Building a No-Frills Motor

The Idea

In this project you will build a very basic electric motor. This project has been broken down into a number of steps for clarity, but the overall device is simple. It's like assembling a barbeque grill— the first time you do it may take a little longer, but once you get the overall idea, it gets easier each time. It takes just a few minutes to build, but it can keep running until the battery runs out.

What You Need

• C or D cell battery
• ceramic disc magnet
• 1 meter of enamel-coated (thin) 22 American Wire Gauge (AWG) wire. It is much easier to work with red or green coated enamel, rather than clear-coated
• 2 paper clips or a few inches of at least 20 AWG wire
• electrical tape
• optional: battery holder, Styrofoam cup

Method

1. Wind about 25–30 turns of the 22 gauge wire around a cylindrical coil form, such as a ballpoint pen or a small AAA battery.
2. Leave a few of inches of wire free at each end.
3. Pull the coil off the form you wound it around. Be careful and hold the wire, so it doesn't spring out of shape (it doesn't have to be perfect to work).
4. Weave each of the ends of the wire around the coil a few times to hold the coil together. This becomes the armature of the motor. If you prefer, you can also use tape to help keep the coil together.
5. The ends of the wire should be placed in a straight line to make a good axle. It can help if you double back, so the end sections consist of more than one thickness of wire. It also helps to over wrap the ends with the last segment of wire or tape.
6. Using a utility knife, remove the insulation from the top half of the 22 gauge wire at both ends. You can also use sandpaper to do this. If the wire is coated with a colored layer, you can see when the insulation has been removed. If the wire is clear-coated, you must be more careful and keep track of where you are removing the insulation. Do not remove the insulation from the bottom half of the wire.
7. When you finish, the side with the insulation removed must remain facing up on both ends. 8. Make an armature support by first forming the paper clips into a loop. If you are using wire, remove insulation from each of two 1½-inch sections of wire and form a small circular loop about 1 millimeter in diameter in the center of each wire. A nail can serve as a good form to wrap the loop.
8. Bend the wires to form a shape like a wishbone with the wire ends separated by a few millimeters.
9. The two ends of the coils should easily fit into the armature supports and should be able to turn freely.
10. Secure the armature support wires to the battery holder with tape.
11. Establish electrical contact between the armature supports and the positive and negative terminals of the battery holder. You may need to use jumper wires to do this.
12. Insert the ends of the armature (coil) into the holes of the armature supports. The armature supports should be spaced far enough apart so the coil is supported at both ends.
13. Tape the battery to the top of the cup or insert the battery into the holder.
14. Attach the magnet to the top of the battery holder just underneath the coil. Use tape or Velcro to do this. Make sure the coil can still spin easily and that it is just above the magnet. It may be necessary to raise or lower the armature supports to attain the correct height above the magnet.
15. Spin the armature gently to get the motor started. If it doesn't start spinning, try spinning it in the other direction. It will only spin in one direction.

This may sound like a lot of steps, but it is very simple, as shown by Figure 113-2, which shows what this motor looks like when it is all assembled.

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