Category: Scribe Notes

I. GFCI Outlets

1. GFCI stands for ground fault circuit interruptor.
2. The outlet works by sensing the current flowing in both the neutral (return) and live (outbound) wires.
3. If the current differs by a given amount, this indicates that current is flowing to ground through another medium (i.e. you), and the outlet will break the circuit in hopes of saving your life.
4. GFCI outlets are required in all U.S. kitchens and bathrooms.

II. Recap from Monday

1. Carburetor Group
   1. Brought the ’58 motorcycle to the machine shop with Glen and “did a lot of weighing.”
   2. They couldn’t get this cycle started due to a spark plug issue they’re hoping to diagnose today.
2. Detailing Group
   1. Learned about the intricacies of combustion engines with Glen, realizing just how many things have to work cohesively at the same time for successful operation.
   2. Prepped many parts for painting using a “sandable” primer.
3. Engine Group
   1. Sorted a lot of nuts and bolts in hopes of finding Whitworth hardware in the miscellaneous bin.
   2. Discovered that one of the downsides of fine threads (like Whitwork bolts) is an increased possibility of cross threading.
   3. Put the carburetor back on the blue motorcycle to get it running and check for leaks.
4. Front Fork Group
   1. Restrictor rod was stuck in the bottom of the frame tubing, but they were able to remove it with the help of Professor Littman
5. Fluids
   1. Continued taking apart the engine on the green cycle.
   2. Still trying to access the oil pumps on this cycle.
   3. Learned about the three different fluid chambers/compartments that oil flows through.
6. Frame Group
   1. Accidentally bent the swing arm on the frame while using the hydraulic press.
   2. Will hopefully fix this issue today or figure out another solution.
7. Electrical
   1. Learned about the GFCI outlets as mentioned above and fixed a broken one in the lab.
   2. This outlet uses torx screw heads, which is an uncommon head type that is used for security purposes and anti-tampering.
   3. Found out that the horn they found does work, but it sounds impressively wimpy.

III. How Fast Can the Motorcycle Go?

1. Maximum Speed
   1. The theoretical maximum speed can be determined using the engines RPM at maximum power output and the radius of the rear wheel.
   2. @ 6000RPM, a gearing ratio of about 6.35, and a rear wheel radius of 1ft, we calculated the theoretical max speed to be about 98 feet/second.
2. Friction
   1. The maximum power the cycle can transmit to the road is dependent on the frictional force that prevents the wheel from slipping.
   2. The frictional force can be calculated by multiplying the normal force of the ground on an object by the coefficient of friction (μ).
   3. The coefficient of friction is about 1 between dry asphalt and a rubber tire, and about .2 for metal on metal.
   4. Using our friction calculations, we found that, theoretically, the cycle could accelerate to 60mph in 6 seconds.
   5. In general, an AWD/4WD vehicle will have more friction and be able to accelerate faster than a 2WD vehicle.

IV. Discussion on Zen Chapters 10, 11, and 12

1. Chapter 10
   1. “Science is a temple” and Phaedrus uses it for “escapism into rationality”
   2. Phaedrus was expelled from his university at age 17.
2. Chapter 11
   1. As you increase in altitude, there is less oxygen in the air so the engine can’t intake enough to keep up with normal fuel intake. You have to adjust the amount of fuel accordingly based on altitude.
   2. A Backfire is an explosion outside of the engine either in the intake or the exhaust.
   3. If the cycle backfires in the exhaust, it’s running too rich on fuel. If the cycle backfires in the intake, it’s running too lean on fuel.
   4. Kant and Hume in connection to motorcycle maintenance. A key highlight was the idea that knowledge is a result of the senses.
3. Chapter 12
   1. The character Deweese was introduced, who is an old friend of Phaedrus (who no longer exists in the literary present).
   2. Chris is nervous to interact with Deweese given the awkward nature of his father’s relationship with the man.
   3. Talked about the Meta nature of the book, especially when the author attempts to justify not giving John or Sylvia a significant backstory.

I. Announcements

1. Professor Littman rearranged some of the groups’ responsibilities and focuses. (see the Teams page)
2. A spark plug observations guide was added to the FRS 106 Website, along with a Carburetor Tuning Manual
3. A new frame was purchased on eBay along with grips and some other accessories.

