SpudFiles

I've been building combustion cannons and want to try something new.

I'm looking to launch AAA, AA C or D size batteries, out of a pneumatic at the highest velocity possible using a valve setup, no pistons,or diaphragms. I want to fire larger projectiles, I was considering a 1" barrel since that's optimal with a sprinkler valve right? Plus, will 1" fit D batteries?

Any help is greatly appreciated, my cumbustion cannon would fire Ds with tape around them and they would flatten into a pancake on impact with a boulder. It was like steel, acid filled paintballs...

I'd like to see even more power and be able to totally obliterate batteries on boulders.

maybe a valvless design or burst disk?

http://www.spudfiles.com/forums/valvele ... 15495.html check out this topic on 'valveless' pellet guns and click the link to the google patent to show a design for one.

I would suggest a burst disk.

Also, go with the longest barrel that's still practical.

Inline is what I suggest

QEV I would say
better then a sprinkler
no problems making a piston
no modding needed

I don't know about the measurements from all those batteries
find the batteries and try it out in the shop

BTW, C batteries fit in 1", not D batteries.

My first ball valve pneumatic used d batteries it had a 1.25'' abs barrel

C batteries fit 1" SCH40, AA fit 1/2" with a little tape

QEV I would say
better then a sprinkler
no problems making a piston
no modding needed

As the title said, he wants high velocity. That isn't going to be possible with a regular QEV, as they can't take very much pressure.

If you want the simplest build possible and the most power possible at the same time, burst disks are the way to go. The only problem is if you want to have fun shooting it. In that case, a good piston valve is your best bet.

Well 900psi isn't exactly small beer.

The "highest velocity" (speed) possible is a bit of a huge open ended thing to say you want. An aim of being able to "totally obliterate batteries on boulders" is perfectly possible with any valve down to a ball valve.

Also, I suspect someone has no real idea of what the main valve in a pneumatic is if they want a "valve setup" not "diaphragms and pistons".

I think Kiwi needs to do some research on pneumatic cannons and come back with some kind of solid aim plus what he's up for making.

Hey, I was thinking of using a modded sprinkler or quarter turn ball valve to release the pressure into the barrel.

Hotwired, I know exactly how a piston or diaphragm works inside a cannon, and I just don't feel like making a piston or dealing with a diaphragm in one of those cannons.

I have established that I'm going to use a 1" diameter barrel and I plan on putting the air chamber below the barrel, and I still haven't decided on whether I'm going to use a modded sprinkler valve or quarter turn ball valve.

A sprinkler is a diaphragm valve

For a first pneumatic a modded sprinkler should be good, ball valves have an awkward twisting action which can fiddle with aim a bit.

Sorry for being especially spiky in the last post, just fishing to see if it was a spoon feeding request

Kiwi,

Pay attention to the words of hotwired. He's right. You either (a) are not communicating well or (b) don't have a clue. I don't know which is the case (only you could know that at the moment). So....

If a) Do a bit of reading around here to figure out the difference in vocabulary between this forum and your own source of knowledge.

If b) Do a bit of reading around here to get the proverbial clue because your statements are contradictory. You want a sprinkler valve but you don't want to deal with diaphrams? That's like saying you want to drink a fifth of vodka but don't want to get drunk. Which is it, 'cause you can't have both!

This is a diaphragm setup.



I understand a sprinkler valve uses a diaphragm, but it's a contained piece that's easy to mod and install.

The picture I posted shows a cannon that uses a diaphragm to seal the barrel.

If you haven't seen this before, the clean out plug holds the diaphragm in place and some copper air pipe is screwed into the back of the clean out plug. It leads to a ball valve that releases the pressure in the pilot chamber.