The hollow rotary DG Series actuators from Oriental Motor USA Corp., Torrance, Calif. (orientalmotor.com), handle higher torque to deliver stable, high-speed positioning of relatively large inertial loads. And output tables let users directly couple the unit to application loads, reducing parts and complexity. A single-stage reduction gear lets the company increase the diameter of the driven gear in the output table and the through hole. Repeatability is ±15 arc-sec and total backlash is less than 2 min. The 60-mm (2.36-in.) actuator generates 7.9 lb-in. of torque, and the 85-mm (3.35-in.) and 130-mm (5.12-in.) versions turn out 24 and 106 lb-in. of torque, respectively. Maximum speed on all units is 200 rpm or 250-kHz input frequency, depending on the resolution setting.