Koford Engineering (Winchester, OH) offers a 6,300-rpm, hollow shaft, 48-mm-diameter, slotless, 2-pole motor with a shaft bore size of .400". The motor is designed for low temperature rise and low operating current (.06 amps at 12v for 6,300 rpm). The cogless design results in smooth rotation. Applications include optics, filter, beam choppers, and any application where access through the center of the motor is required. Matching sensorless drives are also available.