Sudden Print Issues
I printed over night just fine, went to make another print this morning and all hell broke loose, I can't figure out what's going on. Everything is ending up like a rats nest. When I look at the nozzle near the bed, half the time the filament is curling back, not sticking to the bed. Initially I thought maybe something changed with my z-adj, so I did a calibration, and that came out perfect. I put a new bed sheet on, did another calibration, perfect again. So I started the print again, and it still prints like a rats nest. Could this be a filament issue by chance? I'm not sure where else to look.
Just tried a brand new, unopened roll from Prusa, it started printing fine, then went got loose and made a mess.
Sounds like adhesion problems, throughly wash the sheet with dish soap and hot water and dry with paper towels. Alcohol is OK for between prints when you haven't touched the sheet but it doesn't properly remove grease.
Posting us some pictures is useful for us to give more suggestions.