THIS MAGNET MOTOR WASN'T BUILT BY ME
More info here: http://peswiki.com/index.php/OS:Screw-Magnet_Motor
This motor uses magnetic attraction to spin. It is basically a cylinder with flat screws attached to the outside. I mounted this on a hard drive spindle. Four neodymium magnets line up with the four rows of screws. The magnets are attracted to the screws, but are attracted more to the heads than the tail ends. The head of a bottom-row screw will be attracted to the bottom-most magnet. So will the head of the screw above it. The cylinder will turn to compensate this imbalance. The same with the next two rows of screws. The lowest magnet now prefers the head of the next screw rather than the tail of the previous screw because magnets are attracted more to the thicker part of the screw. When I move the magnets close enough, the magnetic attraction makes it spin.
This device is a very crude rough draft. The screw placement is off, and it doesn't rotate smoothly. This is a quiet, environmentally-safe, free-energy device. On a large scale it could produce useful energy.