How to Build a Simple Electric Motor

It is important that your coil is as symmetrical as possible.

Make sure the two wires extend from the coil on opposite sides.

Disconnect your battery for 1 minute before touching the coil.
The coil might be hot.

 

Electric motors are used in tape recorders, toys, robots and thousands of other appliances and tools. A typical battery operated electric motor uses both permanent magnets and electromagnets. The magnets are arranged such that one magnet "chases" the other magnet in a circular motion.

Supplies:
- 2 pieces 2 cm X 6 cm of thin aluminum (cut from thin aluminum cookie sheets)
- 1.5 meters of magnet wire (24 or 25 guage, Radio Shack #278-1345)
- 2 metal tacks
- 2 lengths copper wire, 15 cm (Radio Shack #278-1306)
- 1 ring magnet (Radio Shack #64-1885)
- 1 AA battery (Do not use any battery rated above 1.5 volts, overheating of coil will result)
- 1 block of wood, 6 cm X 15 cm
- small piece sandpaper, 1 elastic band.

Procedure:
Wind the magnet wire around the battery to form a ring. Leave 6 cm of each end extended. Carefully slide the coil of wire off of the battery. Wind the two ends around the coil three times, they will hold it together. You should have 2 cm of wire sticking out each side of the coil. Sand all of the insulation off of these two ends. Make sure the two wires extend from the coil opposite the centre.

Bend aluminum strips to size and shape indicated on drawing. Push a pin through the centre of the folded end as indicated on drawing. Use thumb tacks to pin these two brackets to the wood block. Make sure the magnet will fit easily between the brackets and connect the two battery wires as shown (make sure the plastic is removed from each end of the battery wires).
Slip each end of coil wires into pinholes on aluminum brackets. Place magnet underneath coil. Connect battery to wires using an elastic band. The coil should attempt to turn, give it a gentle spin to start it.

The coil will get hot, disconnect battery and let it cool before touching.

Finished Motor
My motor won't work!
- Check the sanding on your coil wires. Both wires should be bare metal. If your coil is not hot then more sanding is needed, you need a new battery or the battery wires are not connected properly.
- Make sure your coil is balanced and that your brackets are solid.
- A freshly charged battery is important.
Going Further:
- Experiment with adding more magnets to your motor. Does this improve it's performance?

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Projects developed by Carol and Wayne Campbell, Hila Science Camp
Comments? e-mail:  hila@hilaroad.com