Neodymium magnet 1/4 x 1/4 inch square or cylindrical
1 sheet 3/16th inch balsa or thinner (actually any thin sheet of wood will work)
Wooden base around 3 x 6 inches
1 (or 2) AA battery - rechargeable ones if you want to be responsible.
bit of plastic or small piece of hardwood
drill and drill bits
Push the straight part of the strips of bent balsa into the base.
Glue it down. Let the glue dry.
Put the battery in the hole positive (+) side down.
Attach the magnet to the head of the nail.
Attach the point of the nail to the positive (+) end of the battery. the magnet will hold it in place.
Adjust the wire so one end is touching the negative (-) end of the battery.
Adjust the other end of the wire so it is barely touching the magnet.
watch it spin. try adding a second AA battery. Consider using rechargeable batteries.
Another video, this one with my extra messy desk at work.
A note about Round magnets versus Square magnets. Both shapes work, but the square magnet is easier to see the spin and makes a clicking noise. The round magnet is quiter and runs smoother. Becuase the round magnet can be in constant contact with the wire, it spins up much, much faster. The square, because of its corners bounce off the wire and is limited in speed but is more lively.