A homopolar motor is a battery that has a magnet on one side and a copper wire that goes from the top of the battery to the magnets on the botton. If this connection happens on both sides, the copper wire will spin around in a circle, very fast, although sometimes, it can fall off!
Step 1: 1. Stripping Wire
First thing you'll need to get some copper wire. Usually copper wire comes insulated, so you'll need to strip the wire. Sometimes stripping can be quite hard, so it's best to have a partner.
Step 2: 2. Magnets
Attach 2 medium power magnets to the flat side of of your battery. THIS IS IMPORTANT!!!!!!!!!
Step 3: 3. Metal Bender
Take your stripped copper wire and twist it into a square shape, with a hole in the bottom where it fits around the ,magnets at the bottom.
Step 4: 4. Add!
Put it onto the battery like so. it should spin!