<p>Please see my video:</p><p>https://youtu.be/tx-hJR_-eFg</p><p>During printing, a thumping noise is heard, and printing is disturbed. It leaves bumps in the lines of filament, as seen in still photo.</p><p>I can’t figure out what’s wrong. The three axes travel smoothly, and the filament feeds smoothly–nothing appears to be binding.</p><p>Any suggestions?</p><p> </p>
<p>Without knowing what the bumps look like (I can’t tell from your video) I would guess that the extruder not feeding properly is the issue.</p>
Try using isopropyl alcohol on a lint-free cloth to remove any filament debris from the print-bed
I know this thread is a bit old by now but try drying your filament. I had a similar thing happen and a few hours in a food dryer for my reel of filament fixed it completely.
I was using eSun PLA+ BTW.
Hope this helps
It was obvious to me within seconds of seeing the video as my Cetus has had the exact same problem since new. It only does it on the first two layers so I have just put up with it. I can confirm however that it is the extruder slipping on the filament. I used a negative head offset to help lessen the problem, -0.2 -> -0.3mm seemed to help.
This thread also covers the same problem: