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piston valve
Posted: Sun Jan 01, 2006 3:11 pm
by b-nice
does it need to be air tight in the chamber and does it have to have and spring? if so should it be a compression or recoil. (push aginst barrel seal of pull away from barrel seal.)
Posted: Mon Jan 02, 2006 3:22 am
by Copperboy
That depends on a number of factors, it could be all pneumatic operated or all mechanical.
I suggest you try the "theories" buttom above and then look at "flow in piston valves" or something similar.
Posted: Mon Jan 02, 2006 2:17 pm
by boilingleadbath
The piston should fit pretty well in the chamber, and this is often done with disks of slightly oversize rubber glued to a washer and put on a bolt. There is enough leakage in this system to allow you to pressurize the gun from behind the piston, but if you machein it with o-rings, you'll have to drill a small (like 1/16") hole.
The spring is to help seat the valve (make it seal) - you want a compression spring. It should be noted that the effect of a spring during firing is ignorable; even a relitivly strong 1 lb spring in a small 1" chambered launcher is only 1.3% of the force.