Stall homing: Is it less accurate with a 24v supply vs 12v?



  • So I am in the middle of designing a printer mainly based around the framework of my FT-5.

    I found that stall homing is a thing and think it is very interesting. But from my understanding on how it works, the driver monitors the current draw and checks for a spike.

    So that being said does 12v yield higher accuracy results vs 24v? Since 12v would require higher current to drive the components, a spike at higher current as well as with a spike at 12v would be more noticeable as an offset or outlier vs a spike at 24v since it would need less current to drive the components.

    Or am I overthinking this? Never thought going down to 12v would be so appealing until now.


  • administrators

    The drivers measure the phase of the back EMF, not the current. If anything, I would expect higher inductance motors with a 24v supply to provide better stall detection than low inductance motors and a 12V supply. That's also what Prusa uses in the i3.



  • I am not super familiar with EMF but if it isn't using current as its measuring parameter then that is all I was concerned with.

    As for the high inductance motors, is there something specific I would need to search for to determine a high inductance motor vs a standard/low inductance motor? I am looking to use a 0.9 degree stepper on my z axis, is there something else I should be shooting for?


  • administrators

    @fickert said in Stall homing: Is it less accurate with a 24v supply vs 12v?:

    I am not super familiar with EMF but if it isn't using current as its measuring parameter then that is all I was concerned with.

    As for the high inductance motors, is there something specific I would need to search for to determine a high inductance motor vs a standard/low inductance motor? I am looking to use a 0.9 degree stepper on my z axis, is there something else I should be shooting for?

    Lower current motors have higher inductance. For the Duet WiFi/Ethernet, choose motors with a rated current of at least 1A, preferably a little higher. There are motors available with rated currents of 1.2A and 1.33A.

    High inductance motors limit the maximum speed you can use before torque starts to drop off and stall detection stops working, but using 24V power instead of 12V mitigates this.


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