Baseball Air Cannon

I designed and built a baseball cannon as a group project in high school. The plumbing was pvc rated to 120 PSI, and at 100 psi we fired a baseball at 80 mph.

It was pneumatically triggered. The air pump would pressurize an air reservoir on the cannon. When a valve was turned to fire the cannon, a piston would move due to the pressure differential, releasing the air from the reservoir into the barrel and firing the ball. Unfortunately, the 1/4” thick PVC piston shattered after a handful of shots, even with attempts to add padding. Oops. If I was doing this again, I’d have stiff springs or an air cylinder to stop the piston.

Interestingly, since only the bottom of the baseball was the touching the barrel as it was being fired, the baseball was released with topspin, so the cannon only shot curveballs!