Gyroscopic Exercise Ball

This is my take on the venerable Dyna Bee gyroscopic exercise ball that came out in the late 1970's. It uses 48 pennies (US) as the flywheel mass. As a twist, I've added a geared zip starter to get the rotor spinning up to speed. From there, you keep it going with pure wrist power.Aside from the 3D printed parts, you will need a 0.125" diameter steel rod and some superglue to put it together.UPDATE: I've modified the shell to make it easier to align the zip starter with the slots in the side.Pri