Do you guys know a stepper motor that is compatible with Neptune 3 pro ?

Mine looks like it’s locked, it makes a short click but doesn’t move.

I try to open it but don’t find anything wrong.

So two questions, what motor can I buy to replace it ?

And there is a way to fix this motor ? Like, rewind it will make it works again ?

Thank you guys

  • @srqwertOPEnglish
    1•1 year ago

    First of all thank you for your answer.

    I will try to test it with the x axis I don’t know that will work.

    I try to put a led and it light up ok on both poles.

    I did search using the number on the motor, but I wasn’t able to find the exact model.

    So can I just buy a similar size and wires and fine tuning in the firmware if anything goes wrong ?

    The bill of material just says 42HD1418-01,Two-phase,25mm.

    So any nema with 25 mm and 4 wires will work ?

    Sorry for the lots of questions, but I’m a little lost in this replacement.

    • @rambosEnglish
      1•1 year ago

      Ye I couldn’t find any datasheet of that one. Maybe e-mail them and ask?

      Well, I’d say any Nema17 bipolar (4 wires) 25 mm in length (similar current) and probably 1.8°/step or 200 steps/revolution (like most of them) should work. If you get wrong resolution (steps/revolution) your extruder will move wrong distance (like double), but you can change that in FW. And you should fine tune Vref (small screw on your stepper driver or in FW) to find sweet spot between heating and torque

      • @rambosEnglish
        2•1 year ago

        You can do some math to identify resolution. Check your FW, quick search got me:

        * Default Axis Steps Per Unit (linear=steps/mm, rotational=steps/°)
 * Override with M92
 *                                      X, Y, Z [, I [, J [, K...]]], E0 [, E1[, E2...]]
 */
#if NEPTUNE_3_PRO
  #define DEFAULT_AXIS_STEPS_PER_UNIT   {80.00, 80.00, 400.00, 380.00}
#elif NEPTUNE_3_PLUS
  #define DEFAULT_AXIS_STEPS_PER_UNIT   {80.00, 80.00, 400.00, 390.00}
#elif NEPTUNE_3_MAX
  #define DEFAULT_AXIS_STEPS_PER_UNIT   {80.20, 80.20, 400.00, 390.00}
#endif

        I guess its 380 steps/mm, but I should go deeper in that and do some math (gear teeth numbers, grub screw diameter) to confirm what resolution is original. Shouldnt be hard if you get all information needed, but still easier to ask them what stepper is that. Since its kinda standard 200 steps/rev would be my bet