{"id":80,"date":"2018-08-09T16:09:36","date_gmt":"2018-08-09T16:09:36","guid":{"rendered":"http:\/\/commons.princeton.edu\/57-tiger-cub\/?p=80"},"modified":"2018-08-15T13:39:01","modified_gmt":"2018-08-15T13:39:01","slug":"tuesday-7-april","status":"publish","type":"post","link":"https:\/\/commons.princeton.edu\/57-tiger-cub\/2018\/08\/09\/tuesday-7-april\/","title":{"rendered":"Tuesday, 7 April"},"content":{"rendered":"
\n

In Last Week’s Lab<\/h4>\n
\n
Mikhail: worked on the Clutch<\/div>\n
Caitlin: \u00a0worked on removing paint from the Racers (where the ball-bearing hits)<\/div>\n
Mark: gasket work<\/div>\n
Mun: tried to get points onto the wires, but could only find 6, so were trying to figure out if we could use some that were on the extra wires<\/div>\n
Kate: (same)<\/div>\n
Francesco: worked on the fork assembly, tried to figure out what goes where and started putting the front end together<\/div>\n
Max: figured out the configuration of the brake and clutch levers ; calculated the mechanical advantage for each of the levers.<\/div>\n
Phil: pressed the gearing into the engine cover; cleaned out and started to put the front end back together.<\/div>\n
Mary Kate: put the bottom end back together<\/div>\n
Sydney: put bottom end back together<\/div>\n
Leslie: put bottom end back together.<\/div>\n
Max B: put the top end together, switched one of the springs in the carburetor, painted the cylinder<\/div>\n
Jaime: helped paint the cylinder head so that it wouldn\u2019t get rusty (with the silver paint) so that it wouldn\u2019t oxidize and get rusty<\/div>\n
Samone: figured out how to put the transmission together; there was a broken tooth, with a washer that had welded with one of the gear shafts; figuring out how to put separate it<\/div>\n
\n
Devon: putting the clutch back together, working with the missing\/fused washer.<\/div>\n<\/div>\n<\/div>\n
<\/div>\n<\/div>\n
\n

