While the principles behind electric current and magnet […]
While the principles behind electric current and magnetic fields interacting can be a bit technical, building a basic engine is easy. We've hunted for the facts on how to build an electric motor most effectively, and we’ve got all the answers you need.
Winding the Coil
Tape together four pencils. Tape the pencils in a two by two cluster. This will give you something solid to wrap your coil around. You can substitute the pencils for a cylinder that’s roughly half an inch in diameter.
Wrap wire around the pencils. Once you have the pencils taped or find a suitable cylinder, begin wrapping your wire around it tightly. Start in the middle of the wire and wrap the coil fifteen times toward one end and fifteen times toward the other. Once you have finished wrapping the coil, remove the pencils from the middle. This will leave you with two loose leads at either end of the coil.
Loop the loose ends around the coil. Wrap the loose ends around either side of the coil three or four times. This will help keep the coil wound tightly. Point the remaining loose ends straight out away from the coil.
Connecting the Battery
Secure the battery. Use tape or clay to hold the battery in place on a flat surface like a tabletop or desk. This will allow you to connect it to the coil without having to hold it with your hands. Make sure the battery is laying on its side so that you can easily reach both terminals.
Strip the ends of the coil wire. Use wire strippers to remove the insulation on either end of the wire, but only one half of the insulation, such that the bare wire will be connected to the circuit only half the time. These leads will connect to the battery and allow current to flow through the coil. If you sand the wire all the way around, the wire will heat up or move back and forth, and the motor will not work.
Slide each end through the eye of a needle. A needle makes the perfect holder for the wire leads. Insert each end into the eye of a separate needle. You can also bend two paper clips (one for each side) to make a holder.
Tape the needles to the battery terminals. Once you have the wire in both needles, it’s time to hook your wire up to the battery. Tape one needle to the positive side of the battery (marked with a “+”). Tape the other needle to the negative side of the battery (marked with a “-”).
Be sure the needles are pointing with the sharp end down toward the battery and the eye at the top holding the coil.
Do not let either needle touch both sides of the battery.
Once both leads are connected, there will be an electric current running through the needles and the wire. It is best to use rubber or insulated gloves for this step.
Introducing the Magnet
Bring a magnet close to the coil. Once a current is flowing through the coil, it can interact with a magnet. Either hold the magnet close to the coil, or tape it to the battery right underneath the coil. The closer the magnet is to the coil the stronger it will interact.
Spin the coil. See what happens when you spin the coil. Depending on the direction the current is flowing and the side of the magnet that is interacting with the coil, the coil may continue to spin or may not. If the coil does not keep spinning, try spinning the other direction.
Experiment with different methods. Different variations will give you different results. The coil may spin faster, slower, or not at all if you change something. Try moving the magnet closer to or further from the coil, pick a stronger or weaker magnet, or use the other side of the magnet. These variations are a fun way to understand the forces in an electric motor.