Hardware

Ball Screw

A ball screw is a linear actuation mechanism that converts rotary motion to linear motion via a threaded shaft and a nut containing recirculating balls, achieving efficiencies above ninety percent compared with roughly a quarter to half for sliding lead screws. Preloaded nuts eliminate backlash, giving the precision and stiffness required in CNC machine tools, humanoid leg linear actuators, and high-force linear axes.

Why it matters for physical AI

Several current humanoid designs use ball-screw linear actuators for high force density and impact robustness in legs, a hardware choice that shapes the torque bandwidth available to learned locomotion controllers.