Electric Motors Science Project

Where would we be without motors? Do you know the difference between a ‘motor’ and an ‘engine?’ An engine generates its own power, internally, like a steam engine. Burning fuel, whether it’s wood, coal or oil creates steam which is used to power the mechanism. A volatile substance ignited in a combustion chamber drives a piston which ultimately powers an automobile. But a motor uses energy which has been generated somewhere else and not in the mechanism, itself. An electric motor uses electricity which is not generated by the motor, but brought to it from a source such as a hydroelectric power generating station. Solar powered motors are becoming more common.

The electric motor operates on the principle of electro-magnetism. Basically, the principle is that an electric conductor passing through a magnetic field will generate an electric current in that conductor.

There are motors bigger than a house! There are motors small enough to go inside a wristwatch! Motors have revolutionized our lives in just over seventy years.

Can you name one hundred different kinds of motors before making the following one?

This motor consists of a battery, a magnet, and a small coil of wire.

You will need the following, which you can get at Radio Shack:

*A battery holder.

*A battery to fit the holder.

*A magnet.

*Some enamel coated 22 gauge magnet wires.

*Bare 18 or 20 gauge wire.

Make the armature, which is the part of the electric motor that moves. Use a form like a pen, pencil, or AAA battery. Wind 20 to 30 coils of wire around the form, leaving a couple of inches of wire free at one end. The diameter of the form should be proportional to the wire size: thin wire requires a small form; thick wire requires a larger form.

Carefully pull the wire off the form. Wrap each free end of the wire around the coil a couple of times. Make sure that the new binding turns are exactly opposite each other. Wrap the coils with wire so they will keep their shape. Have the two ends of the wire anchored well, and aligned in a straight line so they form a tight axel.

Strip the top half of the insulation from the free wire end. Be careful to leave the bottom half of the wire with the enamel insulation intact. The top half of the wire will be shiny bare copper, and the bottom half will be the color of the insulation.

Do the same thing to the other free wire end. The bare copper side should face up on both wire ends.

The armature is going to rest on two supports of bare wire. These supports will be attached to each end of the battery, so electricity can flow from one support into the armature and back through the other support to the battery. This will only happen when the bare half of the wire is facing down, touching the supports. When the bare copper half is facing up, the insulated half is touching the supports, and no current can flow.

The next step is to make the axle supports. These are simple loops of wire that hold up the armature and allow it to spin. They are made of bare wire, since they will also act to get electricity to the armature.

Take a stiff piece of bare wire (copper or brass will work, as will a straightened paper clip) and bend it around a small nail to make a loop in the middle. Do the same to another wire, so you have two supports.

The base for this first motor will be the battery holder. Attach the bare wire armature supports to the holes in the plastic base.

Wind the free ends of wire several times through the small holes in the plastic at each end. Bend the support wires so the rings are just far enough apart for the armature to spin freely. Bend them apart a little and insert the armature into both rings, then bend them back so they are close to the coil, but not touching it.

P.S. Insert a strip of paper in between the battery and the electrical contact in the holder. This is the on/off switch. Remove the paper to allow electricity to flow into the motor, and replace the paper when you want to stop the motor and save the battery.

Spin the armature gently to start the motor.