R: pitch diameter of the fixed sun gear
r: pitch diameter of the planetary gear
k = R/r = 4
Distance between the pin axis and the gear axis of the planetary gear is (11/30)r to get a square locus of straight side for the center of the pin.
This produces a smoother indexing motion of the orange Geneva disk rotates because the driving pin moves on a noncircular path, unlike in standard Geneva mechanism.