Easy DIY Homopolar Motor

Motors are great but making one is more fun. So in this instructable we’ll make our own and you only need common items and hand tools.

Homopolar motor was the first electrical motor to be built. Its operation was demonstrated by Michael Faraday in 1821 at the Royal Institution in London.

A homopolar motor is a direct current electric motor with two magnetic poles, the conductors of which always cut unidirectional lines of magnetic flux by rotating a conductor around a fixed axis so that the conductor is at right angles to a static magnetic field. The resulting EMF (Electromotive Force) being continuous in one direction, the homopolar motor needs no commutator but still requires slip rings.

For this instructable you need-

1. AA 1.5v cell (get more because they run out quickly)

2. Neodymium Magnets

3. Thick Copper wire

Tools-

1. Pliers

2. Wire cutter

3. Pipe or a cylindrical body with dia. more than the dia. of the cell (We are using a marker)

Place the battery on top of a stack of small

neodymium magnets, stacked high enough to leave a surface for the wire to contact.

Take the pipe and wrap the copper wire around it in spiral. The coil

must be a little longer than the length of the cell. It doesn’t matter much if you wrap it clockwise or counterclockwise.

Then remove the coil and cut it an inch longer from one side. Then bend it in the shape show in the photo and make sure that the tip is in centre.

Place the tip at the top of the battery and if the coil is too short, or too long, you can stretch or squeeze the coil until it's the proper height. Let the coil hang freely and see if the free end of the wire contacts the magnet below the battery.

If the free end of the wire contacts the magnet below the battery,

a current will pass through the wire, and if the wire has a light enough contact with the magnet, the wire will begin to move, either clockwise or counterclockwise, depending on the polarity of the magnets.

You can get creative by making your custom shapes of coils. Try different shapes like heart, butterfly, rectangle, diamond, circle, etc. Just keep in mind the following points:

1) The wire can be bent to form any shape but one end must be touching the positive terminal of the battery and the other end must be in contact with the neodymium magnet.

2) The key is to make a shape with the wire that allows it to balance properly, if it is unbalanced it will soon fall off the battery as it begins to spin.

3) Please be careful while making your own DIY homopolar motor as the wire and battery can become very hot.

4) Neodymium magnets are the strongest in the world that’s why you will often see a neodymium disc magnet used in this configuration. The stronger the magnet, the faster the coil will spin. If using an AA battery to make a homopolar motor an ideal magnet to use is a 12mm diameter x 6mm thick neodymium disc magnet.