Maestro with 2A steppers?



  • Hi, I am relatively unexperienced with 3d printing hardware. I have a cartesian machine with 2 amps steppermotors (Rated Current/phase: 2.0A, Voltage: 2.8V, Phase Resistance: 1.4ohms) and a 12V power supply that I used for engraving with the Arduino CNC shield.
    I wanted to turn the machine into a printer, so I got a 24V power supply and a Duet2 Maestro. I suspected that I could just reduce the motor current by software and should get away with it. But after reading the Duet3d documentation I am not sure if I can run these motors with the Maestro. I dont need all the torque, but I fear that the board might get too hot.
    Is it possible to run those steppers or do I need to get something like the Duet2 Ethernet?

    Thanks


  • administrators

    2A motors are not ideal for the Maestro, but workable. Use a fan - see the cooling recommendations for the Maestro. Try motor currents in the range 1.2A to 1.5A.


  • Moderator

    @jhenn You usually aim to run motors at 85% of their rated current, so a 2A stepper motor would run at 1.7A. This is to stop the motor overheating. See https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors#Section_Rated_current
    The Maestro motor drivers can provide up to 1.6A. This is a bit lower than ideal, but should still be plenty to drive the steppers. As for overheating at this current, see my post here: https://forum.duet3d.com/post/120307
    Mounting the board vertically, and with a fan blowing on the backside would help keep it cool, too. You could drop the current to 1.4A to keep it running without additional cooling, assuming your ambient temperature isn't too high.

    Ian



  • Thanks, both of you!

    So reducing the current via firmware does reduce the heat produced. This is what I originally thought (and what my understanding of physics tells me 😉 ) but the Duet-documentation kind of confused me there.


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