Week 10: Thursday Scribe Notes

Recap of Last Week’s Lab

• Detailing: Primed the oil and gas tank, they are painting today.

• Frame: Got the seat done!

• Wheels: Finished one of the wheels with Bill Becker.

• Top-End: Finished assembling the carburetor, fixed the exhaust pipe, and put the blue bike back together.

• Bottom End: Didn’t put in the sprocket, therefore had to unseal the case again and put it in.

• Electrical: Drilled hole in the case cover then re-attached it back on to the bike and tested it.

Representation:

• What happens to the rear wheel when you just accelerate? What happens to the tension in the chain? The tension goes up on the top.
• Spring arm allows the whole wheel to bounce up and down.
• Braking locks the hub and causes the whole assembly to twist.
  • If not designed well, it will snap. In a previous year, it snapped (due to large stress). Glen drew the part and 3D printed it. Then, manufactured it out of high steel aluminum.
• Another year found that the last gear on the lay shift is missing a tooth. Believe it case hardened.
• Involute curve:
  • It has the property, when the gears are matching, one tooth rolls on the other. By having the right shape, you have a low mechanical loss. Sliding causes friction loss.
• Friction
  • Clutch plates
  • Coefficient of friction
    • F = (Mu) * N
      • F = force of static friction.
      • Mu = coefficient of static friction.
      • N = normal force.
  • To calculate theta, the coefficient of friction.
    • Mu = tan(theta)
• Friction is important in the motorcycle, without friction motorcycle would not go.