Just got a 750 - 1,000 lb. Lazy Susan bearing (16$) from Amazon so I can build an industrial Lazy Susan. The purpose of the Lazy Susan is to let my kids experience angular momentum for themselves.
Can wait. This will be a super simple build and the kids will love it!!! I remember when my Physics teacher handed me the bicycle wheel while I was standing on the Lazy Susan in class. He then spun the wheel and around and around I went. It was a truly magical moment.
Go to 3:49 in this video to see it in action --> Angular Momentum - Science Theater 24