GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Nick Hammack on January 15, 2014, 08:34:13 PM
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I visited with Mike and was quizzing him about the BAM 51's that he had in stock , after visiting a bit on the BAM he shared with me the FLYING DRAGON PCP that he was converting .
I ended up purchasing 1 B-51 , 2 - .177 , 1-.22 FLYING DRAGONS PCP and 2 spare .22 cal barrels , the B-51 shipped first and I received that .177 last week .
I received the .22 cal on Monday and received the 2 .177's yesterday with a note in the box that the .22 Cal . barrels would follow at the end of the month .
I pumped the .22 cal up to 1500 psi and proceeded to shoot in the dark at the tree line , the 1500 psi fill was almost too much , the gun was on the verge of valve locking . I shot it down till the point it sounded right and checked the fill pressure it was 1100 psi where the gun started shooting correctly down to the 600 psi mark .
I shot around 80 pellets thru the gun and then went indoors and took the trigger out and proceeded to adjust and polish the sear engagments , it is a wonderfully simply trigger arrangement and is very easy to adjust and polish out to a very nice hunting trigger .
I then loaded up again started to shoot another string to adjust and try out the new trigger job and it is wonderful indeed , after a few shots the gun dumped the fill pressure at the shot , I figured the valve gave way .
I pulled the gun down part way that evening and then finished the job completely dismantaling the gun 100% last night , it is a wonderful design and very easy to work on , this gun is the VW'S of PCP'S , it is wonderfully easy to work on and what I love about is that it is so easy to work on , fully adjustable trigger and an overall great design that is very affordable to own and operate , I have been following the thread that everyone is having problems with the guns that they got .
Well if your new to PCP's your going to have to pay your due diligence and will have a learning curve , if one has no mechanical aptitude or little to no patience then this or any PCP is certainly something that your going to have a hard time with .
One thing that everyone has to get a grip on is that this is a tinker gun , as Mike said , your going to have to work on it , it is a wonderful and very easy design that is going to be a wonderful gun for my needs which is hunting , I will set it up to give me 10 full power shots with very little deviation in velocity .
Some of you guys are valve locking these guns and how to unlock them is put your hand pump on them , pump them up till you hear the fill valve click open , then very slowly open your bleeder valve up and let the air creep out until you get down around 1200 psi or below , these guns need tuned to use higher pressures it would appear and you will have to do the work to get them there . If your gun will still bleed off air even if it is a little bit then keep dry firing the gun until one gets enough of a shot pressure to discharge a pellet and shoot the gun down and keep it down low on pressure until you get the work done to your gun to allow you to use the larger fill pressures .
As far as sights are concerned this is a pcp it deserves to have a scope on it , it is a long range set up , sights are for springers 30 yards and under , this gun is for + type ranges . Sights are to be taken off and a hush method to be used on the end of the barrel . with scope mounted and the sweet spot found with a chrony and all the data worked up for this gun .
I am going to put my .22 back together now and get off here , I found the valve seat cocked and I will explain in a night or so as to what is going on , but this little gun is a diamond in the rough and for $ 100 I will be buying several more to lay back and make wonderful little hunting gun for some friends , Oh don't worry about the fill tubes as a weak link they are not , it will take 8K to burst these things , the weak link is the two 5MM screws under the action , one holding the pin valve assy and the other holding the backing , but don't worry too much for in the machine shop we lift 12K chunks of steel with a hole drilled in the center and tapped using a 1/2" bolt to do the lifting .
The weak link are these 5MM screws but 2K is well within the stress limits for such things but do not exceed this much or your just asking for it unless you drill and tap more anchor points .
Had to jump on here and share this with you for it is getting out of hand and Mike will take care of things when he gets back , but everyone is going to have to work on these guns bar none , if you do not want to tinker then perhaps one should purchase a springer for PCP'S are a labor of love .
Now back to putting together my .22
Regards, Nick
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I put the .177 together with the parts from the .22 after I polished all the parts .
the inside of the main spring , outside of main spring , the spring guide , the hammer external and internal where the mainspring slides up into the hammer and the trigger group was all polished to a mirror .
(http://www.hunt101.com/data/583/medium/DSCF2241.JPG)
The valve wanted to lock out of the stock gun at 1500psi now after the tune I charged the gun to 2000 psi and got the following string with the washer removed from the spring tensioner and screwed all the way in .
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After getting what I wanted a 10 shot string that was this powerful , I proceeded to shoot a 20 shot group at 35 yards off of shooting sticks , will shoot off of bench in the future when I am done working on the little gun .
just wanted to see what she was capable of in the rough , I have found my little dream gun of $100 indeed .
(http://www.hunt101.com/data/583/medium/DSCF22451.JPG)
Took the little girl hunting this evening for a short time and took this pair at 30+ yards one shot each .
(http://www.hunt101.com/data/583/medium/DSCF2243.JPG)
Will be doing more to the little gun as we go along and I will post pictures
Regards, Nick
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Nice shooting. Where about are you in mo? I am near st. Louie
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fantastic job Nick great report 8)
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Thanks for the posting Nick and WELCOME!!
I agree with you, and went into this purchase with eyes open. Fully expecting a tinker project, as per a couple conversations via email with Mike.
I too really like the gun, I also plan on a complete tear down and fluff and buff. You have found (now confirmed) what I suspected. The gun needs some massaging!
Congrats on the harvest too!!
CW
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Hello Brandyman I am down by Lake of the Ozarks .
