The levitron is an experiment with a spinning top that flies over a big ring ferrite magnet. There is also a small ring neodymium magnet inside the spinning top.The same magnetic poles must be opposite each other .Near the center of the ferrite magnet, the magnet attracts the spinning top but a little far (5 cm or more) the ferrite magnet repulse the spinning top. You can see why it happens in the photos. The balance is very sensitive. We put iron washers on the spinning top ( to the up side) to control the weight.In the summer the spinning top levitates more easy if we put it in the freezer for a few minutes.The spinning top levitates for about three minutes or 20 minutes if we put it in vacuum .
The dimentions here are. 120X25X50 for the ferrite magnet and 27X5X16 (all in mm) for the small neodymium magnet.I put a ring of aluminium around the magnet to protect it. The axis of the spinning top must be from wood or plastic.
YOU CAN WATCH THIS EXPERIMENT HERE: