Posts tagged with :tennis:

new tennis racquet came :roodab: :yay:
I did some fun math today on finding velocity of a shooting object. I’m trying to design a tennis ball shooter which uses a single wheel and spins it along an arc to get up to speed, before launching at a certain angle. Originally I assumed the velocity of the ball would be half that of the angular velocity of the flywheel, but quickly realized it’s more complicated than that. I did some research, and found what I’m doing to be similar to equations modeling reductions on a planetary gear systems. I got a few equations for determining planetary gear reduction, and solved for the relative angular velocity of the ball and speed of the ball based on the diameter of the flywheel and tennis ball. Then I added the speed of the motor and solved for the speed of the ball. TLDR; A 1200 rmp motor with 6" diameter drum can launch a 3" diameter ball around 10 mph.