Z axis stepper motor problem - mini rambo

Hi guys,

Have found that the issue I was having is that the stepper motor does not move properly at all.

I have got the Mini rambo board running on 12v, am using 40nm Nema17 motors. If I take one of the nema motors from the X or Y and plug it into the port of Z, then it does not turn the motor much at all. Rather a bit of a funny grinding noise.

All other ports on the Mini Rambo work as expected, and run very smoothly. Am at the point to start trying to use the machine now to cut some thin MDF and polycarbonate.

Any hints as to what I can try?

I have plugged the stepper motor into the extruder port on the mini rambo and can confirm that it turns the Z stepper motor with no issue, however when plugging into the Z Axis port/s it just makes a rumbling sound and doesn’t quite rotate the motor.

I forgot to mention that I am testing using the LCD controller only at the moment and X and Y are moving smooth as silk. I have also taken the stepper motor off the Z axis for testing so it is loose and confirming it cannot bind etc.


Here is a video of the issue

To show the motor works on Extruder port and wires up right.


Y Port with the same motor working great

If the driver for Z is dead or has issues, can I swap out the pins somehow in the firmware to use the extruder port?

Disregard, read farther down.

For now I have amended the pins_MINIRAMBO.h to switch the Z and E over.
It seems to work well. Please advise if this will cause any later issues. I don’t ever plan to use this machine for a printer as I already have 2 printers.

#define Z_STEP_PIN 34 #define Z_DIR_PIN 43 #define Z_ENABLE_PIN 26

#define E0_STEP_PIN 35
#define E0_DIR_PIN 47
#define E0_ENABLE_PIN 27