This is my first Air cannon an Instructable i have done. This Air cannon uses compressed air. It is released by a electrical irrigation valve. The barrel is easy to change size. The barrel i used shoots bouncy balls over 100yrds at only 50-40psi. I have tested mine up to 100psi before it started to leak. This is a very easy an fun thing to build. I get a big kick out of seeing a rubber ball flying accross the sky.
My camera has just broke. I will try to post pics up asap. Sry for the horrible drawings an diagrams.
Also the hot glue gun is for making a holder for the 9volts an a mount for the buttons.Video of it as of July 20th 2007