someone here before (the name escapes me atm...LOL).
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Seems they want you .com domain or just more internet BS. You have 3 choices that come to mind. 1) Ignore it. 2) Buy up all the stalwart.X domains. 3) See if they are serious about buying your .com.
I have had no offers to buy the domain...
I asked what I could do to prevent it's use... we'll see if they suggest I buy every permutation.
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I think you just hit the jackpot! From what little I know about internet naming, if you have registered and purchased "Stalwart Arms.com" they cannot use it. You can of course sell them the name and that could be a large chunk of money.
I would get an attorney of internet law and discuss the matter, but I think you could make a good amount (if this is legit).
Wow! Best of luck, Eric!
Tom
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Guys, I just got this email, from a domain registration company (they say):
"Dear CEO,
(If you are not the person who is in charge of this, please forward this to your CEO, because this is urgent, Thanks)
We are a Network Service Company which is the domain name registration center in Shanghai, China.
We received an application from Huayi Ltd on July 13, 2015. They want to register " stalwartarms " as their Internet Keyword and " stalwartarms .cn "、" stalwartarms .com.cn " 、" stalwartarms .net.cn "、" stalwartarms .org.cn " 、" stalwartarms .asia " domain names etc.., they are in China and Asia domain names. But after checking it, we find " stalwartarms " conflicts with your company. In order to deal with this matter better, so we send you email and confirm whether this company is your distributor or business partner in China or not?
Best Regards, ..."
What should I do?
This is a well known scam and can be safely ignored. The truth is, if you respond in any way, you will be in for an ordeal. Ignore it, throw it away and forget about it. The prices they want to "protect" your branded domain name are stupid and they will do nothing if you send them money. Stay FAR FAR AWAY from this scam!
If your domain registrar has a way to hide your identity as the domain owner, you will not receive any of this BS. GoDaddy has this and most others do as well. Worth the $10 per year.
Here is an example:
http://squelchdesign.com/featured/chinese-domain-name-registration-scams/ (http://squelchdesign.com/featured/chinese-domain-name-registration-scams/)
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Makes sense... my registrar keeps my name private, these guys contacted me through the address in my contact page.
I can't imagine anyone in China wanting to use a name as obscure and "un-sexy" as mine.
:)
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Guys, I just got this email, from a domain registration company (they say):
"Dear CEO,
(If you are not the person who is in charge of this, please forward this to your CEO, because this is urgent, Thanks)
We are a Network Service Company which is the domain name registration center in Shanghai, China.
We received an application from Huayi Ltd on July 13, 2015. They want to register " stalwartarms " as their Internet Keyword and " stalwartarms .cn "、" stalwartarms .com.cn " 、" stalwartarms .net.cn "、" stalwartarms .org.cn " 、" stalwartarms .asia " domain names etc.., they are in China and Asia domain names. But after checking it, we find " stalwartarms " conflicts with your company. In order to deal with this matter better, so we send you email and confirm whether this company is your distributor or business partner in China or not?
Best Regards, ..."
What should I do?
Ignore them, they are name squatters. They want any single word or double domain name to auction off.
These folks are the scum of the earth, only spammers are worse. They are wasting valuable air that could be powering our guns.
Private registration is worth just about nothing, since the actual owner has to be supplied to ICANN by your registrar. It just keeps you out of WHOIS, nothing more. So they can still get the contact info, just takes more work for them. Mind you most will not bother.
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They are wasting valuable air that could be powering our guns.
I think you just succinctly stated the bottom line here... ;D
Now, where were we?
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LOL... just got this from jiang_zhihai86@vip.163.com :
"Dear Sirs,
Our company based in chinese office, our company has submitted the " stalwartarms " as CN/ASIA(.asia/.cn/.com.cn/.net.cn/.org.cn) domain name and Internet Keyword, we are waiting for Mr. Jim's approval. We think this name is very important for our products in Chinese and Asia market. Even though Mr. Jim advises us to change another name, we will persist in this name.
Best regards
Jiang zhihai "
It went straight to my spam folder.
As I don't see SA ever becoming an exporter to Asia, I may have some fun with this. What do you think? Should I offer to leave my legal dept out of this for, say, $10,000?
;D It's always something, isn't it? There is something familiar about that domain "163.com"...
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BTW... I am currently looking for a "legal dept."
Anyone bored enough to become said dept.?
;D ;) ;D
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I'm about to order materials, and would appreciate some oversight.
I'm getting 1144 steel for the caps and piston guide, and 01 tool steel rod for the piston rods.
Am I correct in assuming that a high polish on the rod will give the most consistent lock times? The cost of this stuff is chump change compared to the time it would take to polish lesser stuff.
Also, will making a well fitted (and relieved for flow) guide for this be worth the time, given that goal?
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I guess I'll just try it, and find out.
Getting 2" of GRS stroke out of the Fusion will require some effort, but 1.75" is easy. The stock is the limiting factor. The Slayer mag has postponed any 1" experiments for now. I'm going to build the gun I want... without having to consider how I'm going to make it efficient to dupe.
I asked about pump action set ups a while back... got crickets. The only one I'm aware of is the Hatsan, so I looked into 2 designs experience has shown me only get sweeter with age: the Mossberg 500, and the Remington 7600. The Fusion stock is quite thick around the receiver, there's room to play. If I can't figure something out, soon, I'll go with a separate lever.
My new friends from China did what was predicted here... saying that if I don't register with them, the name will be used throughout Asia. Scroom.
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;) ;) ;D Hire a couple of ninjas to pay them a visit and make them an offer they can't refuse ;D ;D
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;) ;) ;D Hire a couple of ninjas to pay them a visit and make them an offer they can't refuse ;D ;D
;D
I'm making a list. So far, I'll need ninjas and lawyers... anything else?
This place teaches me so many things having nothing to do with shooting... gotta love that. In fact, it was a thread on vaping, here, that convinced me to try it almost a year ago. It's so nice being free of tobacco! 11 months, and counting.
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Reply with this.........
I can't thank you enough. With all of Asia using my name I can expect to see 99 out of 100 looking for Stalwart arrive at my .com first. Some will be smart enough to try the .net .org .tv etc. but most will not. Again thank you, this type is visibility is invaluable to me.
Sincerely,
Stalwart
CEO, CFO, Legal Dept, Customer Service Rep, Shop worker and FOREIGN SALES SPECIALIST
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LOL.... Cut, pasted, and sent.... with a simple signature.
Tom, be sure to stop by HR asap... there's a little something waiting in an envelope for you. I'll personally tell Legal that Engineering has just kicked their butts... for pennies on the dollar.
You guys are fun!
;D
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What's the most stroke anyone has gotten out of QB7Xs?
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What's the most stroke anyone has gotten out of QB7Xs?
Can you find a hammer arrangement capable of handling a 2" cocking stroke?
(a short but heavy hammer? Should I get some tungsten rod/bar?)
;)
p.s.: no worries - I can 'waste' all you need, via the plates' slot (-s- even for the bolt.)
- but it looks like the corkscrew R&P's will do that much.
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Anything over about 1.75" will not fit in the tail.... and therefore the stock.
We can have all we want with a longer tail, but you'd have to mod the stock quite a bit.
You have all the stroke you need right now, for .30 cal.
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Anything over about 1.75" will not fit in the tail.... and therefore the stock.
We can have all we want with a longer tail, but you'd have to mod the stock quite a bit.
You have all the stroke you need right now, for .30 cal.
Remember, this is an AR match stock - not an FD/XS stock.
It will get VERY heavy modding already.
This is where an FD action will fit in it after inletting.
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2.5" will easily fit, long before it pokes you in the face. Your thumb would have lots of room under a tail.
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Got a package from Pellet Garden. 55gr .25 bullets in .249, .250, and .251. I got them to test barrels for fit. Should take some of the the guesswork out of customer's search for proper pellet size.
Double sealed, and packed in cork granules.... they're like little lead jewels!
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2.5" will easily fit, long before it pokes you in the face. Your thumb would have lots of room under a tail.
I think a 1.5" (max) tail will be plenty...
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Looks like my Thru-Tube set up could be considered good insurance even at 1.5K.
http://www.network54.com/Forum/79537/thread/1440284787/last-1440350522/Expand+Thread (http://www.network54.com/Forum/79537/thread/1440284787/last-1440350522/Expand+Thread)
http://www.gatewaytoairguns.org/GTA/index.php?topic=96148.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=96148.0)
It hasn't been shown, to my knowledge, what failed... exactly. I do know that I run into receivers with threads of a too large ID. The tubes can be rocked slightly in them, even run in to finger tight. Those go into the TT pile, and make great 3K-4.5K guns.
If you look way back in this thread, there was an example of a customer who ran into this problem. Since then, I have chased and checked every receiver that comes in for repeater conversion. The sloppy ones get replaced from stock, and the parts are shipped back with confidence.
There is a lot left to know about this particular example. One thing to remember, guys... if one of these is overfilled, just ONCE, even if it didn't show any immediate effect... it could be set up for failure at "safe" pressures later.
Bottom line? More info needed, and there is nothing left to say here until that info is gained. Except, perhaps this: The Thru-Tube conversion ain't cheap... or, is it?
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You say that you have run into receivers where the threads are too large an ID.... By that do you mean that a stock XS-60c tube is loose in the receiver.... and that a tap of the appropriate size is also loose?....
Trying to figure out if the problem is likely the receiver too big or the tube too small, here?.... In any case, as you say, the Thru-tube conversion is the 100% solution, either way....
Bob
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Correct... on all counts. The stock tubes are sometimes small.... and a surprising number of the receivers are a bit big.
I check and refit all guns sent to me, as a matter of course. It costs me me only time, as any "bad" receivers are simply called to a higher purpose.
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Makes perfect sense.... If the receiver is on the large side, and the tube in question on the small side, it is a disaster waiting to happen.... Well in this case it didn't wait, I guess, fortunately nobody was hurt.... It makes me glad my FD-PCP has nicely fitting threads, as most probably do.... It also makes me glad the Grizzly has the Thru-tube conversion....
Bob
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Great insight Eric.
So I guess if a threaded tube has some movement it should set off an alarm.
I will need to do some checking.
thanks
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If the tube can still be rocked after about 4-5 turns in, they are already out of quality tolerances. I suspect the enormous amount of part overlap was designed in just to overcome production tolerances.
I'd pay to own that tube. There is a lot of "good" threads left in that receiver. I hope they find it.
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Agreed, the threads are extremely long (3/4"+), if the tube has a lot of movement when fully engaged, something is amiss.... Alarm bells should be ringing at that point.... My son's FD-PCP tube wobbles about 1/10" sideways at the front end when fully engaged, but not tightened against the seal.... loose to be sure, but not enough to worry me....
Bob
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I degassed and took my .177 apart tonight and the tube wobbles when tightened down but no movement when the flat oring/seal is removed. It will remain in parts!
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I degassed and took my .177 apart tonight and the tube wobbles when tightened down but no movement when the flat oring/seal is removed. It will remain in parts!
That's the smart move, unless you are willing to have a new tube cut with an adjustable die, so it can be properly fitted.
edit: Should have looked at your list.
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I degassed and took my .177 apart tonight and the tube wobbles when tightened down but no movement when the flat oring/seal is removed. It will remain in parts!
That's the smart move, unless you are willing to have a new tube cut with an adjustable die, so it can be properly fitted.
Is yours an FDPCP, or does it have the stock tube?
It's the FDPCP.
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Thanks for the response... I didn't look at your list.
YGPM
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Eric, it's nice that you have an adjustable die, and a tap to chase the threads, and can supply custom fitted tubes if someone has an oversize receiver.... No reason to scrap a gun that isn't too far out of spec when it just might need a new tube, as I know you have lots of that handy.... Of course if the receiver is way oversize, like you say, it just becomes a candidate for the thru-tube setup....
Bob
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The 2 things that DQ a receiver here are the threads and the extrusion flaw inside at the valve seal. Of those, the flaw is far more often seen. As I posted a long time ago, many of them can be reamed out nicely, keeping the threaded tube... so, there aren't a lot of either DQed here now. I will be reaming out perfectly good receivers for 4.5K, soon.
To properly make precise threads in this stuff takes work. As the tube is oversize OD, it has to be turned down to the receiver's ID, before cutting even begins. If the die is forced to reduce the OD, the effect of "rolling" the excess ahead of the cut is tearing good metal loose, and flowing the now weak metal into the thread's peaks... . This, along with chips rolling under (if the cut isn't reversed regularly, to clear them), can even create what looks like saw teeth along the peaks. They are weak... very weak. At least, that was what I was taught...:)
The cost of making a fitted tube is high enough here that I have been working toward, and spending some good money on, simply reducing the cost of thru-tubes. I'm getting close enough to a quality threaded tube's cost that I'm planning to ditch the threads for good. At that point, it will either be CO2... or 4.5K... and I'll cheerfully lose some part #s.
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Eric your are correct about making a quality thread is work and what you describe is accurate. Generally speaking dies are not full profile, meaning they do not cut the crest of the thread but there are exceptions.
Automated threads can be cut with die heads that are progressive. The first tooth will take a small cut then the next tooth will take a bigger bite and the root depth is usually reach by the 4th tooth. This prevents all the bad things you described provided the part is cut to the correct major diameter before threading.
Precision threads are usually cut with a single point full profile tool. Cut depth is progressively deeper using multiple passes.
Tom
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So that means that if a 7/8" (0.875") tube was not turned down prior to threading with a 22 mm (0.866") die the results may not be good....
Bob
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3' of .065 4130 is about $35 shipped. Ream the receiver, cut the slots, and drill the holes, add 2 high strength #10 screws to the valve and you have a 3000psi. gun. ..... And the square o-ring will never leak again, cause it's gone. :D
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3' of .065 4130 is about $35 shipped. Ream the receiver, cut the slots, and drill the holes, add 2 high strength #10 screws to the valve and you have a 3000psi. gun. ..... And the square o-ring will never leak again, cause it's gone. :D
...and make a new "plug"....
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Correct, you also need to deal with the front fill fitting, because the retaining nut/ring on the standard setup is for CO2 pressures only (<1800 psi).... Same applies to the QB78.... The easiest is to thread the tube internally and use a Disco fill fitting....
Bob
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Correct, you also need to deal with the front fill fitting, because the retaining nut/ring on the standard setup is for CO2 pressures only (<1800 psi).... Same applies to the QB78.... The easiest is to thread the tube internally and use a Disco fill fitting....
Bob
Thank you Bob. This is the first thing I thought of when I read his post. If the threads are the weak points then we need to address both ends of the tube.
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I was figuring a P-Rod front plug. They might be the same part for all I know.
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Properly made, in-spec. threads are fine, but much better of course if the thinner tube wall remaining is not pressurized.... ie the seal is inboard of them.... However, the retaining nut/ring on the front of the XS-60c and QB78 tubes has a rather thin flange on the end that takes all the end load, too thin to use at over ~1800 psi and still have a proper safety margin.... QVTom ran a Finite Element Analysis on it and what he saw concerned him greatly.... It would certainly be possible to make a new nut, out of better material and/or with larger dimensions.... but not a good idea to use the stock one on HPA without a 1.8K burst disc installed....
Bob
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3' of .065 4130 is about $35 shipped. Ream the receiver, cut the slots, and drill the holes, add 2 high strength #10 screws to the valve and you have a 3000psi. gun. ..... And the square o-ring will never leak again, cause it's gone. :D
Pat, read back a bit.... it's all been figured out, the math has all been checked, and the prototyping is done. I'm currently trying to reduce my costs, to pass the savings on. As you made clear in the explosion thread, you plan to make your own thru-tubes... and that's fine... but, please do so on your own thread. At this point, especially considering the time I spent with you, building your dream 60 (27 emails??)... and considering that when it came time to actually pay me, and start the project.... you vanished... I'm not really interested in teaching you any more about how to take food off of my plate.
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Well stated, Eric....
Bob
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I had asked if I applied epoxy to permanently screw in the tube into the receiver and was advised that there was still a chance of failure if the threads weren't matched right.
So if I were to epoxy the tube and epoxy couple of screws through the receiver penetrating the tube. While leaving enough room for a long modified screw driver to loosen the valve nut and push the valve out through the back of the receiver. Would that be something that might work?
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Paul, if anyone can make that work, I suspect it would be you. Check your dimensions and placement with Our Beloved (I mean that) Safety Officer... and go for 1.
My suggestion to simply cut 3/4" off the tube, and re-thread it larger, is all I can feel safe recommending. The part overlap is so overkill, properly fitted, that the quality of the tube material and the cap nut's strength are the next questions to answer.
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^X2.... If the threads in the receiver are in good shape, a shortened tube, custom threaded to match the receiver, is overkill in terms of the tensile (end) loads on the tube.... It still isn't as good as a Thru-tube setup, because the thinned area of tube where the threads end is under pressure, and well.... it's thinner than the rest of the tube.... My son's gun has a stock FD-PCP tube, albeit with good fitting threads.... so that should give you an indication of my level of confidence of that setup using a 1500 psi fill.... I do love him, BTW....
Bob
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LOL... I believe you do.
I can tell you who's motives I don't trust: Go to the Pismo Beach dunes any weekend, and you will see little kids, without helmets, riding around on race-prepped Quads. Someone is just BEGGING for it... and, it isn't those kids.
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Yeah, we had a Dad with son on board his Quad doing Wheelies down Main St. in front of our Motel the last long weekend here.... so I know exactly what you mean....
Bob
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Paul, if anyone can make that work, I suspect it would be you. Check your dimensions and placement with Our Beloved (I mean that) Safety Officer... and go for 1.
My suggestion to simply cut 3/4" off the tube, and re-thread it larger, is all I can feel safe recommending. The part overlap is so overkill, properly fitted, that the quality of the tube material and the cap nut's strength are the next questions to answer.
[/quotePaul, if anyone can make that work, I suspect it would be you. Check your dimensions and placement with Our Beloved (I mean that) Safety Officer... and go for 1.
My suggestion to simply cut 3/4" off the tube, and re-thread it larger, is all I can feel safe recommending. The part overlap is so overkill, properly fitted, that the quality of the tube material and the cap nut's strength are the next questions to answer.
Thanks Eric and Bob,
From what I have and what was suggested. I am guessing I should be safe at receiver connection. Must have gotten a little paranoid. If it wasn't for the guidance from you folks and others here on the GTA I probably would be into building sling shots. :)
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Yet another attempt at getting the tube of my FD-PCP to seal to the receiver....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/FD-PCP%20Extended%20Valve%20Front_zps0idmh87q.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/FD-PCP%20Extended%20Valve%20Front_zps0idmh87q.jpg.html)
I made an extended valve front end.... The ID is drilled and tapped to 16mm x 1.5mm to fit the valve, with a 1/2" ID spring seat to fit the tapered spring that is 1.5" from the back end.... The rest of the valve is drilled through to 13/32", the same as the ID of the large end of the spring.... Therefore, there is tons of flow into the valve, without having any slots in the sides.... The extension sticks out about 1/2" past the end of the receiver, and has an O-ring groove for a #113 Quad Seal, like the one I will use between the valve halves (shown).... There is a slot on the front to snug the two halves together.... The back half of the extension is 0.743" to fit nicely in the inside of the receiver, and the front half is machined down to 0.737" to slide easily into the tube.... The O-ring is past the threads in the tube, and so seals where the tube is full wall thickness.... This puts the threaded part of the tube only in tension, there is no pressure against that portion where the wall is thinner, an added safety benefit.... I sincerely hope this will stop my son's gun from leaking, which has plagued it ever since new....
Bob
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Elegant solution Bob
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Here is the receiver with the extended valve fitted....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/FD-PCP%20Tube%20Seal_zpsb6jrsir2.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/FD-PCP%20Tube%20Seal_zpsb6jrsir2.jpg.html)
Now to thread the tube into place, fill it, and hopefully tomorrow it will still be full.... Cross your fingers....
Bob
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Did it again Bob
That is such a simple solution. I am not sure anyone else would think of it. Which is amazing!!!
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Elegant
That is precisely the word for it.
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The guy is not human...
Bob, couldn't something similar be done with the other end of the tube?
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LOL... I believe you do.
I can tell you who's motives I don't trust: Go to the Pismo Beach dunes any weekend, and you will see little kids, without helmets, riding around on race-prepped Quads. Someone is just BEGGING for it... and, it isn't those kids.
Just about every year we lose a kid on a snowmobile that way. Dad puts him in front, gets a few beers in him and hits a tree. Tree on one side, dad on the other, both closing in real fast, you do the math.
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Rsterne, I think we should all chip in and get you Rosetta Stone for Mandarin.
A couple phone calls and you could change the whole industry. If I get a vote your first call should probably be about that extended valve.
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Well, I think I got it ! .... I filled it and topped it last night to 1500 psi, and this morning it is at 1410 psi, and the shop is about 20* cooler, so that is likely just the effect of the charge cooling.... I'll leave it today and see if it stays the same (or even increases a whisker).... I also need to shoot a string and may need to readjust the RVA because the tapered valve spring, although it has similar seat pressure, may not close exactly the same.... so I may need to adjust the preload to get my original velocity and shot count back....
The way I did my gauge mount in the front, the O-ring is behind the threads, so it's on the full thickness of the tube already.... similar to a Disco fill fitting.... The problem with using higher pressures on the front is not the threads (initially), but the flange on the retaining nut, which is too thin to have a proper safety margin at 3K.... If you stay with CO2 pressures (1900 psi at 120*F, remember) it should be OK, although not over-designed....
Please note, this does NOT change any problem associated with the threads pulling apart and launching the tube out of the receiver (which should be a non-issue).... The end load is essentially still the same.... Well, not quite, because it is now based on the ID of the tube instead of the OD/pitch diameter of the threads, which drops it from ~900 lbs. to ~650 lbs.... but the threads still have a large axial load in tension, so have to be in good shape.... However, it does significantly improve the safety margin of the tube itself, because the thin wall below the threads is no longer pressurized.... If the valve extension was made longer, say over 3/4" (1 diameter), it would also make it almost impossible for the tube to fracture at the end of the threads if somebody fell on the gun, because the extension would brace the tube to prevent bending right at the end of the receiver where the last thread is.... However, the longer you make it, the more volume you lose in the reservoir.... I lost about 5 cc with mine....
Bob
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The way I did my gauge mount in the front, the O-ring is behind the threads, so it's on the full thickness of the tube already.... similar to a Disco fill fitting.... The problem with using higher pressures on the front is not the threads (initially), but the flange on the retaining nut, which is too thin to have a proper safety margin at 3K.... If you stay with CO2 pressures (1900 psi at 120*F, remember) it should be OK, although not over-designed....
Got it.
Thanks
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Ding-dang poppet started to leak (out the barrel) as soon as I test fired it.... I guess I didn't clean the inside of the tube well enough and a bit of grit got lodged in the poppet.... sooooooooooo it comes apart yet again.... ::)
Bob
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Ding-dang poppet started to leak (out the barrel) as soon as I test fired it.... I guess I didn't clean the inside of the tube well enough and a bit of grit got lodged in the poppet.... sooooooooooo it comes apart yet again.... ::)
Bob
Turns out Bob is human after all.... ;)
Seriously though, I almost missed the VERY good discussion here re the air tube threads on the FDPCP. I will be degassing and checking mine to see how tight/loose everything fits together.
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Ding-dang poppet started to leak (out the barrel) as soon as I test fired it.... I guess I didn't clean the inside of the tube well enough and a bit of grit got lodged in the poppet.... sooooooooooo it comes apart yet again.... ::)
Bob
Turns out Bob is human after all.... ;)
Seriously though, I almost missed the VERY good discussion here re the air tube threads on the FDPCP. I will be degassing and checking mine to see how tight/loose everything fits together.
That is one good idea. Maaaybeee the GTA staff might want to post a sticky on precautions on the FDPCP and or other pcp safety measures. Like inspecting the tube threads and following fill pressure requirements. I even remember someone saying his fill hose was not connected properly and the hose went flying when filling from a tank. Also what ever else one can think of. So yes I have been told many times how dangerous HPA can be. Maybe what happened this time and thank god no one was injured was a blessing. Not saying or not knowing what happen to the FDPCP but like others have mentioned it could happen to any PCP airgun and a safe practice guideline might help future failures. JMO :)
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Turns out Bob is human after all.... ;)
Well, if you think about that... it's pretty flimsy evidence. Gunk could have come out of the pump.
I remain unconvinced.
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I got a chance today to make a limited travel spring guide for the Grizzly.... It looks like this....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Limited%20Stroke_zpskvdgiaqn.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Limited%20Stroke_zpskvdgiaqn.jpg.html)
The 7/32" OD spring guide is threaded both ends to 10-32.... On the front, the single nut is loctited and peened in place and turned down to 0.36" OD (same as the spring) to be a loose fit in the 3/8" hole in the hammer, and tapered to match the bottom of the drilled hole.... The space between that and the rear nuts is the length of the spring plus RVA screw, minus just over 1/2", which results in 7 lbs. of preload in the spring as installed in the photo above.... The two nuts at the back are installed against the shoulder on the rod and locked together.... When they hit the back of the adjusting screw, they stop the guide in its tracks, leaving the hammer to fly forward on its own to open the valve.... I had to drill the hole in the stock deeper to miss the nuts when the gun is cocked.... Moving the RVA screw forward reduces the space between the front of the guide and the hammer, which results in less distance for the hammer to coast before hitting the valve, and also results in compressing the spring further when the gun is cocked, storing more energy in the spring.... Therefore the RVA still works as intended....
The original plan was to use a 3" long, 11 lb/in. spring, with 5 lbs. preload and 15 lbs. force when cocked, but to get that to work I had to run it right up until it touched the hammer.... I ended up with a 13 lb/in. spring, with 7 lbs. of preload.... I think I needed more force because the guide is no longer part of the hammer weight, reducing the weight available to open the valve from 102 gr. to 84 gr.... The end of the guide misses the hammer by 0.12", meaning that the 1" cocking stroke compresses the spring an additional 0.88", giving about 18 lbs. force when cocked.... This is when adjusted for 971 fps average (94 FPE) with the 44.8 gr. JSB, the same as I had previously.... Although the maximum cocking force is only 3 lbs. less than with the previous short, stiff spring (2.5" long with a 24 lb/in. rate), the gun is much nicer to cock, with no tendency to not complete the cocking stroke.... I think this is because the force on the bolt handle is much more constant (7-18 lbs.) instead of increasing so rapidly as you pull the bolt back (0-21 lbs.).... With the sudden increase of force at the end of the bolt travel previously, you had a tendency to not complete cocking the gun, which could lead to double loading pellets....
So, how did it work?.... did it make the gun any more efficient?.... Yes, it did, and there is no longer any audible hammer bounce.... When I first assembled and tested the gun, I got 17 shots with the 44.8 gr. JSBs at just under 94 FPE.... However, with use and wear, the gun has developed an audible hammer bounce, and in addition a leak between the barrel and receiver at the transfer port, and was down to 13-14 shots per fill.... It still leaks, but you can no longer hear any hammer bounce (a very obvious difference in the sound), and the shot count is up to 15 shots before any velocity loss.... It is only down 10 fps at 17 shots, by which time it is down to 2000 psi (the setpoint is 2200).... Basically, by changing from a short, heavy spring (which gave me the previous best efficiency) to a lighter, longer spring with preload and a positive stop that holds it 1/8" clear of the hammer when uncocked, I gained at least a shot or two, putting me back over 2 complete magazines, even with the present leak.... I can say with confidence that using a preloaded spring that is not sitting against the hammer can reduce or eliminate hammer bounce.... We now have one more arrow in our quiver for tuning PCPs....
Bob
Bob, what's the OAL of your spring guide (including the head that goes inside the hammer) in this version?
I'm trying to work out some of my internals so I can source more than I have to fab or have built....
(Just a not-reinventing-the-wheel mania of mine -
"they" make almost everything, if you know what to call it.)
Thanks,
Rod
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You should be able to scale it off that photo.... The spring is 3" long, and compressed about 1/2", so what you see in the photo is about 2.5".... That would make the overall length about 4.2"....
Bob
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You should be able to scale it off that photo.... The spring is 3" long, and compressed about 1/2", so what you see in the photo is about 2.5".... That would make the overall length about 4.2"....
