Turntable

Principle: circular motion

What to do with it:

drop marbles or bouncy balls on it
build ramps, etc., on it, from blocks or Legos
sit on it

Construction:
Large versions made of metal or wood with rounded edges. Small versions plastic. Uses bearings to rotate smoothly, like a lazy-Susan.

Durability:
Larger versions will be more durable. They have to be made of stronger materials to support more weight. This has the side-effect of making them heavier and less likely to be thrown or moved around.

Safety:
It would be a good idea to have a non-skid surface on the top of anything people will sit on. The larger, heavier versions should have a very stable base, and should not be able to rotate at unsafe speeds.
Throwing balls at the turntable could be unsafe because it's not necessarily predictable which way they'll bounce.
The top should be high enough from the floor that it won't pinch people when they try to spin it.

Margaret DeLap
39-245 D