NEMA 23 Shaft Adapters?

Does anyone know if there are adapters to couple a NEMA 23 motor to something made to be driven by a servo motor with a 19mm round shaft? I’m thinking they probably don’t exist, since it’s an almost 3x shaft diameter increase, but it doesn’t hurt to ask around.

I bought a rotary axis a couple days ago to test out an idea. I kept looking after that and ended up finding some zero-backlash roller drives, which I’m going to attempt to turn into a horizontal rotary table, selling for cheap online. Trying to come up with a good way to couple a NEMA 23 motor to a Sankyo RA80 RollerDrive, without using belts, now…

Hey Dan,

possibly here, but if your motor diameter is smaller than 10 mm, you need two use two coupler in series.

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Thanks for the link. A smaller one of those couplings will probably work.

I’ll use one of the 3Nm Masso steppers, which I think have a 6.5mm shaft diameter. Haven’t gotten to the point of ordering one yet. I’ll have the original rotary table I ordered, so my first rotary project can be creating an aluminum shaft to link the RollerDrive to the motor coupler. It’ll be a good test to verify the stiffness of the rotary table mounts I’ll be fabricating, if nothing else.

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May have found a quicker solution that would be better than using an aluminum shaft. Bored and figured I’d measure some things at work…

The drill bit adapter for a small size Milwaukee hole saw has a 9.85mm shaft, and the coupling on the bit side has an 18.7mm OD, which is probably close enough. Could cut off the threads, remove the set screws and use that with a 6.35-10mm coupling.

Also, found that a 1/2" adapter for a 3/8" impact has an OD of 18.86mm. Could tack that to something that’d reduce the shaft size to 1/4" on the flats and go that route.

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Great find - thank you for sharing, as I had not seen this type of drive in my searches.
I registered with Sankyo so that I could access their downloads. It looks like there may be shaft sleeve adapters available, and they also show a reducer unit available.
Perhaps if you contact the USA office they can advise.

I have bookmarked the company page and saved the manuals for future reference.

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I believe the shaft sleeves are for the motors listed on page 21 of this manual.

The Mitsubishi motors seem easy enough to get, though they’re all 200V, 0.75kW+ servos which would require additional power supplies and drives. Maybe something I’ll look into eventually.

I’ll reach out to Sankyo about the reducers. It would be nice to have a mount that looks like it belongs on there, rather than a bunch of angle iron welded together to hold the smaller motor, which is the current plan.

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I did see that page, but thought since they have these sleeves already, there may be some for smaller shafts - worth a call/email.

They also have a smaller series that look to be made for stepper motors, but the backlash specs do not seem as good.

I’ll definitely look into the reducers. Not sure about just a shaft sleeve, since a mount will have to made to accommodate the smaller motor frame size of a NEMA 23 motor.

I looked at the other drive series, but didn’t come across any pricing info. I only bought the RA80 because it was really cheap online.

Please keep me updated on what you find out. I would appreciate seeing your solution.

I was considering a drive such as this for indexed work with aluminum. What I am not sure about is the holding force of the directly connected motor - I know they make brakes for such applications. I would also need a way to add a sensor to allow homing of this 4th axis. Definitely a future upgrade I was planning.

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I’ll put up a post once I have everything figured out and verify that it’s working.

I’ll probably play around with the Sherline rotary table for a bit, since it’s already made to work with the Masso system and should arrive at my house on Wednesday. The Sankyo looks like it’ll be a more precise option, but it’s going to require fabricating some components (motor mounts, table to mount chuck, possibly a shaft adapter, etc.).

I’m not sure about the motor’s holding force, either. Or how zero-backlash the “zero-backlash technology” is in reality. The RA80 table does have a hole through the center of rotation and mounting holes on multiple sides, so it seems like it would be fairly easy to install a shaft and mount a custom made bracket for the brake.

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