Pneumatic Snowball Cannon

Step 6 Modify the ball valve

The ball valve is designed to stop after turning 180 degrees, which isn't what we want. This, like a normal ball valve, is open with a quarter of a turn. 180 degrees is 2 quarter turns, so it starts on off, and stops on off. You need to take out the hack saw or grinder for this step. First, you have to take off the bolt that holds on the lever. Then chop off the section shown in the first picture.