Nozzle rubs on print leading to blob/lifting
I've recently upgraded my MK3S+ to a stock MK4S via the kit. The first 20 or so prints were spot on a problem free. However, now every print fails. I've performed a full recalibration of the machine, but that hasn't helped. I find that very early on in the print, on the first layers, the nozzle accumulates filament which eventually rubs against the print, causing it to lift. From what I can tell, it is not poor adhesion – I'm using a smooth plate, freshly cleaned with IPA, printing PETG – which I gather is not usually recommended as there is usually too much adhesion. I'm using a brand-new reel of Prusament PETG, and have previously had no issues with this type of filament.
I would much appreciate any suggestions on a methodical approach to debugging and resolving this problem. Thanks.
RE: Nozzle rubs on print leading to blob/lifting
I would try a cold pull test first. You should be able to access this in your settings menu on the MK4S. Another thing I noticed is with the new update, it does seem to change some settings or clearances. I had some custom settings on the MK4s, but with the new update I reverted certain things back to its original or default state and it seemed to fix the issue. Not sure if anyone else had this issue or not, but mine was extremely similar to the issue you are having. Good luck and keep us updated.
RE:
I tried a cold-pull, no joy. Then I replaced with a brand new nozzle. However, still suffering from the same behaviour unfortunately. I've also tried reducing flow rate to 95%. I miss Z-adjust 🙁
RE: Nozzle rubs on print leading to blob/lifting
Ok, so tried another spool of the filament - a 1kg instead of 2kg. There was still a little blobbing on the nozzle but overall the print was much better. Now to figure out what factor is the source of the difference.