Pneumatic Cannon

[j.turner13]

Hello Everyone,

I have a few questions, they're basic so if the answers are somewhere else please point me in the right direction.

I am planning on building a CO2 powered pneumatic cannon with inter-changeable barrels. I have the plans pretty much set out in my head, the only thing I am having trouble with is how to connect the tank to the sprinkler valve then the sprinkler valve to the interchangeable barrels.

I also have a few different ideas for an interchangeable barrel system, so any suggestions on the best way to do it would be great.

I have built several combustion cannons before, however this is my first attempt at pneumatic. Any suggestions, no matter how basic, are appreciated.

Thanks

[spudtyrrant]

uh. threaded fittings lol

[kjjohn]

In terms of connecting the tank to the sprinkler valve, do you mean the C02 tank, or the chamber? If you are referring to the C02 tank, this will not work. Discharging an entire C02 tank at once through a sprinkler valve will be inefficient, dangerous, and provide mediocre performance at best. You would be much better using the C02 tank as a "bulk storage" tank, and having a separate chamber. With this design, you could get many shots out of one C02 tank.

However, if you were referring to the chamber, then isn't it obvious? Standard PVC fittings.

For an interchangeable barrel system, I would suggest cam lever, or Banjo couplings. They will allow you to switch barrels quickly and easily.

[jhalek90]

Be careful!, the C02 does not mic well with pvc.... especially at higher pressures.

[Technician1002]

If you use CO2, plan on only using a soda fountian type with a primary regulator to provide a maximum of 100 PSI to the PVC parts. Do not use single shot disposable cartridges. Overpressure is a very real danger as well as the cooling of boiling liquid CO2. PVC becomes very brittle when cold and behaves like glass.

Warm regulated CO2 is the only way to use it in a PVC launcher.

Screw on barrels is an easy way to provide a large variety of barrels for a given outlet from a valve.