No swash cylinder in this one. In this design the reciprocation is converted to rotation via pins that engage in a cam groove in the face of the flywheel. I initially imagined the track for the groove would be diamond shaped and initially made it like that. Then I ran the animation and noticed the pins were running out of the groove except on the long and short axes, observed a bit more and saw that the track was more lip-shaped and so I changed the cam track to match where the pins tracked. In the end it's a bit more like distorted lips: on one half the track moves a little further out than the other half. Anyway, it looks like it will do just what I want now.How did you calculate the drive ratio to the swash cylinder?