XS60C PCP Repeater project

[Gertrude]

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

[RHytonen]

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

(or is that yet another job for Eric? Any brass left?

Rod

[stalwart]

"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.

[student1946]

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.

[stalwart]

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.

[RHytonen]

VERY interested...

[rsterne]

over 300 FP in .357 with a 27inch barrel

at what pressure?

Bob

[rsterne]

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

[stalwart]

Is a Disco tube 7/8 ID?

[rsterne]

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

[stalwart]

With the valve mounted to the striker block, as my design does, there will be nothing in our way. 

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.

[RHytonen]

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

[stalwart]

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

[stalwart]

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.

[RHytonen]

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

[rsterne]

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

[RHytonen]

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

[rsterne]

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....



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

[RHytonen]

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....



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

[rsterne]

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