BTT SKR 1.4 Turbo - No Z Movement

I got back to working on my Herculien - replacing the smoothieboard with the BTT SKR 1.4 Turbo. I cannot seem to get the Z Axis working. X, Y, Extruder, and heated bed are all functioning.
I swapped the Y and Z to test the motor, and swapped the drivers (2209) to make sure the driver was good

I did add a BLTouch and have it wired to the servo and probe port.

Would anyone have time to look at my configuration.h to see if I have done something wrong?

I know C and have edited my own Marlin Configuration.h before to get an induction sensor working, so I have some idea of what I’m doing. I recall my misconfiguration permanently triggering end stop hits causing similar movement errors.

But, I haven’t used the BLTouch before, so here are some guesses from another pair of eyes, so take these ideas with a grain of salt:

Does it need to be inverted from default config?
#define Z_MIN_PROBE_ENDSTOP_INVERTING false // Set to true to invert the logic of the probe.

Also, I see you commented this out, perhaps by mistake?

  • Enable this option for a probe connected to the Z-MIN pin.
  • The probe replaces the Z-MIN endstop and is used for Z homing.
  • (Automatically enables USE_PROBE_FOR_Z_HOMING.)
    //#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN //commented out 11-29-2020 BL

Also this:
// Force the use of the probe for Z-axis homing

Or this (if this pin on your board needs to be defined):
//#define Z_MIN_PROBE_PIN 32 // Pin 32 is the RAMPS default

Comment says BLTouch emulates a servo–do you need to uncomment the servo probe line(s)?

  • Z Servo Probe, such as an endstop switch on a rotating arm.
    //#define Z_PROBE_SERVO_NR 0 // Defaults to SERVO 0 connector.
    //#define Z_SERVO_ANGLES { 70, 0 } // Z Servo Deploy and Stow angles


  • The BLTouch probe uses a Hall effect sensor and emulates a servo.
    #define BLTOUCH

I doubt this is the problem, but possibly good to uncomment?
//#define Z_SAFE_HOMING

Hope this helps, or at least gives you ideas for something else to check.


Thanks! I will study these areas and see if these suggestions will get me rolling.