raphm

Hi, Thanks DidierKlein, I will try lowering the Z current value, but the solution you give says that "the bed can move down unpredictably", and in my situation I think that it's the opposite, it seems that the bed moves up since the nozzle makes a hole. Anyway I will try to see if it helps. I don't think that the hole can be done by the head that stops moving, it is quite deep, like 4mm, and really has the shape of the nozzle (they fit nicely one into each other). That particular piece may have fallen, I don't remember, but I have a second piece where the same problem occurred and I know that it didn't fall. One last thing: on the one that had fallen, I remember noticing "warping'. The bottom of the piece was not flat, it's corners were bent. I don't know if it fell because of that or if it happened after falling. All I can say is that the bottom had been printed many hours before the problem occurred (like halfway of the total 13h). As I said previously, I've done many atomic pull... I won't have much time next week to work on it, but I will try out what you say and come back with more info as soon as I can. Thanks.

Thanks for the quick reply. Yes I'm using brim, but I've printed like more than 20 of these pieces before this problem happens, with same settings, and same brim, so I'm not sure it comes from that. The nozzle hole is what I fear most. I haven't read anything about that anywhere. No I'm printing from the SD-card, not from USB. Corrupted gcode seems strange, I actually haven't modified if for a long time, I always print the same piece, the .stl is on the SD-card, I didn't modify it. I know the PTFE coupler is old (that's why I'm changing it) and my guess is that some burnt residue sometimes gets in the nozzle (I've had blocked nozzle a few times lately). I don't know if the nozzle is damaged or anything, even if I don't like the way the PLA extrudes: almost always a little bit sideways, very prompt to curling up around the nozzle... but it still doesn't explain why the bed would move up into the nozzle...

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