Rotating Platform

The turntable works pretty well for demonstrating angular momentum conservation by standing on it with weights in both hands or a rotating bicycle wheel. There are probably much higher quality platforms available for a much higher price, but for the size and budget of my school, this one had low enough friction that I could do the demonstrations successfully. I like this style better than the pancake shaped ones, because the bearings are so close to the center that they exert little frictional torque. With the other style, even excellent bearings exert more frictional torque because the bearings are farther from the rotation axis. If the frictional torque is too high, certain demonstrations of angular momentum conservation won't work well. Because this turntable has only three feet, it is a bit prone to tipping, so it needs to be approached with caution. This is very likely a teacher-only demonstration rather than an activity that students will participate in, but that can be left to the discretion of the instructor. I also use it to demonstrate moment of inertia by placing two weights on it and inviting students to place the weights close to or far from the center and then feel how easily it can be rotated (i.e. how much torque is required to change its rotation) in the various configurations. The bottom line is, for under $100, this is the only turntable I've found that was adequate for my demonstrations. Even though I only use it a few days a year, I'm sure my students will remember being able to feel the concepts I am teaching.

Used this device to demonstrate the Conservation of Angular Momentum two times and the platform fell off the rotating shaft. This could be such a great device. I do not recommend!

Rotating Platform fell apart quickly - In its first use in my high school classroom to demonstrate conservation of angular momentum, and under supervision (so it wasn't being abused) the platform and bearing detached from the base. It appears to be press-fit and can't be repaired.Before it fell apart it seemed very sturdy and had very nice low friction. But now its useless and I am contacting the vendor to deal with replacement.