SpudFiles

Question

How small do you think could I make the air chamber of a pneumatic cannon if it has a 1'' modified sprinkler valve with a 2'' barrel roughly 1-1/2' long and still achieve decent velocities of around the 250fps margin while running at around 50-70psi?

I have been wanting to build a launcher for paintball use for a long time but have always come up with these criteria that could prove problematic for the design:

1) Must be compact (as small as possible)
2) Must be able to load quickly (breach design done, perfect seal)
3) Must be able to recharge quickly (pump connected onto chamber)*
4) Must achieve decent velocity of around 250fps (for distance)
5) Must be low pressure
6) Can't spend heaps of cash
7) Must be as simple as possible (for best reliability)

*possible mini compressor fitted onto chamber

Trying to combine speed, power and reliability is not easy

A 1 foot long 3" chamber could probably do it, and isn't too huge.

Well, from my ggdt results, you're not going to get much better than 230 fps with an 18ing barrel at 70 psi.
Also what is your projectile weight? I just used 50 grams.
Are you going to be using co2? it would be a lot more stealthy than a compressor.

That should be ok. I will fiddle around a little with the ggdt now that I have the values for the valve and such. Never figured those out before.

You left inner diameter of reservoir as 0 in your ggdt.

um, a quick question, what should I put as dead volume for the valve?

A coxial? 2'' chamber and 1'' barrel and then have your 2'' pipe screw on to the front. Use a 1 1/4'' end cap for the piston. It should work but you might lose a little pressure from the space of the 1'' barrel to the 2''. Ill draw a picture of it.

What are you planing to shoot?


801 posts!

No, too much dead space.

I am planning to shoot multiple paintball rounds, no need for nerf rockets cause we don't have tanks.

Oh, inner diameter is for a coaxial I didn't know that. Sorry. This cannon is going to be an over and under.

I got a really good idea, but I am still working on it. You take 2-3 3/4''CPVC and put together and slip it inside of some bugger PVC and then expoxy them in there, and then atach it to the valve like a regular barrel but now you can load 5-6 paintballs each "mini barrel" so you get a good amount of paint.

Ill try and make a drawing of it.

Yeah a drawing would help.

You guys are going to like my breech design