[RyanN]

We're using a freon tank on our robot now. We used a PVC tank for over 3 years and never had trouble with it, but the team, including myself, were waiting on it to blow like a bomb anytime. Since this robot's main purpose is to demonstrate around people (most of the time little children) we changed the tank to metal with a blowout hole in case something goes catastrophically wrong. We are still using PVC for the shooter, and regular flexible hose for delivering the air, but all the pressure is behind the valve and really never on the cannon. We've also limited the amount of time that the valve can remain on for. I think its like 1/10 of a second or something so it uses less air, and also reduces the chances for something to go wrong. I think we will limit the pressure to 100PSI even though the tank can handle 300PSI. I'm not sure how much pressure our sprinkler valve can handle, and I don't want to find out either . With 60PSI I can shoot a t-shirt over 300 feet over a tree with with a 1/10 of a second shoot. Here are some pictures of our setup: