To create a functioning motor.
Styrofoam cup, magnet, magnet wire, dry-erase marker, two paperclips, tape, and a plug-in AC adapter.
Notes & Observations
The paperclips have to be bent into small holders and taped to the sides of the cup. The magnet has to be placed on top.
The magnet wire has to be tightly coiled around the marker to create a dense ring. The tails must be wrapped around the ring to keep it from unwinding. Half of each end of wire must have its coating stripped away. The easiest way to do this is to shave it with an open pair of scissors. This structure, called an armature, must be rested on the paperclip holders as shown below.
Attach one wire from the AC adapter to each paperclip at the bottom and plug it in and the armature should start to spin as shown below.
What Problems (if any) did you have getting your motor to work? What did you do to fix the problems?
We had quite the fight with our motor. First, we tried shaving more of the coating off of the magnet wire, but that didn’t work. We had to ask for help. Our coil wasn’t balanced well, and as a result, it had a tendency to settle in in one position due to one side being heavier. The balance was still a little off. You can tell because of the way the armature jumps off of the stands. We also didn’t get the stands positioned quite right and we had to hold the magnet in position to get the coil to rotate.
The most glaring observation I made during this lab is how finicky the motor is. As you can tell by the paragraph above, we had a lot of trouble getting the motor to work. Even a small error will likely stop the motor from working. The positioning of the magnet and the balance of the coil both must be nearly exact for it to work right. Based on what I know about electricity and what I have observed during this lab, my understanding of how this motor works is as follows:
When electricity is is run through the paperclips and into the armature, it becomes magnetically charged. This makes it attracted to the magnet. Since half of the tails of the coil have an insulating coating, the coil in no longer magnetic when the bare wire isn’t touching the paper clips, causing gravity to pull it back into position. When the bare wire is touching the paperclips, the armature becomes magnetic again. This constant switching causes the coil to spin. Feel free to correct me if I am wrong about anything.