Introduction: Homopolar Motor

My goal of this project is to learn about homopolar motors. I also want to learn about magnetic fields and how they work with homopolar motors. I hope to create a motor using only a battery, a wire and a magnet. The electricity will cause the wire to spin.

Step 1: What Is a Homopolar Motor

The kind of electromagnetic motor I’m building is a homopolar motor. A homopolar motor is a direct current electric motor which produces consistent circular motion. The basic parts of a homopolar motor are: a battery, a magnet and a coil wire

Step 2: How a Homopolar Motor Works

A homopolar motor works by creating electric currents. The current moves from the positive side of the battery into the negative side of the battery and then into the magnet. This electricity makes the wire spin.

Step 3: Materials/Tools Used


  • Battery
  • Magnet
  • Copper Wire
  • Sandpaper.


  • Wire Cutters
  • Tweezers

Step 4: Methods

Here are the methods I used to create my motor:

  • Gathered materials
  • Cut the wire to make it the right size for my square.
  • Used sandpaper to remove the wire coating on the two ends.
  • Pinched the wire to make a point, so the wire could stand on the battery.
  • Bent the wire into a square shape.
  • Make curves in the wire at the ends so they could go around the magnet.
  • Cut off the extra length
  • Fit the wire on the battery

Step 5: Building Process

Here are pictures of the steps in my building process

1. This is me cutting the wire to make it the right size for my square.

2. This is me sanding the wire to get the coating off the wire. This will help the electrons flow easier

3. Now I am pinching the middle to make a point to sit on the battery.

4. Here I am shaping the wire into a square.

5. Here I am cutting the extra wire off.

6. Here I am testing the Motor.

Step 6: My Final Product

Here is a picture of my final product. I used a C battery and shaped the thinner wire into a square. I used the thinner wire because I found it made the motor go faster.

Step 7: Resources

I used the videos above and the instructable website below to help me learn about homopolar motors.

Step 8: Testing My Motor

I tested my motor using two different size batteries and two different wire sizes.

Here is the first video of me using the thicker wire. As you can see, the wire spins, but it’s spinning pretty slowly.

Here is the second video of my testing. In this video I modified the size wire that I used. As you can see, the wire spins a lot faster with this size wire than the thicker one.

Step 9: Modifications

The modifications I used on my homopolar motor was to try changing the battery size and the wire size. My first modification was to try using a different battery size. I tried both a C battery and a D battery. The size of the battery did not change the speed of my motor. I learned the battery size did not make a difference because both batteries have the same voltage, 1.5 volts.Therefore, this modification was not needed.

My second modification was to try different size wires. I started with a thicker wire and found that the motor worked, however it wasn’t spinning too fast. I tried using a thinner wire, and was very happy with the results as I watched my square spin faster.