3dTouch auto leveller

[geoff]

It a Geeetech I3 Pro B gt2560 rev A+ Every thing works except calibrating it when you get to The LCD display should show Z = 0

From the display go to the Menu then Prepare/Move axis/0.1mm/Move Z

Now move the Z axis slowly down until the nozzle is the right distance from the build plate (folded piece of paper or thin card).
I can not move it down by the display or by the repeater does any know what i'm doing wrong
Thanks Geoff

[JohnDeere630]

geoff, did you get this sorted? There is a setting in config.h that allows negative z movements, but where it is depends on the firmware version. On Marlin 1.1.8, it is this, in the z-probe section, starting at line 803:

// Min software endstops curtail movement below minimum coordinate bounds
#define MIN_SOFTWARE_ENDSTOPS
#if ENABLED(MIN_SOFTWARE_ENDSTOPS)
#define MIN_SOFTWARE_ENDSTOP_X
#define MIN_SOFTWARE_ENDSTOP_Y
//#define MIN_SOFTWARE_ENDSTOP_Z
#endif

Note that the #define MIN_SOFTWARE_ENDSTOP_Z is commented out.

[William]

geoff, did you get this sorted? There is a setting in config.h that allows negative z movements, but where it is depends on the firmware version. On Marlin 1.1.8, it is this, in the z-probe section, starting at line 803:

// Min software endstops curtail movement below minimum coordinate bounds
#define MIN_SOFTWARE_ENDSTOPS
#if ENABLED(MIN_SOFTWARE_ENDSTOPS)
#define MIN_SOFTWARE_ENDSTOP_X
#define MIN_SOFTWARE_ENDSTOP_Y
//#define MIN_SOFTWARE_ENDSTOP_Z
#endif

Note that the #define MIN_SOFTWARE_ENDSTOP_Z is commented out.

You are correct

[GJRTimmer]

Also; when you connect with USB, and for example Repetier-Host, you can simple send the Following commands:

"M211 S0" => Disable Software endstops
Do your calibration, after sending M211 S0, you will be able to select Move Z-Axis => 0.1mm and move negative.
"M211 S1" => Enable Software endstops.

Benefits are that the firmware software endstop is enforced on printer restart.
So you only need it for calibration.