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I've noticed several times that one of my stepper motors is making a slight noise after a print is finished, indicating it's still enabled; also, the axes are still statically positioned and unmovable.

I meant that the stepper motors are still powered. Usually, after a print, the extruder moves up and away, and the bed moves to the front. However, some X seconds after that, I would like to automatically turn off the steppers because it could potentially preserve the lifetime of my stepper motors.

  • Is this a common practice, and if so, does this method have a name?
  • Does it indeed potentially increase lifetime?
  • How to do it? (By simply adding M18/M84 at the end of my G-code using a Cura script or using an OctoPi plugin?)
  • Are there any other pros or cons to powering off stepper motors after the print has finished?
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    $\begingroup$ NAA: De-energising coils will probably extend the life by a certain amount, depending upon usage patterns. That is to say that the gain would be proportional to the times that (1) the printer is normally operational & (2) operationally idle. IOW, if you generally just switch the printer on for a job and then off, then disabling the steppers probably won't extend life much. But at the other extreme, if the printer is on 24/7, but idling for most of that time, then de-energising the steppers coils will help considerably more. Also, saving any amount of electricity is always a good idea :-) $\endgroup$
    – Greenonline
    Nov 27, 2023 at 17:47

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While it's plausible that it might increase lifetime, I doubt it. Unless you're driving them out of spec and allowing them to overheat, motor coils should last pretty much indefinitely. The main wear component in a stepper motor is the bearings, not the coils, and the bearings do not get any additional wear from having the coils energized, only from actually turning.

The advantage you do get from turning off the steppers is energy savings. As long as the stepper is energized, you're burning roughly $I^2R$ watts, where $I$ is the current you're driving the motor at and $R$ is the coil resistance. You also eliminate the stepper hum, which can be really infuriating to some people's ears, and if your board has properly firmware-switchable fans, you let the fans power down too, which also saves energy and cuts noise.

Another aspect that can be an advantage or a disadvantage is that, once steppers are powered off, you can move the motion components by hand. This can be nice for adjusting the toolhead and bed to remove the completed print, but it can also cause the toolhead or bed to fall due to gravity, which can lead to damage to the printed part or the printer. If this is an issue, on most kinematic systems (pretty much anything but delta or corexz) you can leave the Z stepper(s) energized between prints, and only disable the X/Y ones. The reduction gearing/leadscrew lead on most printers makes it so Z doesn't need anywhere near the current of X/Y, so turning off X/Y and just leaving Z engaged still gets you most of the power conservation.

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