507 Mechanical Movements

67

Another modification of 64; a weight or tumbler, E, secured on the…

Another modification of 64; a weight or tumbler, E, secured on the hollow shaft, being used instead of spring and cam, and operating in combination with pin, C, in the shaft of worm-gear.

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
No. 64's worm and 30-tooth worm-gear B; pin C on B's shaft drives the half-cut-away hollow shaft, on which an iron crescent tumbler E replaces spring and cam. C carries E over the top; E tumbles half a turn ahead and hangs until C catches up.
Measured
tumbler/wheel 1.000 while lifted (1-4.5 s); E still at 2π±0.001 over 7.5-9.5 s; wheel/worm 1/30; max pen 0.02 mm
Notes
j_tumbler damping 0.05: overshoot 0.30 rad, short of the shaft face (free arc π+0.6); at 0.01 the heavier tumbler bounced off it.

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

Figure 67 from Brown, 1868
Brown's figure 67 (1868)