Tuesday, February 19, 2013

• Fork: Connects motorcycle front wheel to frame. Part of suspension mechanism. Sort of like a front “shock absorber”
• Gator: Rubber part
• Stanchion: long, stainless-steel tubes (approx <1m) with brass slide movers
• Suspension: allows wheel to bounce up on uneven ground, but pushes wheel back ground. Makes rider comfortable.
• Keepers: A washers that pushes against the springs
• Rotor: 6-pole magnet that spins around the stator (series of metal coils) to produce a current
• “Spark advanced:” when the spark fires before the piston gets to the top. Reverses direction of crank shaft and leads to kickback. The opposite of this is when the spark is too retarded. Then there is too little power and too much exhaust.
• Trail: Distance between point of contact of the road and wheel and the the point of rotation (defined by the handlebars)

Recaps from 2/14 Lab

• Frame: Removed forks, gator, after spraying with Yield. Gator might need replacing. Stanchion was wobbly. Suspension was very greasy. Brake drums probably will be replaced because of asbestos
• Clutch: Had trouble removing frozen bolt that was stuck in engine casing. Prof. Littman had to grind down head of bolt to remove
• Top-End: Removed rocker arms, rods were caked in paint. Removed valve and one spring using Glenn’s special aluminum tool.
• Bottom-End: Removed cam and transmission. John explained mechanism of transmission and why Neutral is above 1st gear. Glenn made a new screw with his chisel
• Electrical: Measured frequency and voltage of rotor. Graph was perfectly linear.

Book Discussion:

* means Motorcycle Reference

Shop Class as Soulcraft

• Do we have control over own technology? There exist layers of bureaucracy between us and the machine. Companies have a vested interest in your technology working to give us free time and convenience. Does this truly grant us freedom?
• What are the “opportunity costs” of fixing something yourself? Is there something else intangible gained by giving up your time to learn how something works? Discussed Crawford’s view of economists as possibly dismissive.
• Passive User vs Skilled Use: examples of steroe vs guitar, hand pump oil on old motorcycles, Betty Crocker cake mix
• *Motorcycles shifted from cast-iron pistons to alumnium because engine speed is related to mass. Metal with less mass -> more efficient engine. Our bike has an aluminum piston.
• *Model-T Engine demonstration. Able to see series of alternating intake and exhaust valves. Engine is “square,” up and down movement is equally to the size of the diameter. Plugs fire in order of 1,2,4,3. Made with high school labor. It was super cool.

Zen and the Art of Motorcycle Maintenance

• *Hot and dry chains: need lubricant, because chain can break as it rubs on sprocket due to frictional heat and erosion. When accelerating, front side of sprockets get worn. When decelerating, back side of sprockets get worn.
• *Exhaust pipe gets blue, because chrome turns blue when heated.
• *Pistons, wheels, and gears all move at once (84).
• Further exploration of the analytic knife, examples of sand and dividing it by properties
• Analysis -> Loosening; Synthesis -> putting together
• Difference between precision and accuracy. Precision: cutting or marking into many divisions (“cision” means to cut). Accuracy: correctness or closest to outside standard (“curacy” meaning correctness).
• Plot Updates: better understanding of Phaedrus as the former personality of Narrator’s body. Removed via electric shock.
• Philosophy: Buddha and Twain. Something is lost when examining something from an analytic point of view, but something else is gained too. Twain may have felt he lost the beauty of the Mississippi when he learned how to pilot it, but another beauty of understanding is also gained. Buddha “exists within analytic thought, and gives that analytic thought its direction” (81).