0x20 Mechanical Engineering

Machine Elements


  • rack and pinion: translate rotational motion to linear motion

crank: translates circular motion to reciprocating motion


Mechanics of Materials

Fluid Dynamics


Dynamics of Machinary

Control Theory

Lecture: Youtube

Computing Devices

Mechanical Relay

  • frequency: 10Hz

Vacuum Cube

  • vacuum cube was invented to enable coast to coast telephone
  • frequency 1000Hz
  • Pro: more reliable as an amplifier compared with relays
  • Cons: burn-out, heat, big…

Famous Devices

  • babage difference engine -> Analytical engine
  • Harvard Mark 1 (WW2)
  • Colossus (1600 vacuum cube, programmable)
  • ENIAC (general purpose programmable)


Textbook: Modern Robotics: Mechanics, Planning, and Control