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Posted: Sun Apr 22, 2007 9:22 pm
by noname
Hi, like my competetion gun was going to be, he probably needs the space where the top elbow is for something, like a bolt-action asssembly or something.

Re: wooden piston

Posted: Sun Apr 22, 2007 9:39 pm
by jrrdw
singularity wrote:it there any reason why i have never seen a wooden piston before? im thinking about making one from oak on a lathe, that way it would be easy to add o-ring groves.
Dude check out the dates on the post.

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Posted: Mon Apr 23, 2007 2:17 pm
by limestonerox
what keeps the pilot chamber air from escaping up the Tee into the barrel? I don't see how you could ever pressurize the air chamber.

Posted: Mon Apr 23, 2007 4:48 pm
by singularity
okay so the diagram isn't draw exactly right there is a stopper at the firing chamber side that prevents the piston from sliding further forward and there are o-rings on both sides of the the piston. the valve is pressurized from the pilot side there is an equalization port going through the piston

as fro not using a barrel sealing valve it would create more dead space, the idea on this gun is a small efficiently chamber so i can use a set of tanks i made for a previous project. the problem is they are small tanks so i need a small chamber. this is the most compact and efficient valve to use that would fit the requirements.

Posted: Mon Apr 23, 2007 6:18 pm
by limestonerox
I am intrigued by your design components. I've yet to build one of these and often wondered how wood would perform as a piston. Apparently well! You have answered my question about the equalization hole in the piston. Just how big should this hole be if I use a 3" pvc coupler inside a 4" pipe? The diameter of a finishing nail? Am I correct in assuming these o=rings have to be machined to a tight tolerance so air won't slip up into the Tee from the pilot chamber?

I appreciate your response. Thanks

Posted: Mon Apr 23, 2007 6:21 pm
by limestonerox
BTW. what is that material wrapped around the piston on each side of the o-ring?

Posted: Mon Apr 23, 2007 6:27 pm
by jrrdw
My equilization hole is 1/8th" placed under the rubber barrel seal to come up with a instent check valve. As for the o-rings, custom fit untill it has a slight drag on the pipe. Allways start bigger and work your way to the proper size. Mine takes a little push to get it moving, but once it starts, it's realy smooth.

Posted: Mon Apr 23, 2007 6:29 pm
by jrrdw
limestonerox wrote:BTW. what is that material wrapped around the piston on each side of the o-ring?
It's just the wood grain, it looks wierd because i used 2 different pieces of 2X4.