benstern, judgement_arms, thank you for that information. I didn't know that the ball valve was DWV or i would have steered clear of it. We didn't have the time (or knowledge) at the time to modify a sprinkler valve, but we plan on making another one for fun in a few weeks so we will use a sprinkler...

My friends and i decided on a potato gun for a physics project but our teacher wouldn't let us use combustibles so we used air. It looks pretty sweet and this forum really helped us make it so i thought i'd share. The barrel is a 5' piece of 2"pvc, the chamber is a 2' section of 3" pvc, filled up wi...