Common mode of raising water from wells of inconsiderable depth
Common mode of raising water from wells of inconsiderable depth. Counterbalance equals about one-half of weight to be raised, so that the bucket has to be pulled down when empty, and is assisted in elevating it when full by counterbalance.
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
- Seen from in front and a little above, as Brown, gravity on. A pole 130 cm long turns on a pin in the fork of a post 75 cm up, its long arm 100 cm out over the well and its short arm 30 cm back, where a lashed block of stones of 9.9 kg is bound on. A rope 85 cm long hangs from the end of the long arm to the bail of a bucket standing just above the well's curb. The bucket is full: 4.8 kg of water in a 0.9 kg staved bucket. The stones are sized by Brown's rule, so that through the rope they hold up half of the full bucket's weight, the pole's own overhang included. The hand on the rope lifts the bucket at 7 cm/s on a plumb guide; this is the only input. The rope is a real chain of links, and it is the only thing that turns the pole.
- Measured
- The bucket rises 24 cm in 3.4 s and the pole turns up through 16 degrees with it. The hand's mean pull is 27.8 N, about half the full bucket's weight of 55.6 N (27.8 N), the stones lifting the rest.
- Notes
- The full bucket is a solid: its water is a solid block of 1 g/cm³, and the run shows only the lift of the full bucket out of the well. The bucket rises on a plumb guide, the hand's, so the rope leans a few degrees as the end of the pole swings. The stones are a lashed block on the pole's butt rather than Brown's bundle hung from it.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