Guest Lecturer – Bill Becker<\/h4>\n
\n
\n
<\/div>\n<\/div>\n
\n
<\/div>\n<\/div>\n<\/div>\n
\n
Bill Becker: The Wheel as a Structural Subsystem on a Motorcycle <\/b><\/div>\n
-Background:<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 From Philadelphia<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Works on mostly vintage machines, but also enjoys bringing them up to modern standards\u2026 attracted to the \u201cbeauty of mechanical work\u201d<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 goes to his shop, and \u201ccreates problems and then solves problems\u201d<\/div>\n
-Some Basic Physics:<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Need to understand Mass, Matter, and Force<\/div>\n
o \u00a0\u00a0 Forces are what act<\/i> on mass<\/div>\n
o \u00a0\u00a0 With a motorcycle, dealing with forces like gravity, inertia, momentum, and velocity<\/div>\n
o \u00a0\u00a0 Velocity is a force acting in a direction <\/i><\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 It takes work <\/i>to stop momentum and to stop inertia<\/div>\n
For Manufacturing:<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 If you\u2019re designing for racing, staying streamlined is very important for becoming faster and better\u2026 this means reducing mass and reducing friction.<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 If you\u2019re producing for mass production, materials have to be affordable and not too expensive<\/div>\n
<\/div>\n
-Looking at the wheel:<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 On Japanese motorcycles, there\u2019s usually 36 spokes (9×4), but on our British bike there\u2019s 40 spokes (10×4)\u2026 it doesn\u2019t really make a difference.<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Outer piece: \u201crim\u201d, connected via the \u201cspokes\u201d to the \u201chub\u201d<\/div>\n
o \u00a0\u00a0 The hub contains a brake, with shoes that expand (for the brake), and some bearings.<\/div>\n
-Materiality of Motorcycle wheels<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 In the modern motorcycle, there\u2019s 12 different materials used on every wheel<\/div>\n
o \u00a0\u00a0 Why so many? Because each material is good for different things! For example\u2026<\/div>\n
\u00a7\u00a0 Aluminum, for the rim<\/div>\n
\u00a7\u00a0 Stainless steel, for the spokes<\/div>\n
\u00a7\u00a0 Cast iron for the hubs<\/div>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\n
<\/div>\n<\/td>\n
\n
Strength<\/div>\n<\/td>\n
\n
Flexibility<\/div>\n<\/td>\n
\n
Weight<\/div>\n<\/td>\n
\n
Hard\/Soft<\/div>\n<\/td>\n
\n
Workability<\/div>\n<\/td>\n
\n
Resist Corrosion?<\/div>\n<\/td>\n
\n
Conductivity<\/div>\n<\/td>\n
\n
Cost<\/div>\n<\/td>\n
\n
Available?<\/div>\n<\/td>\n<\/tr>\n
\n
Aluminum<\/div>\n<\/td>\n
\n
x<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
Light<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
very<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
very<\/div>\n<\/td>\n<\/tr>\n
\n
Cast Iron<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
Heavy<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
Good<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Mild Steel<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Hardened Steel<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Stainless Steel<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
Heavy<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
Exp<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n<\/tr>\n
\n
Rubber<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
Light<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
X<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
cheap<\/div>\n<\/td>\n
\n
very<\/div>\n<\/td>\n<\/tr>\n
\n
Polyester<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Brass<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Chromium<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Asbestos<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Plastic<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n
\n
Air<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n
\n
<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
<\/div>\n
-Because Rubber is so readily available, that\u2019s why it was chosen as the material that undergoes a large amount of friction between the bike and the road.<\/div>\n
-Basic Forces that work on the wheels:<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Compression, Tension, Shear (and Bending, which is a combination of all 3)<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Young\u2019s Modulus of Elasticity: describes how different materials respond under stress (load) and strain (deformation)<\/div>\n
o \u00a0\u00a0 The stronger the material, the steeper the slope<\/div>\n
o \u00a0\u00a0 This chart also measures the yield point and the fracture point.<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 In a wheel, only about a quarter of the spokes are working at a time (bearing a load)<\/div>\n
o \u00a0\u00a0 Each spoke can support about 850 pounds<\/div>\n
o \u00a0\u00a0 So each wheel can support about 8000-8500 pounds.<\/div>\n
\u00b7 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 However, a wheel is supporting a much bigger load than just the rider\u2019s weight.<\/div>\n
o \u00a0\u00a0 Especially with gravity, impact, acceleration and deceleration\/braking, there\u2019s a lot of stress on the spokes of the wheel.<\/div>\n
o \u00a0\u00a0 At any given time, you could get have as many as 50% of the spokes contributing to the wheel\u2019s strength<\/div>\n
o \u00a0\u00a0 The spokes\u2019 orientation provides different triangulations, which strengthen the wheel for different motions (like banking, etc…)<\/div>\n
\u00a7\u00a0 Only for the rear wheel\u2026. The front wheel doesn\u2019t provide any braking or any power, so radial spokes are OK<\/div>\n
<\/div>\n
HW for next meeting (Thursday 4\/9): CHS 16-18 in Zen <\/i>(next three chapters, first three chapters of part III)<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

In Last Week’s Lab Mikhail: worked on the Clutch Caitlin: \u00a0worked on removing paint from the Racers (where the ball-bearing hits) Mark: gasket work Mun: tried to get points onto the wires, but could only find 6, so were trying to figure out if we could use some that were on the extra wires Kate: … Continue reading “Tuesday, 7 April”<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-80","post","type-post","status-publish","format-standard","hentry","category-diary"],"_links":{"self":[{"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/posts\/80","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/comments?post=80"}],"version-history":[{"count":1,"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/posts\/80\/revisions"}],"predecessor-version":[{"id":81,"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/posts\/80\/revisions\/81"}],"wp:attachment":[{"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/media?parent=80"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/categories?post=80"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/commons.princeton.edu\/57-tiger-cub\/wp-json\/wp\/v2\/tags?post=80"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}