When I was in first grade, I won my school’s science fair. It wasn’t too hard. All I did was build a Styrofoam model of the solar system, complete with the asteroid belt and all nine planets (yes, there were nine planets back then). I made a moon for the earth, I didn’t bother for all of the other planets. Saturn alone has 62 moons, so it would have taken me an extra week to build my model, and I think I forgot to mention the part that this project was based off of a last minute idea, conceived of at most two days before submissions were due. In subsequent years, I frequently at least placed in the school’s science fair, thanks to projects that included the building of a small-scale volcano and a dry ice experiment. One project that never would have occurred to me then, however, would have been the construction of a portable electric generator. Even up until recently that project would have seemed ludicrous to me. But it turns out that an individual can actually build his or her own generator in a quick and easy fashion. Now understand, using these steps, you won’t be able to build a generator that will be able to power your entire house in an emergency; the end product will be a low wattage generator. But this is a fun and educational project nonetheless.
The materials you will need include 500 feet of 22-28 gauge enameled copper wire, a four inch bar magnet, a steel rod that is twelve inches in length and has a quarter inch diameter, a cardboard tube with a four inch diameter, 24 inches of 1×4 lumber and two quarter inch flat washers.
The first step is to build a frame in the shape of a “U” to support the rotor. The rotor is the permanent bar magnet mounted on a steel shaft. To do this, cut the lumber into two six inch pieces and one 12 inch piece (inches in length), then nail the two pieces to the twelve inch piece at a perpendicular angle. This is when you need to drill two quarter inch holes in the two uprights of this frame. Make sure they align so that the steel rod will go through both without binding. Don’t put away the drill just yet; you’re going to need it again to drill another quarter inch hole through the center of the bar magnet, preferably on the widest side.
After the drilling, slide the metal shaft through one side of the frame and slide the magnet onto the shaft. This is when you should cut a four inch section of the cardboard tube. Then wind your copper wire around the tube and leave roughly 18 inches of wire loose on each end to connect to the device you wish to supply power to. For purposes of this hypothetical, let’s use a light bulb. The more winds you can get during this process, the more power you will produce. Now you should slide the tube over the shaft and magnet, and then slide that shaft through the other support frame. After this is done, glue the magnet to the shaft at the center of the two supports. Use the strongest glue you have at your disposal for this step. Now, support your cardboard cylinder with the wire windings at the center of the shaft with the bar magnet centered on the wire windings. You can build a wire frame from a coat hanger to do this. Now, you need to test it. Slowly turn the shaft with your fingers in order to see if the ends of the magnet hit the inside of the tube. If it spins freely, glue a washer on each end of the shaft, outside of the wood supports. Finally, attach the two wires that are loose at the end of the windings to the light bulb and spin the shaft as fast as possible. You now should have a low wattage electric generator.
That wasn’t too hard, was it? Like my solar system model, this can be done at the last minute as well. It will certainly impress any judges at any science fair, or any of your friends if you’re too old for science fairs.