17BB-H132-11 Stepper Warm to the Touch

I just got my stepper motor working. Plugged it into a TB6612FNG and a 12V wall wart for power. Been spinning it like crazy on my desk, reveling in my new accomplishment. However, I just noticed it's quite warm. Not "oh I just burned myself" warm, but too warm for me to just hold comfortably. From what I gather, this is normal. I am, afterall, running current through it constantly. What I don't know is whether or not I should worry about it overheating. I don't have any load on it yet, just toying around with it free-spinning on my desk. Any concerns?


  • Warm steppers are usually nothing to be concerned about. But, just to be sure, what's the winding resistance and current rating of the stepper?

  • Once the motor is up to speed you can drop the current but in the case of this chip it happens to be fixed but I noticed it had PWM input so maybe if you apply a little PWM at a suitable frequency you can reduce power consumption.
  • Haven't found a current rating. Sticker on the motor says 75 ohms and 12V.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,624
    edited 2017-07-14 - 04:53:06
    Okay, that would imply 160 mA, or 1.92 W per winding. With two windings dissipating power at the same time, that would amount to about 4W. So, yeah, it's gonna get a little warm. 'Nothing to worry about.

    But Peter is right: you don't need maximum input current if the motor is holding a position or up to speed -- unless there's an opposing torque.

Sign In or Register to comment.