pancakebot/linkage_notes.txt at master · rootfoo/pancakebot · GitHub

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g = ground link
s = input link (driven by motor)
p = output link
l = coupler

rocking motion: s+l < p+q

closest to 180 rocker, is also the fastest to flip:
    g = l        # ground link must equal coupler for best 180 motion
    g = l = p    # all other variables equal
    s < p        # input link is marginally shorter than output

    e.g.
    1) very fast, nearly 180 flip:
        q = l = p = 40cm
        s = 39cm

    2) a little slower, nearly 180
        q = l = 40cm
        p = 37cm
        s = 36cm

    3) slow, close to 180
        q = l = 40cm
        p = 16cm
        s = 15cm

    4) decent balance
        q = l = 26
        p = 21
        s = 20

    observations:
        with constant rpm, shorter links means slower travel (proportional to circumference)
        input link less than output link also prevent interference of axis
        the longer the ground link, the smoother the motion. Shorter groundlink create more whip


experiment at:
    http://dynref.engr.illinois.edu/aml.html#aml-sl