Bob
Thanks - I guessed four, but that's the longest 1/4" shoulder screw/bolt I could find (and that's minus the threads anyway - and the low head. Inside my striker will be flat, and I haven't yet decided its depth.)
I wish somebody carried the metrics (6mm) in the longest lengths - 100, 110, 120.
Here's a pic of what I found- 4.5565" OAL... but the shoulder is .25 od. (4.186"L shoulder, Plus ~0.3"+ of 10-32 thread. May need a spacer there for the short unthreaded portion, or to adjust the range. The bolts are also available shorter, of course.)
Hopefully spring (i.d.) selection will compensate for the 1/4"OD without having to
turn down the bolt's shoulder (also a possibility - as is drilling out the 7/8"OD, .5"ID hammer,
for a larger spring O.D..)
But you know me.
I practically insist on standard replaceable parts where possible.
(And still don't have a lathe or mill.
Working on reconditioning the W-T DP this weekend)
Photo is the best I could do - VERY tricky shot with the reflective scale...
Rod
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I made my spring guide from a length of drill rod, threaded both ends.... The front cone is a nut screwed on, the end peened over (with Loctite for good measure) and then turned to the shape I wanted to match the bottom of the drilled hole in the hammer....
Bob
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A couple of months ago Stalwart contacted me and asked if I would mind testing a couple of his modified XS-60c trigger groups. He asked Betty Lou and I to each shoot 500 shots with them and report our findings. Needless to say, I jumped at the chance. Eric has done his magic on 2 of our Beeman P-17 pistols in the past and he knows our trigger pull prefernces. Betty Lou a long pull for her smallish hands and surprisingly enough, she also likes her's a bit heavy. I like mine to snap right at the top. Break like glass with very little first stage. This is exacly how he set these 2 trigger groups up. We made zero adjustment to them. Betty Lou loved her's right out of the gate. She may be a little less critical than you and I.... cuz she's a girl.... I felt a whisp of a sticky spot in mine for the first 20 or so shots that soon developed into an easy touch of a first stage and a crisp snap. I have about 250 shots on mine now and it seems to just get better. A month or so prior Eric sent me one of his teflon coated hammers which is also in this gun. Along with the b-staley o-ring mod and set for low count/high power this .22 is my goto 50yd. de-nutter. When we are out plinking it always sits at the ready right next to the shooting bench waiting for Alvin and the crows. Eric has genoerously made a Birthday gift of Betty Lou's trigger group but, mine will be sent back to him so he can study how the improvments have held up. I'm going to miss it... Now I know what you're thinking.. I thought about it too but.... she puts it under her mattress at night.
Guys... contact Eric at StalwartArms.com or right here on the good ole GTA and get the skinny on these trigger groups... I'm sure there will be one in my future.
Stalwart... please jump in here and give us a little rundown on what you did to these things.
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I'm going to miss it... Now I know what you're thinking.. I thought about it too but.... she puts it under her mattress at night.
Bill,
I've got one of Eric's trigger groups sitting here on the shelf waiting for the rest of the gun to be finished, and knowing what I know about it...
I think if I was you, I'd chance it!!! ;D
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Plotting as we type...
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( .oO ...hope there's still one in "my box")
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Plotting as we type...
Bill, let us know when you are transferred from the ER to the ICU, so we can send flowers? Also, let us know if you still have teeth, and we'll send some appropriate snacks.
I'm going to miss it... Now I know what you're thinking.. I thought about it too but.... she puts it under her mattress at night.
Bill,
I've got one of Eric's trigger groups sitting here on the shelf waiting for the rest of the gun to be finished, and knowing what I know about it...
I think if I was you, I'd chance it!!! ;D
Guys, you are going to like the touches Butch has done to his 60.
( .oO ...hope there's still one in "my box")
Oh, yeah. It's in there.
These triggers are stout, but not very refined. It takes a while, but squaring off the sears, and putting just a touch more engagement angle in, does wonders for them. As they are nice and wide, a good safe engagement is still there without a lot of overlap. The metal is good enough to take (and keep) a fairly sharp edge, so they can be tuned for a very crisp release.
I ship them set for hunting, but after some use, they can be tuned to be decent target triggers (top screw, sets amount of overlap), too. My experience, backed by Bill and others, is that within 100 rounds, the faces mate nicely... for a smooth release.
I can polish them to eliminate a break in, but this takes time (spelled $$$), and if overdone, will take away some of the precise squaring I do. I'm doing these precisely the way I do my own triggers... and I like the results enough that I don't bother going back for the last adjustment unless the gun is purely for target use. I'm not, technically, a "trigger nazi", but I do like to bring a design up to the designer's intended quality. With the 60s/Fusions it's straightforward, and effective.
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Stalwart,
I am new here and I just "cleaned up" my trigger. (Gen 1 )
400,600,1000 and some molly grease really helped ( a lot)
But, when you said that you slightly change the engagement angle,
well, not being an expert I was very careful not to change any angles.
I would very much appreciate a picture , written or visual, of just where
and how much ( indeed, and how little) you change that engagement angle.
you spoke of.
Thank you.
Bob K
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I finished off the tin of 500 pellets this afternoon and the trigger is buttery smooth and predictable. I can really focus all my attention on the shot instead of trying to anticipate break. If I were not sending this trigger back to be analyzed I would take a little more first stage out of it. Everything else feels right for my taste.
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I finished off the tin of 500 pellets this afternoon and the trigger is buttery smooth and predictable. I can really focus all my attention on the shot instead of trying to anticipate break. If I were not sending this trigger back to be analyzed I would take a little more first stage out of it. Everything else feels right for my taste.
Got the trigger back, and have to thank you for shooting the heck out of it (would have taken me forever to accumulate that many shots with it). I agree with your assessment of it. It's going in one of my demos...
Stalwart,
I am new here and I just "cleaned up" my trigger. (Gen 1 )
400,600,1000 and some molly grease really helped ( a lot)
But, when you said that you slightly change the engagement angle,
well, not being an expert I was very careful not to change any angles.
I would very much appreciate a picture , written or visual, of just where
and how much ( indeed, and how little) you change that engagement angle.
you spoke of.
Thank you.
Bob K
Bob, if your sear needs lube to function, the last thing you need is more engagement angle. I would suggest setting up something that absolutely squares the faces, and then go for lighter spring pressure to get that feel you want. A good trigger job should never need lube on the sear faces.
As supplied, most triggers I have seen in AGs do what is called "rolling off", where the last tiny bit of overlap is actually overcome without more input. This is caused by the tiny bit of roundness at the sear's edge, allowing the striker spring (not you) to finish the action. You cannot get a crisp and predictable trigger without eliminating as much roll off as possible, with a square and sharp edge.
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LMBO..... My friend... anytime you need any of your amazing works of art tested/demoed, I'm your huckleberry. I completely enjoyed the trigger. It was a great advantage to have another gun with a stock trigger in it to compare side by side. It was also interesting to have another one of your triggers in Betty Lou's gun with the different pull setup. (3 guns total) Thank you for the opportunity.
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Bill, there is more to come. That, I can promise... but, as everyone knows by now, I cannot promise when. :)
Just plugging away here... it'll all happen, eventually.
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Guys, although I had intended to go for 4.5K, or nothing on these... I am contemplating doing some 2K (almost thru-tube, as seen in my earlier prototyping) setups, in response to the tube problems in some FDPCPs. This would vastly increase the safety margin, and could have internal fill cap threading, if desired.
It would eliminate the tube seal as well. I would include a Teflon striker, and if you polish the striker's channel, it would still be pretty slick... but, without some of the costs associated with machining the full TT (4.5K) rigs.
Please LMK if this sounds like a viable option? These things are a ton of fun at 2K, and this option would make the best of that pressure, at a more affordable price.
Also, any prices quoted to date will be good until Nov 1.
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Sounds neat. I take it you mean burst at 6k?
No way could I pump to 4.5k anyway.
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The weakest part will be the fill cap retaining nut, as always with a well fitted tube. QVT's finite analysis (posted here, earlier) shows that clearly... that's why I'm thinking internal threads for the cap.
If there is interest, I'll proto one, and submit it to Our Beloved Safety Officer for some hard numbers.
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Here's some prelim numbers on the new design... I'm pretty happy with them!
"The safety margin for the bearing load would be about 2:1.... compared to about 1.2:1 now.... For my money, that’s good enough, I mean they aren’t crushing the reciever now, at over 2000 psi, and you are nearly doubling the thickness by adding steel.... If you drill the rear hole through to the head diameter of the screw, and use a full depth head, plus the stock installation on the front screw, that goes to about 3.5:1.... overkill, IMO.... I don’t mind if the bearing load is “only” 2:1.... You do need to use better screws, though.... minimum 120K tensile.... "
There is a minor twist to this design, that makes all the difference in the strength. More soon...
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Two 5mm screws, used in the current manner (shank in shear) would have a 3:1 safety margin at 2000 psi if the screws used are 120K tensile strength.... The increased thickness of the tube plus receiver increases the bearing load safety factor to an acceptable level.... because of the "twist" that Eric mentions, quite clever I might add.... The big bonus is that leaks should be a thing of the past, due to the tube extending past the valve.... No weak point where the tube threads into the front of the receiver, either.... and it won't matter if your receiver is worn or out of tolerance.... 8)
Bob
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That makes me feel a lot more comfortable to hear. I still shoot my gen1, but I do keep it in a rack pointed at a concrete basement wall.
I defer to the combined wisdom of the fine folks here, but 3:1 makes me feel better than 2:1, which of course makes me feel a lot better than 1.2:1.
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Makes me feel good that when I receive my two 60's from Stalwart they are going to be engineered safe. Keep up the good work gents.
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Cut the first of the 2K protos... I'm really liking it. Solid. I'm rethinking all this, and given that with a bit more tooling, I can make them quickly enough to make the difference in my costs translate to a great value for the price... and the fact that at 2k, they can be real hitters if needed... they may be a permanent part of my eventual product line.
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Very good stalwart on the work everything you have been doing looks awesome I'm looking forward to packaging mine up to send for work going to be great
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Thanks, Chris.... welcome to GTA!
Guys, I have decided to go for ChroMoly tubes, across the product line. One of the things I wanted to do with these rifles was to make sure everything I sell can take an accidental overfill (max pressure possible... 4.5K) without danger to the operator. The design, in 1018 steel, can do that... but, would have to be inspected for malformation before refilling. However, in CrMoly...
"The CrMoly tubing is 3.7:1 to yield at 3000 psi.... Two 120K 5mm screws are 3.0:1 in shear (higher tensile would be greater) at 2000 psi.... but only 1.4:1 on bearing area in the tube itself (using just the screw shanks).... Add on the receiver thickness (0.055”?) and you’re at about 2.6:1 at 2000 psi for the bearing load, not an issue.... That would allow a 4500 psi overfill at a safety margin of 1.16:1.... probably just mark the holes from the threads...."
It will cost me (and therefore, you) a *few* more bucks, but I will sleep well knowing they have that margin between us and injury or damage. If you put 4.5K in, it will be up to you to figure out how to get the air back out (drift and big hammer?)... but, you can go right back to shooting the gun.
If anyone wants in on the first short run, holler soon. I will be cutting as soon as the materials and tools arrive. I'll be making only 6 in the first go around (and timing every pass).
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Not much I can add to this, except the R screws will definitely be set into the blocks. A few more bucks yields a 50% increase in margin:
"If you use screws that are 180K tensile, you have a 3:1 safety margin at 3000 psi in shear.... The front screw, with the shank through the tube and receiver, takes a load to yield of 618 lbs. in the tube, plus 332 lbs. in the receiver (based on aluminum at 0.055” thick), for a total of 950 lbs.... The rear screw, with a 5/16” head through the tube and receiver, takes a load to yield of 1278 lbs. in the tube, plus 686 lbs. in the receiver, for a total of 1964 lbs.... so the total for the two screws would be 2914 lbs.... The load at 2000 psi is 872 lbs., so the safety margin would be 3.3:1.... At 3000 psi, it would be 1308 lbs. load, so that is a safety margin of 2.2:1.... (With just the two shanks bearing against the tube and receiver, you have 1237 for the tube and 664 for the receiver, for a total of 1900 lbs.... The load at 2000 psi is 872 lbs, so the safety margin would be 2.2:1).... Setting the rear screw down so that the head takes the bearing load increases the safety factor by just over 50%....
Basically, if you use really good screws (180K minimum), and a good fit in both the tube and receiver (so the load is shared by both), the gun would be OK at 3000 psi, for the strength of the tube (3.7:1), the screws in shear (3:1), and even the bearing load (2.2:1).... At 2000 psi, it should be bulletproof, with all three factors being over 3:1.... This assumes a Disco fill fitting, if you use the XS fitting the limit is ~1500 psi / CO2 pressures...."
8)
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Note, the key to the above numbers is that the tube and receiver act as one piece, so that the bearing loads of the screws is shared by the total thickness of both parts....
Bob
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https://www.youtube.com/watch?v=pHGXwQeUk7M (https://www.youtube.com/watch?v=pHGXwQeUk7M)
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Here's the "twist". Took me quite a few tries, but I got a pic inside the receiver.
The tube threads into the receiver with a 12mm overlap, just behind the R screw. Nothing fancy.... but it's stout. The use of both good threads (past the pressurized area), and pinning with the screws are what gives this the strength.
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Bob... just for fun... how much could this tube take if we put them together with Loctite? We have 4.5" of well fitted overlap. Could we hang a bus from it?
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I don't have the data for steel to aluminum, but Loctite 638 is listed at 4500 psi shear strength for steel to steel.... You are talking over 12 sq.in., so in theory 55,000 lbs.... *LOL*.... Epoxies are typically 3000+ psi, the weakest Loctite I found was 1700 psi.... That is still over 20,000 lbs.... so, yeah, pretty much hang a bus on it.... Once you cover the tube with glue and screw it into the back of the receiver and it sets.... you can treat the assembly as one piece.... The valve screws then do all the work.... and you have more thickness for the screw heads to bear on than just the tube by itself, which is the really kewl part....
Actually, the load limit on pulling the tube out of the receiver will end up being the strength of the tube itself.... Using CrMoly, with a tensile of 97K, and the area of the tube, which is about 0.165 sq.in.... that works out to about 16,000 lbs. load before the tube will break....
Bob
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Bob... just for fun... how much could this tube take if we put them together with Loctite? We have 4.5" of well fitted overlap. Could we hang a bus from it?
Hey Bob...
Don't you just love how he uses you for his personal calculator..... j/k
You guys amaze me.
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awwwwwwwwww.... he knows what buttons to push is all.... *LOL*....
Bob
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Bob... just for fun... how much could this tube take if we put them together with Loctite? We have 4.5" of well fitted overlap. Could we hang a bus from it?
Hey Bob...
Don't you just love how he uses you for his personal calculator..... j/k
You guys amaze me.
LOL... if you think this is a long process already... without Bob, it would take years!
I've never pretended, even for a moment, that I would get anywhere without this help. Given the dangers if a mistake is made... I'd be afraid to try. You haven't seen the half of it.... I run every dumb idea past Bob, backstage. He's always been kind enough not to laugh (at least, not to my face).
;)
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awwwwwwwwww.... he knows what buttons to push is all.... *LOL*....
Bob
For reasons I haven't quite figured out, you seem to be quite certain you don't want to see me blown up!
All I can say is "whew!".
;)
I'm having so much fun... just love this place.
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I would give up all my worldly possessions to be able to walk around the shop and watch you guys do what you do.... ok that's a lie... I think I'd like to keep my Silver Streak.... and my Harley... and... and... oh nevermind, I'll just keep on reading about it.
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;D I think it is Bob's mission in life to drag us all up to his stratospheric level of air gun smarts ;) ;) And Yes Bill that makes two of us I'm convinced that the next time I retire I am going to take some math and mechanical engineering classes ::) ::)
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LOL... funny thing is, a couple years ago I bought 5 B2-1 from a wholesale club. I built a spring compressor and took them apart. Filed a little here and sanded a little there, slopped on some heavy tar and moly paste. Painted them black, green, camo and even pink. I got them to shoot quarter size groups at 20 feet and I thought I was a master airgunist...... Thanks Bob and Erik, for poppin that balloon.
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LOL... funny thing is, a couple years ago I bought 5 B2-1 from a wholesale club. I built a spring compressor and took them apart. Filed a little here and sanded a little there, slopped on some heavy tar and moly paste. Painted them black, green, camo and even pink. I got them to shoot quarter size groups at 20 feet and I thought I was a master airgunist...... Thanks Bob and Erik, for poppin that balloon.
;D Bill I remember those posts has it been that long? Yes Bob's esoteric studies tend to leave me scratching my head for at least 2 or 3 readings then I sort of understand kinda ::) ::) ;D
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Yep, I think it's been right about 2 years.....
I think I've even thanked Bob a time or 2 for toning things down a bit so I could understand. More often than not, his answers leave me with more questions.
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The kewl thing is I'm still learning.... Somebody asked me today about lightening a hammer to reduce bounce, which led me to explain that hammers always bounced the only bounces that were important were ones that waste air.... which led to talking about plenum size, and then the light went on and I realized that small plenums were more prone to hammer bounce.... Bear with me.... The smaller the plenum is, the more the pressure drops during the shot.... because the regulator can't top the pressure up fast enough.... The more the pressure drops, the easier the valve is to smack open a second time.... Therefore, take two identical guns, one with a larger plenum, and tune them for the same FPE.... The smaller plenum is not only less efficient because the pressure drops faster, that pressure drop also means it is more susceptible to air-wasting hammer bounce.... which amounts to a double whammy on efficiency.... It also means that if you skimp on the plenum, you have to be more concerned about eliminating bounce.... Perhaps this is why guys running minimal plenums tend to use light hammers.... because they have to?....
We now return to our regular insanity errrrrr program....
Bob
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;D Thanks for the insight now when I install a reg in my .177 AA S510 I know to max the regulator plenum kewll
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We did a bunch of math on plenum sizes for in-tube regs. a while back.... Each installation will be different.... but the best shot count (but not the best efficiency) will generally occur with a plenum somewhat less than 1 cc per FPE.... but larger than 1/2 cc per FPE.... This is because as you increase plenum, you lose reservoir.... so it's a balancing act.... Certainly a 1/2 cc per FPE plenum will be more susceptible to hammer bounce, so you would be advised to tune it further down the knee of the curve, more towards the downslope.... It's no coincidence that is the best place to tune in-tube regged guns.... A bit high on the pressure, and low on the knee.... Since that means light on the hammer strike, it encourages lighter hammers.... I think Scott figured that out a while ago, but I think today I just figured out why (greater pressure drop = more likely bounce problems).... Since my regged guns use big plenums, and a separate bottle with a Ninja reg, bounce is generally not an issue.... except for the Grizzly where I was pushing it trying to get 100 FPE on only 2200 psi.... hence the time I spent chasing hammer bounce until I came up with the spring travel limiter....
Bob
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Yep, I think it's been right about 2 years.....
I think I've even thanked Bob a time or 2 for toning things down a bit so I could understand. More often than not, his answers leave me with more questions.
Yeah, welcome to my world. The thing is, he has answers to the questions that arise from his answers. I get the snowball effect... I find myself applying ice to my temples, to cool my processor before I go all blue screen on you guys.
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Coffee all over the screen on that one!
Bob
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The kewl thing is I'm still learning.... Somebody asked me today about lightening a hammer to reduce bounce, which led me to explain that hammers always bounced the only bounces that were important were ones that waste air.... which led to talking about plenum size, and then the light went on and I realized that small plenums were more prone to hammer bounce.... Bear with me.... The smaller the plenum is, the more the pressure drops during the shot.... because the regulator can't top the pressure up fast enough.... The more the pressure drops, the easier the valve is to smack open a second time.... Therefore, take two identical guns, one with a larger plenum, and tune them for the same FPE.... The smaller plenum is not only less efficient because the pressure drops faster, that pressure drop also means it is more susceptible to air-wasting hammer bounce.... which amounts to a double whammy on efficiency.... It also means that if you skimp on the plenum, you have to be more concerned about eliminating bounce.... Perhaps this is why guys running minimal plenums tend to use light hammers.... because they have to?....
We now return to our regular insanity errrrrr program....
Bob
Well then, you may want to swallow before your read this one.....
The post above emphasizes exactly what my point was.. I actually understood it. 2 years ago I thought plenum was a bad thing that you needed to have removed from the rectal area.
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::) ::) No Bill that's a pollup
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::) ::) No Bill that's a pollup
Once again, my knowledge is expanded... thanks guys.
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::) ::) No Bill that's a pollup
Once again, my knowledge is expanded... thanks guys.
;D ;D ;D ???
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The kewl thing is I'm still learning.... Somebody asked me today about lightening a hammer to reduce bounce, which led me to explain that hammers always bounced the only bounces that were important were ones that waste air.... which led to talking about plenum size, and then the light went on and I realized that small plenums were more prone to hammer bounce.... Bear with me.... The smaller the plenum is, the more the pressure drops during the shot.... because the regulator can't top the pressure up fast enough.... The more the pressure drops, the easier the valve is to smack open a second time.... Therefore, take two identical guns, one with a larger plenum, and tune them for the same FPE.... The smaller plenum is not only less efficient because the pressure drops faster, that pressure drop also means it is more susceptible to air-wasting hammer bounce.... which amounts to a double whammy on efficiency.... It also means that if you skimp on the plenum, you have to be more concerned about eliminating bounce.... Perhaps this is why guys running minimal plenums tend to use light hammers.... because they have to?....
We now return to our regular insanity errrrrr program....
Bob
I think it's a good time to follow these directions
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Does anyone know if putting a sound absorbing coating on the tube (bedliner?) will reduce "ping"?
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It might lessen what you hear, but to eliminate it at the source you need something to disrupt the sound bouncing around inside the tube.... The problem I have with depingers is that if they have a small hole (quieter?), they cut down the plenum size.... Also, they need a rigid spacer between them and the valve so they don't slide back when you fire.... I don't think bedliner inside the tube is a good idea, could flake off or trap moisture?....
Bob
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I have the option of a rubberized (they call it "armor") powder coating I could put inside and out. Matte black.
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It would be slick if you assemble the tube into the receiver and then powdercoat the assembly....
Bob
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That's definitely an option here. I need to find a thin epoxy that can take the 400F cure.
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Maybe check into Loctite 620 High Temperature (450*F).... 0.008" gap fill on the diameter....
Bob
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The fit is a whole lot tighter than that. I'm really happy with the fit I'm getting with the latest set up.
Just waiting on the CrMoly tubing, and a reamer now... looking forward to this.
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Anyone happen to have a Mossberg 500 shotgun nearby? If you could could measure the OD of the mag tube, and the distance between the barrel and the tube for me, it would be most appreciated.
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Got the measurements (thanks John)... and the results of that knowledge will be posted next year some time...lol.
The initial run of the new design has been increased to 8... and is all booked up. Again, the brave among you have decided to fund the development of an efficient production set up. Thanks, guys... a bunch.
:) Gotta love this place...
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Just a thought for exterior de-pinging experimentation.
The sound deadening sheets that the boys with the big car stereos use
is pretty well engineered. I would pretty much guarentee if you
chatted up a shop owner with your idea he would be happy to give you a few
cut-off scraps to try. They are self adhesive coated as well!
Bob K
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You mean dynamat?
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That is the one name brand I know of.
Peel and stick.
Quick, easy and reversible.
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That is the one name brand I know of.
Peel and stick.
Quick, easy and reversible.
That's a great idea.
I have to wonder what a small piece inside would do. I bought a stamped SS sink that had a 2" x 2" square on the underside of each bowl, and it sounded like it was a casting... "thunk".
Keep up the good thinking, Bob.... we need all the brains we can get, around here...
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Guys... I (we) need to thank some contributors to the cause of destructive hydrotesting of some 60s, to develop a database. They aren't in this for credit... only knowledge, for all of us.
Completely unsolicited, 2 guns (FDPCPs) are coming... and I just got some help procuring the equipment needed (didn't even know it was coming until I checked my PP email, and found it there... marked "For the GTA cause"). A 20K pump is now on it's way.
We're gonna hurt some guns, bad... and learn a lot.
The word "family" is tossed around a lot... Rest assured, guys, this family has your backs.
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In job long long ago, I had to make test specimens to be tested to destruction.
The old engineer in charge insisted that dial indicators needed to be used in
conjunction with the strain gauges. Long story short, the strain gauges did not
locate the failure mode, the dial indicators ( which were destroyed) did.
My point, how the test is set up is crucial as the results need to be analyzed
from more that a few view points. Like, is the aluminum receiver swelling
a bit under pressure? Is this "stacking tolerances " in relation to minimum "acceptable" thread depths?
Perhaps a dial indicator on the aluminum receiver during a hydro is possibly
a reasonable idea?
Food for thought.
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That is something to think about.
The plan is concentrated more on "when" than "why".... but, there is no reason the pressure couldn't be increased in increments (I planned a slow, steady sadism), and various measurements made. The receiver, at the threads, would be easy to chronicle in the vid. A cheap set of digital calipers could be clamped to it.
Can anyone suggest an easy to learn editing program? The simpler, the better.
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I've been asked if I could fit a Hatsan reservoir to a 60.
Anyone know what that would take?
https://www.pyramydair.com/product/hatsan-air-cylinder-fits-hatsan-at44-short-at44pa-hammerli-pneuma?a=4883 (https://www.pyramydair.com/product/hatsan-air-cylinder-fits-hatsan-at44-short-at44pa-hammerli-pneuma?a=4883)
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The valve is in the reservoir in the Hatsans.... I don't know how you would accomplish that.... If you just wanted to use the reservoir, with no valve, and have it removable (when empty) you could probably machine a sleeve that you pin into the 60 receiver and that has threads to accept the valve threads from the Hatsan (with the guts removed).... I think the OD would hit the barrel, if you didn't lower the C/L, however.... I can measure the OD of the one on an AT-44 if you wish....
Bob
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Please do. This guy wants a special 60... and I want to build it.
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The AT-44 reservoir is 31mm OD.... The valve threads are 18mm x something (1.5mm?).... With the C/L of the Hatsan reservoir lined up with the C/L of the 60 receiver, it hits the barrel....
Bob
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Thank you.
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After a visual inspection, I pumped my rifle up to 1500 psi ( my usual)
and shot a consistent 20 shot string at 14 paces ( my usual).
A bit high for the first 5 shot and a bit low for the last 5 shots ( my usual)
I really enjoyed shooting this rifle , as usual.
I believe I will do it again.
As usual.
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The last part needed to set up the DT rig is due tomorrow.
Is there any reason I couldn't use water in this, as long as I flush with oil before storing?
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You can use water, AFAIK, but thorough cleaning is a given afterwards.... You can use alcohol or acetone to absorb water, but it would probably destroy the O-rings / seals....
Bob
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Cool. I don't see this thing seeing much use (I sure hope), so, I'll just dry it all out and replace the fluid for storage.
Steven G is going to do the editing, etc. on the vids, so they shouldn't be painful to watch.
This might actually work! ;D
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Eric, I enjoyed our chat last night
I'm very happy to see this is getting close to testing time.
looking forward to the results, as well as "The Movie", haha.
I May have a couple of short Factory XS60c tubes that I'd be willing to send, if you think it would benefit the testing/pretesting in any way ?
Also, don't sell the testing rig short after the FD testing project is complete.
I'd be VERY interested in some burst testing done on some 22XX tubes, set up in different sealing configurations.
Carry on Captain('s) !
I'm confident this mission will be a success ! ;D
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I hope that at least one of the burst tests will be on a unit with marginal thread material so we can see at what pressure a poorly made unit can be expected to fail
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Likewise, Ron. As always.
Bring 'em ON! We'll blow 'em up.
Knowing I won't be mopping up oil makes it easier to imagine doing plenty of tests... and, given the help I got covering the cost of the rig, it's not like I'd have to charge a ton to break even (thanks, unsolicited benefactor!).
If you want to send the tubes, do so. I have a couple receivers that I can't use (proto/mistakes) that could be used to make failure prone examples, for educational purposes.
