Hot stepper driver

  • Good afternoon, everyone,

    I have a little problem, when I run my engines on X and Y for more than 3 minutes, the stepper drivers on the X and Y axis get very hot. I don't have a precise temperature but when I put my finger on the driver to check, we can be surprised. I supply my Duet Ethernet card with 24 Volts and the motors are Nema 23 with the following characteristics :

    • Manufacturer Part Number: 23HS22-1504S
    • Motor Type: Bipolar Stepper
    • Step Angle: 1.8 deg
    • Holding Torque: 1.16Nm (
    • Rated Current/phase: 1.5A
    • Voltage: 5.4V
    • Phase Resistance: 3.6ohms
    • Inductance: 13mH ± 20%(1KHz)

    and here is the link to the complete doc :[Bipolar]%2C149-step-angle[1.8]%2C145-holding-torque-ncm[90%2C116%2C126%2C135%2C189%2C190%2C240%2C250%2C280%2C283%2C300]

    I don't know if it's my voltage or my inductance that's too high? or if it's something completely different.

    Thank you in advance for your future answers

  • Do you have the stepper currents set around 80% of the max?

    So if your steppers are rated at 1.5A the current should be about 1.2A or 1200 in your config file.

  • The question is how much current can your drivers handle supplying?

  • administrators

    @philmeiklejohn the drivers are limited in firmware to 2.4A RMS. With good passive cooling and fairly low ambient temperatures we have users using them up to 2A (standby current reduction helps to give them a chance to cool when not is use) Anything over that, or situations where there is a high ambient then a fan to cool the back of the board is required.

  • Hello and thank for your answers

    my config file :

    ; Drives
    M569 P0 S1                     ; Drive 0 goes forwards
    M569 P1 S1                     ; Drive 1 goes forwards
    M569 P2 S1                     ; Drive 2 goes forwards
    M569 P3 S1                     ; Drive 3 goes forwards
    M350 X16 Y16 Z16 E16 I1        ; Configure microstepping with interpolation
    M92 X80 Y80 Z4000 E420         ; Set steps per mm
    M566 X900 Y900 Z12 E120        ; Set maximum instantaneous speed changes (mm/min)
    M203 X6000 Y6000 Z180 E1200    ; Set maximum speeds (mm/min)
    M201 X500 Y20 Z250 E250        ; Set accelerations (mm/s^2)
    M906 X800 Y800 Z800 E800 I30   ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30                        ; Set idle timeout

    I've tried different currents, but nothing works.
    For the ambient temperature, the card is located in a room where the temperature is maintained at 22°C with air conditioning.

  • 800 is not a lot of current to the motors. Are you getting a drive over temperature alarm or just going by touch?

    If you aren't getting an alarm I would worry about how hot it feels. I run my Nema 23 steppers at 1800 with temp controlled active cooling but the fan doesn't run very often.

  • actually, I've never had an alarm before. I wanted to know if it wouldn't damage the engine pilots, but it doesn't seem to be the case.
    Thank you very much for your answers


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