Stepper interface small servos

[Dave SParticipant @daves59043]

Idly browsing around I have come across these:

**LINK**

Look like an ideal small cnc motor.
Anyone used them?

Dave

[Dave SParticipant @daves59043]

[John HaineParticipant @johnhaine32865]

That looks very interesting and quite competitive price-wise with a stepper+driver. As it has a gearbox presumably the backlash is removed in the electronics which might be a bit iffy as it wears – the encoder resolution is 1800 lines so presumably the backlash could be 0.2 degrees without being detected. With a typical 5mm pitch ballscrew that would equate to 5/1800 = 2.7 microns, quite a lot less than probably even a good ballnut. Definitely a potential alternative for a CNC conversion or upgrade.

[HOWARDTParticipant @howardt]

I think it is 0.2deg error per revolution on the output shaft with an 1800 per revolution pulse on the motor. Adequate for a robot not a machine axis.

[Martin ConnellyParticipant @martinconnelly55370]

How well it works will be dependent on the control electronics. Servos can get issues with hunting if not set up properly and the set up can go awry if the gibs are loosened or tightened. Older systems reduced the power to zero at the demand position so there was no holding power when stationary. Electrically/electronically the only real difference between setting up a hybrid servo stepper and a servo is that the hybrid servo stepper probably does not need tuning to suit the system. I expect there will be reviews on YouTube soon, I await them with interest.

Martin C

[Dave SParticipant @daves59043]

My reading of the data sheet is that it’s a brushed motor servo with electronics to provide a step/direction interface.

there are also ones with a position input: **LINK**

If you search nema23 in the site they have a variety of rpm and interfaces.

I was thinking step direction would just “plug” into a grbl type controller without rewriting it.

Dave

[Ex contributorParticipant @mgnbuk]

18000 rpm base motor – can't see those being too quiet in operation !

EUStepperonline have 4Nm closed loop stepper motors including drive & 1.7metre power and encoder cables for around £89 delivered (Ebay – UK stock) – probably a better choice for an axis drive than the geared motor at around £69 + £5 P&P + sort your own cable ?

Nigel B.

[Author]

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