Hi,
I am recently having problems with a print that used to go (almost) perfectly fine. It is a long PLA print (> 10 hours).
At some point of the print, it apparently stops extruding on the previous layer but the printer keeps on going, and extrudes "in the air". The result is shown on the following picture:
As you can see, the extruded filament makes a small "ball", which I'm almost sure corresponds to the extrusion curling around the nozzle instead of falling straight down (I've already seen this happen, at the beginning of a print). Then at some point it's too heavy and detaches itself from the nozzle and falls down, until it breaks and starts over again.
Another strange thing is that I can see on the top layers of the print a sort of hole where the PLA seems melted, which seems to correspond (size and shape) to the nozzle, just like if the nozzle would pierce down through the top layers...
I tried to highlight it on the next picture:
Maybe this is the beginning of the problem, and what I described above the consequence, I don't really know.
For your information, this does not happen always at the same time during the print, it really varies.
And some times, not every time, I find that the print has fallen on the side.
Another type of problem that I have sometimes (regularly but not systematically and that I have failed to solve yet) is the "skipped layer" problem (http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#z-drop), maybe it is related?
This is what I've tried:
- really clean the nozzle, doing many Atomic method
- clean the Z trapezoidal leadscrew
- print at 220°C instead of 210°C (because I thought that it could come from a partially clogged nozzle and that was why the extruded filament was curling around the nozzle)
- I relevel the bed before each print
- I ordered a new PTFE coupler (the printer has about 400h of run time) but haven't received it yet
Maybe some of you have ideas of things I could try, or method I could set up in order to identify the cause.
Thanks !
Raph