I have recently received some Clearpath CPM-SDSK-3421S-ELN servos and realized that the motor shaft is not keyed like the steppers that Avid sells. Instead of a key sticking out of the shaft, the Clearpaths have a notch machined into the shaft. I assume the notch is intended for couplers with set screws (although Clearpath advises against these in their manual)? Is it ok to use the keyed Oldham couplers that the Avid machine ships with despite the shafts not being keyed?
I believe somewhere in the Clearpath manual, there is mention of shaft setting compounds. The brand recommended by teknic is Loctite and the number is 348. Expensive stuff, but it works. If you search the Teknic website, you'll find a circular on it.
Hi dermeister545: We (Teknic) strongly advise against the use of keys or set screws in any application with dynamic motion (i.e., lots of starts/stops/ torque reversals), which means almost all ClearPath applications. Our first recommendation is to use a clamp style coupling. If that’s not possible for some reason, the next best choice is to use a shaft retaining compound like Loctite 638. For more technical details on why we make this recommendation and how to implement it, we wrote a white paper on the subject that you can read here:
If you have any questions or concerns, please feel free to give Teknic a call to speak to an Applications Engineer (585-784-7454), or use our "Contact Us" form online (https://www.teknic.com/contact/ . Usually speaking to an engineer will give you the most complete answer that takes into consideration any unique details of your specific application.
Best regards,
Abe A. - Teknic Servo Systems Engineer
I'm just using the Oldham couplers that came with my Avid and there's no problem at all with slippage on the clear path shafts. I chose the largest diameter shafts to give it the most surface area but other than that, didn't really do anything and it's all good.