[Luigip]

Hi,
I have this stepper, the bipolar version, NEMA 16 (http://www.nidec-advancedmotor.com/e.../pdf/KH39E.pdf) and I would like to control it with a driver.
I'm trying a fake inexpensive TB6600 (but it's actually soldered a TB67S109AFTG driver https://toshiba.semicon-storage.com/...7S109AFTG.html ), and I'm driving the motor at 0.5A, target are slow (40-100 step/s) but reliable movements, actually I'm setting 1/4 microstepping.

It's not working well, is missing steps, maybe due to EMI or bad grounding (I'm double checking) or I'm hitting a resonant frequency. However I'm not sure that this driver could be the right solution for me.

Do you have better (cheap) options possibly with the same external case of the one I have? (this is the packaged driver: https://www.watelectronics.com/tb660...driver-module/)

[joeavaerage]

Hi,
that stepper is high inductance, 5.5mH by the spec sheet. As a consequence, it will miss steps at low speed. I very much doubt it will do 200rpm with any useful
residual torque capability.

All steppers lose torque the faster they go, it the plain physics of how they work. Inductance is a reasonable measure of how bad that torque degradation (with speed) will be.

For example a 23 size stepper of 400oz.in and 1mH inductance may well do 1000rpm with as much as 100oz.in torque remaining. The exact same size motor, again of 400oz.in
but 5mH inductance probably will not even be able to do 1000rpm, in fact it may do only 250rpm with 100oz.in remaining. The bottom line is that low inductance is required for reasonable speeds.

If you were to use many turns in a fine wire the resulting stepper motor would have high torque but also high inductance, and therefore start missing steps very early, but would be cheap to make.
Thats what manufacturers do because they know that most people don't understand inductance, all they know is torque. To sell to those people you need a high torque motor but who cares about inductance?
If you made the same stepper with fewer turns but thicker wire you'd end up with less torque but low inductance. I'd rather have this motor, sure the torque is lower but it will retain that torque right
up to high rpm.

The classic way to overcome inductance is to use the highest possible voltage driver you can get. At the current time there are many Chinese made drivers rated to 80VDC at very reasonable prices.
Thats what you want, a high voltage driver with an 80VDC power supply. That would certainly help your steppes run, but you'd still be better off buying decent low inductance steppers from the get go.
High voltage drivers help, but they do not cure high inductance.

Craig

[Luigip]

Thanks Craig.
I'm running the motor very slowly (30rpm) and I'm forced to use 24V and those motors (I'm replacing a missing MCU in an already existing equipment. I have a Stack Exchange thread on this with all the details + video of the strange behaviour (https://electronics.stackexchange.co...1955050_734015).

But I'm starting to believe that the issue is related to a bad choice of driver, and I thought that here I can find the experts on steppers and drivers that can already have tested this driver limits.

Luigi

[metalmayhem]

this would be a better driver to use https://www.automationtechnologiesin...drivers/kl5042

[Luigip]

this would be a better driver to use https://www.automationtechnologiesin...drivers/kl5042

If i understand correctly min current is 1A, I need to drive the motors at 0.5A

[metalmayhem]

check out stepperonline they'll have drivers for .5amp motors

[Luigip]

Thanks, I found DM320T, which seems to be, current-wise, suitable. I have a very messy environment, with a lot of emi and noise. The goal is to replace a missing mcu, in an instrument made in the 90's. The original mcu had l297+l298, and there was no shielding in the wiring (2m long). Probably l297+l298 had a very low noise sensitivity. The TB67S109AFTG I'm using is apparently extremely sensible to noise.

Do you think that it's worth to buy 3 DM320T and they could have a good chance to behave better?

[metalmayhem]

from what I've read anything will work better than the tb drivers , it seems they are plagued with issues . If your putting out a good clean signal and everything is wired properly then you shouldn't have much problem if any at all with the stepperonline drivers. If you do have problems then it's likely something other than the motors and drivers

[Luigip]

Thanks, I'm going to try the stepperonline driver. If anyone has additional suggestions/hints is welcome