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Beautiful area out that way. Enjoy your rifle and get some more of those squirrels. We only have about a month left in the season. I desperately need to get out and do some nutter sniping!
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Hello and Thanks for the great informational write-up!
I too have the .177 FD-PCP and a the 10.5-grain CPUM pellets. It's nice to see someone else with a lot of experience posting information on a .177!
I have not yet tried any accuracy shooting with it, as I am still waiting to get some glass for it. I was able to pump mine up to 1500-psi from the get go, and have had it successfully up to around 1650-psi without any valve-lock issues. I did go beyond the 1650-psi once and did have valve-lock issues, but it self remedied itself after a few dry fires to release some of the pressure.
I am still waiting on a chrony as well, just as soon as I get one, I want to post a few shot strings using the 10.5-grain and 10.34-grain pellets.
All I know is that as of right now, with a 1500-psi fill, I can penetrate tin can material with up to 35-shots from 15-yards away. Mike did a chrony on mine and got a reading of around 900-fps using the 8.4-grain pellets.
I am shipping mine off to have some custom work done to it and upon its return, will attempt to do some of the things that you have done to yours in an effort to get all of its potential out of it.
I look forward to more of your posts on this $100.00 PCP!
Respectfully,
Al.
p.s. I will be transferring your data to the "Flying Dragon-PCP Tech Data Section". It is a "clean" section for those seeking some tech data in a hurry.
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I am posting pictures of the disassembled FDPCP.
Here is a pic of the action and pressure tube .
(http://www.hunt101.com/data/583/medium/DSCF22551.JPG)
Here is a pic of the fill valve and check valve assy .
(http://www.hunt101.com/data/583/medium/DSCF2253.JPG)
Here is a pic of the parts in order of assy
(http://www.hunt101.com/data/583/medium/DSCF2254.JPG)
Pic of the top part of the barrel , note the indention for the set screw retainer
(http://www.hunt101.com/data/583/medium/DSCF2249.JPG)
Here is a pic of the port on the bottom of the barrel
(http://www.hunt101.com/data/583/medium/DSCF2248.JPG)
Pic of the crown job and the flat that is under the front sight . Might have to work on the Crown , will have to shoot and she how she does .
(http://www.hunt101.com/data/583/medium/DSCF2251.JPG)
Pic of the valve assy , this is the .22 gun that has a few parts missing , will get those fixed soon as Mike gets back on his feet . Or just make the parts myself , either way it will get fixed .
(http://www.hunt101.com/data/583/medium/DSCF2252.JPG)
Pic of the polished trigger and hammer that all got polished , note the spring guide in this gun has been cut off , I would theorize that was done to reduce friction , a thing that could have been taken care of by polishing .
(http://www.hunt101.com/data/583/medium/DSCF22461.JPG)
Well all for now , visit later , Nick
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Oh by the way , this gun can be totally disassembled and put back together in under 5 minutes each way , I can do it in under 3 minutes each way , just incase anyone wants to know .
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Nick, you are an FD-PCP Animal...and I really appreciate your post. There are many of us, me included, that came from the springer world and this gun is our first PCP. We have a lot to learn and appreciate someone that has the patience to provide us great information and pictures. Please keep those coming!! I currently have my FD-PCP shooting a somewhat similiar string as your post, with a high of 954 and about 12 good shots, but have only gone up to less than 1600 psi.
I trudged 6.5 miles through the North GA woods last weekend and never saw a critter move, but your two nutters and CW's nutter proves that this gun is a capable hunter. By the way, I can't find my screw driver in under five minutes, much less three... :o
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I don't know if it was mentioned but just found out the hard way there is a spring in the bolt held in by the bolt handle. Also when taking out the safety watch out for pin that may come flying out unless you are not going to use the safety no worries.
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I don't doubt this gun can benefit from some tinkering, but I haven't done anything other than clean my barrel and shoot it. Don't have a chrony, so I cant say much about it's performance, but it seems to be hitting ALOT harder than my 15 fpe springers, it's sure as heck more accurate (in my hands) definitely a taste of the "darkside". I haven't had time to tinker, and If I do have time this weekend, I will probably take it hunting, before I do any tinkering :) Perhaps I got lucky, but so far it does not appear that my gun has to have tinkering done to it... Good lord it's loud though, have to wear ear protection when shooting it inside for sure.
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If you do find time I would at least polish the hammer.
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After getting what I wanted a 10 shot string that was this powerful , I proceeded to shoot a 20 shot group at 35 yards off of shooting sticks , will shoot off of bench in the future when I am done working on the little gun .
Not a PCP expert may any measure but your shot string indicates that you are not close to valve lock and you could benefit from a higher fill pressure. If you increase the fill in 100 psi increments until you see your first shots velocities start to decline a bit more you will get closer to coveted bell curve and a few more shots to boot.
Nice gun and what a value! Enjoy.
I should add that a non regulated PCPs first shots will sound very short and crisp, this is not necessarily an indication that you are too close to valve lock. The chrony results are the only true indicator.
Tom
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Good information. Thanks for posting it!
CW
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Hello Tom:
I did take the gun up a bit at the time I was doing the test , 2100PSI yielded 520 FPS , 2050 PSI gave me 850 FPS so the margin is razor thin , 2000 PSI is where my gun likes after the polish job to start .
