Moment of inertia disk

I designed these disks to fit together, if you print two of them. They are designed to fit 16 mm ball bearings, which can be found on Amazon for cheap (also happens to be the same size my projectile launchers use). The center hole is ¼ inch, for you to add an axel. Very good demo for moment of inertia, or print a bunch and use them as a lab. Students like playing with them. 

I should note, the moment of inertia about the rim of the disks does not change large enough in order to make the rolling along the rim noticeable.