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That is what we need to see because we can safely assume that those that are well within safety specs will not be hazardous to your health unless severely abused
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Don, it will happen.
The pile of test subjects is growing.
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Well as it turns out, after speaking with my buddy Jeff, we have a few of the short factory Xisico XS60c tubes we can spare,...
... as well as an extra receiver too !... (providing this receiver will be suitable the test).
It is one that sometime back, we used as a test unit, we attempted to machine on to do our own repeaters. (I think Jeff went a little too deep on it or something). So, we never tried it on our "good" rifles.
Either way, it didn't work for what we were trying, but the lower threaded reservoir hole is unmolested, and should still be ok for the boom-boom test I think. ;) ;D
I'll get it from him in the next couple of days, and send it along with 3 or 4 short tubes.
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I'll bet your receiver looks a lot like the ones I'll be using. They'll be perfect... glad I didn't pitch mine out (pack rat wins again!). Thanks, Ron. The FDPCP you sent is coded "DT1", in case you want to cheer on it's destruction. It has .017" engagement (.034 difference).
Given some time, I could easily reproduce some pretty bad fits, and try them.
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The FDPCP you Santa Clause sent is coded "DT1", in case you want to cheer on it's destruction.
AHEM,... ;) 8)
Above quote Edited by Moderator for ACCURACY ! ;) ;D ;) ;D
( I'm confident Santa will be watching with great interest ! )
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Gotta love that guy! He doesn't ever send me what I think I want.... but, always knows what I need!
;D ;D
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BTW... DT2 (FDPCP, as delivered) has only .0095" engagement. The tube rocks even when sealed.
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BTW... DT2 (FDPCP, as delivered) has only .0095" engagement. The tube rocks even when sealed.
8) that will give us a worst case test right out of the gate awesome
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Yup. If not the worst, it is certainly close enough for our purposes.
I'm just glad the thing is out of service.
Guys, I'm not here to make judgements on specs... my task is to provide numbers as clean and accurate as possible... the Big Dogs here can give us the concise determinations... but, I have to say this: Unless your tube can't be rocked after about 6 turns in, you NEED to know the numbers. And, it is not costly or difficult to get them.
Think about it. A cheap set of calipers will give you all you need... even if they are not "dead nuts" capable. If you measure both the ID of the receiver and the OD of the tube with the same undamaged calipers, you have the difference... that's the only number you need to be accurate. You're using the same area of the caliper's scale for both measurements... and if it somehow reads .005 high (for example), it will read both .005 high... and the difference remains the same.
And, I promise you, if you buy a set you will never regret it. Until you own a set, you have no idea how many times it will come in handy.
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Where's the emoticon for cheering?
Thank you Eric (stalwart) for taking this on! I'm looking forward to your results and potential solutions.
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I'll be watching these tests with interest.... My son's FD-PCP is barely within specs, with a difference of 0.028" (an engagement of 0.014").... According to the tolerances I found, using the minimum tube OD (0.8580") and the maximum receiver ID (0.8328"), that works out to a difference of 0.0252" (an engagement of 0.0126").... Doing the opposite, with the maximum tube OD (0.8651") and the minimum receiver ID (0.8235"), works out to a difference of 0.0416" (an engagement of 0.0208").... Certainly an engagement of only 0.0095" is way below specified tolerances....
The thing we can't easily measure with calipers is the remaining thickness of the tube wall between the valley of the threads on the tube and the ID of the tube.... If, in fact, the failure was a "spiral failure" following the bottom of the threads in the tube, the OD of the tube could provide a clue if that was likely to happen.... but not definitive proof.... I will be more interested in seeing if any of the failures occur leaving the receiver threads mostly intact and a long spring hanging off the end of the tube.... I wonder if because the water can't expand when the pressure is released if all we will see is a crack (leak) in the tube, at the bottom of the threads, immediately outboard of the receiver....
Bob
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Where's the emoticon for cheering?
Thank you Eric (stalwart) for taking this on! I'm looking forward to your results and potential solutions.
It's my pleasure, Andy. The newer guns have much tighter tolerances (LOVE my Fusions), but I will always have a soft spot for the runts (Gen1). We need to get them back out there to be beaten (or modded) to death.
Bob, if I made a slug that replaced the valve, and extended it back to include the back mount screws, would that protect the holes enough that we could blow the tube threads out without damaging anything else (allowing a quick 3K conversion afterwards)? That would let me test a bunch of variables without losing a receiver (stretched holes) each time.
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BTW... ebay has digital calipers for as low as $5.
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_sop=15&_nkw=digital+caliper&rt=nc&LH_BIN=1 (http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_sop=15&_nkw=digital+caliper&rt=nc&LH_BIN=1)
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The more screws you pick up with your blanking plug, the less likely to stretch the holes in a receiver.... but you DO need to test one with stock valve screws and a pretty good tube (the one with the 0.017" engagement?) to find out what fails first.... After all, we have no idea what quality those two 5mm screws that hold the valve and backing block are made of, and I was never very happy with those.... The tube threads failing was never really on my radar initially, because I had always assumed them to be within tolerance, and the engagement is huge.... My greatest concerns were for the screws and the reduced tube wall where the threaded portion exits the receiver.... Check out my original post on this matter, from Feb. 21, 2014, Reply #4 in this thread.... http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=62302.0) .... Note that I also missed picking up on the thickness of the flange on the nut retaining the fill fitting, which QVTom suggested was marginal at over (hot) CO2 pressures.... It would be great if you can quantify the failure points of all those items....
Bob
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Any FDPCPs sent complete will be stripped to the pressure vessel and tested as delivered. I haven't even touched the screws.
I have also been sent FD tubes. I'm thinking of testing them, using receivers I have slated for 3K conversions, for more data on fit vs strength. I could match them up to any overlap you could imagine... down to nearly zero...lol.
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I did a quick drawing for standard ISO Metric threads.... Assuming threads are properly shaped, and perfectly formed (and we know they are not) a set to the tightest tolerance has a shear plane of half the circumference of the pitch circle times the depth of thread engagement.... Using the loosest tolerances listed, the engagement is ~60% of the maximum.... and the shear plane is reduced to ~75% of theoretical.... ie each thread has only 3/4 of the material in shear.... If the threads are more "pointed" it could be even less.... What this means is, that if both tube and receiver were the same material (they aren't), then at best case, a tube/receiver combo on the minimum overlap (0.0126") would be 25% weaker than one at the maximum overlap (0.0208").... The threads are still amazingly strong, particularly considering how loose they are, even at the loosest tolerance specified....
This calculation leads me to suspect even more the wall thickness below the valleys of the threads in the tube as the failure point.... a "spiral" failure....
Bob
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Here is a drawing of 22mm x 1mm threads, to scale, as cut into a 0.875" OD x 0.065" wall tube.... The upper horizontal dotted line is where the outer wall would be, if it were not threaded.... The lower horizontal line is the inner wall of the tube....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Thread%20Strength%2022mm_zpstwj9kezc.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Thread%20Strength%2022mm_zpstwj9kezc.jpg.html)
The black zig-zag line represents both the maximum tolerance for the tube threads and the minimum tolerance for the receiver threads.... They actually clear by a thou or so, but the lines would be superimposed, so I only used one line.... The short horizontal dotted line across the thread is at the pitch diameter, and represents the total shear plane, and therefore the strength of the threads.... It is 0.040" long, half on the tube and half in the receiver....
The Blue zig-zag line represents the minimum tolerance for the tube.... The Red zig-zag line is the maximum tolerance for the receiver.... The short horizontal lines are the shear plane for those, and is a total of 0.029".... You can visually see the gap in the threads which causes the wiggle in the tube, and the roughly 27% loss in shear area that results, even if both components are within tolerance....
The lower dimensions show the thickness of tube wall remaining if perfectly formed threads are cut in the tube.... It is actually slightly less than that, because there is usually a slight radius at the bottom of the valley of the threads.... For a tube with maximum size threads, the wall thickness will be less than 0.039" instead of 0.065".... For a tube with threads at the minimum tolerance, the thickness of the remaining tube will be half what it started at.... If the threads are cut with a pointed threading tool, that comes down to only 0.026"..... It the threads are also pointed on the top, for a tube where the thread OD is right on the minimum tolerance, it could be even less.... For a tube that measures smaller than the minimum tolerance, depending on the shape of the threads, it is quite possible that less than a third of the original tube wall remains.... Of course the reduced overlap would also reduce the amount of material in shear as well....
Please note I am not stating that these conditions exist, or who is responsible for them being that way.... I am only showing you what the threads look like, drawn to scale, on a tube wall of 0.065".... I hope it will give you a visual representation of what the concern is, and why.... I can't state a maximum safe working pressure for the FD-PCP tube is we have no idea what the material is (despite asking Mike numerous times).... A 0.875" OD x 0.065" wall DOM tube made from 1018 steel would have more than a 3:1 safety margin at 3000 psi.... If the wall is a third of that, well you do the math.... Then add stress risers at the sharp corner at the bottom of the threads, and the possibility of striking the pressurized tube when handling the gun (or falling on it) adding more stress to the metal.... well, you get the idea....
Bob
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Well, heck! :(
The last fitting came today, I set it up to pressure test.... and it leaks (weeps, given time. Loses about 100psi per min starting at 9K). Not a lot, but enough that leaving it alone for a while, under pressure, made a nice little mess.
Also, to get the pressure to even 9K requires quite a serious push on the pump handle. I may need to make a longer handle (or, with a rat trap bicycle pedal?)... and a base so that handle doesn't try to flip the pump in use at 15k (gauge limit).
I have decided to make my own stuff.... with good overlap. I changed my mind about feeding from the fill fitting end, and will make an adapter that replaces the valve... which will allow testing the entire system from the foster fitting back.
I'm going to have a lot of time into this before I get to blow anything up... so... I want to blow up everything I can get my hands on. Bring 'em on.
I'm off to enjoy the holiday... Merry Christmas, guys! We'll be roaching guns in '16!
;D
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1144 steel, with enough meat to put screw holes for a bunch of different patterns. I'll set it up to test the stock pattern, my 3K and 4.5K designs... and there is enough left to set it up for any other 3/4" patterns (Ron's?).
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Well, I just blew something up.
I was using the QD fitting to block off the pump while I took it to 15K, to see if I had to make the handle longer... or, if I could just step on it. Stepping on it works, and I left it pressurized... for about 5 seconds...
The ring blew out in the fitting. Made a cloud of mist about the size of a basketball, and a fairly loud pop. No fireball, no shock wave, no shrapnel (half of the ring is sticking out of the nose).
Now I'm afraid the movies are going to be pretty dull.
;D
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You blew up a QD Fitting?.... guess you won't be using those for testing, HUH?.... *LOL*....
Bob
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No. LOL... looks like it's going to have to be 1 piece. That's OK, it is a dedicated rig... but, I'm now going to mount the gauge to the pump, instead of the probe. If I don't, I will end up smashing it.
The good news is that the pump and the hose are 15K ready. I'll be able to take the 4.5Ks to 3:1... that was all I needed.
I'm a happy guy, with 1 very shiny shoe. 8)
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;) This place is always an adventure and sometimes it is fun to read about the missteps as long as nobody gets hurt. So now you have a waterproof shoe which isn't all bad either that way when you leak on your shoe your sock will not get wet. ;D ;D
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That's right.
And, if I stand just right when DT2 goes up, I can make a matched pair.
These things have a way of working out, if you put in some effort!
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That's right.
And, if I stand just right when DT2 goes up, I can make a matched pair.
These things have a way of working out, if you put in some effort!
;) ;D Sometimes I'm glad I don't have a machine shop handy or I would really get myself in trouble with doing extensive mods to my rifles. Luckily I am forced to limit my work to over the counter parts and light modifications to my toys ::) ;D ;D ;)
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If I didn't have mine, I wouldn't survive long. I would revert to a Wild Child, but without the "bulletproof" factor I was mysteriously blessed with... for a while.
It wouldn't be pretty.
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Ron, what are the specs (screw size and placement) of the guns you are thinking of testing?
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Ron, what are the specs (screw size and placement) of the guns you are thinking of testing?
Eric,
PM sent
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Got it. No problem... all tooled up for them.
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What is the brand and length of a good 3/4" internal regulator?
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OK, the probe is done. I decided to give up on making this rig to try to blow up my 4.5K design... I have to make fittings of my own to do that (it'll happen later), and I have to wonder if the hose won't be the next to fail (already ruined 2 fittings, this one showed up 2 hrs ago), if I attempt that. Blowing up stuff to answer our immediate questions is in the bag... the branch tee shown is rated as high as I could find (retail) @6K.
When the time comes to test the 3K design, we'll see what that fitting and the hose can really take... I'm thinking the 4.5K will not use either.
Done for the day here... more very soon. I'll admit, there must be some vandal blood in me (latent)... I'm looking forward to ruining something more than fittings.
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Blowing up stuff to answer our immediate questions is in the bag... Done for the day here... more very soon. I'll admit, there must be some vandal blood in me (latent)... I'm looking forward to ruining something more than fittings.
Am I the only one here who detects some faint background noise,...
... that sounds strangely like Dr. Frankenstein's "evil laugh" ? ? ? ;) :o ;D
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Blowing up stuff to answer our immediate questions is in the bag... Done for the day here... more very soon. I'll admit, there must be some vandal blood in me (latent)... I'm looking forward to ruining something more than fittings.
Am I the only one here who detects some faint background noise,...
... that sounds strangely like Dr. Frankenstein's "evil laugh" ? ? ? ;) :o ;D
The reason you can't hear me laugh very clearly, is the 12' Jacobs Ladder.
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Guys, I found something very interesting when searching "XS60C PCP repeater" on google:
There isn't a single trace of my guns, or SA there. Since I started this, I have held the first image, with a bunch more right after, and have always been on the first page of results.
There are a bunch of irrelevant pics there now, and A****r is up there... In spite of the number of views here... and the fact that no one else makes a repeater.
What is going on? Is someone playing games here?? Could someone be reporting the images, and getting them pulled?
I have to know this. It's pointless to pour my guts into this, if I'm not going to get any credit for all this, or exposure I feel I have more than earned... Things got tough enough here, after that FDPCP blew up... I have been dealing with it as well as I can, but if I'm in a fight with a sneaky bastid, I need to know.
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Guys, I found something very interesting when searching "XS60C PCP repeater" on google:
There isn't a single trace of my guns, or SA there. Since I started this, I have held the first image, with a bunch more right after, and have always been on the first page of results.
There are a bunch of irrelevant pics there now, and A****r is up there... In spite of the number of views here... and the fact that no one else makes a repeater.
What is going on? Is someone playing games here?? Could someone be reporting the images, and getting them pulled?
I have to know this. It's pointless to pour my guts into this, if I'm not going to get any credit for all this, or exposure I feel I have more than earned... Things got tough enough here, after that FDPCP blew up... I have been dealing with it as well as I can, but if I'm in a fight with a sneaky bastid, I need to know.
I just googled " XS60C repeater " and this is what I got on the first page of hits :
XS60C PCP Repeater project - Airguns & Guns Forum
www.gatewaytoairguns.org/GTA/index.php?topic=59114.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=59114.0)
Jan 5, 2014 - 20 posts - 5 authors
XS60C PCP Repeater project, Air guns, Airgun Forum.
XS60c pcp repeater 1 post Jan 3, 2015
Xisico xs60c co2 multishot 18 posts Jun 11, 2014
More results from www.gatewaytoairguns.org (http://www.gatewaytoairguns.org)
XS60C/Fusion repeater - STALWART ARMS
www.stalwartarms.com/xs60cfusion-repeater.html (http://www.stalwartarms.com/xs60cfusion-repeater.html)
Available in .177, .22, .25 and .30 caliber, this conversion uses Benjamin Marauder magazines. Offered in various states of finish, including complete custom ...
STALWART ARMS - Home
www.stalwartarms.com/ (http://www.stalwartarms.com/)
We are the originators of the XS60C/Fusion repeater modification, their 3K and 4.5K psi HPA Thru-Tube conversion, and a variety of quality upgrades for the ...
Canadian Airgun Forum | Flying Dragons PCP - XS60C based
www.airgunforum.ca (http://www.airgunforum.ca) › Board index › Main Forum › Mods and Repair
Feb 23, 2014 - 15 posts - 4 authors
I can now set the gun up as a repeater using the 8-shot PRod magazine and get 2 full magazines at the 20 FPE level I wanted.... The best 20 ...
Flying Dragons PCP - XS60C based - Canadian Airguns
www.canadianairguns.com/showthread.php?1210-Flying...PCP-XS60C (http://www.canadianairguns.com/showthread.php?1210-Flying...PCP-XS60C)...
Feb 20, 2014 - 10 posts - 2 authors
I'd like to set this gun up as a Grouse gun for my son, as a repeater using the MRod mags, and the ideal would be 20 shots (2 magazines) at 20 ...
@=S+S%^$# on Airguns: The Xisico XS60C. Do You Want ...
www.@#$%^.info/.../the-xisico-xs60c-do-you-want-maximum.htm (http://www.@#$%^.info/.../the-xisico-xs60c-do-you-want-maximum.htm)...
Oct 29, 2013 - Here's the test data for a .177 cal Xisico XS60C shooting a variety of pellets. .... The QB79 PCP Repeater · New Custom Wood Pistol Grips for ...
Gateway to Air Guns - Facebook
https://www.facebook.com/GatewayToAirGuns (https://www.facebook.com/GatewayToAirGuns)
... it into a repeater. Ingenious! This is the same gun that Flying Dragon Air Rifles sells converted to PCP. XS60C PCP Repeater project - Airguns & Guns Forum.
CO2 AIRGUNS | XISICO USA, INC
xisicousa.com/xisicousawebsite/airgun-4/co2-airguns/
The Model XS60C is designed to accommodate up to two 12 gram CO2 cartridges or a bulk fill ... XISICO XSP226 is a CO2 powered 18 shot BB repeater pistol.
XS60C CO2 Repeater by George_Bowen | Photobucket
s1364.photobucket.com/user/George.../XS60C%20CO2%20Repeater
XS60C CO2 Repeater by George_Bowen. 9 photos.
XS60C PCP Air Rifle /xisico/ - YouTube
Video for XS60C repeater▶ 3:14
https://www.youtube.com/watch?v=NgU--Bmxi0M (https://www.youtube.com/watch?v=NgU--Bmxi0M)
Mar 30, 2015 - Uploaded by Sustekov
Airgun xisico xs60 pcp /.177/ fun video. do not buy -Flying Dragon,bad gun.
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I got the same results after pulling the "PCP" part out of the search.
I wish I knew more about how all this works. I have been checking the search engines all along, using the full phrase. I have always ruled the results.
Any ideas?
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Leaving the "PCP" in now results in 39 results... and SA isn't included in any of them.
I just don't get it.
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https://www.google.com/search?q=XS60C+Repeater&sourceid=ie7&rls=com.microsoft:en-US:IE-Address&ie=&oe= (https://www.google.com/search?q=XS60C+Repeater&sourceid=ie7&rls=com.microsoft:en-US:IE-Address&ie=&oe=)
I just did a search and you are the #1 result....
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Actually...the #1, #2 and #3 result.
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Now I'm completely baffled.
Adding PCP eliminates me... this thread is there, but no images or other references.
This is a relatively new development. I need an internet mentor.
If I'm being paranoid, or ignorant, please forgive me guys. Given the sneaky stuff pulled by our "buddy" in the past, and the fact that I have invested in all this WAY beyond the hobby budget... I have to be ready to fight, if needed.
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What can I say....
Did a search, you are top of the heap.
Used XS60C Repeater as the keyword search. You #1 - 2 - 3 on the results.
Added PCP and your thread here is still the #1 result.
You either have browser issues or being overly paranoid.
:)
I don't think anyone is messing with you Eric. And I do understand and respect that you have a LOT riding on this project.
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Looks like the Canadian Airgun forum has a lot on it too.
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Only thing you could POSSIBLY do is pay for SEO (Site Engine Optimization) service for your website to get it up higher?
But if you show as #1 with the XS60C Repeater search, you is already there.
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I just tried it again... still no mention.
I need help learning how this all works... we are getting completely different result with the same phrase.
Thanks, Dave.... you have always been a calming influence on me (inside joke, guys... don't ask!).
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LOL
You might try clearing the cache of your internet browser and try again.
I just tried it on a different computer. XS60C Repeater
You are top 3 results with the top 2 being directed to your website and the #3 directed to this thread.
After that, you are followed by a few from the Canadian Airgun forum, then one by our buddy, and a few all over the place including the GTA Facebook page and a youtube video.
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Edit: The vid is of a Gen 2. He needs to slot his trigger housing's R hole a tiny bit. I saw later he got it to shoot, but he didn't explain why.
Off to clear my cache... Thanks.
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Cleared, and got the same result:
About 855 results (0.24 seconds)
Search Results
XS60C PCP Repeater project - Airguns & Guns Forum
www.gatewaytoairguns.org/GTA/index.php?topic=59114.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=59114.0)
Jan 5, 2014 - 20 posts - 5 authors
XS60C PCP Repeater project, Air guns, Airgun Forum.
XS60C PCP Air Rifle /xisico/ - YouTube
Video for xs60c pcp repeater
▶ 3:14
https://www.youtube.com/watch?v=NgU--Bmxi0M (https://www.youtube.com/watch?v=NgU--Bmxi0M)
Mar 30, 2015 - Uploaded by Sustekov
Airgun xisico xs60 pcp /.177/ fun video. do not buy -Flying Dragon,bad gun.
Flying Dragons PCP - XS60C based - Canadian Airguns
www.canadianairguns.com/showthread.php?1210-Flying...PCP-XS60C (http://www.canadianairguns.com/showthread.php?1210-Flying...PCP-XS60C)...
Feb 20, 2014 - 10 posts - 2 authors
I got my FD-PCP in the mail today, filled it to 1500 psi and shot a few ... I'd like to set this gun up as a Grouse gun for my son, as a repeater ...
@=S+S%^$# on Airguns: The Xisico XS60C. Do You Want ...
www.@#$%^.info/.../the-xisico-xs60c-do-you-want-maximum.htm (http://www.@#$%^.info/.../the-xisico-xs60c-do-you-want-maximum.htm)...
Oct 29, 2013 - Here's the test data for a .177 cal Xisico XS60C shooting a variety of pellets. .... The QB79 PCP Repeater · New Custom Wood Pistol Grips for ...
Canadian Airgun Forum | Flying Dragons PCP - XS60C based
www.airgunforum.ca (http://www.airgunforum.ca) › Board index › Main Forum › Mods and Repair
Feb 23, 2014 - 15 posts - 4 authors
I can now set the gun up as a repeater using the 8-shot PRod magazine and get 2 full magazines at the 20 FPE level I wanted.... The best 20 ...
Flying Dragon Air Rifles
www.flyingdragonairrifles.org/ (http://www.flyingdragonairrifles.org/)
XS60C CO2 Air Rifle The XISICO XS60C is based on a design by our own Mike ... XS60C PCP Air Rifle: Second Gen Flying Dragon Air Rifles is proud to be the ...
Airgun forum: Best bang for a buck on a budget - Network54
www.network54.com/Forum/79537/thread/1397413770 (http://www.network54.com/Forum/79537/thread/1397413770)
Apr 13, 2014 - 9 posts
http://www.airgundepot.com/hatsan-at44pa-10-shot-pcp-25-caliber-air-rifle.html (http://www.airgundepot.com/hatsan-at44pa-10-shot-pcp-25-caliber-air-rifle.html) ... Even with some oddness about it, am going to put the Flying Dragons XS60C PCP on the list, even .... If you care about it being a repeater. #5.
This fellow has taken a single shot... - Gateway to Air Guns
https://www.facebook.com/GatewayToAirGuns/posts/751856531551771 (https://www.facebook.com/GatewayToAirGuns/posts/751856531551771)
This is the same gun that Flying Dragon Air Rifles sells converted to PCP. XS60C PCP Repeater project ... XS60C PCP Repeater project, Air guns, Airgun Forum.
Gateway to Air Guns - Facebook
https://www.facebook.com/GatewayToAirGuns (https://www.facebook.com/GatewayToAirGuns)
... it into a repeater. Ingenious! This is the same gun that Flying Dragon Air Rifles sells converted to PCP. XS60C PCP Repeater project - Airguns & Guns Forum.
Need help with a decision. .22lr or .22 PCP? : airguns - Reddit
https://www.reddit.com/.../need_help_with_a_decision_22lr_or_2... (https://www.reddit.com/.../need_help_with_a_decision_22lr_or_2...)
Reddit
Feb 2, 2015 - Notably, the BNM repeater breeches: ... This was my first pcp, and I still love it. I take it .... check out the flying dragon xs60c pcp ($305 w/pump) ...
I guess as long as people can find me...
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I think you're OK Eric, no worries.
and I don't think Archie has any power over Google's search engines.
No more Extra Large Triple Expresso's for you today ! :o ;) ;) ;) ;D (JUST KIDDING !)
LOL ! ! !
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Awww,c'monmanjustonemore!IpromiseIwon'tdrinkanymorethanthat!PLEASE?!?
As for archie, I wouldn't put anything past him. IIRC there was a time you could report images on google. Don't see that feature now.
Just checked again (full phrase). Nothing. Now I'm just dying of curiosity...
Oh well. So much I don't know. Just one more thing on the list.
Ron, trust me... you wouldn't like me without caffeine. You think I'm scatterbrained now...
;D
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Only thing you could POSSIBLY do is pay for SEO (Site Engine Optimization) service for your website to get it up higher?
But if you show as #1 with the XS60C Repeater search, you is already there.
Please NO. SEO scumbags are almost as bad as spammers. They are both subhuman filth. To be clear I mean the link farming kind, not the here is how to make your website more easily found in searches.
The difference is one will guarantee you top results the non-scum kind just makes them possible to get.
You could however make some simply changes to your website.
"Repeater XS60c" you already seem to have #1. "XS60c Repeater" #2 behind GTA thread that you started about this.
Your website not using the word "PCP" anywhere on the XS60C/Fusion page it is hurting you for those search terms. Also those should be two pages, ideally.
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Thanks, Steven. On it.
Funny thing... I just tried to call Xisico twice.... rang a bunch, then got a recording saying "answer system off".
I have some decisions to make, soon. If they cannot be reached on a weekday, before lunch... it will make some of those decisions easier.
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I compare SEO services to lawyers. And we all know what they are called. But like lawyers, these folks do supply a service that we can benefit from. They have the negotiating power or a link to the search engine folks we do not have.
Not that I like it but just a fact.
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Thanks, Steven. On it.
Funny thing... I just tried to call Xisico twice.... rang a bunch, then got a recording saying "answer system off".
I have some decisions to make, soon. If they cannot be reached on a weekday, before lunch... it will make some of those decisions easier.
They are local to me and I have never gotten them to answer. I wanted to see if I could buy from them instead of FD. I work about 20 minutes from their office.
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Searching XS-60c Repeater, SA is # 1 on Google for me.... Remove the hyphen, it is #1 & #2.... Add PCP and it drops from the top of the list completely....
I would suggest that you need to include "PCP" in the keywords list on your website, both versions of XS-60c, with and without the hyphen, and probably without the "c" as well.... Somewhere on your site should be a list of keywords that the Search Engines find to let them know what you do.... Add every keyword that you can think of that pertains to what you are trying to sell.... ( eg "airgunsmith", "airgun customizing", "airgun tuning", etc.etc.etc).... In addition, you can register your site on Google, with you as the website owner, and request they run their 'bot over your site.... You can also get your site rated by Norton as "safe", a good idea as well....
Go to "Google Webmaster Tools", create an account, and take advantage of all the free services they offer.... NO need to pay, and it will help immensely with your SEO results....
Bob
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I compare SEO services to lawyers. And we all know what they are called. But like lawyers, these folks do supply a service that we can benefit from. They have the negotiating power or a link to the search engine folks we do not have.
Not that I like it but just a fact.
As someone who works in this field, I must disagree. They do not primarily operate in that manner, most have no negotiating power nor any link to any search engines. They typically use link farms and other cons to change search results. This is why we all see so many spam posts on the internet. Remember if you hire them you are part of the problem.
