Ok, so I have decided to use a sprinkler solenoid valve to let the air pressure out of the air chamber. Can someone tell me how I would make this work? With batteries & wiring. And is this even possible?

What is you recommendation for the valve from the air chamber to the barrel? I need something that is consistent because we are running 3 trials for each target. And the accuracy is our grade.

My mission is to build a launcher that will launch a tennis ball into a basket. The basket will be placed at 3 different distances of 3.0, 5.0, and 10.0 meters from my launcher. My launcher must be free standing. I will not be allowed to support your launcher off the ground as I launch. Combustion m...