The simple machines are mechanisms that use an applied force ... It’s also found in lead screws such as those used in linear actuators found in everything from DVD players to CNC machines.

Keen-eyed readers will recall [Andy]’s recent scratch-built ball screw build ... were a great lesson in how to machine a complex mechanism to work in a constrained space. Still, it left folks ...

Hu J, Wang M and Zan T. The kinematics of ball-screw mechanisms via the slide–roll ratio. Mech Mach Theory 2014; 79: 158–172. 13. Nakashima K, Tamaru Y and Takafuji K. Ultraprecision positioning by ...