Crank motion, with the crank-wrist working in a slotted yoke,…
Crank motion, with the crank-wrist working in a slotted yoke, thereby dispensing with the oscillating connecting-rod or pitman.
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
- The crank-disc (6.5 cm) turns clockwise at 30 rpm and is the only driven joint; its crank-wrist (a 1.2 cm pin) is 4 cm from the centre. The wrist works by real contact in the horizontal slot of a yoke (1.2 cm wide, 0.1 mm clearance a side) whose rod, above and below, slides up and down in fixed guides: the slot lets the wrist pass to and fro and the yoke takes only its height, z = r cos t, 8 cm in all, exactly harmonic, with no connecting-rod.
- Measured
- Slopes of the yoke against the crank: -0.0400 (ideal -0.03995) at 90 deg; -0.0282 and -0.0281 (-0.02825) at 45 and 135 deg alike (no rod obliquity), r2 0.9996-1.0000; stroke -8.010..-0.010 cm (ideal 8). Max penetration 0.002 mm.
- Notes
- The guides are the slide joint (drawn), damping 3 loads one slot face each way; a range stop 1.5 cm below the stroke only catches the yoke in the control.
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
