How to Make a Simple Electric Generator

 Building a simple, low powered electric generator can be a fun science fair project, or just a workshop experiment for a would-be engineer. The parts are simple, inexpensive, and easy to find.

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Steps

1. 
   1
   Decide how large a project you are interested in building. There are design and engineering considerations that could be taken up, but for simplicity's sake, this article will give instructions for a simple, low output generator.
   
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2. 
   2
   Acquire the materials you will need. The sizes and specifications can be adjusted to raise the output capacity of your generator, but this is a basic overview of the project.
   

   • 22-28 ga. enameled copper wire. About 500 feet (152.4 m) will produce a modest electrical current. More "windings", coupled with a stronger magnet will increase the power output.
   • 3 or 4 inch (7.6 or 10.2 cm) bar magnet. (Should fit lengthwise in the cardboard tube, below, with a little clearance)
   • ¹⁄₄ inch (0.6 cm) diameter steel or aluminum rod, 12 inches (30.5 cm) in length.
   • 24 inches (61.0 cm) of 1X4 lumber.
   • 1 - large paper or cardboard tube, 4-inch (10-cm) diameter.
   • 2 - 1/4 inch (5.7 cm) flat washers.
3. 
   3
   Build a "U" shaped frame to support your "rotor", ie, the permanent bar magnet mounted on a steel shaft. by
   

   • Cut the 1X4 lumber into pieces, 2, at 6 inch (15.2 cm) lengths, one at 12 inches (30.5 cm) in length.
   • Nail or screw the two 6 inch (15.2 cm) boards to the 12 inch (30.5 cm) board at a perpendicular angle to the 12 inch (30.5 cm) board, which is the base for the rotor frame.
4. 
   4
   Drill two ¹⁄₄ inch (0.6 cm) holes in the two uprights of your frame, aligning them so that the ¹⁄₄ inch (0.6 cm) rod, (the rotor shaft) will go through both without binding.
5. 
   5
   Drill a ¹⁄₄ inch (0.6 cm) hole through the center of your bar magnet, on the flat, or widest side. Be careful to measure the center both in length and width, and drill perpendicularly, so that when the shaft goes through, the magnet will be "square" to the shaft.
6. 
   6
   Slide the metal shaft through one side of the support frame, slide the magnet onto the shaft.
7. 
   7
   Cut a 4 inch (10.2 cm) section of the paper or cardboard tube. If you don't have a piece of tubing available, you can make one by rolling a sheet of construction paper into a cylinder and gluing or taping it to secure it in this shape. The ideal diameter of the tube will be just large enough to allow the bar magnet to spin freely inside the tube, keeping the magnetic field as near the copper windings as possible.
8. 
   8
   Wind the copper wire around the cardboard or paper tube, leaving about 16 to 18 inches (40.6 to 45.7 cm) of wire loose on each end to connect to your power test device, an electric light bulb, or other device you will supply power to. The more "turns" or winds around the tube you make, the more power your generator should produce.
9. 
   9
   Slide the tube over the shaft and magnet, then slide the shaft on through the other support frame. You will want several inches of the shaft sticking through each end of the frame.
10. 
    10
    Glue the magnet to the shaft at the center of the two supports, using a high strength hot melt glue or epoxy. You may choose to drill and tap threads into the magnet for a "set screw" if you have the tools to do so, but the idea is for the magnet to be stationary in relation to the shaft. This will be inside of the paper tube later on.
11. 
    11
    Support the paper cylinder with the wire windings at the center of the shaft with the bar magnet centered on the wire windings. You may simply cut cardboard legs that can be glued to the cylinder, or build a wire frame from a coat hanger or similar stiff wire to accomplish this.
12. 
    12
    Turn the shaft with your fingers to see if the ends of the magnet hit the inside of the tube. It must turn freely, but be as close as possible to the tube. Again, having the magnet's ends as close the copper wire windings will increase the "exciting" action of the magnetic fields the magnet produces.
13. 
    13
    Glue a washer on each end of the shaft outside the wood supports.
14. 
    14
    Attach the two wires you have loose at the ends of the windings to a flashlight bulb or other low voltage lamp, or connect the test leads from a voltmeter or multimeter to them.
15. 
    15
    Spin the shaft as fast as possible. You may want to wind a string around the end of the shaft as you would a toy "top", then pull it sharply, or just spin it with your fingers. You should get a small voltage, enough to light a 1.5 volt light bulb by manually spinning the shaft.