Lecture Notes

http://academy.cba.mit.edu/classes/mechanical_design/index.html

Reviews:

  • Schmitt trigger: separate threshold levels for rising and falling edge

Mechanical Design

Principles

http://solidmechanics.org/

  • Stress-Strain: stress = force per area; strain = reaction of the material
    • Elasic range: where stress and strain linearly correlate
  • Spalling: when rubbing two parts of the same material, they start to pill…
  • Hysteresis: introduced by play between two parts (eg. screw + nut)
  • Kinematic coupling: Arrange parts precisely towards each other by constructing a situation that has exactly one low-energy state that it’s gonna approach by itself

Materials

  • Machinable / castable ceramics: http://www.aremco.com/
  • Garolite is also a nicely machinable structural material
  • Hydro-Stone, Dry-Stone
  • Good machine building tends to not use adhesives: They’re irreversible (non-destructively) and represent points of failure
  • Good machine design requires little and does not heavily rely on lubricants

Components

  • Gears: involute

Construction