Motor and Gearboxes lab

# Motor and Gearboxes lab - When Coef1 friction 1 we tested...

This preview shows pages 1–3. Sign up to view the full content.

Figure 1 Table 1 Friction Loss Coef of friction test 1. When we tested the motor by itself, we found it had an average speed of 16544 rpm, and used a current of 0.254 A. Then we applied a force to the motor and the speed decreased whereas the current consumption increased. Under stall condition the current consumption was 3.75 A. Next, we added the gearbox (101:1) and hex shaft (Figure 1). The speed of the hex shaft at this point was 145 rpm with a current of 0.41 A. Next, we added the flexible tube and Aluminum shaft to attach a load. We measured the speed/current with no load, with scissors (1.75 oz), and with a wrench (3.625 oz). Then we changed the gearbox ratio from 101:1 to 269:1 and repeated. Our values are recorded in Table 1. We calculated the torque by using the equation torque = force * radius. Both trials lifted the same force so the torque was the same; however, the speed and current were considerably lower in the 269:1 gearbox. 101 to 1 F (oz) R (in) T (in oz) speed (rpm) current (A) 1.75 0.125 0.21875 96.17 1.265 3.625 0.125 0.453125 77.2 1.84 0 0.125 0 109 0.955 269 to 1 1.75 0.125 0.21875 50.15 0.45 3.625 0.125 0.453125 46.67 0.567 0 0.125 0 58.6 0.38

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Above, we plotted speed (rpm) vs torque for the two different gearbox ratios. Based on our data, it is evident that the lower gearbox ratio has a much steeper slope that the higher gearbox ratio. With the lower gearbox ratio the speed was 96.17 rpm and the amperage was 1.265. The higher gearbox, on the other hand, was way down at 50.15 rpm and 0.45 amps with the same torque and voltage. It seems that as the gear ratio is increased, the speed decreases and the amps used decreases.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern