How To Build A Cannon That Shoots Wiffle Balls At 50MPH [Video]
Repurpose your leaf blower into a pitching machine

Chances are, your leaf blower is collecting dust in a garage right now–and it will until this fall. So rescue that yard-clearing device for a far nobler purpose: blasting lightweight projectiles at top speed.
Channeling the air from the leaf blower through a simple assembly of PVC pipes turns it into a Wiffle ball pitcher. It can also hurl foam balls and even water balloons and snowballs, although heavier projectiles should be avoided.
Watch the video here, or check out William Gurstelle‘s full-text instructions to build this project.