Jumping or intermittent rotary motion, used for meters and…
Jumping or intermittent rotary motion, used for meters and revolution-counters. The drop and attached pawl, carried by a spring at the left, are lifted by pins in the disk at the right. Pins escape first from pawl, which drops into next space of the star-wheel. When pin escapes from drop, spring throws down suddenly the drop, the pin on which strikes the pawl, which, by its action on star-wheel, rapidly gives it a portion of a revolution. This is repeated as each pin passes.
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
- Brown's figure 63: a disk with three pins (the driven shaft) lifts the drop, a lever pivoted at the left and pressed down by its spring; the pawl hangs from a pin in the drop, its light spring keeping its point in the twelve-pointed star-wheel
- Measured
- star/disk 0.2569 (3 pins × 1/12 turn = 0.25); the pawl riding back over a point drags the star back at most 3.7°; the star stands while the drop is lifted (still); max penetration 0.29 mm
- Notes
- The star's arbor has a little friction (frictionloss 0.05) to hold it between jumps, as a counter's detent would. Pins, nose and pawl point collide as capsules. batch7/gen063.py. Negative control: the pawl out of contact → the drop rises and falls, the star stands (0.000).
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
