Weird random problem with nozzle getting full of filament that solved itself
Hey, so I've had this really weird problem this morning when I tried printing my first parts for the day, I am quite new to 3D printing and couldn't really figure out what was going on, so that's why I am trying to look for any explanations for this.
Basically what happened was that there was an unusually high amount of filament oozing out of the nozzle which was already a weird thing in the first place as I used the same material (Janbex PLA), same temperature (215° C) as well as the standard heating-cycle as I have always used before. It's not like there was never filament coming from the nozzle during the 9-Point bed leveling, but this time it just seemed way more. Anyways, as there was a lot more filament it obviously had to start sticking to the nozzle in weird places. This was also nothing new, I already had this happening previously, but normally all the stuck filament would just stick to the purge line the printer does before starting the actual print and for some reason, this didn't really happen this time. Then when continuing to print the actual part all this leftover plastic on the nozzle prevented proper extrusion or completely started sticking to the first layer tearing it off the print bed again.
After this happened I just thought that my bed may not be as clean as it should be (even though I clean it before every print with unfortunately only 70% isopropanol without any issues so far) so I cleaned that again and also cleaned all the gunk from the nozzle. I also reloaded the filament just to see if there was anything stuck in the nozzle, but when reloading the filament all came out fine and fully straight, just as it should be. So that's when I thought I would have fixed everything, unfortunately, this wasn't the case tho and the exact same thing happened again and again. Then I thought that my sliced g-code was the problem even though I sliced it as I always had before, so I then tried to just print a standard part that's on the printer's SD card from the factory. However, the same thing happened which really left me confused.
I then decided to just randomly power cycle the entire machine, not thinking that this would have any effect, but somehow it actually worked well enough so that my first print is finally stuck to the bed and all looks fine.
Now I am honestly wondering if there is any logical explanation for this, especially as I really want to prevent this from happening in the future as this issue cost me a lot of time to "fix".
Best Answer by Diem:
Dry your filament.
Just this morning I had a part printed without any problems whatsoever and yesterday evening it also worked as I wrote in the original message. However, just after the first print today finished I tried to print a second thing with a ten-minute or so break in between and suddenly there was the original problem again.
When left for a while in a warm hotend the first few centimetres of filament has time to dry a little. When it has too short a time it is still too wet and expanding steam compromises the extruder pressure.
Even PLA shows humidity defects in under a week's exposure.
Cheerio,
RE: Weird random problem with nozzle getting full of filament that solved itself
Well, if there's a problem (random or not), I don't believe in "it fixed itself". There was a reason why problem happened and unless you find out what it was (and fix that), it will happen again.
And when I hear oozing (and stringing), I start wondering... you do dry your filament, right?
[Mini+] [MK3S+BEAR]
RE: Weird random problem with nozzle getting full of filament that solved itself
Hi, thanks for the reply. Exactly that's my problem, I also don't think it fixed itself, that's why I am trying to get some input on this issue and how to solve/prevent it.
I actually don't dry my filament at all, to be honest. From what I've read and heard PLA isn't too sensitive for moisture, at least not over a decently short period of time and that's why I haven't really worried about that so far. Is that anything I should change from your experience? What I do however, is putting each spool right back into a sealable plastic bag together with those moisture absorbing packs that already come in the bag when spools are shipped, right after finishing a print.
What's really weird is that everything is printing just as I had prior to my issue, literally without changing anything, filament and filament condition are the same, print settings and even the codes I tried were the same.
RE: Weird random problem with nozzle getting full of filament that solved itself
It's hard to say what exactly is the reason for changed printing behavior. Just keep in mind: if slicer settings have not changed, then don't try to "fix" the problem by changing settings now -settings in slicer are meant to be changed for printer that works normally.
Of course, there can be physical reasons why printer started to behave differently. For example, for whatever reason thermistor sends wrong temperature value and now your nozzle temperature is higher than what you see on display. But these things happen very rarely.
So, what's left?
Yes, PLA absorbs moisture much slower than other filaments. Still, absorption exist! And after a while, there's just too much. Keep in mind, that those desiccant bags don't dry filament -they can only attract humidity from the air. After a while, desiccant gets saturated with humidity too, so we need to dry it now and then -otherwise it becomes useless.
