If I'm in the wrong section of stack exchange, please help me go to the right place.

I am trying to find out if this combination of motor shaft and clamps will work out.

I found these clamps/bushings


and I'm curious if they will work out with the kind of shaft on this motor


The main problem is that the shaft of that motor is machined and the clamp relies on the full surface of the shaft.

By the way, those clamps work for the motors with a shaft containing removable key ( for example MiGE 130ST-M15015 ).

Aliexpress is full of these shaft couplings, but i do not believe that they are sufficient to hold these kinds of torque levels, for example :


or these :


The good thing about these sahft couplers is that they can be made to fir the shaft perfectly, with 2 screws for the 2 machined parts i was talking about.

The forces are around 10 Nm and I want to avoid any kind of slipping.

  • $\begingroup$ I'm voting to close this question as off-topic because it should be migrated to engineering.SE $\endgroup$ Commented Jan 23, 2020 at 14:29
  • $\begingroup$ What are you trying to attach to the motor? Sometimes this helps guide the bushing selection process. $\endgroup$
    – jko
    Commented Jan 23, 2020 at 21:23
  • $\begingroup$ @jko I want to attach a steering wheel with 70mm bolt pattern, those are standard car racing wheels. An adapter would be needed between the clamp/coupler/bushing and the wheel. $\endgroup$ Commented Jan 23, 2020 at 22:59

1 Answer 1


I am going to say that no, your chosen coupling would not work. Based on the K-K cross-section in the drawing, there would be a large portion of the shaft that is not in contact with the coupling.

I believe what you need is a coupling where it is held against a flat in the shaft by a set screw, like the one here (though in your size): https://www.omc-stepperonline.com/shaft-coupling/5mm-6mm-flexible-coupling-18x25mm-cnc-stepper-motor-shaft-coupler-st-fc02.html

You will need to match your torque requirements to the coupling as well.

  • $\begingroup$ Thank you for the answer. A big problem is the mentioned torque rating. Those coupling are pretty weak, the toughest one that i saw maxed around 4 Nm. Is there any alternative that you can think of? $\endgroup$ Commented Jan 27, 2020 at 11:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.