The green disk lower end moves along a 3D curve. When blue disk is immobile, green plate (fixed to green disk) performs spatial motion without rotation around all three coordinate axes thanks to yellow planar and orange spatial parallelogram mechanisms.
The grey cylinder is connected to the base via a spherical joint (not shown). The blue piston is connected to the green disk via a spherical joint.
Pay attention to violet universal joints (2 DoF).
Angular position of the green plate in horizontal plane can be adjusted by turning the blue disk. The video shows such adjustment occurring after first double strokes of the piston.
Gravity maintains contact between the green disk lower end and the groove bottom of the popcorn runway.