Month: February 2019

Last Lab Recap

Detailing: Went down into shop and looked at hubs with the wheel group, then went back to sanding the oil and gas tanks. They also experimented with the grit of the sandpaper (600, 800, + 1000 grit).

Electrical: Learned how to sauter: how to cut the wires, take out the insulation, and solder them together. Also looked at the wiring harness.

Top and Bottom End: Wanted to check the oil pump system, but to do that they had to remove the gears. They also learned why the clutch plates are designed the way they are and that there is a duplex chain on our motorcycle.

Frame: Started by disassembling the fork, then they degreased the parts. Today, they’re going to put them through the part cleaner in the shop.

Wheels: Sanded the hubs

 

Finding Top Speed of the Motorcycle

Problem: There is a chain connecting the crankshaft to the clutchbasket. There are two sprockets connected to the clutchbasket; in the highest gear these two sprockets spring together. That will turn the rear wheel. We want to figure out how fast the rear wheel is spinning when the crank is 6000rpm (top engine rpm). The second thing we want to figure out is how fast would the motorcycle be going at that pace.

Answer: The motorcycle is going 60mph.

A sprocket engaging with the chain (meshes with the chain); a gear has teeth, which look very similar to the procket, and they mesh with another gear, so there’s a point of contact and when you turn one, you end up turning another (involute shape, roll on one another).

Reading Discussion

• Discussion Leader: Charles
• Chapter 11: Wake up and have a nice morning in the hotel, decide to take a different route which goes by Yellowstone Park, talks about Phaedrus and lateral truth, then goes into Phaedrus’s history in the army in Korea.
  • P.124, engine backfires because there wasn’t enough oxygen. Backfiring through the intake can be harmful; the flame will burn all the fuel in the intake all the way up to the carburetor, creating a volume of air with no air and no fuel. This means the engine runs lean and if this keeps happening, the engine can stall out. Higher than normal engine temperatures, the engine being deaccelerated too quickly, too much alcohol in the fuel, etc. can all cause backfire.
  • A priori motorcycle: Narrator explains that Hume’s approach got Kant thinking. Kant introduces the idea of reason. A priori is knowledge that’s theoretical; for example, when driving a motorcycle you know that gas is being used. Even though you can’t see or sense it, you know it’s happening and can reason that gas is being used.
• Chapter 12: Wake up in the hotel again and start talking about the DeWeeses, who they’re going to stay with the next day. The narrator starts talking about how Phaedrus knew them in college.
  • A lot of electrical problems are mechanical: if something’s not working, shake it.
• Chapter 13: They’re going to Boseman. The narrator talks about how he tried to discredit the university he worked with and his students disagreed with him. He describes what the mission of the university is: to seek truth.

Last Class Lab Recap

Bottom and Top End: They continued to take apart the engine. They took off another cover and started looking in to see what was happening on timing side; some weird pieces were found and they dug into the manuals to figure out how to get a couple pieces out. They also removed the cam. There was a problem with a piece near the transmission; there was a nut and when it turned with a wrench, the whole engine turned. A pin was needed to lock the flywheel so they could turn the nut. Also, the engine was identified as dry sump, meaning that the motorcycle was not circulating oil. Compared rotation of crank to rotation of rear sprocket (last class). Close ratio transmission

Transmission: A set of gears that is between the crankshaft and the wheels. It allows you to improve the mechanical advantage going from the engine to the wheel. For example, bikes have a low and high gear; low gear lets you get up a hill and high gear lets you go fast. The transmission does the same thing for a motorcycle.

Electrical and Wheels: Read power generator section of the manual, then went outside, filled the generator with oil and fuel and got it running. The manual says don’t operate without grounding it, but they did it anyway. The manual says that as a disclaimer, since grounding makes certain that you never get a shock.

Frame: Told to either powdercoat or bondo the hubs. Al said that the indents were less than 1/16th of an inch so they just used putty. Glen was skeptical about this solution.

Detailing: Sanded down the headlight, oil and gas tanks to clean off the paint and take off orange peel. They wet-sanded so that grit wouldn’t fill up the sandpaper. However, a thicker grit would make sure the paint sticks; on a smooth surface, the paint won’t stick as well. The wet sanding will leave a smooth finish, so they’ll need primer to make sure that the paint sticks.

Reading Discussion

• Discussion Leader: Maya
• Chapter 8 Summary: They’re in Montana. They get in really exhausted and the innkeeper doesn’t understand them because they’re acting loopy. He spends a lot of time fixing the motorcycle and describes the difference between classical and romantic. They like the town and there’s a part where he goes to buy the jets.
  • P. 96 tappet adjustment: He was tuning the motorcycle because he heard a noise that sounded like a loose tappet. Since they were at a higher altitude, the elevation made the engine richer. He finds that the porcelain inside the plugs is dark which means the engine is running rich; then he went to go check the cylinders to see which one it was.
  • He was afraid that the connecting rod would tear itself free and destroy the engine.
  • Also mentioned that jets needed to be changed in the carburetor. At high altitude, there is less oxygen, and putting in too much fuel causes the engine to run rich. He put in a smaller jet to have the correct balance of air and fuel.
• Chapter 9 Summary: Primarily focuses on the scientific method, but near the end they narrowly avoid getting into an accident.
  • P. 104, misfiring of the engine is caused by bumps in the road: Bumps can cause misfires in multiple ways; for example, creating bad electrical contact, causing the throttle can open briefly, etc.
  • P. 107 Induction vs. Deduction. He talks about testing the battery to figure out what’s happening in the electrical system.
  • He talks about the scientific method and how to create a hypotheses.
    • “Asks the right questions, choose the right tests, and draw the right conclusions”
• Chapter 10 Summary: This chapter was about Phaedrus and how he was successful in school because he wanted to understand science. However, he moved on to philosophy to understand the questions science couldn’t answer and ends up being expelled from school.
  • P.113, Discusses how science is always advancing

Electricity Demo

• Voltage can be produced with a moving magnet. You would find that the signal goes positive to negative and back to positve. When the field is increasing, it is positive and when it is decreasing, it is negative. Diodes on this model lets current go in only one direction.
• There are three sets of coils. To run the motorcycle ignition system, you only need one set. Another set is needed for the lights and another for the horn.
• Self-Induction
• Energy can be stored in an inductor
• There is simulation software for the Electrical team that can help with planning for the motorcycle

Readings for Thursday: Chapters 11-13

Last Class Lab Recap