I visited with Mike today about my Valve Cartridge and the parts internal , I will be machining a standoff to replace the washer and create a spring guide in the process , I will also be drilling and tap the sides of the receiver and stop block behind the valve cartridge to place two more set screws in place to help prevent the movement of valve cartridge and stop block with only the two 5 mm screws holding the assy I will feel better and it will way overkill the pressure issue .
I will take pictures of the parts and how I have done the work , later everyone .
Regards, Nick
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Outstanding . . . . . . 8)
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Nick,
I missed the part about filling to 2k after the clean up and thought those were the 1.1k numbers.
A nice write up with lots of good info for those wondering about these guns.
Tom
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I just ordered 2 more .177 FD's and 2 more .22 cal barrels and a pump this evening for others that have shot mine and wanted one , I should just buy a dozen and lay them back for me , for Mike is selling out fast .
Regards, Nick
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Yeah, I talked to Mike yesterday and there were 35 orders in front of mine... money is in his hands and I should have mine in hand in a couple weeks :), he apparently just got 400ish more of the guns in...
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Still not up to par and under the weather a bit , I wanted to get out of the house and use an air rifle .
I grabbed the newest addition to the stable the FDPCP in .177 shooting CHP's and headed to a ditch line that intersected a brushy fence line , not feeling up to par I did not want to take any free hand shots or sneak up the ditch line , so I set up with my shooting sticks .
I chose the open high ground and waited , just before dark the rabbits started to come out , none close to me so I relocated about 50 yards further up the hill .
I seen no less than 2 dozen rabbits along this line and could have shot my limit but not feeling quite up to par I felt 4 was all I cared about cleaning and it will make a few dinners besides with a few taters and onions thrown in and a slice of homemade bread .
The nearest rabbit I took was over 30 paces and the furthest one out was a tad over 60 steps , one shot each is all it took .
I sure do love my little $100 PCP and will continue to work on it to make it better and will post the upgrades and a tutorial on the break down and assembly of the little gun as well as the parts that I am going to make for it that will correct some things that need addressed .
(http://www.hunt101.com/data/583/medium/DSCF2259.JPG)
(http://www.hunt101.com/data/583/medium/DSCF2257.JPG)
Regards, Nick
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Great shooting Nick. I got me a bunny today with my 12 gauge. Yummy meal for sure.
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I sure do love my little $100 PCP and will continue to work on it to make it better and will post the upgrades and a tutorial on the break down and assembly of the little gun as well as the parts that I am going to make for it that will correct some things that need addressed .
Regards, Nick
Hey Nick.
If you don't I'm thinking of putting up a Google Site similar to the one I have for the B50 in order to catalog these tips and tricks along with those from others on the forum. See my link below for an example of what I tossed together for my B50
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We definitely need some how-to for disassembling this little rifle and putting it back together.
We also need some info on the different o-rings and what needs to be done when the valve locks up.
I am sure there are a few other issues that all of us have experienced or will experience in the future. All of these issues can be fixed fairly easily. But if we can consolidate all the different solutions and workarounds, that would be terrific.
This little gun is a keeper once you get it working the way it's supposed to.
As Nick told me the other day, it's a "nice platform" for would be tinkerers and fixers.
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Nick,
Can you please provide me with pictures of you disassembling your FDAR?
I would also like to know the size of the urethane o-rings that seal the valve and its assembly.
Thanks
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Awesome hunting Nick the carrots are safe!
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This is a pic of the Flying Dragon PCP valve , notice the spring stand off that I made for the valve .
(http://www.hunt101.com/data/583/medium/DSCF2260.JPG)
This is what the stand off does , it acts as a spring guide and a stand off for spring tension .
(http://www.hunt101.com/data/583/medium/DSCF22631.JPG)
This is a pic of the stand off mounted in the valve cartridge .
(http://www.hunt101.com/data/583/medium/DSCF2261.JPG)
This pic is of the valve cartridge with the stand off installed looking inside .
(http://www.hunt101.com/data/583/medium/DSCF2262.JPG)
a lot of folks have been asking me about this and this is the only flaw I have found in the FDPCP which is pretty remarkable , this is a wonderful little platform for the tinkerer and the hunter for the stately price of $100
Regards, Nick
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Did you mill that spring stand, or was it something you repurposed?
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I turned it on the lath , not on a mill .
it was out of a alum bar stock lying around , turned and threaded for 6-32 screw for attachment .
Regards, Nick
Oh tonie you can post my stuff to a site if you wish , I will put it here and that is all the time I will have to dedicate to it , thanks for the effort in advance .
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This is a pic of the Flying Dragon PCP valve , notice the spring stand off that I made for the valve .
(http://www.hunt101.com/data/583/medium/DSCF2260.JPG)
This is what the stand off does , it acts as a spring guide and a stand off for spring tension .
(http://www.hunt101.com/data/583/medium/DSCF22631.JPG)
This is a pic of the stand off mounted in the valve cartridge .
(http://www.hunt101.com/data/583/medium/DSCF2261.JPG)
This pic is of the valve cartridge with the stand off installed looking inside .
(http://www.hunt101.com/data/583/medium/DSCF2262.JPG)
a lot of folks have been asking me about this and this is the only flaw I have found in the FDPCP which is pretty remarkable , this is a wonderful little platform for the tinkerer and the hunter for the stately price of $100
Regards, Nick
Nick,
would this not prohibit any air-flow to the valve? Making sure there is enough air available at the valve seal for a full powered shot is really important, right?
Thanks!
Al.
EDIT: I know that Mike has taken these types of valves (QB-VALVES) and has taken the poppet, turned it down to fit the spring, so the poppet is a guide in itself. Would something like that not work?
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Look close Al :
This has nothing to do with the valve except to hold it straight in line just like the co2 set up , as it came the piercing valve was the spring guide and if we had all the parts for this set up then this part would not be needed.
As it stands we have a spring that is resting on a washer that has a hole in it just barely smaller than spring diameter and it will eventually cock not if but when .
The guide puts the valve cartridge back to the way it was designed originally , with a spring guide .
I do think all of the guns will experience the valve failure due to this condition like a couple already have , this will fix em so it does not happen .
Regards, Nick
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Do you have to remove the air tube to remove the valve?
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No.
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The FD-pcp uses a qb valve that is slotted on the sides for additional airflow. There is a large amount of info available on modding the qb valve for improved airflow to the valve seat in order to ensure enough unimpeded air flow to prevent starving a shot. If you look into the air reservoir with the fill cap removed you can see that the air tube seal covers a bit of the slots and only leaves a small gap for airflow.The slots by themselves only provide a .154 x .276 passage and that's before the seal blocks off some off it. I open the center hole as much as possible and turn down the spring end of the poppet so that the spring fits tight onto the poppet so it can't cant to far to one side or another. There are several ways to "skin the cat" on improving this valve but from my research opening the front side is always desired. It would seem to me that since Mike is removing the piercing pin to improve airflow then blocking off the hole would be defeating this step.
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I think we need Mike to chime in and let us know what he thinks about this whole setup.
If he removed the stand off and spring from the CO2 gun, then he probably have a very good reason to do so.
I disassembled my gun under Nick's recommendations only because the gun was leaking from day one. In fact I haven't been able to shoot a single shot with it.
I am waiting for a thicker seal to try and see if this takes care of the leak. I am almost certain it will fix my issue.
I would love it if someone could provide me with some urethane o-rings to use as spare parts for the valve assembly. My gun had 2 urethane o-rings nicked. It might explain why it was leaking in the first place.
There is also an extremely small urethane o-ring on the valve pin itself. It would be nice if Mike would provide us with sizes and maybe even where we can get those o-rings.
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Hi Nick,
I'm sorry, I'm late to this thread but I am having trouble understanding how the spring guide is helping to remedy a leak. I have modified several QB valves so I am familiar with their components and how they work.
At low pressure (or no pressure), the spring helps to seal the poppet against the valve seat. At normal operating pressures, the spring is comparatively less important as the force closing the valve is dominated by the high pressure in the air tube.
You mentioned that it keeps the spring from canting but I would be surprised if a slight cant allowed the valve to leak with 1000psi or more of pressure encouraging it to close. If it did, I would be looking at the mating surfaces for a scratch or other imperfection.
Based on the length of the guide, it looks like its main function is to apply a preload to the spring.
Thanks in advance for your reply. I'm trying to pick up on any and all technical information I can about these rifles because I'm sure to be working one at some point.
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The more I think about this, the more I am convinced that my gun leak is related to a seal or o-ring that is nicked or simply defective.
I think that the standoff and spring might be useful if a gun is leaking from the transfer port. My gun leaks from the thread of the tank. So it is probably the seal (urethane o-ring) that is bad. I know that a couple of other urethane o-rings that seal the valve are damaged. So they need to be replaced.
I will see if Mike is willing to send me those as I think it is the cheapest solution for both of us.
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The more I think about this, the more I am convinced that my gun leak is related to a seal or o-ring that is nicked or simply defective.
I think that the standoff and spring might be useful if a gun is leaking from the transfer port. My gun leaks from the thread of the tank. So it is probably the seal (urethane o-ring) that is bad. I know that a couple of other urethane o-rings that seal the valve are damaged. So they need to be replaced.
I will see if Mike is willing to send me those as I think it is the cheapest solution for both of us.
Just go to Autozone and buy an O-ring kit. Every thread I see you complaining about your rifle not shooting. Try and fix it instead of posting on the forums, seems like time would be better spent trying to remedy the rifle.
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The more I think about this, the more I am convinced that my gun leak is related to a seal or o-ring that is nicked or simply defective.
I think that the standoff and spring might be useful if a gun is leaking from the transfer port. My gun leaks from the thread of the tank. So it is probably the seal (urethane o-ring) that is bad. I know that a couple of other urethane o-rings that seal the valve are damaged. So they need to be replaced.
I will see if Mike is willing to send me those as I think it is the cheapest solution for both of us.
Just go to Autozone and buy an O-ring kit. Every thread I see you complaining about your rifle not shooting. Try and fix it instead of posting on the forums, seems like time would be better spent trying to remedy the rifle.
The o-rings in the 60C Valve are the same as the QB-Valve. All of the information is already here in GTA, just got to search for it!:)
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The more I think about this, the more I am convinced that my gun leak is related to a seal or o-ring that is nicked or simply defective.
I think that the standoff and spring might be useful if a gun is leaking from the transfer port. My gun leaks from the thread of the tank. So it is probably the seal (urethane o-ring) that is bad. I know that a couple of other urethane o-rings that seal the valve are damaged. So they need to be replaced.
I will see if Mike is willing to send me those as I think it is the cheapest solution for both of us.
Seems like a bit of bad luck with your 22. Fortunately mine are still holding original air pressure as delivered from Mike a couple weeks back! Good thing too. I know these are project guns, but I'm not ready to open mine up yet. I'm actively following everyone else's hands on learning in case I need to work on mine.
