Bed-leveling - Probe grinds over surface between measured point

Domingo

Hello,
I tried implementing a 3Dtouch bed level sensor in repetier 0.92.9 and am probing a 4x4 matrix. It does work as expected, the only problem is, that when moving between the points, the probe grinds over the surface and is triggered here and there, depending on the bed level and on some bed coating wrinkles. How can I make the Z-axis move a bit up, e.g. 5mm, to give the probe some room while moving XY, and then probe the next point?

// #################### Z-Probing #####################

#define Z_PROBE_Z_OFFSET 0

#define Z_PROBE_Z_OFFSET_MODE 0

#define UI_BED_COATING 0

#define FEATURE_Z_PROBE 1

#define Z_PROBE_BED_DISTANCE 10

#define Z_PROBE_PIN 51

#define Z_PROBE_PULLUP 0

#define Z_PROBE_ON_HIGH 1

#define Z_PROBE_X_OFFSET -25

#define Z_PROBE_Y_OFFSET 12

#define Z_PROBE_WAIT_BEFORE_TEST 0

#define Z_PROBE_SPEED 2

#define Z_PROBE_XY_SPEED 500

#define Z_PROBE_SWITCHING_DISTANCE 2

#define Z_PROBE_REPETITIONS 2

#define Z_PROBE_HEIGHT 2

#define Z_PROBE_START_SCRIPT "M340 P1 S650"

#define Z_PROBE_FINISHED_SCRIPT "M340 P1 S1500"

#define Z_PROBE_REQUIRES_HEATING 0

#define Z_PROBE_MIN_TEMPERATURE 150

#define FEATURE_AUTOLEVEL 1

#define Z_PROBE_X1 30

#define Z_PROBE_Y1 0

#define Z_PROBE_X2 750

#define Z_PROBE_Y2 0

#define Z_PROBE_X3 30

#define Z_PROBE_Y3 680

#define BED_LEVELING_METHOD 1

#define BED_CORRECTION_METHOD 0

#define BED_LEVELING_GRID_SIZE 4

#define BED_LEVELING_REPETITIONS 2

#define BED_MOTOR_1_X 0

#define BED_MOTOR_1_Y 0

#define BED_MOTOR_2_X 200

#define BED_MOTOR_2_Y 0

#define BED_MOTOR_3_X 100

#define BED_MOTOR_3_Y 200

#define BENDING_CORRECTION_A 0

#define BENDING_CORRECTION_B 0

#define BENDING_CORRECTION_C 0

#define FEATURE_AXISCOMP 0

#define AXISCOMP_TANXY 0

#define AXISCOMP_TANYZ 0

#define AXISCOMP_TANXZ 0

Repetier

That is what Z_PROBE_BED_DISTANCE is for. Increase that value (in eeprom I think it also exists). If you start it after homing make sure the start height you are at is high enough.

Domingo

what does the value mean? I had it at 10 and 30 and 100, it doesn't change anything. what distance from where to where is meant?

Repetier

Between z probe bottom and bed is meant. You also need to check in eeprom what value is set there.

If you use z max homing a z height being too high will reduce the distance as well.

Domingo

I use z-min homing with the printhead being off the bed and homing about 3mm sub surface. then I move to Z10 (which leads to about 7mm nozzle to bed and 5mm 3d-touch to bed) and start bed sensing. the first point starts with about 5mm from untriggered 3Dtouch to the bed, goes down until trigger, repeat one time, go up until the probe does not trigger any more and move to the next point. the sensor pin is grinding over the surface.

Repetier

So your bed is more then 5mm in height difference?

When you run G30 P0 several times does it always return to original height? It uses same function as G32 but should be easier to see what happens what you manually do it.

You said you have repetitions. For repetitions there is a short distance up value. That must be high enough  so you can redeploy the pin or you get problems. So might also be that that value is too low.