You have deeply insulted lawyers.
Also if Google or Bing catch wind of this kind of thing, they will drop your site to the back pages. This happens regularly.
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Last year Google Webmaster tools was rebranded to Google Search Console.
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I just searched it as stated, and it came right up.... *grin*....
Bob
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Yeah, Google is good like that, usually. Sometimes not so much.
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Good advice. Thanks, guys.
Waiting for the weather to back off here, and puttering. Set up a laptop to record, and a cheap cam I can afford to have sprayed... soon it will be Amateur Hour.
Is there a certain amount of time the tests should hold steady at the increments, to give it time to fail, or should I just slowly increase the pressure?
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Don't know... or, just don't care?
Admit it, guys. You are no better than me... you just want to see boobs, fast cars, and big explosions.
This is not going to end well for me...
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Don't know... or, just don't care?
Admit it, guys. You are no better than me... you just want to see boobs, fast cars, and big explosions.
This is not going to end well for me...
Are you offering all 3 or just the explosions?
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Are you offering all 3 or just the explosions?
Amen. I thought he could settle on big, fast, explosive boobs... That could cover a dime at 50 yards.
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The first is a real rarity around here, unless you count the big guy in the auto shop at the end (I could ask him!). Would a burnout in my van work for you? Everything is drenched out there, I could probably get some wheelspin...
Are you offering all 3 or just the explosions?
Amen. I thought he could settle on big, fast, explosive boobs... That could cover a dime at 50 yards.
You are good at cost effective solutions. You are welcome in my shop... anytime.
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;D ROFLMBO you guys crack me up this is better than any therapist any day, this place and a nice glass of Glenn Fidich and I'm good
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Also, demonstrably, cost effective. I mimic that, with a different liquid.
On that theme, as we wait for favorable conditions, I present the cam even I can afford to ruin. Sold on ebay, the clip didn't even have a spring (they didn't mention that)... $5. I just hated the idea of ruining the "fine" camera I combine with my even worse photographic skills to bring you all into the shop.
The base is very magnetic, I'll be using a can of paint to get the height (won't have to wipe down a tripod). Salvage...
If you don't count the ruined fittings, the entire rig came in under $100, parts and materials. There's no excuse for not knowing what we are going to learn.
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Well, guys... here's something. I got sick of waiting on the weather to dry up, and did this inside. Mistake. I have a real mess to clean up.
This vid isn't worth editing (I pre-focused the cam, then moved it a couple feet back without remembering to refocus it), so I just posted it up here: https://youtu.be/CwL5x_vF0s0
As you can see, the new fitting started to leak before any other failures. You can see the gauge dropping before each new stroke (at about 3K), then the puddle forming as the leak develops. The screws failed at 6K, after seriously stretching the holes in the receiver.... and, for some reason that ruined the gauge... somehow leaving it permanently stuck at a pressure it never saw. Any ideas why?
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So the gauge was mounted to a piece of steel that simulates the valve, fastened in with the two stock screws and sealed with an O-ring just ahead of the screws?.... What was the test subject gun?.... thread tolerances?....
Bob
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Correct. The screws failed as the designer intended. If it was a valve/block in there, it would have vented out the bottom of the receiver and into the stock cavity (in an intact gun), leaving the shooter intact, and wondering what the h*** just happened.
The gun is DT1... .017" thread engagement. Again the unknown designer I have come to respect (very much) knew what he was doing by putting in an "absurd" amount of overlap between the tube and receiver.
I have been DQing set ups with equal or slightly more engagement... I don't regret that a bit, and this just makes me feel even better about that standard.
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That 0.017" is per side?.... so a diameter difference of 0.034" between the tube OD and the receiver ID?.... pretty much in the middle of the tolerance range, IIRC....
Bob
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Correct. I'm thrilled with the result... quite reassured.
I just noticed something in the vid: You can see the blue fluid, I added directly to the tube, leaking out the fitting, yet much of the stuff seen in frame after the failure is the brown stuff from the pump. I was a bit shocked at the force generated... as the mess seen, in frame, prior to the test was made carefully bleeding the air (as you suggested).
The action and the probe each moved quite a ways (over 2')... and I couldn't figure out how enough air remained to do that. The shock even very slightly moved the cam (at least the lens, 40" away).
I now believe I have demonstrated how much force can be retained (and quickly returned) by the hose. The splatter pattern is pretty clear...
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Maybe you had some air in the pump?.... you sure had some, somewhere.... or as you say the hose was expanding.... Lots of stored energy there, so be careful....
Bob
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I back fed some blue, tube raised, then closed the valve and pumped it back through... topped it off, sealed it, and bled through the Fosters. The gauge came off zero within a fraction of a pump. You can't see it (thanks, Eric ::) ) but the test started with just a few pounds in it.
That's why the leak showed blue. I think it would have turned brown, soon, if I had just stayed under 6K. The blue mess the gun left was pure... and the oil stayed in until it stopped (separate mess). I grabbed a screen shot of the vapor trail as it left the frame... somewhere in the 46th second. I'll see if it can be seen within the 200KB limits.
I'm convinced it was the hose... and, I don't want to get any closer to the guns. Got some thinking to do. About containment.
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Actually, those screws did pretty good to stand 6000 psi.... The end load is 2615 lbs.... The root diameter of 5mm x 0.8mm screws is 0.152-0.162", so that works out to an area of 0.0181-0.0206 sq.in. each... and a stress at failure of 63Ksi - 72Ksi.... which if the 60% of tensile at shear is correct, means they had a Tensile strength of 106Ksi - 120Ksi.... That places them at about a Grade 5 or just under.... It also means that with a 3:1 safety margin, the gun should never see more than 2000 psi.... so right there, you have your first important piece of information.... BTW, the information I have on safety margins for pressure vessels is a minimum of 3.5:1 using UTS (ie to burst).... Using that, with a 6000 psi failure, we get MSWP of 1700 psi.... with the test data to back it up.... Incidently, when I first did my safety assessment of the FD-PCP I warned that the screws were the weak point (after the pockets stretched first), but all of that was based on mild steel because I was not privy to what the materials are....
Bob
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Correct. The screws failed as the designer intended. If it was a valve/block in there, it would have vented out the bottom of the receiver and into the stock cavity (in an intact gun), leaving the shooter intact, and wondering what the h*** just happened.
I am pretty sure a change of pants would have been required as well.
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You guys sure know how to have fun !!!
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Bob, I'm impressed with all I've seen here. To take a random sample, and see it perform EXACTLY to spec, says a lot about the gun.
I'm tickled I could put together something good enough (but, only once) to do it's end.
I'm still mystified by the gauge damage. It didn't strike anything... trying to figure out what might have caused a pulse in the last micro-seconds. I cannot afford to buy a gauge for every test.
Steven, I'm not going to pretend, even for a second, that your statement wouldn't apply to me.
Bill, is that an offer to help clean up? That will be "fun"! I just walked away... with all the broken stuff in hand... lol.
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Guys, next time you see Santa, be sure to thank him. There is abundant proof we destroyed a perfectly good gun.
Edit: never mind... it's not downloading properly.
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I was asked a question I should have anticipated, and answered in the first post about this:
There is no measurable change in any of the other parts.... not a single thousandth. Nothing puffed up enough to stretch.
I remain impressed.
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Yes, it would appear, based on a random sample of one, that a 2000 psi fill pressure is not completely unreasonable, but certainly not above that, to maintain a 3:1 safety margin to the failure point of the weakest link, the screws.... I assume you were using the stock front fill fitting and CO2 retaining collar/nut?.... and that the threads there had the same 0.017" overlap?.... Any sign of angling or other strain on the retaining flange on the CO2 nut?....
It will be interesting to see what happens when you test guns with less thread overlap and the threads cut deeper into the tubing wall....
Bob
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Have you yet found the worst possible combo, oversize receiver and undersize tube?
A random sample of one is nice, but let's see what happens when you lose the pcp lottery, so to speak.
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The nut had only .001" less engagement, and showed no damage.
I have a wide range of sizes to try, as soon as I figure out why the gauge failed... and find a good substitute fluid. I'm not interested in spraying $9 worth of fluid everywhere, and buying a new gauge for each test. I will tap the fitting deeper to see if I can save it... and will look into cutting additives to see what can be done to water to allow it to be left in the pump between tests. Could use some help with that.
As to worst case... DT2 is, as it was delivered, as close as we need to go, I'm betting. I'll set up even worse, if it's fate leaves any doubts.
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Guys, am I correct in assuming that ya'll are testing the Gen I FD-PCP? If this is the case, is it possible to dedicate a thread? I suppose I could read through 68 pages of information to be certain.. if I weren't so old and lazy. And... Bob, did you just say that (if my random FD-PCP has the same or better match up on the threads as the one Eric tested) that filling to 2k would fall within safety margins? As stated before, I've degassed all three of mine and found no substantial loose or wiggle but, it would be nice to be able to enjoy these gun in the same comfortable fashion as I did before the "disaster". I did not specifically mic ID or OD but, I have been reluctant to put more than 1200 psi in any one of them since the formal GTA warning. With a 36" fill hose, I'm wasting a lot of air per fill with my 3300 psi 100 cf tank.
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BTW... I do realize that this testing is very preliminary.
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That's a great idea.
I can't speak for Bob, but strongly suspect he will remind us that although we can determine thread size and quality... only Mr. Melick knows the metallurgy, and if it was consistent across the board.
I'm sure I'm not the only person who would be grateful to see a dedicated thread. If you want to fire one up, you can compile data from more sources than I can. I'll crank out all the data you need, on pressures.
It would be a service to many, and a big help to me.
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BTW... guys, the plan is to blow up a lot of guns, eventually. If needed I will destroy more G1s, after the 2 FDPCPs... but, the sooner I can get to putting together a rig that will ruin my 3K design, and get back to the present, the better. I have remained, for over a year, the very last guy who needs this data.
I am obligated, willingly, to generate data. That is it. I'm not capable of, nor am I willing to certify guns. I have an opinion formed, that is being proven here, based on data I have had since before the first production FDPCP was made. I am under an informal NDA, and frankly.... I'm glad of that.
This whole thing can be fixed... but not by just me. And, Bob's contribution goes deeper (and more costly) than all but a handful will ever know.
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That's a great idea.
I can't speak for Bob, but strongly suspect he will remind us that although we can determine thread size and quality... only Mr. Melick knows the metallurgy, and if it was consistent across the board.
I'm sure I'm not the only person who would be grateful to see a dedicated thread. If you want to fire one up, you can compile data from more sources than I can. I'll crank out all the data you need, on pressures.
It would be a service to many, and a big help to me.
I respectfully decline... something as important to the safety of my GTA brothers and sisters should be left in much more capable hands than mine.
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I qualified my comment on the safety at 2K by saying "based on this sample of one", and with threads at mid-tolerance.... As stalwart says, we have no idea (despite asking) what material has been used for the tube, or if it has changed along the way, or for that matter what the specified tolerances are.... Users also must be aware that the tubes supplied as an FD-PCP are longer and of different dimensions than those originally supplied with the XS-60c.... When stalwart tests a tube with minimum thread overlap we may see different results, the screws may no longer fail first (as they should).... Time will tell....
Bob
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I qualified my comment on the safety at 2K by saying "based on this sample of one", and with threads at mid-tolerance.... As stalwart says, we have no idea (despite asking) what material has been used for the tube, or if it has changed along the way, or for that matter what the specified tolerances are.... Users also must be aware that the tubes supplied as an FD-PCP are longer and of different dimensions than those originally supplied with the XS-60c.... When stalwart tests a tube with minimum thread overlap we may see different results, the screws may no longer fail first (as they should).... Time will tell....
Bob
An important and appreciated clarification/reminder.
Thank You.
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I respectfully decline... something as important to the safety of my GTA brothers and sisters should be left in much more capable hands than mine.
That's cool. I was thinking something along the lines of a compilation effort, but can certainly understand anyone being hesitant to expose themselves to expectations of having to make judgements (see my above disclaimer).
I put another couple turns of room in the fitting, for more overlap. It was either that, or over tightening... which NEVER works. Got the screw remnants out... the R was pretty smeared into the hole... and as soon as a gauge comes, will be back to wrecking guns.
I'll be very surprised if DT2 doesn't show completely different results, but... I'm easy to surprise (and startle). We shall see!
In the meantime, I have a couple things cooking up to show off. Back soon!
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I think your gauge likely suffered as a result of too many "g" being applied when the first test parts accelerated out of the video frame on failure.... I would suggest you mount the gauge part (above) to something heavy (or bolted down) that won't see that rapid acceleration if you want the gauge to live....
Bob
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I think you're right. I can't imagine another reason... it's odd that the gauge is frozen precisely at the halfway point.
Another is on it's way. I'll figure out something in the meantime. I was thinking tether, but your idea of just adding mass makes a lot of sense. Simple physics, simply applied.
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Eric,
You mentioned a substitute fluid. Could you possibly use ethylene glycol? Plain old antifreeze.
It's what we use in the internal valve jacks on our tank trailers. It keeps them operating even in sub-zero
temperatures, lubricates and even inhibits corrosion ;D Also, there's no ignition risk. I know what can
happen when even a small amount of oil gets atomized. What do you think?
Regards,
Butch
PS - my 60 is assembled for testing/tweaking, but kind of got back-burnered when Mama went in the hospital right before the holidays. But I WILL get to it... ;)
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Butch, it sounds like a great idea. Do you have the mix ratio, or are we talking straight up?
Hope your sweetie is doing well. I am getting used to seeing AGs backburnered when reality sets in.... and have seen them benefit from being simmered a bit.
AG time seems to run slower than real time, but, indulging in it seems to slow aging here.
It'll happen when it happens... and I'm looking forward to seeing the detail work posted. I like your gun.
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Well this is a bit overdue, but better late than never as the saying goes ;) ;D
I just wanted to say that I think it is very nice of Eric to be taking on this task, (at much of his own expense I might add), in the common interest of ALL here.
He is basically doing this all alone, with no bias, with no personal agenda or manipulation, and is providing the data as it presents itself.
He is not profiting in any way on this, and it does take a LOT of time and effort away from his regular shop activities. It's actually COSTING him !
For myself, My HOPES are, that the data will put at rest, the issues and questions on the safety of these guns... or AT LEAST give us the parameters to "self inspect" our own guns to determine if they are within a reasonably safe spec.
These guns ARE a lot of fun, and they DO lend themselves well to some Great upgrades and modifications.
I DO like mine a lot. I will do what is necessary to insure it is safe, and worthy of continued use.
(I'll have a bunch of GS's coming out this spring, and they will need to be introduced to this fun affordable rifle ;) ;D :o 8).
I eventually would like to "massage it" up into a respectable 50yd "yote buster" :o ;) ;D (yeah, we all know who the "Masseuse" will be for that !) Haha.
Keep up the good work Eric ! BRAVO to You !
It's guy's like you, (and lets certainly not forget Mr. Sterne here too ;) ), who once again have continued to demonstrate and share and work, for the common good of everyone in the Airguning Community.
THANK YOU SIR('s) ! ! ,
for all of your time and efforts.
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Well this is a bit overdue, but better late than never as the saying goes ;) ;D
I just wanted to say that I think it is very nice of Eric to be taking on this task, (at much of his own expense I might add), in the common interest of ALL here.
He is basically doing this all alone, with no bias, with no personal agenda or manipulation, and is providing the data as it presents itself.
He is not profiting in any way on this, and it does take a LOT of time and effort away from his regular shop activities. It's actually COSTING him !
For myself, My HOPES are, that the data will put at rest, the issues and questions on the safety of these guns... or AT LEAST give us the parameters to "self inspect" our own guns to determine if they are within a reasonably safe spec.
These guns ARE a lot of fun, and they DO lend themselves well to some Great upgrades and modifications.
I DO like mine a lot. I will do what is necessary to insure it is safe, and worthy of continued use.
(I'll have a bunch of GS's coming out this spring, and they will need to be introduced to this fun affordable rifle ;) ;D :o 8).
I eventually would like to "massage it" up into a respectable 50yd "yote buster" :o ;) ;D (yeah, we all know who the "Masseuse" will be for that !) Haha.
Keep up the good work Eric ! BRAVO to You !
It's guy's like you, (and lets certainly not forget Mr. Sterne here too ;) ), who once again have continued to demonstrate and share and work, for the common good of everyone in the Airguning Community.
THANK YOU SIR('s) ! ! ,
for all of your time and efforts.
Well put Ron.
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Eric,
If I've failed to mention it already, your work IS greatly appreciated. As to the mix ratio, I'd say 50/50
would do the trick. You'll get the benefits of the anti-freeze, but being half water it'll be that much cheaper.
Hooh-rah for shoe-string budgets! ;D
Best Regards,
Butch
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And hopefully easier to clean up... :P
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And hopefully easier to clean up... :P
What HE said!
I am going to take some of what I learned here ( http://www.gatewaytoairguns.org/GTA/index.php?topic=102871.new#new (http://www.gatewaytoairguns.org/GTA/index.php?topic=102871.new#new) ), and refine the rig to restrict flow... go for Butch's idea (it's a good one)... then, after we are done with the destruction of 1.8Ks, I'm going to put all I learned into a rig that is powerful and clean... and not rushed to completion.
Thanks, guys. I can always count on you...
I feel a lot better about this whole thing. Tons.
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Tapped the probe passage to 5mm, drilled a .035" hole through the screw...
Nothing is getting through the probe in a hurry.
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Should work, just pump slowly....
Bob
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Eric,
If I've failed to mention it already, your work IS greatly appreciated. As to the mix ratio, I'd say 50/50
would do the trick. You'll get the benefits of the anti-freeze, but being half water it'll be that much cheaper.
Hooh-rah for shoe-string budgets! ;D
Best Regards,
Butch
Would propylene glycol work? It is used as antifreeze in food and in commercial aircraft deicing. This is because it is non-toxic. It is classified as GRAS.
That way it could be done outside and no cleanup needed at all.
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I don't know, but would love to.
I make my own vape juice, and can get the stuff from 250ml to 55G drums.
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Well, guys, it looks like the gauge will be delayed. Here's why: Northern Tool's site does not allow you to list a PO Box in your shipping address, yet allows UPS to divert their "ground" shipments to "smart post", a USPS system. As my PO will return anything that has no POB number... the odds that someone will actually think to hang on to it, for a long time, frequent customer... are almost nil (happened once, in years of doing business). We'll see.
I mentioned earlier that I have decisions to make, and one is made:
I have decided to limit sales of G1 parts, and the couple dozen MIB G1s left (in the world?), to previous customers and a small hard core of known fanatics. I am amply stocked to cover these people's needs, and want to remain that way... as I have promised I would all along.
More, soon... :)
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Got a response from Northern:
"Hello,
Thank you for contacting us. Most of our orders are shipped via UPS. If the item is a smaller lighter item, UPS changes the delivery to sure post. Unfortunately UPS does not accept PO boxes for shipping address, even if the order goes sure post. Only way to have UPS deliver the smaller lighter items directly to your physical address is you would need to select 2nd day air.
Regards,
Leo"
Would have been nice if they told customers that. Back to shopping for a gauge. Fortunately, I have nothing better to do with my time... ::)
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Are you looking for a 1/4" NPT gauge? I've had good luck getting quality gauges for cheap via eBay.
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Why on earth can't they just chuck your gauge in a flat rate box?
At work we use fedex, if one of our employees out in the world needs something sent to a PO that is what we do. Seems easy enough. Mailman takes it with him when he drops off the mail.
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Why on earth can't they just chuck your gauge in a flat rate box?
At work we use fedex, if one of our employees out in the world needs something sent to a PO that is what we do. Seems easy enough. Mailman takes it with him when he drops off the mail.
My response to Northern:
"Would have been nice to know that before I ordered. I'm not the only person who USPS has decided to quit serving, to save money... while charging them for the only alternative, a PO box.
You have put your reputation in the hands of another company... who chose to put it in the hands of a bankrupt Federal agency (while keeping a policy that will prevent that agency from serving properly). Good luck with that. I paid enough shipping to send it directly Priority Mail... and would have it by now.
If it ends up in my PO Box (it's happened before... ONCE), you won't be hearing from me again. If you get it back (want to hear about how many of my things USPS has lost in transit, this year alone?), I will be asking Paypal directly for a refund... then avoiding your company from now on.
I'm stunned this doesn't concern your company greatly... but, hey it's a game of numbers, right? Screw the small fry... you can make it on the kind of profits USPS has lived on for years...
Eric Kuehn"
I'm not pretending they will care.... but, sometimes, I have to say it anyway. :)
EDIT: to be clear, I put both my street address and my POB in all my orders, everywhere. Northern won't take the order if it has POB#, p.o. box#, or any other recognizable PO markings. The fact that UPS doesn't allow those markings, as long as they have a street address, too... mystifies me. I remember when they were the very best (yeah, yeah, grampa...).
Are you looking for a 1/4" NPT gauge? I've had good luck getting quality gauges for cheap via eBay.
Yes. If this one doesn't show, I'll try that. Couldn't find a (retail) 15K gauge anywhere but Northern. The new design test rig will have a multiplier, so I can use a gauge on it that reads up to that fraction, instead. Those are everywhere.
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Well, guys... there are 2 more FDPCPs on the way here, slated for destruction. Thanks, Andy!
The gauge is 1 day out, let's hope it ends up in the hands of the young cutie at the PO (She's 39... yes, I'm old) who caught the last one of these snafu packages.
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There is another coming. It looks like we will have a small, but significant data base on these, eventually.
I am pondering the booster. Is there any reason I can't consider the volume lost in the first test's leak as an indicator of the max volume I need to calc for? I just don't know enough to properly WAG the needed volume of the rig.
The max volume needed, if known, will determine the size (therefore the cost) of this thing, and help me build it right the first time (important to me, for a list of reasons).
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If most of the leaked volume was from the hose expanding, you won't need to allow for that much, because it will be on the primary side.... but allowing for that would certainly be plenty, I would think....
Bob
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Bob, seeing it take a couple tablespoons to chase the leaky rig from 3K to 6K, leaves me relieved the booster won't be a 50# monstrosity.
Guys, although I'm not a Big Dog here, I am very happy to say that I "know a guy, who knows a guy..." Here's why:
The first Fusion repeater will be a 3K .22 bullet gun (stroked). The liner is a Redman's (from John C at pelletgarden.com ), and it will sport a rare, and beautiful, double set up (airgunlab.com).
The sleeve is aluminum and steel... the overlap (it's already bonded) is 3/4". It's significantly lighter than a stock barrel (numbers when it's fully cut, and weighed).
John also made me an assortment of different bullets to test with... also gorgeous. All about 30gr. They will make a pretty pic, all on their own... which is coming soon.
Happy camper here!
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Guys, I did custom vehicle paint for decades, and although I'm personally a fan of keeping the use of pearls to just a minimum (an accent, not an attack), I have shot enough heavy pearls to have seen what those can do to the lines of an object in direct sun. See where I'm headed?
I can't help but wonder what a really heavy pearl job, in the colors closest to the hunter's environment, would do to obliterate the biggest cue many animals take... straight lines. It wouldn't require a terribly glossy base.. the stuff "dances" even in the jar (basically flat).
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BTW... I have decided to call the concept "Cloaking"... anyone who has been here long knows that 2 of my ideas have already been made public (Russian GRS, and the very first p17 mod I ever brought here), without a mention of me or GTA... and someone here was (is?) planning to copy my thru-tube for sale (and, had the nerve to ask me to sell him a receiver for a production jig). This is why I stopped showing most of what happens here. So...
I offered the concept here to you all... I'll get to it if you don't, first, but I'd love to see it tried elsewhere... but, I would much appreciate it if you would all give me the unspoken gentleman's agreement that using "cloaking" as a process' brand name will be reserved for me.
:)
They make pearls for powder coating.
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Can't get this out of my head...lol. Wondering what a barber pole design with a thin stripe of large metallic flakes, covered with a wider band of pearl, would do. Leave a small separation with little manipulation... optically swelling the rest.
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Sounds "prissy".... but then I don't wear pearls, myself.... *LOL*....
Bob
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LOL... there was a time when, if it would have helped bring in meat, I would have worn a cheerleader's outfit while hunting.
It wouldn't be pretty, and wouldn't be visible except in direct sunlight.... but, that is when even similarly colored objects have enough contrast to stand out... especially straight lines.
It would intentionally have something I normally can't stand when I see a cheap pearl paint job... an optically blotchy appearance.
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Anyone who has seen a perfectly straight car painted so badly (metallics or pearls), that from any distance it looks like a Bondo wagon, knows what I'm trying to get at here.
If you try, you can shoot "dents" into a car.
I'm not talking about replacing camo, just enhancing it during the very times some lose their ability to "blur".
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LOL... there was a time when, if it would have helped bring in meat, I would have worn a cheerleader's outfit while hunting.
It wouldn't be pretty, and wouldn't be visible except in direct sunlight.... but, that is when even similarly colored objects have enough contrast to stand out... especially straight lines.
It would intentionally have something I normally can't stand when I see a cheap pearl paint job... an optically blotchy appearance.
This is normally where I jump right in a thread but, I'm just kinda speechless right now.
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The whole "cheer leader" thing is painting a picture in my mind... :o
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Bob, seeing it take a couple tablespoons to chase the leaky rig from 3K to 6K, leaves me relieved the booster won't be a 50# monstrosity.
Guys, although I'm not a Big Dog here, I am very happy to say that I "know a guy, who knows a guy..." Here's why:
The first Fusion repeater will be a 3K .22 bullet gun (stroked). The liner is a Redman's (from John C at pelletgarden.com ), and it will sport a rare, and beautiful, double set up (airgunlab.com).
Is that a one off or will arigunlab starting offering the double tube for the fusion as a regular thing?
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The whole "cheer leader" thing is painting a picture in my mind... :o
Don't let it! It won't end well...
Steven, that's a standard kit, with a custom upper tube. One off.
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I'll have to go to the s-l-a-u-g-h-t-e-r house to watch them process hogs just to get that picture out of my mind. :o
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That's a good idea. A few hours of watching something more pleasant should work to minimize the damage.
I think we should find out if Bill is ok....
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Funny you say that DEz,
I was just talking this morning to my buddy about needing to s l a u g h t e r the pig we are raising this coming weekend.
Now I'm thinking that pig may need to become bacon and chops TONIGHT !
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I'm really sorry, guys... I didn't mean to hurt anyone...
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I'm really sorry, guys... I didn't mean to hurt anyone...
Is there a resident Emotional Distress Therapist in the house ? ;) ;) ;D ;D
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If not, you are looking at private help.... and it's going to cost you dearly.
This kind of thing isn't dealt with quickly.
... so sorry.
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Mmmmm,
Bacon,
Meat candy.
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"The post office was unable to deliver the UPS SurePost® package as addressed. Please contact the sender for assistance."
::)
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Ordered a 6K gauge from ebay. It will be enough to do the remaining FDPCPs (as we know the screws fail at 6K), and enough for a 3:1 booster to run up to 18K.
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I just have to say this:
I just finished up my email chores for the day, and it is truly heartwarming to me that so many of you want to help me help the FDPCP owners, who are still in limbo, on this.
I can't think of anything more I could need for this project, but, the offers continue to remind me how unselfish some GTA members are... and that I remain in very good company here.
To the handful of readers who may not know this: GTA RULES! ...and I can prove it.
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;D
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XS-60c Double !!
Double Dig It, Man!!....
Bob
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Hi Eric - you've got mail.
-Rod
I just have to say this:
I just finished up my email chores for the day, and it is truly heartwarming to me that so many of you want to help me help the FDPCP owners, who are still in limbo, on this.
I can't think of anything more I could need for this project, but, the offers continue to remind me how unselfish some GTA members are... and that I remain in very good company here.
To the handful of readers who may not know this: GTA RULES! ...and I can prove it.
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;D
Eric, that is freakin sweet. You never cease to amaze.
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Thanks! If you look at where the lower tube ends, in relationship to the shape of the stocks, you'll see how nicely it will go together. It'll be pretty. :)
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As it is raining today... again... I went ahead and made something to speed things up for the destructive testing: A push button bleeder.