Just as a side note: When I had my QB79 apart for minor surgery, the valve seal started leaking even though I didn't touch it! I didn't have a spare so I just rolled it over and reused it. Works fine now. Don't know if it's luck or what so I put in an order for a set of replacement o-rings!
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"I think we need Mike to chime in and let us know what he thinks about this whole setup."
I think it was Mikes intention to release this gun into the wild first, He does not offer a tune for this gun at the moment. So I suspect Mike may be interested in what "we think about this whole setup".
"There is also an extremely small urethane o-ring on the valve pin itself. It would be nice if Mike would provide us with sizes and maybe even where we can get those o-rings."
I thought that someone already provided sizes and a source to you, in the thread you started for your gun? Is there something wrong with the information they provided? (i.e. does it seem to be incorrect, or insufficient?)
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Just go to Autozone and buy an O-ring kit. Every thread I see you complaining about your rifle not shooting. Try and fix it instead of posting on the forums, seems like time would be better spent trying to remedy the rifle.
Nick had specifically said not to use black rubber seals because of a very short lifespan. If you have a different opinion, I wouldn't mind hearing your take on rubber vs. urethane o-rings for the valve system.
I wish that someone could confirm that regular rubber o-rings would work fine. It would mean all i have to do is go to an auto parts store and get a whole set of o-rings and get what I need.
The "experts" think that urethane o-rings are what's needed. And there has to be a good reason why the manufacturer of these guns put urethane o-rings in the first place. Am I missing something?
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Just go to Autozone and buy an O-ring kit. Every thread I see you complaining about your rifle not shooting. Try and fix it instead of posting on the forums, seems like time would be better spent trying to remedy the rifle.
Nick had specifically said not to use black rubber seals because of a very short lifespan. If you have a different opinion, I wouldn't mind hearing your take on rubber vs. urethane o-rings for the valve system.
I wish that someone could confirm that regular rubber o-rings would work fine. It would mean all i have to do is go to an auto parts store and get a whole set of o-rings and get what I need.
The "experts" think that urethane o-rings are what's needed. And there has to be a good reason why the manufacturer of these guns put urethane o-rings in the first place. Am I missing something?
mouka, please watch this video. There are many other videos on youtube in reference to Air-Guns and there inner working that are very informative and can answer many of your questions as well. They may not be the "right" answers, but again, very informative.
http://www.youtube.com/watch?v=PXrk7IwDm6I# (http://www.youtube.com/watch?v=PXrk7IwDm6I#)
Al.
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While we are on the subject of o-rings and seals, I thought you all might find this test interesting:
http://www.youtube.com/watch?v=yfniLIZVR6A# (http://www.youtube.com/watch?v=yfniLIZVR6A#)
Respectfully,
Al.
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Firstly to establish a context, we're talking about whether a polyurethane O-ring is needed for the -113 on the body of the valve.
In this application, regular variety Buna-N (nitrile) O-rings are fine. We're dealing with air, not CO2. CO2 will permeate through Buna-N; air will not.
You want urethane when an O-ring is subject to either abrasion through continuously sliding back and forth on a surface (especially where buildup of heat is a complicating factor), or when the O-ring is subject to being nicked or torn on installation. Polyurethane is tops for toughness if there is a slight burr or sharp edge that the O-ring passes when it is being installed.
The former isn't a factor here; it's a static O-ring. I don't think the latter is either. I don't have one of these rifles but if you install the valve from the end where the fill nipple was installed, I don't think the valve O-ring passes any sharp edges or holes. That can sometimes be an issue with QB rifles that have a tank block because of the two holes cross-drilled through the tube so if there are any sharp edges, debur them before you reassemble.
The way you install the valve is like this: only screw the valve halves together loosely so as not to compress the O-ring. Then slide the valve down into the tube and lock it into its home position by installing its screw(s) through the outside of the tube. Then as a final step, you reach down into the tube with a wide blade and engage the slot in the face of the valve and tighten it to compress the O-ring and form a good seal.
BTW for this step, I use a 3/4"W x 1/8" thick piece of bar stock from the hardware store. I needed to just barely round off the edges with a file to help it fit snugly into the tube, and I used an angle grinder to reduce the thickness at the tip so it would fit into the slot in the face of the valve. Works really well.
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Firstly to establish a context, we're talking about whether a polyurethane O-ring is needed for the -113 on the body of the valve.
In this application, regular variety Buna-N (nitrile) O-rings are fine. We're dealing with air, not CO2. CO2 will permeate through Buna-N; air will not.
You want urethane when an O-ring is subject to either abrasion through continuously sliding back and forth on a surface (especially where buildup of heat is a complicating factor), or when the O-ring is subject to being nicked or torn on installation. Polyurethane is tops for toughness if there is a slight burr or sharp edge that the O-ring passes when it is being installed.
The former isn't a factor here; it's a static O-ring. I don't think the latter is either. I don't have one of these rifles but if you install the valve from the end where the fill nipple was installed, I don't think the valve O-ring passes any sharp edges or holes. That can sometimes be an issue with QB rifles that have a tank block because of the two holes cross-drilled through the tube so if there are any sharp edges, debur them before you reassemble.
The way you install the valve is like this: only screw the valve halves together loosely so as not to compress the O-ring. Then slide the valve down into the tube and lock it into its home position by installing its screw(s) through the outside of the tube. Then as a final step, you reach down into the tube with a wide blade and engage the slot in the face of the valve and tighten it to compress the O-ring and form a good seal.
