Input: pink crank.
Right point of blue slider draws intersection (orange ellipse) of grey cylinder and a plane. The plane is parallel to the face of the green disk, tilt angle of which is adjustable for various intersections.
Yellow spring forces blue slider toward the disk, maintains the contact between left point of the blue slider and the disk.
If the left point is of a sphere, its radius should be as small as possible to reduce error of the intersection.
Cylinder axis and rotary axis of the pink crank are in line.
The right point of the blue bar lays on sliding axis of the blue slider.