How to Build an Electric Windmill for a Science Fair

Cut the ABS pipe with a saw in 1 1/2-inch increments on the diameter.

Mark lines diagonally across each quarter of the pipe, starting at one end and moving halfway to the opposite end. Cut along the lines to create four 24-inch curved pieces. These are the blades of the windmill.

Drill three sets of holes around the perimeter of one of the metal disks. Drill the same holes in both ends of the windmill blades.

Drill a large hole in the center of the metal disk and slide it onto the motor shaft. Secure it with glue or screws.

Cut a 4-foot board from the 2-by-4 wood board. Mount the generator and blades on one end and secure them to the wood with straps and screws.

Cut a rectangle out of the aluminum using the tin snips. Mount it on the opposite end of the wood and secure it with screws. The aluminum should be mounted with the edge facing up towards you. This serves as a weather vane for the windmill.

Secure a metal pipe fitting to the bottom of the wood. Drill a small hole through the fitting and wood. Pass the wires from the generator down through the hole and through the pipe fitting.

Use screws to attach the shorter length of the metal pipe to the longer pipe. Pass the wires through this fitting and set it inside the larger pipe.

Mount the windmill in an area with a draft or breeze to provide wind energy for it. Connect the battery.