A modification of the above
A modification of the above; an elongated yoke being substituted for the circular strap, to obviate the necessity for any vibrating motion of the rod which works in fixed guides.
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 crank-shaft turns clockwise at 30 rpm and is the only driven joint; it carries the eccentric of No. 89 (3.2 cm, 1.5 cm off centre, a 72-sided disc). Instead of a strap, the eccentric works by real contact between the two upright faces of an elongated yoke (0.2 mm clearance a side); the yoke and its rods, one piece, slide in fixed guides on both sides and never vibrate. The rod travel is exactly harmonic, x = e (cos t - 1), 3 cm in all.
- Measured
- At mid-stroke: slope -0.0150 and +0.0149 m/rad vs eccentricity 0.015 (0.0%, -0.7%), r2 1.0000; the yoke runs -3.020..+0.021 cm (throw 3.0 = 2e plus the clearance). Max penetration 0.004 mm.
- Notes
- The guides are the slide joint (drawn); its damping stands for the valve resistance and keeps one face loaded each way. The eccentric is a 72-gon: round-disc contacts chattered.
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
