I'm having an issue with my printer that I rebuilt and installed a Duet 3 and a BLTouch on. The issue I'm having is that my z-offset is not consistent, and I'm not just splitting hairs and talking about +/- 0.05mm, I'm talking about +/-0.8mm. Basically I cannot reliably start a print without needing to be quick on the baby stepping to quickly move the nozzle out of the bed surface, or drop it form mid air to the bed.
When I start a print, in my starting script I have a G30 to probe the bed and reset the 0 offset for Z. Then I load the mesh from a file using the G29 S1. The print head then moves over to the purge bucket and extrudes a bit of platic. Then it quickly moves to the starting point of the print, which is always a skit that is at least 3 to 4 perimeters to give me time to get the baby stepping done.
But here is an example, I will start a print and need to add say 0.3mm in baby stepping. Then I will start that same print again and I may need to either add upto another 0.3mm or I might need to remove some baby steps.
I would think that the obvious is that the probe is loose, but It is not, everything is quite secure. Is there anything else that I should check?