Dead-beat Pendulum Escapement
A dead-beat pendulum escapement. The inner face of the pallet, E, and outer face of D, are concentric with the axis on which the pallets vibrate, and hence there is no recoil.
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
- escapement (contact only: 30 forward-leaning Graham teeth against convex-hull pallets whose locking faces are arcs about the arbor; constant-torque weight on the wheel; pendulum under gravity)
- Measured
- period 0.891 s vs compound pendulum 0.882 s (+1.0%; simple 2π√(L/g), L = 20 cm: 0.897 s); wheel 0.1048 rad per beat (half a tooth, 0.1047); locked wheel still to ±0.004° as the pallets slide (dead beat), largest run-back 0.08° (drop rebound); amplitude 5.2° sustained over 20 s; weight removed → 5.2° → 0.7° in 6 s
- Notes
- Only the escape wheel is driven (constant torque, as a weight). Starts itself from rest. Lift 2.5°, lock 1.5°, drop 1.5°.
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
