Stuck Filament Investigation
My recent print on my week old Core One stopped extruding halfway through. I only noticed the failure a few hours after it occured.
I'm not yet certain what went wrong - but I have found one thing I cannot yet make sense of:
This is the filament I pulled from the printer - you can see exactly where the extruder started spinning freely. Notice that the top of the picture is the direction of the nozzle. The cut was me trying to trim the filament for the next attempt, only afterwards I noticed that the section where I placed the cut was thicker than usual.
Here is the measurement:
Compared to the rest of the filament.
So a thicker part of the filament above the extruder... Now I am wondering, am I looking at a symptom of the clog (this section somehow melted and thus deformed) or am I looking at the cause of the clog - shitty filament with a manufacturing defect. To be fair, I used the cheapest PLA I could find (Geeetech).
Let me know what you think.
RE: Stuck Filament Investigation
To be fair, I used the cheapest PLA I could find (Geeetech).
Let me know what you think.
I think that's your answer. Classic case of square filament in a round hole.
RE: Stuck Filament Investigation
I wouldn't know about this specific spool, but I've been using Geeetech PETG filaments for years without any issues at all. In fact, Geeetch is my preferred brand of PETG, better than the more expensive Prusament or Polymaker.
RE:
I don't use cheap filament anymore for precisely this reason (on in this case, lack of precision). I was using no-name brands until I had to throw out rolls. I mostly print with Overture, Siraya Tech, Polymaker or Prusament.
If Geetech works well for you then stick with it, you probably got unlucky with a spool that didn't pass QA (some how). I surprised because generally diameter variations are checked carefully (and automated) before winding onto the spool.
RE: Stuck Filament Investigation
So what steps did you take to clear the mess?
RE:
So what steps did you take to clear the mess?
I was able to pull it back out (with opened idler) - it was harder than normal but still didn't require excessive force.
RE:
I don't use cheap filament anymore for precisely this reason (on in this case, lack of precision). I was using no-name brands until I had to throw out rolls. I mostly print with Overture, Siraya Tech, Polymaker or Prusament.
If Geetech works well for you then stick with it, you probably got unlucky with a spool that didn't pass QA (some how). I surprised because generally diameter variations are checked carefully (and automated) before winding onto the spool.
The thing is, it did not. Excessive stringing although I took it fresh out of the vacuum packaging. I sent back all unopened spools. It's definitely not the printer because the Prusament that came with the printer works like a dream.
RE: Stuck Filament Investigation
I've had this happen and it was because of a clogged nozzle. What fixed it was to load a much higher temperature material and purge 3-4 times.
The question is why the nozzle clogged in the first place.
RE: Stuck Filament Investigation
I've had this happen and it was because of a clogged nozzle. What fixed it was to load a much higher temperature material and purge 3-4 times.
The question is why the nozzle clogged in the first place.
How can a clogged nozzle cause the material above the extruder to form a bulge?
RE: Stuck Filament Investigation
How can a clogged nozzle cause the material above the extruder to form a bulge?
That would seem intuitive to me: simple backpressure because the nozzle can't support the driven flow rate.
I wouldn't read too much into it if the bulge was spotted behind the final Festa. I've seen deformed filament there that was impossible to get out the way it came in which had nothing to do with filament quality. Not saying it's impossible but if I had to wager a bet I'd put my money on seeing the same failure mode again with a different brand of filament (but there's also the chance that making "any" significant change like selection of filament will make "a" difference, for better or worse).
RE: Stuck Filament Investigation
How can a clogged nozzle cause the material above the extruder to form a bulge?
That would seem intuitive to me: simple backpressure because the nozzle can't support the driven flow rate.
I wouldn't read too much into it if the bulge was spotted behind the final Festa. I've seen deformed filament there that was impossible to get out the way it came in which had nothing to do with filament quality. Not saying it's impossible but if I had to wager a bet I'd put my money on seeing the same failure mode again with a different brand of filament (but there's also the chance that making "any" significant change like selection of filament will make "a" difference, for better or worse).
I am still trying to make sense of it.
The bulge is _behind_ where the extruder ground into the filament. So the area of the bulge was never even close to the nozzle.
I can imagine a clog producing a bulge between the extruder and nozzle, but thats not the case here.
RE: Stuck Filament Investigation
I don't know if I'll explain it very well, but here goes:
In my case, the filament on top of the extruder was warm enough to be melted. As it was being pushed downwards by the gears, the bulge formed. It reached a state where it couldn't go down because of the clog, so the gears ate at the plastic that was sitting in place, as you've seen in the first picture.
RE: Stuck Filament Investigation
Then the bulge formed below the area of the grinding, right?
I don't know if I'll explain it very well, but here goes:
In my case, the filament on top of the extruder was warm enough to be melted. As it was being pushed downwards by the gears, the bulge formed. It reached a state where it couldn't go down because of the clog, so the gears ate at the plastic that was sitting in place, as you've seen in the first picture.
RE: Stuck Filament Investigation
In my case, the filament on top of the extruder was warm enough to be melted.
"heat creep" when the cold end isn't cold anymore.
RE: Stuck Filament Investigation
I just want to show a close up again.
(Click on the image to see all of it, the aspect ratio is awkward)
1. Location of the bulge
2. Grinding location
3. Teethmarks of the extruder
Above the grinding location, there is no teethmarks as you can see. So it was never pulled further down.
RE: Stuck Filament Investigation
IDK, looks again like you got a bad roll of filament. That has happened to me twice with cheap filament.