Chris_Mathews_-_Build_Your_Own_Motor_RA_-_10538633

pdf

School

Smith College *

*We aren’t endorsed by this school

Course

Subject

Mechanical Engineering

Date

Apr 3, 2024

Type

pdf

Pages

Uploaded by MegaSnailPerson191

Rubric for DC Motor RA Directions: You may answer the questions within the body of the text, but please use a different text color if you do so (nothing highlighter colored or difficult to read). If you prefer to answer the questions in a block at the end, be sure to match the number of your answer to the question. Completion of the motor build 20 pts /20 Demonstrated functionality of the motor (proved magnetism in the field coil) 10 pts /10 Question 1 10 pts /10 Question 2 10 pts /10 Question 3 10 pts /10 Question 4 10 pts /10 Question 5 10 pts /10 Question 6 10 pts /10 Conclusion 10 pts /10 Total 100 pts /100 1. What would be the effect on the motor of reversing the direction of the battery? Predict, then test it. What did you discover? It is safe to assume that the change in the battery’s direction in the DC motor will lead to a reverse current of the motor’s movement. This is because the current in the coil would reverse its direction, which changes the magnetic field that is illuminated by the electromagnetic field. 2. Explain the function of the commutator, and predict what would happen to the direction of rotation of the armature if the commutator were reversed. The commutator plays an important role by changing the direction of the current in the coil half-way round so that there is a constant rotational motion. Additionally, if the commutator were to be reversed, the armature would also rotate opposite to the direction, as the direction of the current flow through the coil would be inverted as well. 3. Explain how you are able to use an electromagnet to replace a fixed north-south pole. How does that electromagnet replicate the same effect - be specific, and discuss how the electromagnet works. The electromagnet was a great alternative because when electricity was passed from the battery, current flowed through the wire, and an electromagnetic field was created.

This was responsible for the magnetic effect of the wire because of the right-hand rule for current carrying wires. This caused the interaction with the permanent stationary magnetic, resulting in the rotation of the motor. 4. Suppose you were to short out the commutator by connecting wires from the brushes to the armature. Would the motor spin? If so, would it stop, and if so in what orientation? The motor would initially spin because of uninterrupted movement of the current flowing through the coil, but it would stop eventually and the orientation at which this happens would be random in my opinion. This happens because a commutator is essential for this motor to work and absence of this item wouldn’t cause the reversal of the current’s direction (a key component). Without that, the motor would eventually stop in a random position because there is no mechanism to maintain rotation. 5. What would be the effect of hooking the motor up to a higher voltage source, say 3-4 volts instead of the 1.5 V AA battery? You may use one of the DC power sources to test your hypothesis. Were you correct? Warning: do not leave the motor connected for lon My initial hypothesis was that an increase in voltage will result in higher motor speed and torque, producing a stronger magnetic field. This turned out to be correct, because these variables are directly proportional to one another and the stronger field will cause more rotation. 6. If you were to connect the motor to a significantly higher voltage source (9-12 V), what part do you think would be the first to fail, and why? Be sure to justify your answer… If this scenario happens, I believe that the [discuss with the group] would be the first to fail because it is one of the first components (in the DC motor) that receive the high voltage from the battery. The high current flow will cause damage to these wires by not only causing it to tear but also to demagnetize in certain situations. As a result, [this component] of the motor would fail and will result in the entire thing not working at all. 7. Conclusion, which should include the following: (What did you learn from the build, How would you do the build differently, knowing what you know now, What did you enjoy most about the project and What was your primary role in the build) I’m glad that the build was mostly successful. Getting the motor to work would have been the cherry on top, but I feel that the overall project was successful due to our incredible teamwork and coordination. This project opened my eyes to the idea of magnetism, and I couldn’t fathom the fact that a motor could run using current and a few wires. This helped me understand magnetism in general, but more specifically, the importance of torque that aided in this phenomenon. However, while this was a great learning experience, we made many mistakes along the way. One major error was that, while wrapping the wires, we spread them too much, and the wrapping could have been better and more compact, which I believe is the main reason why our motor didn’t work. Other than that, I believe that all the other parts were assembled correctly, and this is certainly a great lesson that will carry on to our future projects as a team. Lastly, this project was again a success, and I truly enjoyed the team aspect of the build. It was funny how we would be focused for some time and eventually become lazy; the swings during this lab

were something worth remembering. My group didn’t really have specific ‘roles’, and all of us instead worked hard together. That was the main defining characteristic that helped us finish the project on time.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version