Stepper motor overheat


We have 2 STSPIN220 drivers connected to 2 Nema 8 micro stepper motors [ ]

We noticed the stepper motors get very hot after a few minutes. The current limiting procedure: Current Limit=VREF⋅5 was done but did not make a difference.

Please advise.



Hello, Farhad.

It is normal for a stepper motor to get hot when in operation. As long as you are not exceeding the current limit of the stepper motor or driver, it should be fine to operate the motor in that condition. Can you tell me what you set the VREF voltage to when you set your current limit? Is something happening aside from the motors getting hot that makes you think they are overheating?


Hi Brandon:

Thanks. We tried 2 different Vref’s for both both motors, 0.1 v and 0.08 v. The stepper motor is Nema 8 with 0.6 A limit. Is this normal? The stepper motors are inside 3d printed mounts that get quite soft and we want to prevent that.


Hello again:

Just wanted to ask you something related to the above question. We are able to put the driver in stand by mode by hand to cut the current to the motor when idling. Therefore, preventing the overheating.

But we now want to automate putting the motor in stand by mode using a raspberry pi 4. Do you know of a way to do that without using a relay? Please let us know.


Setting the VREF to 0.1V and 0.08V would give you a current per phase limit of 0.5A and 0.4A respectively, so that seems fine (as long as you can still get the performance you need from your stepper).

For reference, it is normal for a stepper motor to get very hot when operating at its rated current limit (sometimes upwards of 100-110°C). You can find some useful information about 3D printing materials and the point at which they start to soften (i.e. the glass transition temperature) in this 3D Solved article. For example, something like ABS is more heat resistant compared to PLA or PETG, and won’t begin softening until around 105°C, so that would probably be your best bet without getting into more exotic materials.

There are a couple ways you could disable the outputs on our STSPIN220 carrier using digital output pins from a Raspberry Pi. From the “Control inputs and status outputs” section of our STSPIN220 carrier product page: