Nanotec Electronic U.S. (Medford, MA) offers the DS16 and DS28 slotless BLDC motors in two models in Nema 6 (16 mm) and Nema 11 (28 mm) sizes. Since there is no iron core, the inductivity of the motor is very low and the current increases very quickly in the windings. In slow operation, the lacking torque tripple has a positive effect. Since the magnetic field is not reinforced on the pole shoes as with standard BLDC motors, there is no cogging torque. The DS16 slotless BLDC motor offers an output of 24 Watts at 25,000 rpm; the speed of the DS28 model is 14,000 rpm at 75 Watts.