A Octagonal shaft is the steel shaft in the roller shutter box onto which the shutter curtain is wound. Its cross-section is octagonal. The size is given by the outer dimension in millimetres, for example SW 40, SW 60 or SW 70.
Which sizes are there?
- 40 mm shaft: for small roller shutters, roller blinds and screens – a 35 mm motor fits, such as the A-OK AM35
- 60 mm shaft: the most common size for roller shutters in housing – 45 mm motors fit, such as the A-OK AM45
- 70 mm shaft and larger: for large and heavy roller shutters, with a suitable adapter
How do I measure the octagonal shaft?
Measure the width across flats, i.e. the distance between two opposite flat sides of the octagon. Also note the length of the shaft and the type of bearing on the opposite side.
Why is the shaft size important for the motor?
The motor is pushed into the shaft, so its diameter must fit. The winding radius also determines the torque required: the larger the shaft, the more force the motor needs for the same curtain weight. The right torque is calculated by the Roller shutter motor calculator.
Related terms: Tubular motor