II. Recap from Last Wednesday

1. Engine Group
   1. Oil was still leaking from the blue motorcycle, so they emptied the oil and replaced a screw and gasket that was overtightened and stripped last year.
   2. Oil was also refilled at the end of lab.
2. Fluids Group
   1. Worked on removing the timing cover on the orange motorcycle.
3. Detailing Group
   1. Looked for new handlebar parts.
   2. Found a method of searching the internet (eBay in specific) using part numbers from the manual.
4. Electrical Group
   1. Learned how a bridge rectifier works (converts Alternating Current to Direct Current [AC to DC]).
5. Frame Group
   1. Attempted to use the hand press and hydraulic press, and learned many useful tips for the future
6. Front Fork Group
   1. Completed a catalog of most pertinent parts and determined each part’s purpose.
   2. Ready to clean everything today.
   3. Learned about the difference between normal springs and progressive springs (on progressive springs, the spring constant changes during the compression process).
7. Carburetor Group
   1. Discovered a fitting issue with one of the carburetors and will work on the motorcycle it came from today.

III. Technical Concepts

1. Gear Ratios
   1. The gear ratios technical data sheet is now posted on the website.
   2. In our drive train, the gears change from small to large twice, effectively reducing the amount of revolutions per minute by the time the power gets to the rear wheel.
   3. In its simplest form, the power flows through these four components in this order : 1) Engine, 2) Clutch Basket, 3) Gearbox, 4) Rear Wheel
2. Spark Plug Operation
   1. The crankshaft’s rotation induces a current in a series of wire coils that powers many of the motorcycle’s components, most importantly, the spark plug.
   2. The voltage produced by the engine is relatively small, but is boosted by a transformer to be able to bridge the gap in the plug and create the all important spark.
   3. The points mechanism is what controls the frequency of the spark based on the engine’s rotation and the position of the piston in the barrel.
   4. The color of the spark can also indicate the health of the spark plugs, as a blue spark represents a hotter, more effective spark, whereas a red spark represents a cooler, less powerful spark.

IV. Discussion on Zen Chapters 7, 8, and 9

1. Highlighted Concepts
   1. Dumb Questions Prevent Dumb Mistakes
   2. Inductive vs. Deductive Reasoning
   3. The Scientific Method has its place in many facets of life, especially when a difficult problem occurs in motorcycle maintenance.

 

 

We started out class by going around and sharing something we learned about or worked on on Monday. Some things we discussed included:

• What is the sand blaster? (it removes paint, rust, and other materials in order to prepare a surface)
• one group cleaned up an oil leak
• one group counted piston movements during a wheel rotation to see what type of engine they were working with
• why wet sand? (prevents overheating and clogging the sandpaper)

Then, we watched a video about motorcycle mechanic and enthusiast Adam Cramer

We discussed the reading for class from Zen and the Art of Motorcycle Maintenance

• Chapter 4:
  • about the tools and equipment that the group brought on the road
    • we passed around examples of such gear
  • how motorcycles gain personality over time
  • the difference between seeing the world from a motorcycle and from the inside of a car
• Chapter 5:
  • Robert’s suggestion of using a beer can to fix a handle vs. John’s distaste for such a solution
  • How the sound of a motorcycle tells you a lot about how it’s running
  • The different views of reality that John and Robert each hold
• Chapter 6:
  • Robert introduces Phaedrus and his views on classical vs. romanic understandings
    • classical is a breakdown of how things work, very technical
    • romantic takes things for how they appear

We started out the class by going around and each student sharing something they learned last week. Some topics included:

• What “running rich” and “running lean” mean
• The design of a carburetor
• A 2 stroke engine vs. a 4 stroke engine

Next, we observed a model of a 4 stroke engine (based on Henry Ford’s Model T) made out of building toys that allowed us to see each step of the process

• intake, compression, power, and exhaust

We then started to discuss the chapters of Zen and the Art of Motorcycle Maintenance we read for class

• Chapter 1: introduces the conflicting attitudes towards motorcycles held by John vs. the narrator
  • themes: what is best? how do you do a good job in your work?
  • motorcycle references: dealing with an engine that is choking
• Chapter 2: the narrator’s experience with mechanics messing up his bike
  • themes: taking pride and ownership in your work
  • motorcycle references: the role of tappets and difficulties with spark plugs
• Chapter 3: the group encounters a bad storm on the roads and the narrator discusses ghost stories
  • themes: how do the scientific and fantastic interact?
  • motorcycle references: how to deal with adverse conditions on the road and the role of instinct connecting you to your bike