BTW for this step, I use a 3/4"W x 1/8" thick piece of bar stock from the hardware store. I needed to just barely round off the edges with a file to help it fit snugly into the tube, and I used an angle grinder to reduce the thickness at the tip so it would fit into the slot in the face of the valve. Works really well.
Stupid newb question: Can you distinguish between nitrile and polyurethane o-rings solely by color? Black vs white?
Also, thanks for the info on valve installation. On the QB-79 I screwed the pieces together tightly, lubed with silicon grease, and tapped it in with a hammer and dowel. Now I see that's the wrong way to do it. I didn't know any better. Doesn't leak though. I'll chalk that one up to beginners luck. ::)
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Can you distinguish between nitrile and polyurethane o-rings solely by color? Black vs white?
There's no sure way to distinguish by color. Generally, polyurethane O-rings that I see are translucent or white or red but there's no guarantees because colorant can be added to make it pretty much anything you want.
Nitrile is generally black but again, can be different colors.
There a whole host of other materials like Viton, PTFE, silicone, etc. Just saying so no one gets the impression it's merely a matter of determining A or B. There's also C, D, E, F and on through the alphabet.
Moral of this story: keep your O-rings separated and labeled!
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I don't know about other airgun rookies, but I am learning a ton here. And having a technical background, I am certain I will be up to speed in no time.
Keep posting your opinions and tricks, this is what us beginners are in desperate need for.
Thanks!
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for the very best in the 113 O-rings for the valve and cap use the ones that Crosman has used for years, cost around a dollar each but will last for years...precisionpellet.com has them, barrel orings can be just about anything and even if they look ratty will still seal, probe use the buna type....silicone grease applied after the o-ring is in place for installing...
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I have to say I have been using the Crosman rings too... they are easy to deal with and a flat 4$ shipping is great!!
CW
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Thanks Mike :
I received the other two FDPCP rifles and the extra barrels , as well as the pump , I think I am going to have to buy one of the pumps for myself after putting this together and using it for a bit .
For those that want to put a drier on the pump , simply get some desicants and place in the handle on both sides and put breather back in and pump away , take out once in awhile and dry in oven and put back in and you have it .
Time will tell but I like this pump a whole lot better than my Airforce pump from what I have seen and used for a few minutes .
Regards Nick
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The 2 guns and the hand pump I played with this evening , I love the pump is all I can say .
The first gun I pulled out of the box is I think valve locked , this is bad enough that I have to pull it down in order to tell it could be a couple of things , we shall see .
The second gun functions but the foster fitting on the fill port leaks like a sieve , will have to remove and put some Teflon tape back on it to replace the tape that is on it , but at least this gun will function .
3 out of 5 guns have little to no problems the other two have lots of work to get em back up and running , this was to be a tinkerer gun and that has been proven , but they are so simple that a shoe cobbler can fix them so this is all the better , just a heads up as to what I have run into .
Regards, Nick
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I had a bit of time today and did some testing with the .22 cal FDPCP
Got 730 fps out of 28 gr. En jin pellet
The following was at a 2K fill and shot down to 1400psi using CP's 14.3 gr.
970,984,975,961,959,947,935,923,913,896 I could have used a bit more fill pressure on this to utilize the bell curve a bit .
This string was a 2K fill and shot down to 1400 using Kodiak Heavy @ 21.1 gr,
880,865,861,849,837,829,820,807,796,781.
I upped the fill pressure a bit to 2200psi and shot the following using the Kodiak 21.1, looks very promising using the .22 cal and I think with a bit of warm weather and a bit of time is shall prove to be a very nice rig .
843,834,850,868,871,869,862,855,844,834,819,813,800,789,777.
The Kodiak's look like it is going to be very promising indeed we shall see how they shoot and I think it will be very consistant from the numbers I see with just a few minutes to play with today .
This takes the energy to 30.5 ftlbs with the cps at 14.3 gr, and 35.47 ftlbs with Kodiaks at 21.1 gr,
Regards , Nick
PS , DenSkin and I have been talking about what I should and can do on valve modification to this platform and I think I will be putting a .30 cal barrel on one of the ole girls and seeing what I can get out of it then , I do love this platform it is a wonderful 100 bucks spent , I can own a .177,.22,.25,.30 and still have no money in the project .
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Hello fellow FD owners :
Now that Bob is onboard with his very own FD I will not worry about the tutorial any longer , for he is covering it in spades for everyone , Thanks Bob.
I changed out the Lead seal that I put in the .22 cal FD and machined an Acetal seal for the valve , the lead gave way after a bit and the Acetal once seated is working much better , I also like the fact that Bob is cautioning folks to keep the pressures down , I know that the M5 screws did not give me much comfort , so I installed the 10-32's at 90' to the M5's in the stop block to give me the comfort margin , I hate having a lot of pressure in my face with out some fudge factor involved .
I did finally strip out the barrel band screw and will take it back apart and drill out and tap to the next larger size , other than that I have things up and running 5 FD's later , I will be finishing out the others like the two guns as time permits .
I will be taking it to the bench one of these days to see exactly what can be done with the little guns .
Oh Mike my buddy I work with ( he is a Master Scientific Instrument Maker ) is very numbers orientated and I showed him my FD's and let him shoot them with open barrel and the extension I made for the other barrels and he has ordered a B-50 and a hand pump from you so please get them out asap he has not an ample supply of patiences LOL , I will keep on selling them for you , keep on shipping them out .
