Machine Design

Hollow-shaft stepper motor leaves room for the imagination

Edited by Stephen J. Mraz

The 66-mm-diameter stepper motor from PRECIstep, a Swiss company and member of the Faulhaber Group (, features a 41-mm hole through the center. Designed from the start to be a hollowshaft motor, the device uses an annular neodymium magnet that lets the eight coils be configured as rings. The coils are linked such that the motor operates as a two-phase stepper motor. Holding torques range up to 250 N-mm and dynamic torques can be as high as 220 N-mm. There are 200 steps/rev. Three options are available: low temperature, high temperature, and vacuum compatible.

The wide hole through the center lets it be used in robotic arms, with the open center acting as a cable raceway to reduce costs and space requirements. Engineers can also use the space to add components such as gearheads or lenses that focus lasers or other forms of light. The motors can also be used to focus cameras.

MICROMO ( represents PRECIstep in the U. S.

© 2011 Penton Media, Inc.

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