A modification of 77.

Only the input is driven; every other part of this model moves by physics (MuJoCo), and its ratios are measured. Run it live, change its parameters, or switch the friction off to see the output stop.

Modelled as

Lever pivoted on the A-frame apex above 30-tooth saw wheel A, rocked by a crank pin in a slot at its right end (rod B, the only driven joint); two hooked pawls hang from the lever on either side of the pivot and pull the wheel on alternate strokes. Hooks clear the tooth tips.

Measured

Ratio A/crank 3-13 s 0.06648 vs 2/30 (-0.28%), two teeth per crank turn; max pen ~0.8 mm

Notes

Rod B modelled as crank-in-slot at lever end; saw teeth rather than plate pin-wheel style.

Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)