About Mechanism Lab

Every moving part on this site is placed by the standard engineering equations, not animated by hand. Gears are true involute gears with a 20° pressure angle; each gear's angle comes from the meshing relation with its neighbour.

The same code makes our short videos, and it is checked by automated tests: over a full turn the teeth of every meshing pair never overlap and keep a constant clearance, no axle passes through another gear, and the speed ratios come out exactly as the formulas say. A deliberately mis-timed gear fails the same tests.

The models are idealised: no friction, perfectly made parts. They are for learning how things work, not for designing machinery.