The rotating nut turns the threaded screw, creating a smooth in-and-out linear motion. Thread friction drives the shaft, directly converting rotary motion to linear motion. This means: * No parasitic drag - less wasted power * Zero backlash (with a light pre-load) * Very high stiffness * Nanometer resolution and high force * High torque at low speeds, with no gearbox * Smooth velocity at microscopic speeds * Off-power hold * Very small diameter * Manual screw rotation for off-power positioning
[Source] The SQUIGGLE motor