Turns a ping pong ball into a caster wheel! Designed to be a front wheel for a Vex robot car. Car turns on a dime. I've uploaded the Inventor file too, although it is pretty messy as I did a lot of iterations. See it in action at http://youtu.be/TAthyN549ns Added new stl - pingpongwheel7. I realized the holes were too close to the ball holder, you could only fit very short screws. The new one goes to the next opening in Vex metal.