when:- R1 is different from R2- pins radius are larger than shafts radius- number of pins is infinite so screw surfaces are created.The working surface of the blue shaft is created when a circle of radius 10 (in the planeperpendicular to the shaft axis, its center is 5 from the shaft axis) moves along a helix ofpitch 20. The working surface of the pink shaft is created similarly by a circle of radius 15 (inthe plane perpendicular to the shaft axis, its center is 5 from the shaft axis) moving along ahelix of pitch 20. Distance between the shafts is 25.Transmission ratio is 1. The mechanism now looks like a gear drive but the two shaftsrotate the same direction.-------------when the number of working surfaces is 3.Transmission ratio is 1. The two shafts rotate the same direction.The mechanism is pourely imaginary product, perhaps no practiseapplication.