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 feed-screw stands in the nut of its upper arm (pitch 1.6 cm, its thread bearing on the thread of the arm) and is hollow: the drill spindle passes down through its centre and is carried with it by a collar under its lower end, while turning freely in it by a crank on its top. The work lies on the lower arm. Turning the feed-screw by its wing 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 goes down 1.6 cm a turn (0.2546 cm to the radian), carried by the thread alone, and takes the spindle down with it until the drill's point comes on the work 4 cm below; there the screw stalls and holds the drill to the work while the crank turns it.
- 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)
