Air Cannon v3

Trebuchet03 writes “A pneumatic cannon for launching plastic soda bottles…. or ketchup packets. Almost all parts can be obtained from home depot and probably any local hardware store with a plumbing section. Bigger is cool looking… But not always better. I have found smaller more robust designs to be far more fun that the gigantic heavy cannons. I can recharge (with a foot pump) and reload in less than 30 seconds and hold this thing much easier than its heavy breathing counterparts. Other than this design, I no longer build using PVC as it does fail catastrophically.” – Link.