Need help setting up motor settings in config.g for delta

  • Here is what I have
    • Printer is Delta style with cross bracing to limit the bending of the towers
    • With Huntley Carriage, effector and magnetic arms
    • 9mm GT2 belt with 16 teeth pully
    • Motors are:
    For XYZ: Nema 17 1.8deg 2A 59Ncm
    Extruder: Nema 17 1.8deg 1.5A bowben drive Type
    • XYZ Motors are installed with Rubber Stepper Motor Vibration Damper
    • Duet WIFI v1.02
    • 24v power supply

    Currently my config.g settings are
    M350 X32 Y32 Z32 E16 I1 ; Configure micro stepping with interpolation
    M92 X200 Y200 Z200 E663 ; Set steps per mm
    M566 X1200 Y1200 Z1200 E1200 ; Set maximum instantaneous speed changes (mm/min)
    M203 X18000 Y18000 Z18000 E18000 ; Set maximum speeds (mm/min)
    M201 X3000 Y3000 Z3000 E3000 ; Set accelerations (mm/s^2)
    M906 X1700 Y1700 Z1700 E1200 I30 ; Set motor currents (mA) and motor idle factor in per cent

    Can my acceleration, speed and Inst. speed setting be increased? Am I better off with 16 micro stepping?
    I’m new to this, any help is appreciated?

  • administrators

    Your settings look good to me, except that you may find the motors are quieter with x16 microstepping because then the I1 parameter will work and give you x256 microstepping by interpolation.

    Increasing maximum speed in M203 is unlikely to help unless your delta is very large. Increasing acceleration in M201 may speed up printing a little, but may also increase ringing.

    You can use the calculator at to find the maximum speed before torque starts to drop off.

  • This is what I got
    Approximate peak back EMF due to rotation per motor: 8.2 V at 200.0 mm/s
    Approximate peak back EMF due to inductance per motor: 1.6 V at 200.0 mm/s
    Step pulse frequency: 20.0 kHz at 200.0 mm/s
    Speed at which torque starts to drop (low slip angle): 152.5 mm/s @ 25.9 kHz
    Speed at which torque starts to drop (high slip angle): 208.9 mm/s @ 35.5 kHz

    This is with 1.7A current.

    If lower my current to 1.5
    I get this
    Speed at which torque starts to drop (low slip angle): 163.4 mm/s @ 27.8 kHz
    Speed at which torque starts to drop (high slip angle): 224.4 mm/s @ 38.1 kHz

    Am I better off with lowering my current?

    Also my printer build area is 200mm wide with 450 mm Hight.

  • administrators

    Reducing current reduces torque at low speeds, but the torque at speeds beyond the drop-off point remains unchanged. So it doesn't help to reduce the current.

    However, the figures from the calculator that you quote don't look consistent to me, so I will check them.

  • oh ok, I misunderstood the drops-off values,
    my stepper motor part # is 17HS19-2004S

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