BLTOUCH BED LEVELING CR-10

BLTouchBedLeveling

BLTOUCH BED LEVELING 

G28 instructs the printer to home itself to the X an Y endstops and the Z sensor determines the homing of the Z axis; i.e. when the sensor triggers, this is not necessarily (and most commonly) not the position where the nozzle is at Z=0.

G29 determines the shape of the bed by probing the bed. This will set the shape of the bed with respect to the sensor trigger point as described earlier. The Z-offset (set by M851 Z-x.xx is needed to set the offset between the nozzle and the sensor trigger point (to the bed).

The sequence to determine the offset is:

M851 Z0; // Set the Z offset to zero height
G28;     // Home Z in the middle of the bed
G1 Z0;   // This will move the head to zero height;
M211 S0; // This will disable the end stops so that you 
         // will be able to proceed lower than Z=0
Now adjust Z height to fit a piece of paper and note the negative Z height (either through the LCD or through an application over USB)

M851 Z-1.23; // Define the Z offset
M500;        // Store the settings
M211 S1;     // Enable the end stops again
Please note that -1.23 is a fictive value that should be replaced by your own value.