Making an electric motor is a great way to illustrate the transfer of energy, and can make a great (if at times finicky) science project. There are many variations on this, so feel free to experiment on lengths, measurements, and supplies.

Your base just needs to be something that you can poke thumbtacks into without them poking through the bottom. Thick Styrofoam would work, but we used foam core and cork board, because we have more of that. Our base was about 12x15 cm (5x7 in), with a 10x17cm piece of cork board covering the area with the thumbtacks.

To make the motor holders, use a disposable cookie sheet or pie tin. Cut out two rectangles, about 2x5 cm (1x2 in). For each, fold the bottom centimeter (half inch) at a right angle, making two L shapes. Use one of the thumbtacks to poke a hole in each, about a half-centimeter (quarter-inch) from the top. While the exact measurements don’t matter, it is important that both holes are at the same height, so that the motor will be well-balanced.

The ceramic magnets can be found at Radio Shack or ordered online. Place the magnet on the base, and use the thumbtacks to position the L-shaped aluminum holders on either side of it, so that that they are facing away from the magnet.

The most important part of the motor is the loop of wire that will become an electromagnet. We used the lightest wire we have, 30-gagued magnet wire that can be found at Radio Shack. Use about two meters of it, and use sandpaper to remove the coating from both ends. Leaving the ends exposed, wrap the rest of the wire around the D battery or a film canister, then wrap the ends around the loop a few times to keep it together. You should be left with a circle with two wire ends sticking out across from each other.

Position the loop above the magnet and stick the ends of the wires through the holes in the aluminum. (Make sure the exposed part of the wire is in contact with the aluminum; if not, you will need to sand the wire some more.) Adjust the loop so that it is well balanced and, once started, will spin for a long time.

The last step involves connecting the battery. For this you will need two more pieces of “regular” insulated wire – the thickness doesn’t matter. Cut two pieces of wire approximately 10 cm (4 in) long, and use wire strippers to remove the coating from the ends. On one end of both wires, fold the exposed wire in half and “hook” it around a thumbtack on each side of the magnet. (You will probably need to lift up the thumbtacks part way to do this, then push them back down into place.) Lay the battery on the base, and connect the other ends of the wires to the positive and negative end of the battery. (If you want, you can tape one wire to the battery, but do not tape both as this will quickly drain the battery – and heat up the wire.)

Did your loop of wire start to spin? Often it will not on the first try, but you will see the loop stiffen its position because, with the electricity running through it, it is an electromagnet attracted or repelled from the permanent magnet below it. If it does this, give the motor a kick-start with your finger. The initial momentum is usually enough to keep the wire going on its own for quite some time. If this doesn’t work, check to make sure the electricity has a clear all-metal path from the battery, to the aluminum, through the loop, and back. Adjusting the balance of the loop can also help.

When your motor is working properly, it is transferring chemical energy to electrical energy in the battery, then electrical energy into magnetic energy in the loop, which causes it to turn into kinetic energy, the energy of motion.

You can experiment to see if the type or length of the wire makes a difference in the experiment. Or, you can try different kinds of batteries. If you have an improvement – or if you’re having technical difficulties – feel free to contact us!