New Firmware Z probe Offset setting

LowRider CNC Troubleshooting
1

I think the setting for probe offset in the latest firmware (415?) is not working correctly. In my previous version (last year sometime) I could set it with the following lines in the configuration.h file (syntax may be off as I am not at my computer)

X_PROBE_OFFSET_FROM_EXTRUDER 10
Y_PROBE_OFFSET_FROM_EXTRUDER 10
Z_PROBE_OFFSET_FROM_EXTRUDER 0.92

The latest seems to have grouped this into a single line (though I cannot recall exact syntax, the correct line is in the configuration.h file). The new style does not seem to be in the marlin docs yet.

XYZ_PROBE_OFFSETS_FROM_NOZZLE ( 10, 10, 0.92)

Problem is it does not seem to be using the value that is set. Probe works, but indicates 0 instead of the probe thickness. I know I could use a G92 in the start gcode but I have become used to having it set in firmware. Has anyone else experienced this?

2

I believe if the Z probe triggers when the tool is above the work piece (as would be the case with a touch-plate), you need a negative Z offset.

Also, if you’re using the tool itself, won’t your X and Y offsets be zero? Do you have a permanently mounted Z probe separate from the tool?

3

Yes. My old value was -0.92 , but since I am in a doctors office waiting I probably typed it wrong in the above post. Pretty sure I have it right in the firmware, but I will double triple check once I get home. It may be I have it wrong and used a positive value. That might result in the zero since I have a zero limit set for z after homing.

The x and y values are the defaults, but ignored as I don’t probe for x or y (yet).

4

You can adjust and see the value of at least the Z offset with an m code. M851.

I wonder if there is an issue with the EEPROM. You can also try an M502 to reset to the defaults (make sure you save with M500.

5

Problem solved. When I did the line by line compare to transfer my settings over from old to new, I missed the line that defines the probe type. Duh!

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