A modification of 168, in which a link is used to connect the…
A modification of 168, in which a link is used to connect the pitman with the main crank, thereby dispensing with the slot in the said crank.
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 main crank (3 cm; the one driven joint, 20 rpm) is joined by a 6.5 cm link to the pitman. The 19 cm pitman is also carried by a second crank of invariable radius (3.6 cm) on its own shaft 7 cm from the main shaft, and its far end works the reciprocating moving power, drawn as a slide in guides. All joints are pins; no gravity (a plan). gen169.py.
- Measured
- The slide follows the main crank at +0.0293, -0.0154, -0.0142 and +0.0293 m/rad (kinematic the same, r2 at least 0.998); the second crank at -0.902, +0.445, +0.489, -0.902 rad/rad (r2 at least 0.995). The slide goes 4.0 cm and the second crank rocks 73 degrees.
- Notes
- The pitman end is not compelled to a circle: the two cranks make the pitman swing 20 degrees while its end is held in the guides. Dimensions were found by a search for a pair that clears every dead point through the whole turn.
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
