Here is our final solution to getting a rapid dump of the compressed air. The piston is actuated via a spike / solenoid set-up which is programmed to the trigger on a joystick.
Not that I want to encourage you the PVC air cannons, but you could have bought that valve setup rather inexpensively with a 90 deg rotarty actuator from many valve manufacturers.
cool. i try not to use ball valves except as a safety measure because they open fairly slow for cannons but that looks like you can open that up on the fly. at work we have bleeds of a jet engine compressor and we use big pneumatic actuated Butterfly valves for there ability to open very quickly with little resistance.
cool beans boys, shoot some holes in some stuff for me