Regards, Nick
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Hello fellow FD owners :
Now that Bob is onboard with his very own FD I will not worry about the tutorial any longer , for he is covering it in spades for everyone , Thanks Bob.
I changed out the Lead seal that I put in the .22 cal FD and machined an Acetal seal for the valve , the lead gave way after a bit and the Acetal once seated is working much better , I also like the fact that Bob is cautioning folks to keep the pressures down , I know that the M5 screws did not give me much comfort , so I installed the 10-32's at 90' to the M5's in the stop block to give me the comfort margin , I hate having a lot of pressure in my face with out some fudge factor involved .
I did finally strip out the barrel band screw and will take it back apart and drill out and tap to the next larger size , other than that I have things up and running 5 FD's later , I will be finishing out the others like the two guns as time permits .
I will be taking it to the bench one of these days to see exactly what can be done with the little guns .
Oh Mike my buddy I work with ( he is a Master Scientific Instrument Maker ) is very numbers orientated and I showed him my FD's and let him shoot them with open barrel and the extension I made for the other barrels and he has ordered a B-50 and a hand pump from you so please get them out asap he has not an ample supply of patiences LOL , I will keep on selling them for you , keep on shipping them out .
Regards, Nick
"4. The valve is located by two 5mm x 0.8 mm steel screws of unknown quality in shear.... Since one of the load-bearing screws is in the steel block behind the valve, is it critical that the valve bear tightly against that block, otherwise only the valve screw would be taking the shear load.... I would highly recommend that when you have your gun apart that you check that, and if they are not in firm contact, add a thin shim between them to insure both screws are doing equal load bearing.... The threaded portion of the screw is subject to the shear load, so I used the minimum listed minor diameter and calculated a total shear force of 1154 lb.f. for the two screws, assuming 1010 mild steel with a 53K tensile strength (32K in shear) .... With a 0.745" ID for the reservoir, at 1500 psi, the load on the valve is 654 lbs. which means the safety margin is 1.8:1.... If the screws were upgraded to high-tensile screws, this would increase, and I would highly recommend that anyone contemplating using more that the recommended fill pressure confirm that the screws are up to the job.... Where the valve screws penetrate the receiver, you could see faint marks from where the threads of the screws were pressing on the back of the hole.... However, the material is thick enough that I was not concerned about the bearing load at the recommended 1500 psi, but it is something to keep an eye on each time you have the gun apart...." Bob"
Nick,
I did the same thing you did, based on Bob's recommendations seen above for those wanting to exceed a 1500-psi fill, but based on the reply below, even that is not good enough. Maybe it just slipped his mind to mention the rest of the information in the write-up above about the screws; what he eventually educated me on in the reply below in addition to using better screws.?.
"Al, now that you addressed the screws so that you can increase the pressure, you have decreased the safety margin on the threaded portion of the tube.... Until we know what the material is, we have to assume mild steel, so at 2000 psi (using 44K to yield) you have reduced the safety margin to 1.9:1.... That means that every time you fill the tube you are "working" the steel past 50% of it's yield strength, which is into the area where fatigue becomes an issue.... Add to that the "stress riser" caused by the sharp vee at the bottom of the threads, and eventually I would expect the tube to fail at that point.... It might take 50,000 cycles, or it might not, and if the tube is CrMoly you might be just fine.... but exposing the threaded portion of the tube to pressure is the weak point of the design, IMO, once you address the screws....
Bob"
So, based on that fact that what we both have done really is not good enough, I have finally elected to go with a lower than 2000-psi pressure.
Your thoughts?
Respectfully,
Al.
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Hello Al:
I deal in pressure vessels and metal requirments every day as a vocation.
That being said I will not go into details.
Liability permeate our society today, with that being said folks should take the current path laid out before them.
I will not talk of fill pressures any further, my comfort zone my differ from others so I would suggest everyone just take the safe road.
I have my FD'S figgured out to my satisfaction and then some, good luck on your journey with your FD.
Regards. Nick
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It's also well accepted, in official racing and aviation safety circles, that (round seamless) steel tube is far stronger than flat sheet or even square tube, and most spectacularly in sizes near and under one inch o.d., where the wall thickess to o.d. ratio is much stronger still. You can't use the same formulae, modulus or stress limits for round tube, as you would for flat sheet or even bolts.
[P.S.: There are places to get burst discs in the 'missing' areas around and just over 2000psi, if you're willing to tolerate a little more bulk from a 1/4" disc, holder, and an adapter from 1/8" NPT. ]
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The more I think about this, the more I am convinced that my gun leak is related to a seal or o-ring that is nicked or simply defective.
I think that the standoff and spring might be useful if a gun is leaking from the transfer port. My gun leaks from the thread of the tank. So it is probably the seal (urethane o-ring) that is bad. I know that a couple of other urethane o-rings that seal the valve are damaged. So they need to be replaced.
I will see if Mike is willing to send me those as I think it is the cheapest solution for both of us.
Seems like a bit of bad luck with your 22. Fortunately mine are still holding original air pressure as delivered from Mike a couple weeks back! Good thing too. I know these are project guns, but I'm not ready to open mine up yet. I'm actively following everyone else's hands on learning in case I need to work on mine.
