Hello all! I'm sure this has been mentioned a number of times, but reading through some of these didn't seem to EXACTLY hit the mark on what I was dealing with, so I figured it might not be a bad idea to share my issue. I was running my printer (Rostock Max V2 with e3d v6 extruder, several other upgrades) for the better part of a week getting some prints ready for a convention coming up. I was printing duplicate pieces that took 11 hours each, so every 11 hours the printer would stop, I'd pull the finished prints off, clean the bed a little, apply adhesive to bed, then start the next print. Rinse and repeat! I went through two rolls of clear filament (solutech clear filament, 1.75mm) with no issue and was starting the third roll when I started to notice a decline in print quality. The pieces were starting to show reduced flow on several layers, thinning, general weak layer adhesion. I stopped my printer and inspected the hot end after it had cooled enough to handle. Eventually, I disassembled the hot end and inspected everywhere that the filament travels once it leaves the PTFE (which I also inspected. It's a flat end, uncut, going right up to the heat break.) and cleaned it. Even took one of those nozzle drills (.4mm) and cleared the nozzle tip, just to be sure there wasn't anything in there. I could see all the way through it and saw no blockages so I thought that maybe whatever I cleaned out of it might have been the problem. Put it all back together, heated it up, fed some filament through it: it worked! Awesome! Started a new print, and went away for an hour. Came back and the same issue returned! The last 20-30 layers were whispy and almost like they were being laid down through a clogged nozzle again. Stopped the print and walked away. I was defeated for the day. I plan on inspecting it some more tonight to see what the problem could be, but I'm reaching out for ANY feedback from the community. This started to creep up slowly over the course of about... 150 meters of filament but before that had no problem so I would be hard pressed to think it is anything north of the hot end (extruder is fine, pushes filament with ease. PTFE has minimal excess length to reduce buckling/springing inside the tube, filament is not binding, etc...). Just as a backup, I've ordered three replacement nozzles so I can have some spares and perhaps hopefully that will solve the problem. If that ends up being the case: Could it be that my filament is just really low quality and slowly bogged down the nozzle? Thanks in advance for your feedback all, it's greatly appreciated!