I'm trying to run a SPS-15RF stepper motor from an old cd rom drive. I'm using a CNC shield and a4988 driver with a 6v power supply. The motion is smooth and fine. I know it has 18 pulse/revolution and works with 5v but It gets quite unexpectedly hot. It feels that it can burn my fingers if I keep it running. What is wrong with it? is it related to micro-stepping or sth else!?enter image description here

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  • 2
    Those motors are not designed to be constantly driven. They are designed to move to one position and then "release" (that is, the power is removed and active driving ceases).
    – Majenko
    Commented May 14, 2021 at 14:16
  • 5
    Maybe you need to trim down the motor current at the driver. When the motor gets hot at continous use with the normal current, you could lower it, so that it doesn't get hot anymore
    – chrisl
    Commented May 14, 2021 at 17:18
  • 1
    don't forget to "release" - disable driver when not actively moving (pin is called EN)
    – Abel
    Commented May 15, 2021 at 3:24
  • 1
    @chrisl How can I trim down the motor current?
    – 2012User
    Commented May 15, 2021 at 5:56
  • 1
    Normally a stepper driver gas a little potentiometer on it, that you can rotate with a small screwdriver. That is used to set the motor current
    – chrisl
    Commented May 15, 2021 at 7:30


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