A second valve now fits as a button, and the hole it goes into is threaded so I can put a screw in to yank on to remove the plug after the ring is jammed by pressure.
This weather is being called the "March Miracle" due to the snow pack in the mountains that will supply water here this summer. It's badly needed, but is really messing with me (I get better looking powder coating when humidity is low, and heating the shop enough to chase the humidity out is prohibitively expensive)... and I creak like rusted hinges. ;D
I'm just about ready to do this indoors again... sick of waiting, and the new "juice" will be a lot easier to clean up than Hydraulic Fluid. We'll see...
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Well, gents... didn't expect this: https://youtu.be/St9Vr9hFHps
Beat the weather in this morning, and blew up DT2. As you can see, even at minimum engagement (.0095), the threads held. I put the good screws I use in, as I wasn't interested in picking remnants of the stockers out of my probe... and I wanted to see what would fail when they didn't (bent them slightly, though). As it became clear that the tube threads would hold way past the gauge's max, I decided to just pump until she blew... and she did, at (I'm guessing) somewhere around 8-10K? 12? Again, the fill cap nut showed no stress.
Interesting results. It made it clear that I will have to build a much stouter rig to blow up the 3Ks...
The restriction (thanks, Lloyd!) sure cut down on the mess!
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Very Good work there Eric.
This should make for some interesting evaluations, (compared to the original gun) that started this whole testing process.
Hopefully this will help to determine the presumable safety margins of the many many guns out in the public.
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I still have 3 left to destroy, but I'm going to have to wait until I have a better set up built, if we want firm numbers.
I'm not in a position to give more than an opinion here, but I'm encouraged by this test, and more than a little curious, now, how the original tube got loose. It sure wasn't a result of over pressurization.
The screws were plowing slots into the receiver.
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What do you think would happen if the tube was only in one turn? Could improper assembly cause the type of failure that was reported that started all this?
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If the tube was within size specs, it would have shown severe damage to the receiver's first threads... if it could have sealed in the first place.
The more we know, the more it looks like my initial guess was correct.
Guys, PLEASE, don't take this thread engagement as safe... the gun was never jostled at pressure, the movement you see is a result of the hose trying to straighten out under pressure... I wasn't moving it on purpose.
It appears, to me, that the design would have failed to spec, if I hadn't put better screws in. In any case, I highly recommend the stock screws be used, to allow a failure to go as the designer intended.
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BTW... I just measured the ID of the receiver threads, at the front half of them, and there is less than .002 difference (if any, I did many measurements, along the dia... got a max of .829).
That tube was going nowhere without some external input.
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Found, and ordered a 10K gauge, so we can see if the remaining 3 will go at least that far.
In the mean time, I thought that given the 6K gauge has suffered in the accuracy dept (lol), I could go for another blow out. Not looking for numbers... a vivisection.
2 things I'm curious about: How far can I plow the screws through the receiver if I don't go to any pressures past what it takes to do that... Or (more fun), see if we can duplicate the damage done to DT2. Sample of 2?
What do you guys want?
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Interesting results, for sure.... It's only a sample of one, but it gives us more confidence that if the tube and receiver are within the normal tolerances I listed previously, it should be OK.... as you were well under the overlap that would create, right?.... I'm not actually surprised that the threads held, because of the very long engagement.... and we didn't see any sign of the tube pulling out of the receiver in the original failure.... This leads credence to the idea that the tube had a "spiral zipper" failure along the bottom of the threads and the threaded portion ended up like a long spring, unwinding out of the receiver.... Without the tube being found, we may never know....
It appears that the valve screws are the weakest link, and if you replace those, then the stronger ones will plow through the receiver.... both pretty much expected, I think....
Bob
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I agree. It seems clear that your recommendations put the guns well into the safe zone.
After the gauge pegged, I was applying less pressure than it took me to test the rig initially (15K), but not a lot less. My WAG, earlier, is pretty close.
DT3 has .0145" engagement... so we know I can't blow it up after mounting the new 10K gauge (should be here in 3 days), so should I try to dupe the DT2 damage? It's a really nice day out there... :). Boom?
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I am glad you are doing this but please be careful
Tom.
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I am glad you are doing this but please be careful
Tom.
No worries, Tom... but, thanks for your concern!
After the first test, I was leery of this whole process. I had expected something like the second test... and the resulting violent mess was a bit of a shock. The force generated was a real eye opener for me (IOW, scared me, although I like the term "startled" better...lol).
Turns out Lloyd's suggestion to restrict the orifice was a great idea, and Butch's suggestion for the juice was a huge help. The process is now quick, not at all as messy as before (cleans up nicely with a rag)... and will be conducted, again, with me around a corner of a steel clad building. I was watching a monitor, and found the whole thing to be rather anticlimactic. When I decided to continue after the gauge pegged, I was expecting a "BOOM", and got a "phttt". Steven G can edit in some 'splosions, if it gets too boring...:) We may need him.
Now, I want to hurt some guns!
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Now, I want to hurt some guns!
And your little dog too!!! hee hee hee hee hee hee hee
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Now, I want to hurt some guns!
And your little dog too!!! hee hee hee hee hee hee hee
It's on. Andy (the donor) has given the thumbs up to destroy DT3, for a second sample.
Butch... I'll think of you, as I clean my hands with a rag.
8)
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Didn't expect this either... https://youtu.be/CmQIZNeHMLw
I ended up stepping on the handle (right at the end, you can see it start to weep). This is what it took to get to 15K, while testing the rig. I was afraid to blow out the hose, or the fitting I was standing over. I let it sit, twice, after that pressure was reached... all it did was weep (not sure from where, but the receiver did swell .006" just behind the tube threads, all the way to my o-ring).
Thank you Andy. It's looking like over pressurization just doesn't explain the "incident".
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The fill cap nut still functions perfectly (measures .824 max in 1 place... unchanged), and the tube threads screw in smoothly (.855 max... also unchanged).
The receiver F ID, again... up .002", if any.
If I wasn't the guy on the handle, I wouldn't believe it.
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DT4 and 5 are both well within tolerance... so, what to do with them?
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I think that with all that has been determined and no missing air tube to examine for failure I think that a brief recap with pictures of the original posted failure pictures and all of your current findings posted under that would go a long way towards reassuring people that the rifles are ok to use when modded correctly. Perhaps some of the experts on these rifles can chime in with their thoughts at this time.
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I assume by "within tolerance" you mean that the "overlap", ie OD of the tube thread minus ID of the receiver, is greater than what you would get by using the maximum receiver ID from the minimum tube OD?.... That would be 0.8580" - 0.8328"= 0.0252".... If the threads exceed that overlap, then at least in theory the threaded joint should have the same strength as the minimum within tolerance threads would.... and you have tested threads less than that without failure....
I am a little gunshy about JUST using the overlap as a measure of safety, however, because we suspect that the mode of failure was not the threads stripping, but the tube cracking at the bottom of the threads because it was tapped too deeply.... It is slightly upsetting that most (all?) of the tubes you have measured are BELOW the 0.858" minimum OD at the threads.... The OD of the DT2, where the threads still held, was only 0.846", a full 0.012" below the minimum tolerance.... If we just go by the minimum OD on the tube threads, it would appear that a large number of the FD-PCP tubes would be disqualified.... while they may well be OK if mated with a receiver that isn't too large on the ID....
The easy answer would be to simply stick with the posted tolerances and tell people that using anything outside that range is totally at their own risk.... Maybe not a bad thing for the GTA to adopt as a policy?.... but it may make a fair number of FD-PCP owners unhappy....
Bob
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I have been reviewing my data on this problem, and I would refer everyone to the scale drawing of the screw threads I made in Reply # 1293 on page 65.... Now that we know that the shear strength of the threads, even at minimum tolerances (or below) is not an issue.... I think we need to concentrate our thoughts on the wall thickness between the bottom of the threads and the ID of the tube.... That area is not only under pressure outboard of the receiver, it may be subject to additional stress from a sideways impact to the tube.... This is similar to the situation on the HiPac that failed at the bottom of the O-ring groove after the valve let go and shot into the guys leg....
Bob
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I assume by "within tolerance" you mean that the "overlap", ie OD of the tube thread minus ID of the receiver, is greater than what you would get by using the maximum receiver ID from the minimum tube OD?.... That would be 0.8580" - 0.8328"= 0.0252".... If the threads exceed that overlap, then at least in theory the threaded joint should have the same strength as the minimum within tolerance threads would.... and you have tested threads less than that without failure....
The easy answer would be to simply stick with the posted tolerances and tell people that using anything outside that range is totally at their own risk.... Maybe not a bad thing for the GTA to adopt as a policy?.... but it may make a fair number of FD-PCP owners unhappy....
Bob
Yeah, I said that wrong!
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The more I think about this, the more I think the GTA should recommend all tubes and receivers be within the standard tolerance ranges for 22mm x 1mm threads.... If the tube threads are smaller, there is a good chance the wall thickness at the bottom of them is reducing the safety margin below acceptable levels, even for the 1500 psi MSWP specified on the FD-PCP website.... IMO....
Bob
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So, is a user friendly safety checklist even advisable? Or do these airguns definitely need to be examined by someone with the proper tools, experience and knowledge? Personally, I would want mine checked out by someone more qualified than myself. Or just park it permanently. Whatever the recommendation is, we need to make certain it is correct the first time before publishing it.
Thanks to all that are helping get this resolved!!!
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Now that we have stepped above my pay grade, I can only say this:
"The easy answer would be to simply stick with the posted tolerances and tell people that using anything outside that range is totally at their own risk.... Maybe not a bad thing for the GTA to adopt as a policy?.... but it may make a fair number of FD-PCP owners unhappy.... ". I don't see GTA as having a choice here. We have proven that the connection is overkill, but without material specs, aren't we asking for trouble if those specs vary? Maybe in the eventual statement, we should specify that 1018 steel, or better, is the basis for these recommendations?
I was thinking about saving the last 2 guns for the boosted tester, and having fun watching the destruction... but, I'm now leaning toward taking them to the "15K" limit my gear is currently capable of, and adding them to the sample list. If we manage to swell the receivers without separation, we would (at least) have a significant indication the threaded connection won't ever be a problem if all the specs are even close to true.
Could we put that to bed with 2 more?
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I would want to see at least 1/8" of exposed threads past the end of the receiver in the next test.... enough to get to where the thread is full depth.... It's hard to tell from the photos, but my FD-PCP looks to have more exposed threads than the ones you have tested so far....
Bob
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I would want to see at least 1/8" of exposed threads past the end of the receiver in the next test.... enough to get to where the thread is full depth.... It's hard to tell from the photos, but my FD-PCP looks to have more exposed threads than the ones you have tested so far....
Bob
Could I stack 2 seals to get that? Or, to retain the full FDPCP threading (instead of adding my own extended threading) go with trimming the receiver in the front?
I'm here, at the shop.. it's a beautiful day... and I'm committed to this thing until not needed any more... say the word.
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Stacking 2 seals might work, if you could get it to seal.... if that won't work, then trimming the front of the receiver.... My tube is no longer in it's original position, it is screwed further into the receiver.... but what I remember is seeing at least 1 full thread that was cut to full depth in front of the receiver....
DEz, one thing that concerns me, is that most (all?) of the tubes Eric has measured are a couple of thou or more under the minimum OD at the threads give in the tolerance tables (mine was right on the minimum).... as in fact is the OD of the XS-60c tubes.... I would hate to come up with a recommend set of measurements that would reject most of the tube out there.... On the other hand, if the threads are below the minimum, then the wall thickness will be reduced as well, and so will the safety margin....
Bob
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Took .125" to get to the min OD. 3 peaks visible, 1st is flush with the face.
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Took it up to "15K", and still no separation.
https://youtu.be/f-JeAk1VIvY
Additional swelling of the receiver about .003", or so.
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More of the same old same old...
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I got nutthin".... :o ::)
Bob
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Yeah, zip here, too.
If I had the time, I'd cut tube threads in decreasing size until we got a separation, but without the metallurgy... it might be just chasing dragons. I'd love to make a Slinky, but...
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It's also clear that if quality screws are used, they will trench until the o-ring partially clears the valve mount hole, and it dumps. In about a million hard pumps...
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This is boring, just cut the threads so deep it has to come apart ;)
I wanna see something blow up.
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Boring? I need to put audio in the next one, so you can hear the check valve squealing, loudly, at ever higher frequencies, as I lean away from the fitting and hose... and stand on the handle! It sounds like a warning buzzer for impending disaster (insufficient altitude?).
I would sure appreciate some ideas on how to best build the booster for a decent cost. The 10K gauge will be here soon... any guesses as to the ratio I will need to destroy 3Ks?
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I'm thinking it might be smart to make the booster so it can be placed in a hydraulic press. I have a little 12 ton that knocks Ford axle bearings off (even rusted) with very little extra effort.
This pump is known for taking abuse, but it looks like the check valve is not liking this.
Guys, I have things going on here that will require a lot of my time (so, what's new??), and would appreciate any thoughts that could help put this to bed.
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WTB a 2078 and a Disco stock for proto work... scratches and dings are fine, even preferred.
;D
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Simple way to go would be to just use a hydraulic press to shove a piston that is 1 sq.in. in area.... that would give you 24K from your 12T press.... Then the only reason for a booster it to allow your gauge to live.... Why not do that the opposite way, and make a pressure reducer whose only job is to run the gauge.... say 3:1 ratio, and the gauge would never go past ~ 8K....
Bob
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That's some good thinking!
The gauge reducer could be tiny... not much volume needed. Considering how much high cap gauges cost, it would be very cost effective to build.
Ok, guys... looks like DT4 and 5 are going to truly blow up, after all. Just not today...
8)
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Eric and I have exciting news to share with everyone. It’s been a long time coming and a lot of work has been going on behind the scenes leading up to this, so I will just go ahead and let it out.
Eric Kuehn and Stalwart Arms will, starting around the end of May, be handling the sales and distribution and customer service of the Airgun Lab Double Tube line of products.
Here is the link to the Airgun Lab announcement (see post # 21 )
http://www.gatewaytoairguns.org/GTA/index.php?topic=101406.20 (http://www.gatewaytoairguns.org/GTA/index.php?topic=101406.20)
Shipments will start with the Disco Double kits, around the end of June. This will be a great match, with Eric and myself working together on this project. I’ve know Eric for a while now, and he comes with the recommendations from many people that I trust and respect on this forum.
The transition will start with the Disco Double, then the P-Rod Double, and finally the M-Rod Double. Plus, there is going to be some crossover of the double tube products into Eric’s product lines. And there will be some new products coming out that folks have asked for.
Eric and I had planned on waiting until the Fun Shoot to make the announcement, but neither of us are very good at keeping secrets, and inquiries about whether or not the Double Tube products were EVER coming back were getting too frequent.
So, for any of you who are coming to the Fun Shoot in Kentucky next week, I will be there with some of the Double Tube products. Maybe not to sell, but at least to look at.
Eric and I both are looking forward to revitalizing the Double Tube products and giving airgunners what they want.
(http://i226.photobucket.com/albums/dd79/loyd500/Dbl%20tube%20specs/BiPod-DD-5b_zpse0e73540.jpg) (http://s226.photobucket.com/user/loyd500/media/Dbl%20tube%20specs/BiPod-DD-5b_zpse0e73540.jpg.html)
I want to say thank you for everyone’s support and patience during the long dry spell when no Double Tube products were shipped. Eric is ramping up, but it will take a little time to get everything rolling again. I will post more info on the Airgun Lab in the GTA vendor gate.
Thanks again,
Lloyd Sikes
The Airgun Lab
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Wow!! Makes me glad I got my gun from him before he got all famous!!! ;D
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Congratulations to Eric, I know he will do a great job.... and for Lloyd, this will free up some time for him to do what he loves and does best.... experiment and develop new and better toys.... I see this as a win-win situation, and wish them both the very best in this new venture.... I have to admit, I've been holding my breath waiting for the announcement.... it's nice to be able to breath again!.... *LOL*
Bob
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Thanks Bob!
You are so right. This will be a good situation all the way around. I have a huge inventory of component parts on hand for all the kits: tubes and fittings and barrel bands and hardware, etc, etc. Now they can finally be assembled and tested and shipped.
And that will definitely help free up my "airgun time" for the new and fun stuff. And some crazy stuff too.
Lloyd
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Can't be a much better duo out there for GTA or the entire airgun community!!!
Although we do have a few here. :)
But you guys are the best of the best. Most excellent news for you and for us!!!
Congrats on making this happen right here!!!
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Can't be a much better duo out there for GTA or the entire airgun community!!!
Although we do have a few here. :)
But you guys are the best of the best. Most excellent news for you and for us!!!
Congrats on making this happen right here!!!
Yep, ... What DEz said x10.
Looking forward to the new projects.
The collective talents and camaraderie are what makes the GTA "Best of the Best" !
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Thanks for the words of encouragement, gentleman!
The positive attitude and cooperative spirit of this forum makes success a whole lot more achievable. Eric and I will do our best.
Lloyd
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Well, well, well... this is GREAT NEWS, for a couple of different reasons:
1. I've watched how you two engage and support fellow enthusiasts, and I know that both of you working together will be even more awesome. Much good will come of this.
2. You just made my job a lot easier: I was tasked with recommending an air gun for a cabin at 7500'. Knowing the doubles will be back, I think a Prod will be the best for their needs.
Congratulations!
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Lloyd
I had no idea the double tubed gun kits had been stalled out for a time as it states here, but glad to see that thing have been worked out to keep them in supply to customers .
Kudos to you both and I am working on a disco based Prod trigger, challenger hammer and RVA franken gun to be a lightweight FT gun and you just gave me an idea od adding the double tube to it to increase shot count with out much extra weight. It would be a 2240 style setup with the 1399 or AR style butt stock and Prod pistol grip assy.
I was going to drill and install 10/32 screws in the valve to be able to fill to 3000 psi safely and would like to know is the disco double kit capable of filling to 3000 psi safely as well.
Please send me a PM when they are back and available for purchase if you would please.
Mike
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Mike,
All of the double tube kits have at least a 3 to 1 safety factor at 3000 psi, so yes, the "kit" is plenty safe. That includes the tube, the threaded fittings, and all the other hardware pieces included in the kit. However, the Benjamin Discovery air rifle, from the factory, is only rated to 2000 psi, so it should not be filled above the factory recommendation. That said, with proper modification of the factory tube and the valve body to use three 10-32x3/16 high strength alloy steel low profile socket head cap screws, the security of the valve body is improved. With that modification done, filling above the factory recommended pressure is still a personal decision.
Just for reference, both the Marauder rifle and pistol are rated at 3000 psi from the factory.
Lloyd
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Wow!! Makes me glad I got my gun from him before he got all famous!!! ;D
Yeah, I'm not sure what to do first.... buy a Maserati, or get extensive, obvious plastic surgery.
Thanks for the words of encouragement, gentleman!
The positive attitude and cooperative spirit of this forum makes success a whole lot more achievable. Eric and I will do our best.
Lloyd
Lloyd has already said it all.
Guys, SA is about to go through some serious changes, including it's location. All efforts here are toward cost effective progress in products and production, and this will be no exception. There are many more announcements coming, believe me...
You have watched SA grow from the seed planted by an unintended sale of a pistol I built for myself (MG 2240) before it was even finished. That $200, as are all proceeds here, still, was turned back into the endeavor... and the rest is, well... history.
Well, well, well... this is GREAT NEWS, for a couple of different reasons:
1. I've watched how you two engage and support fellow enthusiasts, and I know that both of you working together will be even more awesome. Much good will come of this.
2. You just made my job a lot easier: I was tasked with recommending an air gun for a cabin at 7500'. Knowing the doubles will be back, I think a Prod will be the best for their needs.
Congratulations!
GTA rocks... and, I can prove it.
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Mike,
All of the double tube kits have at least a 3 to 1 safety factor at 3000 psi, so yes, the "kit" is plenty safe. That includes the tube, the threaded fittings, and all the other hardware pieces included in the kit. However, the Benjamin Discovery air rifle, from the factory, is only rated to 2000 psi, so it should not be filled above the factory recommendation. That said, with proper modification of the factory tube and the valve body to use three 10-32x3/16 high strength alloy steel low profile socket head cap screws, the security of the valve body is improved. With that modification done, filling above the factory recommended pressure is still a personal decision.
Just for reference, both the Marauder rifle and pistol are rated at 3000 psi from the factory.
Lloyd
Lloyd
Yes the disco valve would be converted to use the same 10-32 screws as the Mrod uses so I would feel safe filling to 3000 psi since the Prod tube is basically a shorter disco tube is it not in that it is the same diameter and wall thickness as a disco tube. ?
I know the Mrod tube is thicker as well as bigger ID/OD so its not truly comparable to the disco/Prods tube IMO. I was just insuring that the disco double kit was intended to be safe at 3000 psi with proper valve mods to the main disco valve and tube.
Thanks for the info so just need to wait for Eric to get it all up and running with kits ready for delivery.
Mike
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Hey guys!! Check this out!!
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/100_5332_zpsr3mlmlts.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/100_5332_zpsr3mlmlts.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/100_5328_zpsnxno71mk.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/100_5328_zpsnxno71mk.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/100_5330_zpsnjam0els.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/100_5330_zpsnjam0els.jpg.html)
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Yes, folks, that's an adjustable regulator.... A little surprise I have been working on behind the scenes with Eric and Lloyd.... It is installed inside the front plug for the upper tube....
Bob
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Care to share the range for which it is adjustable?
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IIRC, about 500-2200 psi, I can't remember what Lloyd ended up with for a final range of adjustment.... The entire upper tube ends up at the output pressure, so it is suitable for lots of power if required....
Bob
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Yes, folks, that's an adjustable regulator.... A little surprise I have been working on behind the scenes with Eric and Lloyd.... It is installed inside the front plug for the upper tube....
Bob
As a matter of fact, this was Bob's idea. A good one... as usual.
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IIRC, about 500-2200 psi, I can't remember what Lloyd ended up with for a final range of adjustment.... The entire upper tube ends up at the output pressure, so it is suitable for lots of power if required....
Bin
Wow!
Stalwart, put me down for one now.
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IIRC, about 500-2200 psi, I can't remember what Lloyd ended up with for a final range of adjustment.... The entire upper tube ends up at the output pressure, so it is suitable for lots of power if required....
Bin
Wow!
Stalwart, put me down for one now.
Done.
:)
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Yes, folks, that's an adjustable regulator.... A little surprise I have been working on behind the scenes with Eric and Lloyd.... It is installed inside the front plug for the upper tube....
Bob
As a matter of fact, this was Bob's idea. A good one... as usual.
Yes, Bob has been after me for a while to put an integral regulator in the upper fitting of the Disco Double tube setup. He had the basic design figured out, and finally, we put our heads together for the final design, and I built a prototype. It worked well and I had parts manufactured. RMM is getting the first production unit.
The range of adjustability is 500-2700 psi. It works equally well with Eric's XS60C project and with the Disco Double. Basically, the bottom tube becomes the high pressure reservoir and the upper tube is the regulated side.
LLoyd
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I might have just soiled myself... Will this be an option for all double-tube kits, across supported platforms?
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Sorry, I couldn't remember what the upper limit was on the setpoint.... 2700 it is.... *LOL*.... Nice to see this project come to fruition.... *grin*....
Bob
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I might have just soiled myself... Will this be an option for all double-tube kits, across supported platforms?
+1 on Drews question as it being an option for the double tube kits and is it also going to be an option to the XS60C PCPs also..
Mike
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Sorry, I couldn't remember what the upper limit was on the setpoint.... 2700 it is.... *LOL*.... Nice to see this project come to fruition.... *grin*....
Bob
Bob, the regulator has been quite a successful team effort for the 3 of us and and is an indicator of the direction of the upcoming transition.
The pressure range of the production units goes slightly higher (2700 psi) than the prototype (2200 psi) because the batch of Bellville washers for the production units, although the same nominal thickness as the proto, were slightly stiffer than the proto Bellvilles. That does however, come with a strong caution that the factory production arrangement of the Discovery is only rated to 2000 psi for the upper tube, and therefore the regulator should be set no higher than the factory recommended 2000 psi unless proper mods are made to the upper tube valve screws. The Disco Double LOWER tube is rated for 3000 psi, which could allow for quite a bit of extra air in the lower tube. An upcoming info sheet about the regulator will have recommendations about the applicability and safe use of the regulator.
I might have just soiled myself... Will this be an option for all double-tube kits, across supported platforms?
Drewciferpike, right now this regulator will work with Eric's XS60C project and the Disco Double kits: kits that have a 7/8" O.D. top and bottom tube, with the air transferring between the tubes at the front front end. It could also be a retrofit for Disco Double kits that are already in the field. Eric will be gauging the interest of the regulator and whether it is "needed" for other platforms.
Lloyd
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I figure the reg + double-tube option is a no-brainer for a Prod...
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First congrats to Eric and Lloyd really excited for you both!
Second excellent idea with the regulator! 8)
very interested and excited to here more about it.
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Lloyd, I think making them for the PRod Double is a no-brainer.... Is there any change required, or will they be a drop (screw) in?....
Bob
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Interested in one for both a disco and XS60C.
Mike
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Lloyd, I think making them for the PRod Double is a no-brainer.... Is there any change required, or will they be a drop (screw) in?....
Bob
The disco double tubes are married together at the front end such that the reg can go easily between the upper and lower tubes, creating two separate chambers for high and low pressure. Conversely, the prod tubes are married together at the rear end, so re-engineering will be needed.
Lloyd
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Can't wait to get this airgun in my hands and start wringing it out.
Thanks gentleman and I am truly honored to be #1.
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Ok, I've lost my way but I'm hoping someone will push me in the right direction. With the new capabilities of stalwart's 3K and it's a double reservoir with regulator I want some heavy .22 bullets that will fit in the 3K magazine. Push me in the right direction gents or lead me to another path.
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Lloyd, I didn't know the PRod tubes joined at the back.... :-[
RMM - JSB have a new 34 gr. Beast pellet, that is my plan.... Alternately, if you want to cast bullets, get in on this Group Buy at NOE....
http://noebulletmolds.com/smf/index.php/topic,1322.0.html (http://noebulletmolds.com/smf/index.php/topic,1322.0.html)
Bob
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RMM - JSB have a new 34 gr. Beast pellet, that is my plan.... Alternately, if you want to cast bullets, get in on this Group Buy at NOE....
http://noebulletmolds.com/smf/index.php/topic,1322.0.html (http://noebulletmolds.com/smf/index.php/topic,1322.0.html)
Bob
Thanks Bob, JSB's will get me started.
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RMM - JSB have a new 34 gr. Beast pellet, that is my plan.... Alternately, if you want to cast bullets, get in on this Group Buy at NOE....
Bob
This came up on AirgunDepot site. The heaviest .22 cal pellet yet! Note: Does not fit in rotary magazines http://tinyurl.com/jbuqhj9 (http://tinyurl.com/jbuqhj9)
I hate to ask but ask I must even though lot of research went into the use of the Prod magazine. Will these fit into the Prod magazine??
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Would it kill manufacturers to include the OAL in their specs?
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The 34 gr. is 0.42" LOA.... MRod .22 cal NO.... PRod .22 cal maybe if modified.... MRod .25 cal with a .22 cal wheel installed OK....
Bob
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How much relief would a PRod mag need? I could cut one to see if it would work. The .25 mag, as you know, requires a lot more work to fit (elongated custom block).
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Would it kill manufacturers to include the OAL in their specs?
Another campaign for another day?? :D
The 34 gr. is 0.42" LOA.... MRod .22 cal NO.... PRod .22 cal maybe if modified.... MRod .25 cal with a .22 cal wheel installed OK....
Bob
Thanks Bob, I'll have to measure the PRod mags and a pellet or bullet hunting I will go.
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John Cripe made me a huge selection of bullet styles, that fit the PRod mag, and all are 30-31gr.
pelletgarden.com
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IIRC, the PRod mag is 0.40" to the flat edges, and a bit deeper in the center, so the 34 gr. JSBs might be VERY close to working.... I'm sure you could tease another 0.020" out of them without too much problem.... In fact the .22 Predator Polymags measure 0.412", and they fit a PRod magazine, because the narrow point fits into the groove in the front of it.... so basically, if you used a 7/32" ball end mill and cut out the front of the mag until you just cut out the bottom of the existing groove, you should be good to go....
Hmmmmmmmmmm.... I'm guessing I just figured out what to do with my new Regulated Disco Double.... ::)
Bob
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.....................................
Hmmmmmmmmmm.... I'm guessing I just figured out what to do with my new Regulated Disco Double.... ::)
Bob
he he he he ;)
Lloyd
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;D I can't keep up with you guys now I will have to see if I can fit a M-rod regulated Double tube into my Purple Beauty
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One of the most interesting parts about the new Disco Double (and it's XS-60c cousin) will be tuning it.... My thought is to come up with a tune that is half way between a regulated tune (flat velocity until setpoint, then dropping) and an unregulated tune (bell curve with 4% ES, low-high-low).... The plan is to use, as an example, a 2200 psi setpoint, and tune the gun for peak velocity at about 2000 psi, and then refill the bottom tube at about 1800, back up to 3000 psi.... This should give (ie can be tuned to give) about a 2% ES over the entire string, with the first part of the string at a constant velocity until the setpoint is reached, then a gradual increase (not more than 2%) and then tapering off back to the original velocity.... In other words, a plateau, followed by a shallow bell-curve.... This represents a slight "downslope" type of tune for a regulated PCP, which results in great efficiency and quiet operation while above the setpoint, which should be about 2/3 - 3/4 of the total shots.... and then a slight drop in efficiency, and corresponding increase in report, as the pressure drops below the setpoint towards the refill point.... I think this may be the best way to take full advantage of the large plenum volume represented by the upper tube....
Bob
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One of the most interesting parts about the new Disco Double (and it's XS-60c cousin) will be tuning it.... My thought is to come up with a tune that is half way between a regulated tune (flat velocity until setpoint, then dropping) and an unregulated tune (bell curve with 4% ES, low-high-low).... The plan is to use, as an example, a 2200 psi setpoint, and tune the gun for peak velocity at about 2000 psi, and then refill the bottom tube at about 1800, back up to 3000 psi.... This should give (ie can be tuned to give) about a 2% ES over the entire string, with the first part of the string at a constant velocity until the setpoint is reached, then a gradual increase (not more than 2%) and then tapering off back to the original velocity.... In other words, a plateau, followed by a shallow bell-curve.... This represents a slight "downslope" type of tune for a regulated PCP, which results in great efficiency and quiet operation while above the setpoint, which should be about 2/3 - 3/4 of the total shots.... and then a slight drop in efficiency, and corresponding increase in report, as the pressure drops below the setpoint towards the refill point.... I think this may be the best way to take full advantage of the large plenum volume represented by the upper tube....
Bob
This is everything we hoped for... can't wait to get some 60s up and running with the big dogs! And, then... :)
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One of the most interesting parts about the new Disco Double (and it's XS-60c cousin) will be tuning it.... My thought is to come up with a tune that is half way between a regulated tune (flat velocity until setpoint, then dropping) and an unregulated tune (bell curve with 4% ES, low-high-low).... The plan is to use, as an example, a 2200 psi setpoint, and tune the gun for peak velocity at about 2000 psi, and then refill the bottom tube at about 1800, back up to 3000 psi.... This should give (ie can be tuned to give) about a 2% ES over the entire string, with the first part of the string at a constant velocity until the setpoint is reached, then a gradual increase (not more than 2%) and then tapering off back to the original velocity.... In other words, a plateau, followed by a shallow bell-curve.... This represents a slight "downslope" type of tune for a regulated PCP, which results in great efficiency and quiet operation while above the setpoint, which should be about 2/3 - 3/4 of the total shots.... and then a slight drop in efficiency, and corresponding increase in report, as the pressure drops below the setpoint towards the refill point.... I think this may be the best way to take full advantage of the large plenum volume represented by the upper tube....
Bob
I'm ever so glad you posted the above because I being a novice was going through the thought process of how to tune my pumped up 3K with my novice capabilities. Now I have a primer to start with, thanks.
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IIRC, the PRod mag is 0.40" to the flat edges, and a bit deeper in the center, so the 34 gr. JSBs might be VERY close to working.... I'm sure you could tease another 0.020" out of them without too much problem.... In fact the .22 Predator Polymags measure 0.412", and they fit a PRod magazine, because the narrow point fits into the groove in the front of it.... so basically, if you used a 7/32" ball end mill and cut out the front of the mag until you just cut out the bottom of the existing groove, you should be good to go....
....................
Bob
Bob,
I just did some measuring, trying a couple of different methods and it looks like the 34 gn beast, if no longer than .42", will just barely fit a .22 cal P-Rod mag. The depth to the flat edges of the bottom is .400/.405, and the depth to the extreme bottom of the groove is .429/.431. The .412 long .410/.412 polymags I tried rattle a little in length in the mag, and measurements indicate about .010 clearance, so the .42 long Beasts ought to just barely fit. I also tried some of the JSB jumbo monsters (25 gn) which are .343 long and the extra clearance measured to indicate that, again, the .42 long pellets will just barely fit.
If binding is experienced, there are a couple of solutions that are easier than a ball nosed endmill. If you disassemble the mag, you'll notice that there are some molding ejection pin witness marks in the bottom of the groove. Some of them have slight raised edges/burrs. A little bit of deburring, and slight deepening of the groove with some 400 grit paper will make the pellets index more reliably. Also, when reassembling, the spring could be set with a little more tension by moving it to the next of the 3 holes in the back. Of course, you'd have to note which was the original hole location before disassembly.
Lloyd
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Yeah, I kind of thought they "might" fit in a PRod mag., my comments erred on the side of caution, so that guys know they might have to ease things a bit.... It will depend on how "blunt" the nose on the 34 gr. is, compared to the skinny point on the Polymags.... Thanks for the info, Lloyd, I know what mags I will be basing my breech on....
Bob
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The potential just keeps growing.
Couldn't be happier, here, to see this.
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Can anyone tell me if the new disco is any different than the old one, as it pertains to their fit in a custom stock?
Also, who currently makes stocks for discos?
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Boyds make custom Disco stocks. Here's my .177
(http://i1036.photobucket.com/albums/a446/Grimeszee/Air%20Guns/20160513_173531_zpsoq7k3cvw.jpg) (http://s1036.photobucket.com/user/Grimeszee/media/Air%20Guns/20160513_173531_zpsoq7k3cvw.jpg.html)
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Can anyone tell me if the new disco is any different than the old one, as it pertains to their fit in a custom stock?
Also, who currently makes stocks for discos?
Eric,
By new Disco, are you referring to the new Benjamin Maximus? Certainly a decent entry level PCP.
Lloyd
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Yup. Oops. :) There was a discussion about the stock being too shallow for DDs, when they came out, but I can't remember if it was determined that they would fit in the custom stocks for Discos.
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I am not sure if the Maximus will fit in a standard Disco stock or not. It looks like it should, but I am not positive. One thing I am pretty sure about is that even though the Disco Double kit will fit the Maximus, the synthetic stock probably cannot be modified to accept the extra tube. The synthetic stocks only have some ribs inside and once you cut into them, there isn't much left.
PA is having their 20% off 20th Birthday sale today and I have been debating about ordering a Maximus to see what makes it tick. You can never have too many airguns, right?
Lloyd
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You can never have too many airguns, right?
Lloyd
This is a claim made by many knowledgeable people. I will defer to their expertise.
:)
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Will the Marauder double tube fit into a Boyd's TH stock?
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Will the Marauder double tube fit into a Boyd's TH stock?
Don, I think Norm at Discos R Us is the best one to answer that one. He is Norm_m on the GTA.
I know it is real close.
Lloyd
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Will the Marauder double tube fit into a Boyd's TH stock?
Don, I think Norm at Discos R Us is the best one to answer that one. He is Norm_m on the GTA.
I know it is real close.
Lloyd
X2 on the Boyds thumbhole stock with double tubes.
Mike
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The Boyd's Blaster TH stock is the one Norm did for the Disco Doubles, Discos, and MRods.... but I thought he was pulling back from inletting stocks because they took too long....
http://www.gatewaytoairguns.org/GTA/index.php?topic=106123.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=106123.0)
Perhaps you should ask Norm if he will still do them for the DD?....
Bob
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The Boyd's Blaster TH stock is the one Norm did for the Disco Doubles, Discos, and MRods.... but I thought he was pulling back from inletting stocks because they took too long....
http://www.gatewaytoairguns.org/GTA/index.php?topic=106123.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=106123.0)
Perhaps you should ask Norm if he will still do them for the DD?....
Bob
Just got a PM response from Norm and it is do able
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OK, I just finished all 76 pages. My head hurts. Other than that, YOU GUYS definitely belong in the big brain club. Great work. Now just have to go back through it all and try to get it to sink in.
Thanks for all your hard work.
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You, Sir, are a glutton for punishment.... *LOL*....
Bob
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Glad to hear the Boyd stock DDs mods are a go so now I just have to go deeper in debt to feed my addiction.
Mike
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OK, I just finished all 76 pages. My head hurts. Other than that, YOU GUYS definitely belong in the big brain club. Great work. Now just have to go back through it all and try to get it to sink in.
Thanks for all your hard work.
Believe me, Matt, it matters to me that someone takes the time to know what they are talking about, when it comes time to order. It pays.
You, Sir, are a glutton for punishment.... *LOL*....
Bob
There ought to be some kind of an award for guys who inform themselves thoroughly, in spite of the drudgery involved here.
I'm looking around...
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Guys, it turns out my spam filter has been overprotective (to put it mildly), and has kept a bunch of mail hidden for a long time... including from long term contacts (like GTA notifications... that should have been my first clue... ::) ).
If you have emailed SA, and didn't get a reply within about 2 days... please resend it?
Thanks!
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Tri-5-Ron and I have been brainstorming tonight, and this is the result:
It appears that the Evanix mags can be fitted to the Fusion/60s. He had one in hand as we measured it all out, and in some ways, it will be easier to fit than the .25 MRod (or Lloyd's .30 conversion of that mag... Lloyd and I discussed bumping that up to .357, but it looked iffy at best).
The reason I'm excited about all this is we know the Fusion/60s will take up to a .357 barrel liner... and now we have a mass produced mag. It appears all the mags from .177 up will fit... including the double mags.
This was figured out as I was looking into using a Bulldog mag... and trying to figure out if I could mount it so it would clear a scope. Ron turned me on to the Evanix .731", and we spent all my battery hashing it out.
Love to play with this guy!
https://www.pyramydair.com/product/evanix-731-wide-357-9mm-single-air-rifle-magazine-fits-evanix-pcp-guns?a=4637 (https://www.pyramydair.com/product/evanix-731-wide-357-9mm-single-air-rifle-magazine-fits-evanix-pcp-guns?a=4637)
https://www.pyramydair.com/search-results-ext?keyword=Tactical+sniper+magazine+evanix&sid=1375A617A415&N=0&Ntk=primary&q=Tactical+sniper+magazine+evanix&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch (https://www.pyramydair.com/search-results-ext?keyword=Tactical+sniper+magazine+evanix&sid=1375A617A415&N=0&Ntk=primary&q=Tactical+sniper+magazine+evanix&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch)
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Got to poking around, and found out something I didn't realize: I can fit a .45 barrel liner in these. With the 1/4 - 28 screws (with the biggest heads that I stock) you are limited to a .373" long port... unless I cut a sleeve for the F screw, allowing a full .45 long port, or go with an even bigger screw. A 5/16 - 18 (145Kpsi) will allow a .437" long port. Close enough?
Evanix .45 mag (ouch) fits .600" long bullets: https://www.pyramydair.com/product/evanix-tactical-sniper-rifle-magazine-45-cal-6rds?a=5091 (https://www.pyramydair.com/product/evanix-tactical-sniper-rifle-magazine-45-cal-6rds?a=5091)
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Pricy mags, especially the .45 cal.... My 244 gr. BBT in .457 would fit for length, though, it is 0.573" long.... In .357, even the 178 gr. BBT would fit, it is 0.714" long....
How much wall thickness will you have on the barrels in .357 and .457 cal?.... You would only notice a difference between a 3/8" port and a 7/16" in the .457 if you are pushing over 400 FPE (200 gr. at 950ish) on 3000 psi.... My Hayabusa hit 550 FPE with a 30" barrel at 3600 psi with a 3/8" port.... Don't forget, once you go past about 80% of bore, you have to make an oblong barrel port....
Bob
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The liners will remain full thickness. The .45 is 5/8", a touch bigger than the channel... I have a 5/8" reamer to bring the receiver to spec, and to allow me to make that dimension standard so I can sleeve anything smaller up to that (like my .22 ultra light barrel, seen previously). That allows the barrels to be interchanged at will. Add 1 barrel, 1 mag and 1 bolt, and you have a dual caliber set up.
The adjustable reg will give us a wide range of easy tunes. GRS will make it a very wide range. I'd be happy with a .22/.45... it would cover a lot of ground.
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Not too sure you can find a valve that would cover that range of calibers, but then again I've never tried a .22 cal barrel on my .45 cal Hayabusa.... Somehow it doesn't make sense to me to use a monster hammer spring to open a huge valve against 4500 psi and then restrict the whole system back down to do what you can do with a smaller, easier to open valve, running much lower pressure....
I'm not saying that one gun can't do it all.... but the concept of just interchanging barrels "at will" and a simple retune seems to me to be just a slightly larger than life goal.... However, the concept of using a single platform, with several sets of internal parts, used in conjunction with the caliber change, is not at all far fetched....
Bob
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Given that the GRS can act as any strength of spring, I'm thinking it and the reg should allow a lot of choices.
Guess we'll see!
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Not speaking specifically about AG's but it has been my experience with tools owning just one saw to fit every job makes no sense any more than having only one pipe wrench or one of any specific tool can you do multiple tasks with one saw or wrench yes but as Bob says why take a .45 and choke it down so you can have a .22 also there are numerous obstacles to having a practical end product and he has way more knowledge about building and performance than I do with AG's
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I'm trying to wrap my head around why, with the GRS, lowering the striker force by lowering the pressure wouldn't work... especially with the reg to play with. I get that it's easier to just own and tune 2 guns, but many I know here don't have the option. They are PB guys, and given that a decent airgun costs more than the equivalent PB, air is already a hard sell. It would be easier to sell a squirrel gun, that could be set up to go big once in a while.
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I think to make that kind of thing reasonable, swapping out internal parts makes sense. Not because you can't do it without swapping them, but because it makes it so much simpler. Instead swapping the barrel and spending 3 days in front of a chrony, drop in internals mean the user can be up and running again in half an hour. I realize that doing this will mean not every gun is getting the best efficiency ever or the ideal tune for that pellet. Let face it, for 99% of use cases that does not matter. That soda can is just as dead with 12fpe or 12.1fpe. Losing one shot at the end of the string does not matter that much.
If I am the imaginary PB guy with one airgun and I only ever use it to shoot tree rats, but I find that just once I want to shoot a pig then I need it to be dead easy. At that point though I wonder how much would really be saved. The barrel, valve, regulator and SSG/GRS have to add up to a considerable fraction of the total cost.
The idea of standardization however is huge for the fellow selling them. He can fab up everything at once and fill boxes to ship out at the customer's request.
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I think to make that kind of thing reasonable, swapping out internal parts makes sense. Not because you can't do it without swapping them, but because it makes it so much simpler. Instead swapping the barrel and spending 3 days in front of a chrony, drop in internals mean the user can be up and running again in half an hour. I realize that doing this will mean not every gun is getting the best efficiency ever or the ideal tune for that pellet. Let face it, for 99% of use cases that does not matter. That soda can is just as dead with 12fpe or 12.1fpe. Losing one shot at the end of the string does not matter that much.
If I am the imaginary PB guy with one airgun and I only ever use it to shoot tree rats, but I find that just once I want to shoot a pig then I need it to be dead easy. At that point though I wonder how much would really be saved. The barrel, valve, regulator and SSG/GRS have to add up to a considerable fraction of the total cost.
The idea of standardization however is huge for the fellow selling them. He can fab up everything at once and fill boxes to ship out at the customer's request.
All true... but... If that guy wanted to shoot a pig once a year, he really wouldn't care about efficiency or shot count. He would probably just crank it all up, and sight it in. As long as he got 3 shots... he'd be happy.
He could then return to his original settings (if he was smart enough to count turns, and write down GRS pressure) then sight it in. Back to the rats for another year.
Makes me think a sticker, with graduations (w/o numbers) might be a cool thing for the new regulators.
Heck, the gunsmith could easily run a few tunes through it, chrony, and produce a spreadsheet (see what you've DONE to me, Lloyd?!?) that that guy could use as a guide. Being able to read (and record) the striker force, in psi, would simplify a lot of things. It would also allow people to share reasonably accurate tune data.
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A gun with a gauge on the upper tube, and GRS, could be accurately tuned (and returned to a specific tune) with a screwdriver and a pump. Or, am I missing something?
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To put it simply, just build it, tune it, and prove it can be done; there is no point arguing about it, because it is uncharted territory.... I personally think that a gun shooting 500 FPE in .45 cal won't produce a .22 with enough efficiency, and consistency, to be an accurate 20-30 FPE gun with lots of shots, which is what most users would want, most of the time, just by retuning with no parts changes.... However, I've never tried (because of the limitations of coil springs, hammer weight and travel, and current valves), and I've been wrong before, so I wish you luck.... Perhaps the GRS, once you perfect it, will allow those order of magnitude changes in FPE within a single gun.... You may need a balanced valve, to be easy enough to open, to accomplish it without a half pound hammer with 2" of travel, of course.... You would have to build the gun as a .45 and then have the ability to detune it to a .22 cal plinker, IMO....
Bob
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I hadn't quite imagined that large a range, but your point is taken. I would be happy if it would go down closer to .22LR power most often used on the ground squirrels here, ~150fpe. You can't get close to them, and lots of guys use .177 CFs to reach out there. I don't see anyone around here paying much for a plinking gun...
I'm not talking about 1 gun to adjust to fit every man, I'm talking about a gun that can entice a PB diehard hunter into the sport, and keep him here. If he decides he wants to shoot beer cans... we have Walmarts, too.
Yup, it will take building one to see what kind of range that would allow without hammer changes, but, within that range... I can't imagine an easier to tune gun.
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I have been keeping up on this thread built seem to have missed out on just what a GRS is as compared to the SSG or if they are in fact similar at all.
So what exactly is a GRS and how does it work or perform in an air gun.
Mike
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Gas Ram Striker... discussed a while back. An air spring, adjustable over a very wide range by changing the pressure in it.
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Bob is correct that a balanced valve would go a long way toward making the gun versatile. http://www.cothranmachine.com/WhatNew.HTML (http://www.cothranmachine.com/WhatNew.HTML) I hope to find out how far, after the move. The Cothran isn't cheap, but the time it takes to work around it isn't either.
I'm hoping 150 to ~400fpe can be pulled off without too many changes to the base design, as that would give SA a line of guns from 7fpe up (with Bob's grizzly specs dead center, after which is the perfect point to go balanced). If I can do 150 and up with 2 or 3 hammers, that's cool.... but, if I can do it with 1? I could built the entire lower gun, and the caliber kits, in advance. Ship in no time. Anyone who knows me, knows how hard I work to eliminate excess part #s... I learned that's never a bad idea.
Also, if "that guy" bought a dual caliber set up, and decided it was enough of a PITA (it is) to change over... he could come to me, and we'd put a gun under his second caliber. In a few mins. If we need multiple hammers to cover him.... oh well, it's coming down.
I can't wait to see what the GRS can do for these.
We'll see. It's all "dreaming out loud" for now.
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Gas Ram Striker... discussed a while back. An air spring, adjustable over a very wide range by changing the pressure in it.
Thanks and sounds very interesting and I can see how it would very adjustable for a wide range of levels. Is it small enough to fit in a normal spring pockets constraints and by chance do you have a page range where it was discussed to narrow it down in rereading the entire thread.
Mike
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Once you start talking 400 FPE, unless you have a balanced valve, the hammer weight, travel, and spring energy required get oppressive in a hurry.... In addition, there is no need to go to 7/16" or full bore porting to get 400 FPE, particularly if you have 4500 psi available.... Going with huge ports means the valve is harder to open.... My .457 Hayabusa hit 550 FPE with a 336 gr. bullet on 3600 psi with "only" 3/8" porting.... but the 0.406" valve throat at 3600 psi still took a 237 gr. hammer with 2" of travel and a 4.5" long, 0.072" wire spring to open it.... It could be tuned for 6 shots at 419 FPE on 640 cc of air.... Could that be tuned down to "only" 150 FPE, possibly.... but you would still have the half-pound hammer slamming around in there....
Bob
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I just ran across this thread about DiscosRUs closing and up for sale.... http://www.gatewaytoairguns.org/GTA/index.php?topic=109598.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=109598.0)
Since Norm recently stated that he could still do inletting of stocks for the Double Tube setups, it might be a good idea to ask him if/how this decision impacts that statement....
Bob
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Once you start talking 400 FPE, unless you have a balanced valve, the hammer weight, travel, and spring energy required get oppressive in a hurry.... In addition, there is no need to go to 7/16" or full bore porting to get 400 FPE, particularly if you have 4500 psi available.... Going with huge ports means the valve is harder to open.... My .457 Hayabusa hit 550 FPE with a 336 gr. bullet on 3600 psi with "only" 3/8" porting.... but the 0.406" valve throat at 3600 psi still took a 237 gr. hammer with 2" of travel and a 4.5" long, 0.072" wire spring to open it.... It could be tuned for 6 shots at 419 FPE on 640 cc of air.... Could that be tuned down to "only" 150 FPE, possibly.... but you would still have the half-pound hammer slamming around in there....
Bob
It looks like the best way is to go with the Cothran, at least until something can be built in house. I looked things over, and there is no way to to come close enough to the cost with a conventional set up, unless I farm the parts out (with 2 hammer choices? 3?)... and that might not be that much cheaper.
I avoid single source parts like the plague, for some good reasons learned the hard way... but, Cothran has a good reputation, and seems to be in this for the long haul.
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Gas Ram Striker... discussed a while back. An air spring, adjustable over a very wide range by changing the pressure in it.
Thanks and sounds very interesting and I can see how it would very adjustable for a wide range of levels. Is it small enough to fit in a normal spring pockets constraints and by chance do you have a page range where it was discussed to narrow it down in rereading the entire thread.
Mike
I don't have a range for you, when you find it please post the beginning post #?
I have been keeping a table of contents, but neglected to put that in it.
I no longer discuss prototypes here. The GRS concept was brought out in Russia, 2 months after it was posted here. The guy got it wrong, but the point remains... I have had people waste a bunch of my time (the list is growing, VRD LLC ring a bell?), trying to steal my ideas while pretending to want to help, invest or buy. I'm quite embarrassed at how much of my time I let these kind steal from me... I don't need to worry any more about being made a fool of.
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I have never had a Cothran valve, but I rather doubt that the Disco version is capable of 400 FPE, I don't think the MRod version is even in that league, but so little information is available on that one (just released) I could be wrong.... The 1/4" (or smaller) ports, throat, etc. in the Disco version will never be able to produce 400 FPE, however, so I think you will be in the situation, just like the GRS, of designing and building your own balanced valve to produce that kind of power in a 3/4" ID tube (if possible)....
BTW, Eric, it is not my intention to rain on your parade here.... only to hand you an umbrella to shelter you from what may be a downpour of (over)enthusiasm.... ie a reality check.... ;)
Bob
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I have never had a Cothran valve, but I rather doubt that the Disco version is capable of 400 FPE, I don't think the MRod version is even in that league, but so little information is available on that one (just released) I could be wrong.... The 1/4" (or smaller) ports, throat, etc. in the Disco version will never be able to produce 400 FPE, however, so I think you will be in the situation, just like the GRS, of designing and building your own balanced valve to produce that kind of power in a 3/4" ID tube (if possible)....
BTW, Eric, it is not my intention to rain on your parade here.... only to hand you an umbrella to shelter you from what may be a downpour of (over)enthusiasm.... ie a reality check.... ;)
Bob
From what I have seen in my years of non-airgun manufacturing in a very mechanically technical environment, truly "original" ideas are extremely rare. But to me, what really matters is who can actually get the ideas to work, first as a proof of concept, and then the really difficult part, getting them to work in a manufacturable manner. That can be extremely difficult, and is often not succesful.
But what I really wanted to comment about is the new Don Cothran valve. I talked to Don at length on the phone the other night and ended up buying an M-Rod Power House valve from him. It is in my hands now, he he, he. :P Don spent a lot of time perfecting this valve and for that I have the ultimate respect. I will be starting a thread about the installation and performance of the valve very shortly, trying it in a couple of different Marauder Rifles. A fella at the Fun Shoot had one in a Disco based rifle and it was pretty scary. >:(
I am excited about this. I have no expectations regarding air efficiency, :( but for power, I am expecting big numbers. :o
Lloyd
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I have never had a Cothran valve, but I rather doubt that the Disco version is capable of 400 FPE, I don't think the MRod version is even in that league, but so little information is available on that one (just released) I could be wrong.... The 1/4" (or smaller) ports, throat, etc. in the Disco version will never be able to produce 400 FPE, however, so I think you will be in the situation, just like the GRS, of designing and building your own balanced valve to produce that kind of power in a 3/4" ID tube (if possible)....
BTW, Eric, it is not my intention to rain on your parade here.... only to hand you an umbrella to shelter you from what may be a downpour of (over)enthusiasm.... ie a reality check.... ;)
Bob
From what I have seen in my years of non-airgun manufacturing in a very mechanically technical environment, truly "original" ideas are extremely rare. But to me, what really matters is who can actually get the ideas to work, first as a proof of concept, and then the really difficult part, getting them to work in a manufacturable manner. That can be extremely difficult, and is often not succesful.
But what I really wanted to comment about is the new Don Cothran valve. I talked to Don at length on the phone the other night and ended up buying an M-Rod Power House valve from him. It is in my hands now, he he, he. :P Don spent a lot of time perfecting this valve and for that I have the ultimate respect. I will be starting a thread about the installation and performance of the valve very shortly, trying it in a couple of different Marauder Rifles. A fella at the Fun Shoot had one in a Disco based rifle and it was pretty scary. >:(
I am excited about this. I have no expectations regarding air efficiency, :( but for power, I am expecting big numbers. :o
Lloyd
Lloyd a suggestion please start a new thread with your Marauder Cothran Powerhouse valve as a part of your project . I am sure myself among others will be following your efforts , but my request is somewhat motivated by my personal Marauder project
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I'm looking forward to your results with the new MRod Powerhouse Valve, Lloyd.... I have no doubt that you will be able to coax some impressive FPE from it.... However, knowing the dimensions available inside a 3/4" tube, as used on the XS-60c (which will accept the Disco version only).... I still have my doubts about reaching 400 FPE using the Disco Powerhouse Valve.... However, I've been wrong before....
Bob
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I'm looking forward to your results with the new MRod Powerhouse Valve, Lloyd.... I have no doubt that you will be able to coax some impressive FPE from it.... However, knowing the dimensions available inside a 3/4" tube, as used on the XS-60c (which will accept the Disco version only).... I still have my doubts about reaching 400 FPE using the Disco Powerhouse Valve.... However, I've been wrong before....
Bob
Lloyds efforts will be closely watched by me and once I start my project I will be sending him my Marauder bolt for upgrading to .30
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Gas Ram Striker... discussed a while back. An air spring, adjustable over a very wide range by changing the pressure in it.
Thanks and sounds very interesting and I can see how it would very adjustable for a wide range of levels. Is it small enough to fit in a normal spring pockets constraints and by chance do you have a page range where it was discussed to narrow it down in rereading the entire thread.
Mike
I don't have a range for you, when you find it please post the beginning post #?
I have been keeping a table of contents, but neglected to put that in it.
I no longer discuss prototypes here. The GRS concept was brought out in Russia, 2 months after it was posted here. The guy got it wrong, but the point remains... I have had people waste a bunch of my time (the list is growing, VRD LLC ring a bell?), trying to steal my ideas while pretending to want to help, invest or buy. I'm quite embarrassed at how much of my time I let these kind steal from me... I don't need to worry any more about being made a fool of.
