Pantograph transmission 1b

Input: pink crank rotating regularly. Output: orange crank rotating regularly. The cranks rotate in the same direction with the same velocity Lengths of cranks : a Lengths of blue bars : Lengths of green bars: Distances between stationary bearings: b b. Green curve: locus of center of joint between two green bars. Because here b = 4a, unstable positions happen when all the bars are in line. One working cycle corresponds 2 revolutions of the input.