Just as a side note: When I had my QB79 apart for minor surgery, the valve seal started leaking even though I didn't touch it! I didn't have a spare so I just rolled it over and reused it. Works fine now. Don't know if it's luck or what so I put in an order for a set of replacement o-rings!
IME with other equipment/systems it's always the last place you look, or the first one you disregarded out of hand, as "couldn't possibly be it." And it's always the cheapest/simplest part, after you've replaced all the expensive/complex ones.
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"4. The valve is located by two 5mm x 0.8 mm steel screws of unknown quality in shear.... Since one of the load-bearing screws is in the steel block behind the valve, ...." Bob"
Your thoughts?
Respectfully,
Al.
JFYI, not in the GEN II.
That block, like the trigger group stop, and the barrel band,
- is plastic.
Rod
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I visited with Mike and was quizzing him about the BAM 51's that he had in stock , after visiting a bit on the BAM he shared with me the FLYING DRAGON PCP that he was converting .
I pumped the .22 cal up to 1500 psi and proceeded to shoot in the dark at the tree line , the 1500 psi fill was almost too much , the gun was on the verge of valve locking . I shot it down till the point it sounded right and checked the fill pressure it was 1100 psi where the gun started shooting correctly down to the 600 psi mark .
I shot around 80 pellets thru the gun and then went indoors and took the trigger out and proceeded to adjust and polish the sear engagments , it is a wonderfully simply trigger arrangement and is very easy to adjust and polish out to a very nice hunting trigger .
I then loaded up again started to shoot another string to adjust and try out the new trigger job and it is wonderful indeed , after a few shots the gun dumped the fill pressure at the shot , I figured the valve gave way .
I pulled the gun down part way that evening and then finished the job completely dismantaling the gun 100% last night , it is a wonderful design and very easy to work on , this gun is the VW'S of PCP'S , it is wonderfully easy to work on and what I love about is that it is so easy to work on , fully adjustable trigger and an overall great design that is very affordable to own and operate , I have been following the thread that everyone is having problems with the guns that they got .
Well if your new to PCP's your going to have to pay your due diligence and will have a learning curve , if one has no mechanical aptitude or little to no patience then this or any PCP is certainly something that your going to have a hard time with .
One thing that everyone has to get a grip on is that this is a tinker gun , as Mike said , your going to have to work on it , it is a wonderful and very easy design that is going to be a wonderful gun for my needs which is hunting , I will set it up to give me 10 full power shots with very little deviation in velocity .
these guns need tuned to use higher pressures it would appear and you will have to do the work to get them there . If your gun will still bleed off air even if it is a little bit then keep dry firing the gun until one gets enough of a shot pressure to discharge a pellet and shoot the gun down and keep it down low on pressure until you get the work done to your gun to allow you to use the larger fill pressures .
As far as sights are concerned this is a pcp it deserves to have a scope on it , it is a long range set up , sights are for springers 30 yards and under , this gun is for + type ranges . Sights are to be taken off and a hush method to be used on the end of the barrel . with scope mounted and the sweet spot found with a chrony and all the data worked up for this gun .
I am going to put my .22 back together now and get off here , I found the valve seat cocked and I will explain in a night or so as to what is going on , but this little gun is a diamond in the rough and for $ 100 I will be buying several more to lay back and make wonderful little hunting gun for some friends , Oh don't worry about the fill tubes as a weak link they are not , it will take 8K to burst these things , the weak link is the two 5MM screws under the action , one holding the pin valve assy and the other holding the backing , but don't worry too much for in the machine shop we lift 12K chunks of steel with a hole drilled in the center and tapped using a 1/2" bolt to do the lifting .
The weak link are these 5MM screws but 2K is well within the stress limits for such things but do not exceed this much or your just asking for it unless you drill and tap more anchor points .
everyone is going to have to work on these guns bar none , if you do not want to tinker then perhaps one should purchase a springer for PCP'S are a labor of love .
Now back to putting together my .22
Regards, Nick
...guess I should have ordered an 1800psi reg with the bottle instead of a 1600#...
Oh well, I'll want a second bottle anyway eventually, and it'll give me time to get the 2000# ballpark (and more granular) burst disc setup, find USA made metric (=ACTUAL class 12.9) bolt/screws -and drill the receiver for side screws and make the new STEEL valve backing plug. (The GEN II's is plastic.)
Check out:
http://high-pressure-products.maxprotech.com/viewitems/medium-pressure-components/1-4-angular-rupture-disc? (http://high-pressure-products.maxprotech.com/viewitems/medium-pressure-components/1-4-angular-rupture-disc?)
http://high-pressure-products.maxprotech.com/item/medium-pressure-components/medium-pressure-safety-head-assembly/21sh4m? (http://high-pressure-products.maxprotech.com/item/medium-pressure-components/medium-pressure-safety-head-assembly/21sh4m?)
and
5404-04-02 | 1/4" NPTF Male x 1/8" NPTF Male
(high pressure) adapter, at:
http://www.discounthydraulichose.com/Hex_Pipe_Nipple_Steel_p/5404.htm (http://www.discounthydraulichose.com/Hex_Pipe_Nipple_Steel_p/5404.htm)
(if as I suspect it may be too bulky, you can always wrap it back, or forward,
along the reg.) with:
5500-04-02 | 1/4" NPTF Male x 1/8" NPTF Male 90°
at:
http://www.discounthydraulichose.com/product_p/5500.htm (http://www.discounthydraulichose.com/product_p/5500.htm)
Rod