The German motor manufacturer Faulhaber claims to have produced the world’s smallest brushless DC servomotor with an integrated motion controller. The BX4 four-pole motor incorporates a single-axis motion controller which fits within its 22mm diameter and controls the motor speed from 5 to 8,000 rpm.

The motors (shown above) are available in 32 or 50mm lengths, and operate from 24V DC supplies. They are said to exhibit flat linear torque/speed curves and high torque-to-volume ratios, with maximum torque levels up to 35mNm. The slot-less design avoids cogging torque.

The drives are available with RS-232 or CAN interfaces and are configured using free software.

The motors are available in the UK from Electro Mechanical Systems.