Super-Precision Models DD100/DD200/DD300 incorporate frameless rare-earth permanent magnet torque motor, with no mechanical gearing, that wraps around spindle to eliminate need for separate motor extension. Encoder with ±0.077 arc/sec resolution, ± 2.19 arc/sec accuracy is mounted directly on spindle to provide accurate positioning. Direct-drive design eliminates backlash, enabling repeatability of ±2 arc/sec, and drawbar actuator lets products accept multiple workholding devices.