Large Surface Print Failing on Top Most Layers Only

[nweishar]

I have a consistent issue where I’m trying to print a large flat surface model, and for 98% of the print it goes perfectly. Only when it starts to print the Top Surface layers, things go sideways and the print quality tanks.

I’ve used clamps on the bed to ensure it stays perfectly flat (thinking that warping was causing this issue), but that didn’t fix it. Whats confusing is that as the print approaches the end, the first top layer goes overtop of the infill perfectly. Its only when it switches to the top shell layers. This further indicates warping isn’t an issue.

Its like the printer all of a sudden changes the settings and the print fails. It literally is perfect until the last 3-5 layers. Lots of fun too when you’re looking at a 10 hour print, it looks great all through out then just fails at the end. So its been hard to troubleshoot and costly - Any help would be so much appreciated!!!

P1S
Bambu Slicer
Bambu Basic PETG

[nweishar]

Found the solution and it was infill combination. Once I turned that off, everything went according to plan.

For the minuscule savings it provides, I’ll be decommissioning that feature as part of my standard set going forward.

[Lenyo]

Nice find, you should mark your answer reply as the solution of the thread to close it out.

I had looked here and didn’t have any idea so never commented until now, glad you found and fixed it!