SpudFiles

The idea is simple. Attach two blowguns to either side of a small chamber and then connect them so when one is closed the other is open.

They seal the best from the back, I took that into account and made it so they except all the pressure from the back.

Now a barrel is connected to one, this one is the main valve. When it is closed the other is open, thus filling the chamber. Now when you open the main valve to fire your bb the fill valve closes, making sure no air is wasted. Then you close the main valve and the cycle repeats. Oviously you need a feed of bb's.

Here's a pic.

The perfect plinker.

looks like it will work but its gonna be a little bulky, it would probably be better if you replaced the 2 blowguns with 2 linked barrel sealing tee valves or something. but of course tats gonna be more work

Why do people keep recommending piston valves for guns that have a limited air supply?

It defeats the purpose of having multiple shots when a valve is too powerful for the job at hand.
Its like using a jackhammer to engrave your name on some wood.

frankrede wrote:Its like using a jackhammer to engrave your name on some wood.

nice analogy frank.

it looks like it would work also, flow wouldnt be great, so no amazing projectile speeds

You can do many things to tone down a piston valve and make it stingier on air expenditure. Far more I would venture than having a valve that depends on your reaction time to meter out air.
Why not try for multiple higher power shots? If you can release a small amount of higher pressure air rapidly and reset a piston valve and shoot again, why not?

Hawkeye, see my thread here for an application of that exact idea.
http://www.spudfiles.com/forums/viewtopic.php?t=7204&

Yes that works. The misconception people have is that venting the pilot volume allows air from the refill chamber to vent needlessly but you can set it up so that the piston moving back holds a valve shut to eliminate this problem. As the spring resets the piston it also relieves the pressure holding the other valve shut and allows the FE chamber to refill the firing chamber.

Oh, I see. You are talking about a gun with two reservoirs! The FE would be dumping into the rest of the gun through a valve in the pilot volume. Hmm, yea, you would need a valve to close off the FE during the firing cycle in that case. My idea just had the FE as the primary chamber like on a conventional o/u pneumo.

Yes, The firing chamber doesn't need to be very large to shoot smaller projectiles and you can operate at a very high pressure.