Wednesday, April 23, 2014

Problems and Conclusion

Despite the fact we were given instructions for this project, I've somehow managed to run into problems that have made my motor unable to work. Here I will describe the problems I faced while trying to succeed in making a working motor.

I found trouble mainly with the commutator and the field magnet. When I finally finished putting the parts of my motor together, I found that I could not make an electrical current from the base magnet. In order to solve this problem I tried re-wrapping the wire on the base magnet. However, I still was unable to find the solution to this problem. Then, I tried fixing the commutator. I had a bigger gap between the copper pieces, so I tried to make the gap slightly smaller to try and fix it. I also made sure that my wires were secure, but alas, it was not enough to revive my motor and bring it to life.

Final Words

Overall, I found that I could not get my motor to work. I troubleshooted for solutions to the problems I faced, but I couldn't find out what was wrong with my motor. This should have been an easier project, but the fact that it took my wire two weeks to ship in and I could not start my project until later made it harder to take my time in doing this project. I enjoyed learning about how a motor should work and I liked seeing that bringing all of these random objects together could create a small motor. Even though I never was able to feel the proud moment when my motor finally worked, I still had a pretty fun time building the motor.If I could change what I would do next time is... well a lot. I would have gone out and bought the wire where I needed it or paid express shipping on my wire so that I could get started earlier, get all needed supplies in the first week to start building right away, and to find multiple sources of information on how to build a motor rather than just the instructions given.


Parts of my Electric Motor

In this simple motor, there are four main components: the field/base magnet, the armature, the commutator, and brushes. Even though I did not follow the instructions word for word because I found that there were better ways that I supplemented.

The first part of the motor is the field magnet. The field magnet is created by making a "U" shape by using two L brackets or bending the metal into shape and part them about 3-4 inches apart. After that take low gauge wire, probably lamp wire or 16 gauge wire should work. Wrap the wire around the two brackets 400 times, but leave extra wire at the end in the beginning and at the end so you have two pieces of wire sticking out and strip the enamel off about a half an inch on both sides. When you're done wrapping, then use electrical tape to secure the wiring.

Next comes the armature. Tape two 3 and a half inch nails together with electrical tape, find the center, and stick a metal rod through. Then, take higher gauge wire, probably 24 or so, and wrap to the right leaving gaps in between each wind, that way on the way back once you reach the end of the nail you aren't overlapping. Then, wind back and forth and back and forth until you've layered it four times. Make sure to keep the wrapping neat and take your time no matter how long it takes and to leave two wires sticking out at the end like with the field magnet.

Next is the commutator. Take an old wine cork and take the copper (the one that Mr. Bostian gives to you) and cut it into two parts.Use electrical tape to tape the two pieces on both sides of the cork leaving two centimeter wide gaps in between them. Make sure you tape the two wires from the armature onto the copper pieces.

Lastly is the brushes. Take two foot long strings of multi-strand lamp wire and strip the plastic wrapping off about a half an inch from both sides. Then attach alligator clips to the ends. Then all of your pieces should be done and you are pretty much ready to go!

Oh and you need a spool with some string on it to help pull the toy car.


Tuesday, April 22, 2014

Electric Motors

The main function of electric motors is to convert electromagnetic energy into mechanical energy. The history of motors began when the fundamentals of electromagnetic induction was introduced. In the early 1800's, three popular scientists named Oersted, Faraday, and Gauss came up with the basic concept of electromagnetic induction.



In the year 1820, Andre Ampere and Hans Oersted discovered that electric current produces magnetic field. Then, ten years later in 1830, Ampere, Oersted, and many other scientists were able to create the basic DC motor.

In addition, another person who contributed a lot to the fundamentals of electromagnetic induction was Michael Faraday. In the year 1831, he discovered electromagnetic induction, which is the concept behind the generator, or a motor like ours. This was a huge achievement for enabling electricity to become better understood by scientists. Faraday built inventions that created what he called electromagnetic rotation, or circular motion from the circular magnetic force around a wire. After he found out this concept, he began experimenting which later resulted in his discovery of electromagnetic induction. Faraday's drive to learn more about electricity came from his desire to disprove what Hans Oersted speculated. One of Faraday's inventions included a dish of mercury with a fixed magnet in the middle, a wire hung above the dish, and a battery to connect the circuit. This was one of the first electric motors. A diagram of this invention is shown below.


After the initial invention of the electric motor, then the expansion began. Ten years after the first motor was built, a scientist named Joseph Henry improved on the motor. He created a motor where the rotating part was an electromagnet with a horizontal axis. The motion resulted in two vertical, permanent magnets that repelled and attracted one another as it swayed. This motion made the magnet swing back and forth at 75 cycles per minute. Joseph Henry's edition of the motor is shown below.


Then, in 1828, William Sturgeon came out with an invention that changed the way motors worked; he invented the commutator. In fact, he is credited with the invention of the first rotary electric motor.