Every mechanism here is generated and solved by @qubekit/solver:
involute gears, a slider-crank steam engine, a centrifugal flyball
governor, an articulated robot arm (inverse kinematics), and a quadcopter
(counter-rotating control mixer) — plus a paper / fabric sheet run as a real
Jolt soft body in the Quine engine, and the SO-100
robot arm as a real QubeKit assembly. Pick one from the menu.