Spinning Chair
A lightweight low friction spinning chair that you can do angular momentum experiments with, and play with gyroscopes.
This is a really low friction chair that will keep spinning for a long time, which allows you to do conservation of angular momentum demos. Including moving mass towards the axis of rotation, and moving gyroscopes.
It is made of aluminium so not too heavy, and will pack into a 600x400x365mm box so it is easy to transport.
Also:
Demonstration