CNC Shaft Couplings, Whats out there?

Hey Guys,

Just stumbled across this site and oh boy what a find! I have been drafting up some designs for a CNC over the past couple months, slowly researching each component of a CNC, but there is one thing that is still a little unclear to me. If I were to go with a threaded drive CNC what kind of shaft coupler should I use? If I were to use a NEMA 34 and a 16mm threaded rod what coupler would be robust enough to handle all that torque. I see some online but they do not look to convincing like this one https://www.vxb.com/D40-L66-14mm-to-...SABEgJV8PD_BwE. Has anyone had any experience with these and or what are you guys doing?

Thanks in advance!!!

All the best,

DMC

I haven't used that particular brand, but that looks like a good coupler to me. I certainly don't see a NEMA 34 motor breaking it, if that's what you're worried about. The usual thing that causes jaw-coupler failure is slippage; either the set screw vibrates loose, or it starts cutting a groove in the shaft so it can wiggle around. The latter problem won't happen with the coupler you've linked to, since it's a clamp-style device that doesn't rely on a set screw directly contacting the shaft. To combat slippage, use a reversible thread sealer on the tightening screw.

I'm not sure which 16mm threaded rod you're talking about using, but don't use the regular "all-thread" from the hardware store. An acme screw works much better as a leadscrew, if you don't want to spring for precision ball screws.

I use Misumi when I can
https://us.misumi-ec.com/vona2/mech/...isplay=mc-list

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Originally Posted by umfan110

I see some online but they do not look to convincing like this one https://www.vxb.com/D40-L66-14mm-to-...SABEgJV8PD_BwE.

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I use that kind of couplers, they work fine. They actually made my machine more quiet compared to "spiral cut" couplers.