Type a branch, a subject or a topic — “round robin”, “paging”, “civil”.

Theory of Machines

A mechanism is a set of rigid bodies whose joints remove exactly enough freedom to leave the motion you wanted. These topics animate the motion rather than describing it, which is the only way a linkage ever makes sense.

Start from the beginning →

1 topic you can watch now, 23 still to come.

Mechanisms and mobility

Links, pairs, and how many inputs a mechanism needs.

  • Kinematic pairs and their classification
  • Kinematic chains and inversions
  • Grashof's criterion
  • Four-bar and slider-crank mechanisms
  • Straight-line and steering mechanisms

Velocity and acceleration analysis

Where each point of a moving linkage is going, and how fast.

  • Relative velocity method
  • Instantaneous centre method
  • Acceleration diagrams and Coriolis component
  • Klein's construction

Cams and followers

Designing a shape so that motion comes out the way you specified.

  • Cam and follower types
  • Displacement diagrams: uniform, SHM, cycloidal
  • Cam profile construction
  • Jump and undercutting

Gears and gear trains

Transmitting rotation at a fixed ratio, without slip.

  • Law of gearing and involute profile
  • Interference and minimum teeth
  • Simple, compound and reverted trains
  • Epicyclic gear trains and torque

Dynamics of machinery

The forces a moving machine puts back into its own frame.

  • Static and dynamic force analysis
  • Flywheels and turning moment diagrams
  • Balancing of rotating and reciprocating masses
  • Governors
  • Gyroscopic couple
  • Free and forced vibration, whirling of shafts
Dashed entries are mapped but not animated yet. The running order is not fixed until a topic is built. Browse the other subjects.