Continuous circular into intermittent rectilinear reciprocating
Continuous circular into intermittent rectilinear reciprocating. A motion used on several sewing machines for driving the shuttle. Same motion applied to three-revolution cylinder printing-presses.
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
- A lever pivoted at its foot has a curved slot; a pin on the crank (the one driven joint) runs in it. The slot's middle is an arc of the pin's own circle about the crank shaft, so while the pin runs through it the lever stands still (a quarter turn of dwell); the straight run-in and run-out swing the lever out and back. A link from the lever's top eye drives the table to and fro. The slot's working faces are chains of capsules so the pin meets true curved walls.
- Measured
- The lever stands at its rest angle (within 0.02 rad) through the dwell each turn, the table travels about 36 cm to and fro, and penetration stays under 2 mm.
- Notes
- The lever's swing (about 58 degrees) and the table's travel are larger than Brown's drawing suggests; the frame is reduced to a foot bearing and two guide rods.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
