Hi eddygara,
did you solve this issue already ?
I had been fighting for z-axis calibration for a long time and can confirm this is very important for the printing.
The first layer must be best on the hole print.
Some of the outcome that I find during my calibration cycles so far.
You need to be sure that the probe mount is good enough to have a reoccuring precission.
I had printed my first z-Probe mount myself and that was always changing the hight of the IR_sensor for some 1/100 to 1/10 mm resulting in the printnozzle being much to high. I change to a metal mount and this has solved this chaning z-Probe height issues
You need adjust the z height parameter in the G31 command in the config and after saving the config.g you need to power cycle the duet (if not already suggested by the firmware anyway) Please be sure, when using a sheet of paper the z value of the nozzle is not 0 but t he thickness of the paper ! You may see that the printed surface is still not close, than reduce the nozzle height in som 1/100 mm steps.
Note I : The height of the nozzle is only set for this one point you adjusted, this is sufficient if your print bed is 100% flat and horizontal. If this is not the case, you need to calibrate the bed or use autocalibration ( that is another story)
Note II : If the nozzle is too high, you need to increase the value for the Z parameter of G31, telling the firmware at the triggered height position the nozzle is a bit higher over the bed. Than the firmware knows the bed is a bit deeper under the nozzle.
Normally if you have set the G31 Z height correctly ,the nozzle height should be always set correctly and reproducable.
You may want to heat up the nozzle and the bed to the temperature you use normaly, as there might be some heat elongation, depending on the materials you have used.
