Bad layer printing part way into print. Layers separating.

[wirlybird]

Solutech PLA at 210 on 60 bed Flashforge Creator Pro and S3D.

The first several layers were printing fine then when I came back I had this mess. The loose strands are from me just scraping my finger nails across the layer and they just peeled like a banana - no adhesion.

You can see the overall poor quality of the top layer and the one below it. Is this mainly just poor filament?

Thanks for your opinions and thoughts.

[jfield]

I had a problem when I first got my printer where when the part cooling fan turned up after the first layers, I would have poor layer adhesion/extrusion gaps. I watched it while printing and saw my actual extrusion temp dropping when the fan was running faster. I adjusted my fans so it wouldn’t blow on the heater block.

[wirlybird]

Thanks. Fan has never been an issue and the temp seems to hold ok. I did however have a problem with the hot end cooling once when the insulation came off. The first 3-4 layers seem to do fine and look ok. Thought it could have been a bad file but I did this several times and get similar results.

One of my guesses is big fluctuations in filament diameter or wet filament.