Eric
I do understand your concern of pirating of ideas and designs and in today arena is all to real so I just want to assure you that it is in no way, shape or form any of my intent to even attempt to do so but rather to gain knowledge to be able to make informed decisions on what projects and parts I would need to source and where from to enjoy this hobby to it fullest.
I understand with the length of this thread it will be a time consuming task to proof read thru it to find the GRS posts but when I get time I will do so and let you know the first post about it so you can add it to your table of contents as that's the least I can do for all you provide for those of us with limited knowledge and means to build and enjoy some of the best innovations thought out and brought to life here in this forum.
Thanks Mike
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Bob, Cothran got a max of 373fpe out of that valve. Frankly, I'd be happy to get close to that. Not to worry about me... many of the things I built (over 40 yrs) started out as "impossible", and I find some joy and satisfaction out of coming as close as possible to the impossible. If I don't get there, at least I'll know why.
Let's play with your "reality" thingy for a bit? LOL... an agile, durable, 7#(or so) 300fpe repeating gun would be a thing of beauty, no? :)
Mike, if I thought you were "that" guy, rest assured I would not be responding to you. Instead, you'd get a post like this: http://www.gatewaytoairguns.org/GTA/index.php?topic=49115.500 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49115.500) , #543 (last page)... take it upstairs... and poof, you'd be gone.
I frequently say "GTA rocks"...and, that I can prove it. Most guys never get a chance to find out just how securely GTA has our backs.... but, I did.
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Eric
I can see just what you mean and I would have to agree that they do have all our backs indeed and I had one incident that I let my judgment and thoughts get out of hand and it was tempered very swiftly and with no uncertain terms from the upstairs as well. I don't need to be told twice that's for sure.
This is the best place to learn and share for all of us in all ways.
Mike
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First of all, I believe this is the first reference that Eric made to using a Gas Ram Striker.... http://www.gatewaytoairguns.org/GTA/index.php?topic=59114.1040 (http://www.gatewaytoairguns.org/GTA/index.php?topic=59114.1040) .... If you start reading at Post #1047, you can see how that idea developed, and ended up being the basis for my SSG (the idea is mentioned in Post #1074, first build in #1089).... Other posts about the GRS system continued for several months from that point onwards....
Eric, you are correct, I see that Don indeed got 374 FPE in .45 cal, although he does not mention barrel length or pressure.... He is at 250 FPE in .357 with a 26" barrel and 270 FPE with a 29.5", with a 232 gr. bullet at 700-725 fps (again, no pressure stated).... As you know, using extreme weight bullets (which a 232 gr. in .357 certainly is) at very low velocities sways the FPE heavily, compared to what might usually be used.... I do not know precisely the exhaust port diameter of the Disco Powerhouse valve, but from the photos it looks to be less than 1/4", which makes sense.... I find about 7/32" to be the maximum practical size in a 3/4" OD valve.... I have never tried building a .45 cal with such small ports (less than 50% of bore area), but it is possible that driving a very heavy, and therefore slow moving bullet, could produce significant power, given enough pressure and barrel length.... I personally think that for more practical use, a .357 cal would max out the capabilities of a 3/4" ID tube.... although using 4500 psi could push that up to .40 or even .45 cal, I suppose.... As you say, doing the "impossible" has a certain charm, and I wish you the best of luck....
Bob
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Bob
Thanks for finding it first about the GRS and it leading to the development of the SSG you came up with for all of us to experiment with and benefit from its simplicity yet superb results.
I have it bookmarked to read as time permits.
Mike
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Bob,
Assuming one wanted to shoot your boat tails and was ok with a very long barrel, 30+ inches, would you go .357 or .308?
Pig would be the largest animal, but real every other weekend use would be to wow folks at the gun range. 3000 psi ideally.
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I've never shot a pig (we don't have any here).... and in any case it would depend on the size (weight) of the pig, and whether you are talking head shots or heart/lung.... Manny shoots a lot of pigs with .22 and .25 cal pellets, at 30ish yards, but only in the fusebox.... IMO, for a heart/lung shot you would not want less than 1 FPE per pound of body weight, at the target, and 2 FPE would be preferable.... Ask yourself if (and where) you would shoot a large boar with a .22 LR rimfire at 50 yards, and you will get my point....
Our Mule Deer bucks here can run 200+ lbs.... Getting 200FPE to arrive downrange, even at 50 yards, would be a challenge for a .308 cal running on 3000 psi, so I would opt for a .357 for that job.... For the "WOW" factor at the range, for picking off small targets at 100-200 yards, my choice would be a .257 cal, shooting ~ 70ish gr. bullets at ~ 150 FPE.... IMO, the .308 is a great caliber for Predators (eg. Coyote), and smallish pigs, but a little small for deer, particularly big ones.... and a little large for target shooting and varmints.... although if you can only have one, I can see it being the best compromise....
Bob
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Eric, I just had one of those DUH! moments.... Here is the way to restrict the velocity when moving down from a 400 FPE gun to one of 40 FPE or less....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/IMG_3800_zps811e14d1.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/IMG_3800_zps811e14d1.jpg.html)
The screw at the back pushes a rod forward which prevents the bolt handle from fully withdrawing into the J-slot.... You can drastically reduce the power, because the full diameter bolt nose progressively covers the barrel port....
(http://i378.photobucket.com/albums/oo221/rsterne/30%20cal%20Disco%20Double/30DiscoDoubleAdjusterSettings_zpsef00c07a.jpg) (http://s378.photobucket.com/user/rsterne/media/30%20cal%20Disco%20Double/30DiscoDoubleAdjusterSettings_zpsef00c07a.jpg.html)
I don't know if you can work a J-slot into the XS-60c, but if you can, this could solve the drastic detuning issue when you change calibers.... You could even do it with a conventional, non-adjustable, probed bolt, by having a threaded sleeve on the probe that could move forward and restrict the barrel port on the smaller caliber.... or just drill a tiny barrel port in the smaller caliber barrel....
Of course you still have to deal with the weight and travel of the hammer needed to open the valve at 400 FPE.... but a balanced valve would go a long ways towards fixing that....
Bob
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Bob you literally just invented an actual on demand power adjuster.
You just did what airforce airguns has been pretending to do for years.
That is awesome in the original sense of the world.
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Not "just invented", I've been using it for a couple of years.... particularly when I go from bullets down to pellets.... It just occurred to me that it might solve Eric's detuning problem between large changes in caliber.... ::)
Bob
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Either way, something no commercial endeavor has yet made work.
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The velocity adjuster in an MRod chokes up the transfer port.... I believe Air Arms have a similar device?.... They just don't restrict the bolt movement....
Bob
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Both of which require pulling the gun out of the stock, I think. So not exactly on demand.
Either way it was just a compliment.
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Much appreciated.... I just don't like to take more credit than due.... *grin*.... Yes, it is extremely easy, and repeatable, to adjust....
Bob
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"...or just drill a tiny barrel port in the smaller caliber barrel.". I figure I could start with that, and my adjustable bolt idea in a custom bolt. Starts at post #273... Results in #317. It's quick and easy. As posted, it made a great dual use gun. It's a favorite here.
A couple passes on the receiver, and I may be able to increase the nose travel quite a bit, and nearly close off the port.
The .731 evanix mags will also allow just enough space behind them to reach the set screw easily. This means all the tuning tools can be accessed without any disassembly of the gun, (past pulling the stock to adjust the GRS, on the fusion/60s).
A dual cal kit would only need a barrel, and a bolt nose. I'm less worried about absolute numbers as being able to create a useful range. What is considered the best FPE range for tree squirrels (something to shoot for?)?
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Go for 20. More than enough for clean hunting, even at range..., and someone can even try in FT! ;D
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I cannot say on an Air Arms but I do know for a fact that on a Mrod it is just a matter of some light filing work to clearance the stock to access the air screw without removing the action from the stock and if done slowly and carefully can end up looking factory done. All three of my Mrods have it done including the one in the Boyds stock and they look factory done.
As far as the required FPE for killing wild pigs I would agree with Bob on at least 2 FPE per pound for best results. But back in the 70s when I lived in Florida and had a friend with a Hog claim on timber company land that meant he owned every wild " Boar " on 450 acres of land we could hunt them year round. The reason I state Boar and not pig is the Boar we hunted would get over 1000 pounds with 12 inch tusks that were razor sharp and if you did not have a BIG enough gun to make a one shot kill shot you would end up being the hunted not the hunter. The only guns we had were 30/30s and a 35 Remington magnum at the time and I can speak from experience that those were not BIG enough. We had more than a couple occasions of encountering a Boar of 800 pound plus and shooting it but not hitting lungs or heart cleanly or hitting the skull only to have the bullet ricochet off and left one angry boar that then proceeded to turn and charge us. The only escape since they can outrun a person two times over is to find the biggest tree and climb it in hopes that the boar can/will not uproot it with you in it.
We had spent several nights in the trees with the Boar trying to uproot the tree to get at us more than I care to remember. I am talking a 1 1/2 to 2 foot diameter tree that would be swaying all night with the Boar digging at the roots trying to knock it over only to come the next sunrise and a discouraged Boar that finally gives up to wander away.
We were in our 20s and met a older man in his mid 40s that lived and hunted those Boar all his life in that area and he did not carry a gun at all but instead hunted them with 8 to 10 Pit Bulls and two Airedales and a 12 inch bowie knife that he used to cut their throats as they would suffocate on their own blood in under 5 minutes. He had times when the Boar had killed all his Pits and was lying in wait for him to show up and would chase him up a tree as they did us.
Wild Russian Boar that had been brought into Florida years earlier are one of the few game that if made angry will hunt you just as fast as you hunt them and will do so with intent to kill.
Just for what's its worth.
Mike
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This would be feral hog in Texas. We hunt from steel raised blinds, so unless they have power tools or learn to climb ladders we are pretty safe.
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(http://www.starrcards.com/wp-content/uploads/doritos-2015-super-bowl-commercial-when-pigs-fly.jpg)
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You'd have to lead these by quite a bit. How fast do they go?
Looks like fun hunting, though.
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Now for those I would invest in a wingshot.
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Well as you all know I'll be getting a Stalwart Arms 3K Double with a regulator so I thought I'd get busy fabbing a stock and the 60 was a good one to work with.
Well here goes.
I figured all I needed to do is add 7/8" filler + the with of the saw cut, thus the layout and cut pics. The cut was determined by half the diameter of the 7/8" CroMoly tube (7/16" radius) which is obvious in the reservoir inlet. Remember this is a prototype subject to bedliner covering. Wood on hand was mahogany (I think oak would have looked nice).
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0528161102_zpsbuhngizj.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0528161102_zpsbuhngizj.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0528161338_zpsnh42qgyv.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0528161338_zpsnh42qgyv.jpg.html)
I used my portaband with a bed and fence to cut off the lower part of forend and cut the mahogany fillers on a table saw. I flushed the fillers with the inside of the stock and left plenty material to all pieces to sand off on the outside. I have just enough meat in the forend lower reservoir channel to remove material for a finish fit.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0528161514_zps8vmdq7iw.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0528161514_zps8vmdq7iw.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0528161613_zpsajksevhz.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0528161613_zpsajksevhz.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0529161429_zpswn47xqdy.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0529161429_zpswn47xqdy.jpg.html)
This pic show I chiseled out approximately 1/2" behind the front of the receiver for any discrepancy in length of the lower reservoir.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0529161430_zpsnjfikjol.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0529161430_zpsnjfikjol.jpg.html)
Stalwart and I talked about routing out the forearm reservoir channel but with this method, careful measuring and fitting a router will no be needed. I'm going to take a 7/8" wooden dowel rod and glue loose sanding grit (it's sold in various grit sizes) then a steel rod glued into 3/8" hole el centro of the wooden dowel then use my cordless drill to deepen the forearm lower reservoir channel if need be. I think I'm with in 1/16" of being deep enough.
Here are some pics showing preliminary sanding and what's left is some dabs of stock filler then finish detailing for the application of bedliner. (Sanding was done with a hand held belt sander, table belt sander and DA sander for rough in. Finish sanding will be done by hand block sanding.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0530160921_zpsohncs8n0.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0530160921_zpsohncs8n0.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0530160922a_zpsha6iznyq.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0530160922a_zpsha6iznyq.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/0530160922_zpspq6qmvzy.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/0530160922_zpspq6qmvzy.jpg.html)
Things I learned.
My mahogany filler assembly could have been prefabbed with radiused corners and installed as a unit. (I pieced all together in place one piece at a time on the stock and forearm.)
As an afterthought I could have radiused and not had square corners, a much better flow and aesthetics. With radiused corners and the use of oak I believe I could have sanded, stained and cleared the entire stock and I think it would look real good.
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This would be feral hog in Texas. We hunt from steel raised blinds, so unless they have power tools or learn to climb ladders we are pretty safe.
Yea I realize the hogs that were being referred to were just feral pigs but just want to let people know that there are pigs/Boar that it would not be wise to attempt to hunt with an air gun much less some firearms as well.
As far as the steel blinds are concerned unless they are cemented into a large flat slab the boar we hunted would have you on the ground in short order since they could uproot the steel legs and topple the whole blind on its side. I would have never believed what they are capable of if I had not experienced it myself. I am talking about Boar that are the size of a medium bull with tusk about as long as a bulls horns.
Believe me or not but they do exist.
Mike
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Nice stock work, Mike!
The only other option would be to cut the forearm bulge flat, add the extra wood, route out the channel, and shape. Your idea looks easier, and needs fewer tool$ to accomplish. It could easily be done with hand tools. Good thinking!
Now, if LW would just hurry up!
8)
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Nice stock work, Mike!
The only other option would be to cut the forearm bulge flat, add the extra wood, route out the channel, and shape. Your idea looks easier, and needs fewer tool$ to accomplish. It could easily be done with hand tools. Good thinking!
Now, if LW would just hurry up!
8)
Less tools and more user friendly was my goal.
But you came up with another stroke of genius with the above and it would entail removing throwing away the old forearm and routing a one piece new forearm. The 7/8" router bit I have is short shanked, like me :D, and it would be best if the routing be done before fit, glue and shaping. I don't believe I have enough bit depth to rout when installed on the stock. The stock in my post is for the .22 and my other stock is for the .25. I got a feelin. Today is gonna be a good time. ;D
Even though the LW transaction was made in the U.S.A it might take a few weeks for me to receive the barrel. I guess that's LW's custom.
If that FD match .25 barrel doesn't work out I see a .25 LW barrel in the future. ;)
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RMM if routing at a deeper depth is a problem. Do you think a router extension would solve the problem?
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjdvbWa4YTNAhUG6WMKHXxxDg4QFghAMAA&url=http%3A%2F%2Fwww.rockler.com%2Frockler-router-collet-extension-for-1-4-in-shank-bits&usg=AFQjCNHerLzOHAbcRyKyw6WD70xoJjZydg&sig2=KEQ0ITZyk3mqCTDambmwWA (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjdvbWa4YTNAhUG6WMKHXxxDg4QFghAMAA&url=http%3A%2F%2Fwww.rockler.com%2Frockler-router-collet-extension-for-1-4-in-shank-bits&usg=AFQjCNHerLzOHAbcRyKyw6WD70xoJjZydg&sig2=KEQ0ITZyk3mqCTDambmwWA)
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Excellent idea! Thanks for the link, that's a very reasonable price.
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Yes it would Kailua ! Thanks!! I can center a 7/8"guide to the center of the router table collet and rout to my hearts content.
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For those guys who have been asking about putting 1/2" OD liners or Marauder barrels in their 60s... here's how you make up the slight difference in the sizes:
I ream the receiver to .5635", (perfect for those bigger liners), turn and bore a sleeve (keeping it a bit smaller ID), bond it in, and turn that section of the barrel down to match (forming a stop shoulder).
It takes time... but, it works great.
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If you are going to sleeve the 1/2" OD barrel with Carbon Fibre, you may also be able to find a CF tube that is the correct diameter to fit inside the XSS-60c receiver.... For sure you can get one that is 9/16" OD, which would fit inside Eric's bored receiver.... That is how I did my Grizzly....
Bob
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The smallest patterned stuff at McMC is the perfect size.
http://www.mcmaster.com/#carbon-fiber-tubing/=12vu1to (http://www.mcmaster.com/#carbon-fiber-tubing/=12vu1to)
Much cheaper: http://www.carbonfibertubeshop.com/small%20tubing.html (http://www.carbonfibertubeshop.com/small%20tubing.html)
Interesting development here: Across the street, in an under-utilized industrial area, the property values instantly quadrupled... and it all sold out... when it was recently zoned for marijuana farming.
One interesting part of all this is that firearms cannot be kept on those properties. And, I am getting inquiries about self defense air guns. More than a few...
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I think I would be more interested in the other part :)
The carbon fiber tubes I mean, of course. Looks like that second link only has .50ID .575OD in 60 inch lengths. That is a heck of a long barrel.
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It may be all we have left for self defense is our air guns in light of the recent tragedies. ???
Need a 45 cal Thompson air gun.
Mike
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I got my tins of 34 gr. JSB Beast .22 cal pellets today, and the first thing I did was try them in a PRod 8-shot magazine.... They are sooooooooooo close to working it's hard to believe.... In fact, some clear and some don't, just the tolerance in the pellets, and wobbling slightly in the wheel in the magazine is enough to make them hang up sometimes.... Often when the magazine is full, it will feed fine, but when the spring tension is at a minimum with only 1 or 2 pellets remaining, if those happen to be on the long side, it sticks.... Of course some mags may have a whisker more clearance and work perfectly, they are that close....
I pulled a magazine apart, and used a 1/4" spherical burr in a Dremel and just relieved the recess in the bottom front of the magazine case.... All you have to do is work it over with the burr until it is uniformly dull from contact with the burr.... Reassemble the mag. and it will work flawlessly.... I realize this is likely not of any interest to guys shooting a PRod, not many of them are going to shoot 60-70 FPE to make use of such a heavy pellet.... However, for anyone who uses that mag. in a custom build, this is great news....
I know my next project, my Disco Double which will be built around shooting these pellets, will be taking full advantage of the fact they can work in a touched up PRod mag....
Bob
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That will be so BA.
FWIW, I tried 1 mag, to see if it would fit in a 3 jaw chuck fairly centered... and it did, just well enough to shave some more depth into that spot.
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Guys, you might want to keep an eye on the Raffle thread, for a couple days...
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Well guys... looks like the saga of the exploding FDPCP is over. http://www.gatewaytoairguns.org/GTA/index.php?topic=96148.new;topicseen#new (http://www.gatewaytoairguns.org/GTA/index.php?topic=96148.new;topicseen#new)
The tube was found, measured, and found to be way below min allowable OD. Not surprising, given the results of my tests... and (like my tests) a vindication of the design.
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Yep, as you proved with your tests, no reason to fear if the threads in the receiver and on the tube are within tolerance.... The weak point is the valve screws in that case.... and even the stock screws are good to about 1700 psi with a 3.5:1 safety margin (6000 / 3.5) .... On a regulated gun, with a 1.8K burst disc, that should be OK as well.... So the gun really was designed to withstand CO2, even on a hot day.... 8)
Of course your through tube setup allows for much higher MWSP, which is always a bonus....
Bob
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For anyone who hasn't seen the results of the destructive testing, post #1342 is a good place to start reading... the second (refined rig) test is around #1413.
The 60s took a real hit last August. An unjustified hit... GTA (with a little luck, right there at the end) saw this through.
SA's commitment to further support and development of this design (Fusion and 60C) will continue unabated. The only visible difference, around here, may be a small smile! :)
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Well guys... looks like the saga of the exploding FDPCP is over. http://www.gatewaytoairguns.org/GTA/index.php?topic=96148.new;topicseen#new (http://www.gatewaytoairguns.org/GTA/index.php?topic=96148.new;topicseen#new)
The tube was found, measured, and found to be way below min allowable OD. Not surprising, given the results of my tests... and (like my tests) a vindication of the design.
No surprise there! It was obvious from several posted pictures of other MM manufactured tubes that the threads were not only undersize but of abysmal quality.
A case of too much drama and not enough common sense.
Tom
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RMM's LW barrel and .25 Evanix mag showed today... I'm tickled pink about this:
Compared to the MRod .25 mag (this one is Lloyd's .30 conversion), the distance between the bore's center and the bottom of the mag is much less on the Evanix. This means the Evanix won't require as deep a cut as the MRod... so, it won't require the extra work of making the valve block into a cover for the bottom of the mag slot. The mags are more expensive, but the work required to nicely mount the big MRod makes that conversion significantly more expensive. It's a win/win.
The mag is nicely made, operates crisply. All the Evanix mags have that same dimension in common, so there will be no need to cut a different slot for each caliber. FWIW, I figured out how to mount Evanix's longer mag, too. The method used will be the "mag/valve forward" set up discussed during the stroking experiments. The room to stroke this set up is beyond all possible need.
Also, I got something in that will eventually be mauled with every claw SA has... can you guess what it is?
Thanks, Lloyd... :)
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Cool!.... what calibers does the Evanix mag come in.... that are interchangeable?....
Bob
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Judging by the pics, the .731" mags are available from .177 to .357. https://www.pyramydair.com/search-results-ext?keyword=evanix+magazine&sid=1375A617A415&N=0&Ntk=primary&q=evanix+magazine&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch (https://www.pyramydair.com/search-results-ext?keyword=evanix+magazine&sid=1375A617A415&N=0&Ntk=primary&q=evanix+magazine&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch)
If there are any Evanix aficionados reading, I would appreciate conformation of this... please.
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The 22 cal is shorter than the 357 and there is rumor that there are two 357 variants with differing depths.
RSII 357 = .477" ( circa 2014)
RSII 22 = .388"
Both the 22 and 357 have the same bore to detent dimensions IIRC.
Tom
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Thanks, Tom.
This is gonna require some homework. To get a standard fitment for as many calibers as possible, I may have to sleeve the compatible big bore mags, like you did Ron's (nice job, BTW).
Guys, no promises until I can get a decent herd of these mags assembled here.
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Here's some good news for anyone contemplating putting a LW .630 OD barrel into a 60... It *just* fits without turning the OD down. Makes a nice looking Bull Barrel... saves a bunch of shop time.
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This gun has been dubbed "BBE"...
Best. Bobcat. Ever.
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NICE!....
Bob
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Thanks!
We have an interesting situation here. Mike wants to bond the barrel (hence BBE)... so it won't have o-rings... so, we can put in a transfer slot up to 9.25mm long (longer if I tilt the receiver in the mill to finish the front of the cut. 10... 11?).
How much is too much?
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I haven't kept up with this thread/project for at least a couple of months.
Glad to see this project has really got some new life back in it.
The progress is looking GREAT Eric !
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Thanks, Ron!
Yeah, things are still a bit nuts here, and the DD thing is adding to that... But... it won't be that way much longer. I found good help (whew!), and as soon as he has a few processes down pat, things will get MUCH faster. SA is growing faster, and in more different directions than I had planned... so this has to happen.
As to the DDs... We will be ready to take orders in a week or so. The first up will be what I call the "Classics"... the kit Lloyd has been selling all along. These are in (very) limited supply, and will be replaced by the new (reg ready) kits when stock is depleted. See my impending announcement for lead times and prices.
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Also... what the heck... Anyone who contributed to the July raffle will be given a $10 discount on a DD kit if purchased within 6 months. Be sure to remind me, with your screen name and the numbers you picked... and I'll buy a number back.
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I just finished my first cerokote job...
If the directions are followed precisely (prep, prep, and more prep), it works well and looks great!
I will be adding this to the coatings SA offers.
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Should be a good durable option. ;)
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It has a good rep for that.
It's a joy to shoot. Much like a metallic base coat, you don't hose it on.
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The project it looking great. I havent been keeping up on it like i wanted but i am glad to see how far it has come. Maybe if i return the Maximus i will try to pick one up.
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Since Stalwart is now doing Disco Doubles, I bet he could do a lot for a Maximus as well.
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Since Stalwart is now doing Disco Doubles, I bet he could do a lot for a Maximus as well.
I bet he could. But I have been just having so many problems with my Maximus. I had to send the first one back because it had so many defects. This one is very inaccurate. 5 inch groups at 10 yards. At this point I don't know if I should just see if I can try to get it to be more accurate with a fluff and buff or just return it and forget the whole thing.
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When in doubt, kick it out.
I vote for starting over.
Since Stalwart is now doing Disco Doubles, I bet he could do a lot for a Maximus as well.
I bet he could. But I have been just having so many problems with my Maximus. I had to send the first one back because it had so many defects. This one is very inaccurate. 5 inch groups at 10 yards. At this point I don't know if I should just see if I can try to get it to be more accurate with a fluff and buff or just return it and forget the whole thing.
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5" at 10 yards is not a group, that is not even a pattern!
You did make sure that the pellets are the right caliber, right? :)
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Not to worry about me... many of the things I built (over 40 yrs) started out as "impossible", and I find some joy and satisfaction out of coming as close as possible to the impossible. If I don't get there, at least I'll know why.
Eric, I was just catching up on this thread and this comment from you reminded me of one of my favorite quotes credited to Edison:
(http://i779.photobucket.com/albums/yy80/jmneal1/memes/failure_zpsk3cdqwtk.jpg)
Keep pushing the limits, brother. Much respect.
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The respect, sir, is mutual. Thank you.
Another Edison quote, that has been on one of the dry erase boards for nearly a decade:
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I have to add: Success or failure, tenacity has it's own rewards.
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When in doubt, kick it out.
I vote for starting over.
Since Stalwart is now doing Disco Doubles, I bet he could do a lot for a Maximus as well.
I bet he could. But I have been just having so many problems with my Maximus. I had to send the first one back because it had so many defects. This one is very inaccurate. 5 inch groups at 10 yards. At this point I don't know if I should just see if I can try to get it to be more accurate with a fluff and buff or just return it and forget the whole thing.
That is what i am leaning towards. But what i actually meant in that post was walk away from airguns as a whole for a while.
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Ah. Noted.
You could do that, but then you'd be leaving on a low note, and if you ever started again, you'd have that sour taste until you find something you like.
I recommend a middle path: Shoot some guns owned by others, that are dialed in and a joy to shoot. Take a break. Then come back and buy one of those guns. Then you're happy.
It took me three years to save for a used S510, because I only allow myself a strict "fun" allowance. Sometimes the slow route is nice...
When in doubt, kick it out.
I vote for starting over.
Since Stalwart is now doing Disco Doubles, I bet he could do a lot for a Maximus as well.
I bet he could. But I have been just having so many problems with my Maximus. I had to send the first one back because it had so many defects. This one is very inaccurate. 5 inch groups at 10 yards. At this point I don't know if I should just see if I can try to get it to be more accurate with a fluff and buff or just return it and forget the whole thing.
That is what i am leaning towards. But what i actually meant in that post was walk away from airguns as a whole for a while.
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Amen.
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I also keep in mind, It won't be wine until it's time. Patience compliments tenacity.
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I also keep in mind, It won't be wine until it's time. Patience compliments tenacity.
Indeed, it does.
Your BBE is one of 3 customer rifles here that are growing better as the time taken is allowing me to incorporate the latest features/methods into them. Your .25 is another.
The point, where the design is as advanced as possible and production methods are as efficient as I can make them... is coming soon. Fast turnaround is the goal now, and all who benefit from that will owe you, and the other daring early clients, for funding it. The last factor inhibiting this is having to teach Andy... and, he is showing that he will be the greatest factor allowing it... given a little time. A good example is the powder coating... Small parts are a real PITA, and my batch size was always limited by my limited ability to stand for a long time. He just pulled off a nice run, and actually enjoys the process. Now, I can throw a bunch of stuff in the tumblers, and walk away... I'm just LOVING that!
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The same parts, after hardening... in very bright sun.
This is Cerakote's "Graphite Black", and pictures don't do it justice.
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The same parts, after hardening... in very bright sun.
This is Cerakote's "Graphite Black", and pictures don't do it justice.
