Torque motors have a large diameter due to the hollow shaft. This makes it possible to run the z-axis rod of a SCARA robot, with the torque motor providing the rotation movement for the z-axis rod. The direct coupling of the motor with the z-axis rod enables high inertia payloads with faster acceleration in comparison to belt drive motors and conventional servo motors.

The large inner diameter of torque motors also allows SCARA designs using concentric shafts, driving different arm segments. This way, the arm itself can be kept compact, with all the motors located in the base: below and away from any sensitive payload, e.g. wafer handlers.