Attendance
Guest Speaker: Doug Repetto of Columbia
Mouse trap car races!
Mid Term Projects:
due the week before spring break
Single or in pairs (tell me by next class)
Guidelines:
- It must have a motor, and not just a vibrating/eccentric one
- You must be able to bring it in for class to present
- Depending on # of groups, expect about ~7 minutes presenting time with ~3 minutes for questions
- Think of our two themes: Abundance and Constraints, and "The line between art and engineering exists only in our minds."
- Your creation must have a defined function. "I wanted to try this because it looks cool" or a spinning platform with a bunch of LEDs is not acceptable unless you can communicate a certain functional goal.
Student pages: create one and use it! Midterm grades depend heavily on this.
Couplings
What's a coupling? Something that joins two rotating things to transfer torque
Types of Couplings
Coupling to a motor shaft:
- ALWAYS look for non-round motor shafts (D-shaped or keyed are popular)
- ANY SHAPE TRANSFERS TORQUE BETTER THAN A CIRCLE!
- Make your circular shaft D shaped with a file
- Rough up shaft (i.e. by sanding) if you must use it circular
DIY couplers
Gears
Amazing kinetic artist of the day: Arthur Ganson
Untitled fragile machine
Spur Gears
- Transfer motion between two parallel shafts
- Most common, simple
spur gear mesh animation
Gear types
Helical
- Quieter running than spurs, less backlash
- More complicated geometry
Gear ratios
Lesley's Gear Tutorial
Making wire gears