NICE!! Glad I got the same color! I bought an HF airbrush compressor and had an airbrush so I'm more than ready to paint. Gotta git that garage project done and the grass has gotta quit growin before I can play BB gun again. Winter is comin soon.
I also add I'm honored to be in collaboration with a fine group of gentlemen.
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It's crunch time and I've been asked what size port I would like and I wish not to make a wrong decision. What we have to work with is a regulator set at 1650psi (it is adjustable) using a 2900psi fill, ,22 JSB Jumbo Beast 33.956 gr (this approx weight to be used exclusively) and an LW barrel approximately 23.8" in length. 17.7 twist rate with 12 grooves.
So here's the question I pose; "What port size and or shape is required to get to the sweet spot when tuned?"
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I have to ask: Given the same areas, does a slot allow the air to turn corners easier than a round port? A NACA duct shape? We have a lot of room to play.
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I'll be interested in seeing what sort of velocity you can get with a 34 gr. in .22 cal at 1650 psi.... I plan on building a regulated Disco Double around that very idea over the winter.... I was hoping that 2000 psi in the 135 cc upper tube would be enough to hit 950 fps with bore-sized porting throughout with a 25" TJ's 0.217" barrel.... For sure you will want all the ports to match the bore area.... For the barrel port, that means an oblong port that is 0.165" wide by about 0.265" long at the boreline.... I would have the back of the port at 90* to the bore, and the front angled forward with the top rounded slightly into the chamber....
My understanding of NACA ducts is that they are designed to bleed off boundary layer air to the inside of a structure with minimum drag penalty on the outside.... I can't see that application in airgun ports, and if so, the design would likely require a CFD program....
Bob
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Thank you, Bob. Will do.
I brought up NACAs just to illustrate a complex shape... but, still have to wonder what that shape (just the outline) might do to direct air.... as well as a few others. Should I set up to do the design and analysis, for a couple percent improvement? LOL... nah.
I'm waiting on delivery of a USB borescope. Hopefully, I'll be able to show everyone the results... from the inside.
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I think Bob has it right again. IIRC the bigger the throat radius the better the flow of air is. The air flow tends to hug the throat when air is redirected. JMO
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Thanks Bob, I'll get this information to the master machinist who is building my rifle. :)
Now it looks like some valve porting to match the barrel port area is in the very near future.
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I just got two of these back from Stalwart. Put one together to prove to myself I still remembered how, and the other tonight will get some pictures. That will take some playing, this stuff is so black it is going to be hard to photograph properly.
Short list of mods;
New tubes, made of 1018 instead of mystery metal. Threads fit perfectly. The old tube fit ok, and was in all likelihood perfectly safe at 1500psi.
Streamlined endcaps with what I think are ninja fittings, or a darn good fitting anyway
Teflon coated striker and bolt
Cerakote all parts except for barrels, which I never sent him and am seriously considering for the future. The barrels do not look good next to all this pretty graphite cerakote.
Trigger mod, not sure what kind of witchcraft is involved exactly, but I bet it requires animal sacrifice or something like that.
I have just test fired it a few times and these changes seem to have cured the galling issues I had before.
I did not however install the safety yet, which I intend to have functional. I also need to get a shorter stiffer spring, as I bet I have plenty of hammer bounce. That or I will let it waste air as a reason to make me exercise more.
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Yup, they're Ninjas.
Trigger mod, not sure what kind of witchcraft is involved exactly, but I bet it requires animal sacrifice or something like that.
I can neither confirm nor deny, but... it would explain all the BBQs?
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Guys, I'm happy to announce we now offer hardened urethane bed liner coating for guns, in these colors, and custom tints! About a zillion colors are possible... and custom textures are no problem.
http://www.stalwartarms.com/coatings.html (http://www.stalwartarms.com/coatings.html)
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Well it must be winter because I'm playing BB gun again. :D
I've the Bobcat bead blasted and ready for CerKote just waiting for airbrush adapters to to hook my Paasche airbrush to my Harbor Freight airhose and airbrush compressor. Uncharted waters for me but the explorer gene in me says tary on.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20161214_054334_zps9nkepo0n.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20161214_054334_zps9nkepo0n.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20161214_054404_zpsdcb0zmpy.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20161214_054404_zpsdcb0zmpy.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20161214_054344_zpsdrj7oeoj.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20161214_054344_zpsdrj7oeoj.jpg.html)
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Here's what happens when Stalwart, Lloyd and Bob get together. I'm gonna put this together and get it shootin before I doll it up with lipstick.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20161214_063344_zps82hhilzu.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20161214_063344_zps82hhilzu.jpg.html)
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Nice setup, Mike!
Those parts are so ready for paint. 8)
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Nice setup, Mike!
Those parts are so ready for paint. 8)
Got the proper adapter today. Wish me luck. ;)
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Mike, I'm convinced you have pretty much eliminated the need for luck!
Guys, SA is now producing something for the diehard Fusion and Gen2 owners:
To produce a fine trigger for all variants of these guns requires all the sear width possible, to maintain good contact surface area while eliminating excessive overlap (cause of "creep"). The loss of contact width in the new guns is to accommodate the automatic safety feature. Engineering compromise... AKA reality.
It takes time, but a superb trigger can be had by eliminating that feature (I do as a matter of course in my personal rifles and pistols... all of them), and installing Gen1 sears with my voodoo in them.
The plastic in the new trigger housings is good stuff, and if you dislike the look as much as I do, I can smooth the seams and CeraKote or polish them. This will be available on the site (Special Editions) beginning around January 1st. Supply is limited (forever) on the G1 sears... and when they're gone, so is this offering.
If you send email with the subject: notifications, you will be sent early info on pricing, and get the first chances to buy.
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Well I got the Bobcat CeraKoted, took me awhile but she's on her way to spittin pellets again.
Pressure test went great. I have to make a new backer block as the one I made before (aluminum) I stripped the threads. I haven't slicked up the trigger yet so that's on the list of things to do also.
I have the forearm to reattach but in the meantime I'm just going to shoot.
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Looking good, Mike!
I have to tell you... your pics were making my trigger fingers itch. Great to see all that bare metal safe and looking sweet.
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Gentlemen Stalwart is building me a a .25 and 9mm 3K convertible, if possible, and if not it will be a 9mm only. The only hold back will be if the centerlines of magazine pellet slots are not the same. With that said we are in the experimental stage, meaning, I've purchase a .25 and 9mm magazines (the 9mm will arrive shortly) to compare. I will be in the market for a 9mm barrel and I know this has been discussed before so I will use GTA search as my homework for barrel and bullets plus I can cast my own.
This will be DD'd, have Stalwart's GRS and Lloyd's regulator which will grace this new creation but some questions I had for Stalwart were pertaining to valve modifications, throat for one, to feed the beast so here's what we will be working with.
1.) 25mm stroke
2.) I would like 20# pull (I'm not getting any younger ;) )
With all the above with and vast experience plus knowledge in GTA please help me and Stalwart bring this .25 and 9mm to fruition. Any information and advice will be appreciated.
P.S. Winter is upon and now is the time for creation something anew even if I'm months behind finishing the Bobcat and Best Bobcat Ever (BBE). Needless to say, I tary on. ;D
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Stalwart is building me a .25with a Cothran valve ,a Marauder barreland a 3K tube.I will post my shooting results here when he finally gets it done.
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Stalwart is building me a .25with a Cothran valve ,a Marauder barreland a 3K tube.I will post my shooting results here when he finally gets it done.
I'm very interested in this...please tell me more.
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He hasn't finished it yet.You can ask him about it.I am having him leave it a single shot so I can use bullets also if I choose,but he can make one which uses a mag also.Looking forward to it.
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Stalwart is building me a .25with a Cothran valve ,a Marauder barreland a 3K tube.I will post my shooting results here when he finally gets it done.
You'll appreciate it when you get it. He's already done two rifles for me, and now you know there's a 3rd. With the Bobcat up and runnin I have the BBE yet to go, I'm way behind on my airgun projects.
Have him do a trigger job for you, I really like mine.
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I found the other 60 stock I had laying around and the Bobcat sits pretty in it. I'll use the stock with the forearm cut off for the .25 and 9mm, I'll have to make another forearm anyway.
Started shooting today and after a couple shots I found the pellets were nicking the top of the TKO so that's now fixed and maybe tomorrow I can run some numbers and start tuning. I'm really happy the way the Bobcat turned out.
Merry Christmas everyone.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Bobcat%20right_zpsvzoyb2f9.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Bobcat%20right_zpsvzoyb2f9.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Bobcat%20left_zpswdksdiap.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Bobcat%20left_zpswdksdiap.jpg.html)
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This gun is in one of my most favorite configurations. PRod mag, and a dot. Pure agility... perfect for snap shooting cans, gallery use, and guarding your garden.
Merry Christmas everyone.
What he said!
The New Year will bring some fun surprises at SA... see y'all then!
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LOL... guys, turns out I was the one who was in for the biggest surprise in the New Year:
http://hardairmagazine.com/news/umarex-gauntlet-sets-new-standard%E2%80%A8-pcp-air-rifle-performance/ (http://hardairmagazine.com/news/umarex-gauntlet-sets-new-standard%E2%80%A8-pcp-air-rifle-performance/)
We were preparing for producing 3K/regged/repeater kits at a much better price. That's over!
This gun has it all, for the .22 pellet shooter. As this has little plenum (so, big bores/bullets are out of the question)... SA will continue our program while concentrating on lightweight big bores for the Fusion/60c.
SA will be getting one of these, asap, and will see if there is anything of consequence we can do to improve them. I predict real problems for sales of guns anywhere near it's $300 price range.
Any thoughts?
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I bet the gauntlet needs a GSR or SSG.
Trigger work, etc.
Stalwart arms should also take a close look at the new MSP pistol uramex announced.
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Basically, I think most people are getting what they wanted.... a low cost, repeating, regulated, moderated PCP with moderate power and (hopefully) a great shot count.... Umarex have obviously been paying attention, and have "thrown down the Gauntlet" to other PCP manufacturers.... I'm betting the plenum volume is small (where would they put a big one?), so big bores, even a powerful .25 cal, are likely a pipe dream.... Wrap up a narrowly focused concept in a snug fitting plastic package, and I'm also betting they will avoid most of the after-market "improvements" we modders get so much pleasure from finding and incorporating....
The golden age of airgun modding may have just seen the results of all our efforts.... and for some, like me, the death of an era, of easily modded PCPs with a lot that could be done to improve them.... Be careful what you wish for.... ::) .... I'll never see one in Canada anyway, with the functional shroud....
Bob
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Ohh what fun we still shall have once the Gauntlet is cast. Modding will continue long after we are gone, it's in the air we breath.
With that said I got a lot of things to post but not enough time to do it so this is just a flyby to say hello and hopefully put a stop to the contrubutions to cover my burial expenses. I still live, but any and all monies will go to the good cause of airgunning, my airgunning. ;D
I'll be back.
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Ohh what fun we still shall have once the Gauntlet is cast. Modding will continue long after we are gone, it's in the air we breath.
With that said I got a lot of things to post but not enough time to do it so this is just a flyby to say hello and hopefully put a stop to the contrubutions to cover my burial expenses. I still live, but any and all monies will go to the good cause of airgunning, my airgunning. ;D
I'll be back.
I'm glad to hear that the reports of your demise were greatly exagerated. ;D
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LOL... if Mike has the same bug that handed Andy and I our butts, on cheap paper plates... the exaggeration wasn't all that great.
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Guys, Mike's 9mm Evanix mag, according to Pyramyd and AD, is supposed to be a 7shot. It is 6. It's the .731 thickness, as listed... and the hole is .368".
Any ideas what is going on?
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Well I finally got to start on the BBE so I abrasive blasted it gave it some new lipstick. Here it is smathered in CeraKote Satin Mag.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20170203_145552_zpszn5ro22c.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20170203_145552_zpszn5ro22c.jpg.html)
I've still got a lot of work to do before she spits lead but she's gonna spit lead.
Here's some other stuff I've done in the quest of reducing friction. I took two hammers, bead blasted one and left the factory coating on the other and threw them into a dedicated vibratory cleaner bowl for Molykote. The hammer on the left with the factory coating and the residual Molykote cleaned from it. The hammer on the right was abrasive blasted and residual Molykote not cleaned from it.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/IMG_3830_zpsob1ku7t1.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/IMG_3830_zpsob1ku7t1.jpg.html)
Next pic is with the Molykote cleaned from both. I let both sit for about two weeks and the abrasive blasted Molykote hammer started rusting so if I were to Molykote hammers again I'll not blast them. The hammer with the Molykote embedded into the factory coating is residing my Bobcat.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/IMG_3832_zpsjjvgh4rm.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/IMG_3832_zpsjjvgh4rm.jpg.html)
So with all the above hammering around you might ask what am I going to do with the blasted rusty hammer? I'm going to reblast it and blast the bolt and try this, https://www.cerakoteguncoatings.com/finishes/C-110Q/micro-slick-dry-film-coating/. (https://www.cerakoteguncoatings.com/finishes/C-110Q/micro-slick-dry-film-coating/.) More to come because I've got more messin around before the BBE is finished.
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Such a pretty color. I'm thinking it would be perfect for the Fusion project.
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Guys, one for the "credit where credit is due" file:
Dealing with Magnum Airpower has turned out not only better than one could expect, but, as well as anyone could hope.
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Cool coincidence: An 850 Hammerli guy wanted a pretty large plenum made, and as the Gauntlet can use a boost, in many roles, I jumped on it.
A modded Trinity tank shut-off provides the ASA attachment, and works well to keep the length reasonable.
Is it May, yet? No?
Dang it!
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Well I've been busy with the BBEDD (Best Bobcat Ever Disco Double), so here goes.
Valve:
1.) Not all valves are created equal as the exhaust ports and 5mm tapped holes are not always centered on the valve body (fore and aft). Care should be taken when laying out the 1/4-28 (highly recommended by Bob and Eric) as centering might move the valve exhaust port off center from an unmodded barrel also one must keep in mind not to molest the o-ring packing gland (ask me how I know. lol) The 1/4-28 is the best valve retention out there, thanks rsterne and stalwart, but an elongated barrel port is the way to go with an off center exhaust port. IMHO
2.) I used one of rsterene's Maxi Valves and moved the the 1/4-28 just enough to not leave any 5mm threads for a 100% 1/4-28 tapped hole. All this was done knowing I had an elongate (slotted) barrel port, so with calculations I knew the barrel wouldn't be blocking the valve exhaust port. Before I forget I felt there was enough cap head (SHCS) engaging in the receiver/CrMoly liner to not face a flat. facing a flat seemed like I would also lose some thread depth. Input anyone??
3.) I didn't use use the OEM valve spring but instead found a smaller O.D. thinner wire gauge spring laying around in my stash. I machined a brass spring guide rod, then drilled and tapped it to the threads I threaded on the poppet shaft. The smaller O.D. spring leaves me more meat in the backer block as I will be using it for the forward stock retention screw (thanks Bob).
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20170306_155834_zps2o9sjzpx.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20170306_155834_zps2o9sjzpx.jpg.html)
Prod mag/JSB 34gr .22 pellets: It's not obvious from the pic but nothing had to be done for those pellets to fit a stock Prod mag. If all mags are not created equal you might just have to loosen the small allen countersunk screw a wee bit to facilitate the 34gr pellets. A big plus for the Prod mag.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20170304_163802_zpslg1rkgrc.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20170304_163802_zpslg1rkgrc.jpg.html)
BBEDD Stock: I am going to use the stock I modded earlier in this thread and get this beast up and running. I have the the barreled receiver with DD fastened in the stock so I can epoxy a pillar into the stock and use the backer block as the new forward stock retention screw.
I made a mistake of .100" in the depth of the lower tube channel (to deep) but as I've mentioned before, JB Weld is my friend so I'll bed the tube.
Everything fore of the new stock pillar is temporary as later on I'll rip the stock (lengthwise) to remove the forearm then fab a new forearm which will be longer and aesthetically pleasing. I don't like the looks of the current forearm.
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20170304_162944_zpsncojfazc.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20170304_162944_zpsncojfazc.jpg.html)
(http://i202.photobucket.com/albums/aa86/madmike77_photos/Airgun%20Stuff/20170306_175645_zpsmx4hv6yk.jpg) (http://s202.photobucket.com/user/madmike77_photos/media/Airgun%20Stuff/20170306_175645_zpsmx4hv6yk.jpg.html)
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Just got to my desk... found this in my email:
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Eric.... what are the maximum length of pellet that the various calibers of Evanix mags will handle?
Bob
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I only have the .25 (10.2mm) and the "short" 9mm (12mm) here.
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Thanks, Eric.... I take it there is, then, a longer 9mm mag?.... Are there other calibers?.... Anyone else have that info?....
Bob
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Yes. This is the .731", and they make a .844".
Best list I've seen is at PA: https://www.pyramydair.com/search-results-ext?keyword=evanix+mag&sid=1375A617A415&N=0&Ntk=primary&q=evanix+mag&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch (https://www.pyramydair.com/search-results-ext?keyword=evanix+mag&sid=1375A617A415&N=0&Ntk=primary&q=evanix+mag&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch)
Would love to have a more informative source.
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Guys, one for the "credit where credit is due" file:
Dealing with Magnum Airpower has turned out not only better than one could expect, but, as well as anyone could hope.
That's how EVERY transaction with Magnum Airpower has been!
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I dragged out my Bobcat to get it ready for Marmot season, as they are starting to poke their heads up already.... The GSs are nowhere to be found, but my new Permission is on the sunny side of the river, and the big'uns are just coming out of their burrows, so I needed to get ready.... I had the action out of the stock, and when I put it back in, I lost 30 fps.... Figured that was pretty weird, and I discovered that the rear trigger screw, which mount the action at the back, was too long, and was hitting the nuts on the SSG.... I ground 1/8" off the end of the screw, and that cured the problem.... While it was apart, I discovered that the SSG gap was pretty big, so in the interests of consistency (and easier cocking) I replaced the hammer spring with a lighter one, 0.047" wire instead of 0.049" (still 3" long with 1/2" preload).... I had to reduce the SSG gap to get the velocity back up, and I can no longer max. out 70 gr. BBTs, but I only use pellets in this gun anyways....
I did some testing with the gun tuned to 90 FPE with the 45 gr. JSBs (94 FPE with the gr.), and got over 4 full mags. (a total of 30 shots) before the velocity dropped off.... The was a slightly lower tune than I had before, but the efficiency increased to 1.40 FPE/CI, which is remarkable.... It seems that the lighter spring helped the efficiency, since the shot count jumped from 3 mags. to 4 (at about 15 fps less velocity).... Before I buttoned the gun up I decreased the SSG gap 1/2 turn, which bumped the velocity back up to what I had last year (~ 965 fps with the 45 gr. and 935 with the 50 gr. (93 and 97 FPE respectively), but I didn't check the shot count after I did that.... I'm sure it will still be close to 4 mags., certainly better than the 3 mags. I had last year with the heavier spring.... All I need to do is check to make sure it is still sighted in, and I'm ready to go.... 8)
Bob
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What a great balance between power and shot count.
8)
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NT
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Bob, what does that gun weigh, ready to go?
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8 lbs. 5 oz. with a Hawke 3-12 x 44 SF w/sunshade and rings.... It has a 22 CI tank regulated at 2200 psi feeding a 90+cc plenum.... CF sleeved barrel and Hatsan air stripper....
(http://i378.photobucket.com/albums/oo221/rsterne/Flying%20Dragon%20PCP/Grizzly%20and%20Marmot_zpsqyhqw1j3.jpg) (http://s378.photobucket.com/user/rsterne/media/Flying%20Dragon%20PCP/Grizzly%20and%20Marmot_zpsqyhqw1j3.jpg.html)
We grow our Yellow-bellied Marmots (aka Rockchucks) BIG out here.... :o .... The gun measures 22" from the trigger to the front of the tank block....
Bob
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When I'm not logged in, quite a few of my posts are not visible to me.
What is happening here?
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It's not just when not logged in because I'm not seeing lots of comments either and I'm logged in. Half the posts are blank
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Looking into this. Send me a pm if this gets fixed.
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It's interesting that if I press the quote button on an empty post then I can see what it originally said.
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Thanks, Wesley. Glad it isn't just me, but...
Looking into this. Send me a pm if this gets fixed.
Will do, Dave.
Hope everyone is enjoying the holiday, and remembering those we cannot thank.
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Lol your reply is blanked out for me anyway. I've checked other threads, same problem. I wonder if certain browsers are having problems or if this is something with the forum that everyone is dealing with. Weird
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LOL... me too, unless I sign in.
One last try: Thanks, man... ;)
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Yeah! Well I wonder why mine won't work even when I am signed in. Anyway hopefully someone can fix it up! This is a great forum! So many amazing tuners and modders such as yourself. Thanks for sharing your projects!
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Life has been hectic the last two years with sporadic time for hobbies, I hope this is a start of getting back in the saddle of my hobby horse.
If you had been following my BBE (Best Bobcat Ever) build I modded my stock and have since painted it with Rust-Oleum black hammered paint (durability on a gun stock yet to come) and started shooting with decent results until I found I had a slow valve leak plus too long of a probe which the later is fixed but the leak persists.
After the probe shortening I was achieving 928fps with CP 14.3gr and 710fps with JSB 25gr and then the discovery of a valve leak. I'm in the process of lapping the acetal poppet to the valve seat and hope to be back in the saddle again with new numbers.
If I haven't mentioned this before I'm using one of Bob's Maxi Valves and his SSG I fabbed up here at the house. I'd like to use the Maxi Valve but I have another modded valve that doesn't leak sitting in the wings. Llyod's valve is doing a fantastic job and I think the numbers will change for the best once I get the valve leakage fixed.
More to come at the end of the day, I HOPE.
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Great looking double tuber!
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Great looking double tuber!
Agreed. What does it weigh, Mike?
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Great looking double tuber!
Agreed. What does it weigh, Mike?
I'll make that the first priority once she's back together.
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Great looking double tuber!
Thank you. Stalwart, Bob and Llyod gave me the canvas all I did was the painting
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Great looking double tuber!
Agreed. What does it weigh, Mike?
Hey Eric, still chasing a slow leak but without optics my BBE weighs 7.4 lbs, 8.7 lbs with a UTG 3x9 BugBuster and rings. I thought it would have weighed more with the double tubes but it's pretty darn nice. I like the feel of it.
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That's what I wanted to hear.
It's a great weight. 8)
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Guys, I am pleased to announce that SA is an official Xisico dealer.
There are some fun things planned for the Sentry... I'll start a thread for them, and announce it here.
Gonna be a fun Spring!
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Good to hear.
Haven't heard from you in a long time.
Have you made any progress on the .30 repeater build for me ?
Heck, at this point I'd be happy to see it in .22 or .25 Cal.
Or is it just never going to happen ?
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Good to hear Eric... Looking forward to it.
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Good to hear.
Haven't heard from you in a long time.
Have you made any progress on the .30 repeater build for me ?
Or is that not going to happen ?
Ron, we were about to sort out what the new deal would be, since you sold the tank that you promised me. We arranged a call that I waited here for nearly 3 hours to receive. It'll happen when you make it happen.
I figure a .30 cal LW barreled custom gun should cost you more than $400... don't you? That's less than my cost.
Call me. Or, we can hash it out right here, if you like.
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Good to hear Eric... Looking forward to it.
I'm kinda excited about it. Xisico reached out to me... they really like our work, and are as curious as I am as to how nasty these things could be.
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Eric,
We've gone back and forth over this so many times it's no longer worth it.
l tried to help you out when you were down. And I am happy you are back on your feet.
No, I will not "hash anything out" with you here on the forum.
Thanks for your reply, I'll just write it off as a done deal.
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Subscribed.
I recently found your website https://www.stalwartarms.com (https://www.stalwartarms.com) when Bill (Avator) referenced you on a P-17 discussion.
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Ron, we have not "gone over this" at all. You changed a deal, without any input from me... leaving me "obligated" to build you a gun for half price. Then left me hanging. There has been NO discussion on this since you sold that tank, and you know it.
I thought you didn't have the cash on hand to make up for the tank, and set the gun aside until you could raise it. Although I have guns here that are well worth $400, and we could have had you shooting in no time... it was your call. Now it's a "done deal", and thank you for your "help".
If you don't want to air something on this forum, I suggest you stop taking shots on it. If you really wanted to know how it's going, I was never more than 10 keystrokes away.
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Subscribed.
I recently found your website https://www.stalwartarms.com (https://www.stalwartarms.com) when Bill (Avator) referenced you on a P-17 discussion.
Yeah, he seemed reasonably happy with his 17s. :)
Bill is a straight shooter, and I hope he someday "needs" more guns (not bloody likely!). He's a blast to work with.
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Yeah, he seemed reasonably happy with his 17s. :)
Bill is a straight shooter, and I hope he someday "needs" more guns (not bloody likely!). He's a blast to work with.
I have an XS60-C and a Sentry so I am interested as well. Hoping to see something that strikes my fancy. ;D
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Let me work on that... stay tuned! ;D
Xisico is working on getting me big bore barrel blanks (slow boat from China), so, if nothing else, we are gonna make some noise.
I have had really good results with their retail barrels. I expect nothing less from their blanks.
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I still have an FD-PCP (GenI XS-60C) that's screaming for a repeater breech. Unfortunately my wallet screams louder from lack of funds.
Yes, we still shoot the SA P-17s and they are both performing as amazingly well as the day the package from the sunny side was opened.
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I still have an FD-PCP (GenI XS-60C) that's screaming for a repeater breech. Unfortunately my wallet screams louder from lack of funds.
Yes, we still shoot the SA P-17s and they are both performing as amazingly well as the day the package from the sunny side was opened.
Bill, your pellet bill alone would leave my wallet screaming!
No rush, you know we are in this for the long haul. When you are ready, we will be, too. Looking forward to that day, bud. Glad you like your 17 and thrilled Mrs. Bill likes hers. 8) ;D
Who is the better 17 shooter, you or her?
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Depends on who you ask....
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Understood!
So, it's close enough to argue... sounds like fun!
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Understood!
So, it's close enough to argue... sounds like fun!
lol.... It's certainly and ongoing rivalry. We enjoy every minute of it. I've moved into the World of PCP leaving her somewhat behind but I visit her pumper level quite often to be schooled.
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Variety is the spice of life, and you two certainly have plenty of that!
Say hi (and a wink*) for me, please?
;)
* inside joke.
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You bet I will... just as she's ready to take her shot.
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If she winks back, you'll tell me, right?
;D ;D ;D
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You and everyone else.
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You and everyone else.
;D
You are a good man, Charlie Brown.
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Let me work on that... stay tuned! ;D
Xisico is working on getting me big bore barrel blanks (slow boat from China), so, if nothing else, we are gonna make some noise.
I have had really good results with their retail barrels. I expect nothing less from their blanks.
Big bore blanks, that got my attention.
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DITTO!
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Guys, I started a Sentry thread, here:
https://www.gatewaytoairguns.org/GTA/index.php?topic=142052.new#new (https://www.gatewaytoairguns.org/GTA/index.php?topic=142052.new#new)
I spent a lot of time analyzing this gun, and have some good news for the power mad...
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Hey guys! There are some things I have to make public knowledge, due to recent developments, and this has to be the perfect place:
1. Zed R. Fatka is not currently associated, in any way, with Stalwart Arms... he does not represent us in any way.
2. Any products that are copies of products we offer (even near copies), are NOT authorized by us, no matter who produces them.
If any of the above changes, there will be immediate notification here.
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Whoa... Déjà vu
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IKR??
LOL!
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;)
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IKR??
LOL!
yeah seems to be loosing his @$%^, please calm down eric
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IKR??
LOL!
yeah seems to be loosing his @$%^, please calm down eric
LOL... as I have pointed out, repeatedly, I am not angry... I am amused by all this. This is not my first rodeo...
You went behind my back, to get Xisico to produce parts for you, and didn't mention the effort until after you were ready to make product... then tried to talk me into GIVING you all my rights. You threatened to make copies that were just enough different to skirt IP law, if I didn't just cough up my rights. If you wonder why some people here are not surprised, you need to lurk moar.
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This thread is locked until review by Admin