Feb. 3

Learning objectives

1. Science behind motorcycles
   1. Structures
   2. Machines
   3. Networks
   4. Processes
2. How to fix your own stuff
3. Compare motorcycles w/ auto
4. Learn tools
5. Dynamics
6. Philosophy
7. Figure out what you like
8. Compare evolution of motorcycle
9. Evaluating design
10. Manual tabor
11. Teamwork

Shop class as soulcraft (second six weeks) —> importance of manual labor

• Focus on motorcycle references

Zen and the art of motorcycle maintenance (first part of course) —> some philosophy

Triumph Tiger Cub —> Notes from readings

• 200 cc (cubic centimeters: cylinder capacity)
• Two-stroke engines (more powerful than four)
• Fork: structure that holds wheel
• Ignition points: where fuel and air mixture are ignited by spark — timed by ignition points
  • Advanced: piston going up when spark fired
  • Retarded: piston already going down when fired (ex. Model T)
• Flaw: top Fram tub flower than normal, so fuel tank needs to support headstock
• Seizure: piston expands & locks into place (due to seating)
• 4 strokes: intake, compression, power, exhaust
• Overhead valve: valves above piston —> has knicks to make room for valve

Feb. 5

Three chapters of reading per class (+ preface & intro for 2/10), no reading over midterms

Categories (9 groups of two)

1. Clutch & clutch cable
2. Transmission & chains & sprocket
3. Top end – valves, rockers, barrel, piston
4. Fluids – oil, gasoline
5. Carburetor & throttle & cables
6. Detailing – painting
7. Front fork & steering
8. Frame & brakes & wheels
9. Electrical

To use website

1. Log in
2. New post
3. Click uncategorized for post to show up under diary

Scribes (by week)

1) Jen

2) Cecilia

3) Jake

4) Kaixing

5) Rupert

6) Barry

Web: Ben

Photographers

Week 1-3) Annie

            4-6) Kate

Unfamiliar terms (& more) in reading

• Dry sump lubrication system – no oil splashing around
  • Better seal on piston rings, separates oil from air in tank, ^ performance
• Rockers & rockerboxes
  • Pushrods open valves (intake, compression, power, exhaust)
• Cast iron barrel w/ no sleeve
  • Advantage: works better, disadvantage: heavy
  • Air-fooled: if gets too hot, m can auto-ignite (fire w/o spark plug)
• Rectifier (goes together w/ coil): electric device w/ one-way valve
  • Convert AC (alternating current) to DC (direct current)
• Front brakes more effective than back brakes
  • Bc forces push downward into ground from front wheel
• Two types of brakes: drum (can lock up) & disk (can get wet & will then work less effectively)

*will do online training and assign people to groups in lab

____________________________________________

Notes as Pictures

Day 1: Objectives & Intro to Tiger Cub

Day 2: Groups and Roles for First 6 weeks

Day 2 (Continued): Discussion on Reading

Hi everyone, I’m Benjamin Benjadol, web person for the first six weeks of FRS106 Spring 2020. This site is where notes and media will be posted throughout the semester. I’m excited to begin my semester-long career of being a professionally amateur motorcycle mechanic.

Here are guidelines for posting your notes to this page.

To access the WordPress dashboard:

Click on the “Log In” button on the side dashboard. This will take you to the Princeton University Central Authentication System. Log-in with Duo as usual.

You should now be in the Dashboard.

Hover over “Posts”, then “Add New”.

Title your post “Week <#> <day of week> Scribe Notes”. For example, Thursday’s notes on Week 8 of the semester should be titled “Week 8 Thursday Scribe Notes”. Copy and paste your note contents into the body.

To add an image, click “Add Media”. First, click “Upload Files”. After uploading, in the lower right hand side, please select “Large” as the attachment display setting to ensure that the image doesn’t display blurry on a monitor.

When you’re ready to publish, ensure that “Scribe Notes” is checked in “Categories” so that your post displays on the “Diary” page. You’re all set!

I will update this post with upload instructions for photographers shortly once we get a page set up for pictures.

Feel free to email me at benjadol@princeton.edu if you have any questions, comments, concerns, or compliments.