Check out this gigantic tennis ball launcher! A must if you are trying to help your son or daughter become the next Venessa Williams. Just make sure to use a nice racket! I built this launcher for a friend of mine after he helped me machine some custom aluminum frames for the 2005 ASME Regional Design Contest. It features a 2.5″ ID pvc pipe barrel (perfect for tennis balls) and a 4″ ID pvc chamber. The valve is a 2″ diaphragm sprinkler valve. I modified it to allow for remote pneumatic actuation rather than using the solenoid provided. I did this by removing the solenoid and covering the opening with epoxy. I then tapped into the chamber above the diaphragm and ran some .170″ ID polyethylene tubing to a push-button valve located midway down the launcher. The valve has the lowest working pressure at 150 psi, although I have only tested the launcher up to 125 psi. via