Update following advice from @R..GitHubSTOPHELPINGICE in the comments - I've increased the Z-offset from -2.97 to -3.10 and all now appears to be much better.
- Printer: Ender 3 V2 with heated glass bed
- Slicer: Cura 4.11
- Temps: extruder 215 °C, bed 65 °C first layer, 60 °C remaining (works the best for the filament I'm using, lower for other filament).
- Filament: 3DTomorrow UK PLA Filament - Anthracite Grey - 1.75 mm (But happens with all others too e.g. ERYONE, ZIRO)
- Summary: On the first layer, every time the printer starts extruding to the bed after a move, the first approx. 10 mm doesn't stick, but the rest sticks perfectly.
The issue, as an example, I'm trying to print a case for a Raspberry Pi which has air vents on the bottom. When the print starts, it does the line down the side which the first ~ 10 mm doesn't stick, but the rest does perfectly. It prints the skirt, which again the first ~ 10 mm doesn't stick, but the rest does, then when it gets to doing the vent slots, the same again.
The photo hopefully shows what I'm trying to explain.
When printing a raft, again the first ~ 10 mm of the extrude doesn't stick, but the remaining does.
Once the raft is printed, the first layer sticks to it perfectly well
The bed is pretty level, I'm using a BLTouch to assist and has been cleaned with alcohol before the print. Bed has been levelled and the Z-offset calibrated to -2.97.
I have Enable Retraction on, 5 mm, 45 mm/s speed. I've tried increasing and reducing these, increasing/decreasing print speed, manual Z-axis offset fine adjustments, etc.
I did think First 3 mm prints poorly, then fine after that was kind of the same issue, but there's no discussion of the issue being for every touch of the bed within the same print job.
Any advice would be appreciated. I've loitered this community for quite a while and lots of Google searching hasn't come up with any suggestions (there's actually very little I could find on this kind of troubleshooting).