In short: you needs some filament (and desiccant) dryer. I highly recommend food dehydrator for that: it's cheap and it actually works. And once you have filament dryer, you can finally start using some more versatile filament (e.g. PETG).
[Mini+] [MK3S+BEAR]
RE: Weird random problem with nozzle getting full of filament that solved itself
What really bugs me is the fact that I cant seem to reproduce this error on purpose. Just this morning I had a part printed without any problems whatsoever and yesterday evening it also worked as I wrote in the original message. However, just after the first print today finished I tried to print a second thing with a ten-minute or so break in between and suddenly there was the original problem again.
After checking the part that printed successfully this morning I checked for any signs of a filament that was too moist, but there weren't any signs at all, everything looked flawless. I will probably still try to dry the filament tho as this is the easiest thing that I can try right now.
Right now this really seems to happen randomly with any filament brand and any model I try printing, from what I feel like no other conditions have changed except for the temperature and composition of air in the room I am printing, but I can't really imagine that the impact of that would be severe enough to cause this. When printing I genuinely try to keep my window shut, as the printer is close enough so that wind gusts can affect the surrounding temperature of the printer which already had me fail one print, due to the part releasing from the heated bed. With the window being closed the air quality may go down over time as I also tend to work in this room, and the temperature may also increase slightly over time. However, this was also the same during all previous prints where I didn't have any issues.
I actually found another forum post concerning this issue, with reasons mentioned from moist filament, to a worn-out nozzle, or a partially clogged nozzle. I don't have any experience with this, but my nozzle has only seen about 72 hours of printing with PLA only so I would guess that can't be the issue. Clogged nozzle seems unlikely as well as material when it comes out, for example after loading new filament, comes out perfectly straight (as long as it doesn't catch on the filament that is already stuck to the nozzle) and with the same diameter as it always had. So I guess this only leaves me with moist filament. All spools I own are not older than maybe 15 days (that's when I initially unpacked them from their original packaging) but maybe that's enough with my conditions to get too moist. It's weird that some parts of the spool seem unaffected by this, at least they must be to explain the prints that still worked with this explanation for my issue, but maybe that's possible.
RE: Weird random problem with nozzle getting full of filament that solved itself
So I have just tried to print something just to take a picture of how it looks, so that you may be able to see any hints on what the problem may be. At first, some parts in the middle may look like bad bed adhesion, but I tried to remove it and it was all properly stuck to the bed. There is some more extreme amount of stringing, and you may be able to see that there was once again a part of the print that the printer dragged with it. I would now assume that it actually is too much moisture in the filament and go try to dry that.
Is it just me or the primeline
Something looks off in your primeline before you even start to print
RE: Weird random problem with nozzle getting full of filament that solved itself
What exactly does look weird to you? Do you mean the way the thickness changes halfway down the line? Or the way it curves in the end? Because I would have attributed that to the filament just sticking to the nozzle already.
Dry your filament.
Just this morning I had a part printed without any problems whatsoever and yesterday evening it also worked as I wrote in the original message. However, just after the first print today finished I tried to print a second thing with a ten-minute or so break in between and suddenly there was the original problem again.
When left for a while in a warm hotend the first few centimetres of filament has time to dry a little. When it has too short a time it is still too wet and expanding steam compromises the extruder pressure.
Even PLA shows humidity defects in under a week's exposure.
Cheerio,
RE: Weird random problem with nozzle getting full of filament that solved itself
Ok, thanks a lot. I am trying it right now using my oven to dry it as I couldn't get my hands on a food dehydrator fast enough. Before putting the PLA in tho I checked if the temperature of the oven would stay consistent enough using my multimeter and a small thermistor and it seemed to be fine. I will try 40° C for 4 hours for now, then I will see if it worked or not and if not I will probably leave it in longer next time.
RE: Weird random problem with nozzle getting full of filament that solved itself
So just a quick update, it was really just a moisture problem. I just started a new print to see if drying it worked and it really did. Everything the printer has done so far looks as beautiful as it always had prior to my issue, so thanks a lot for helping to fix my issue.