Portable cramp drills
379 and 380. Portable cramp drills. In 379 the feed-screw is opposite the drill, and in 380 the drill spindle passes through the center of the feed-screw.
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 cramp is a C-shaped frame. The drill spindle turns in a bearing at the end of its upper arm, by a crank on its top. The feed-screw stands in the lower arm, opposite the drill (pitch 1.6 cm, its thread bearing on the thread of the arm), and carries a swivel pad that does not turn with it; the work lies free on the pad. Turning the feed-screw by its T-handle (24 turns a minute) is the only driven motion; the crank is turned by the operator's hand, half a turn a second.
- Measured
- The feed-screw lifts the pad and the work 1.6 cm a turn (0.2546 cm to the radian), carried by the thread alone, until the work comes up against the drill's point 4 cm above; there the screw stalls and holds the work against the turning drill.
- Notes
- Brown gives no sizes. The drill does not cut into the work: it bears on it and turns. The crank is turned by hand in steps of a twentieth of a turn every tenth of a second.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
