For tennis ball machines to shoot balls with perfect accuracy and at nearly 100 miles per hour, it takes a series of carefully calibrated parts working together. Here's what it looks like inside.

[hw97karbine] has made a pretty cool tennis ball cannon. While making a cannon of this sort is nothing new to us, we were impressed by the effort taken to get a stoichiometrically ideal mixture of ...

Set up the ball machine to feed deep to one corner and place a chair at the center of the baseline. Make sure there is enough time between feeds so you have time for two sprints, one out to the ...