[Cerrado] Extruder completely stuck, heat didn't fix it  

Re: Extruder completely stuck, heat didn't fix it

Gary

One of the settings allows you to set the temperature of the extruder only.

Peter

Re: Extruder completely stuck, heat didn't fix it

Hi, I just had this issue, just after unloading filament.

It's a bit strange, as no filament were staying in the nozzle, it's like all the filament was pumped up in the cold side of the extruder and get stuck there. I used PHA/PLA from colorFabb at 200 °C. The filament is rated for 195/210 °C. Should I increase the temperature for unloading ?

Thanks for the advices there, I fixed the issue. This thread should really be pinned, and an article should be created from it on help.prusa3d.com.

Re: Extruder completely stuck, heat didn't fix it

I personally unload filament like PLA at 170C. I call this "PLA holding temp". This should really be the "preheat" setting, but "preheat" as a term is already taken to mean "go to full temp".

There's no reason that I can tell to heat it all the way to full temp just to pull it out.

This, again, is like the probing temperature issue where there's no reason to be probing at full temp. There's no reason to be unloading at full temp either.

When I want to *load* the new filament in, that's when I boost the temperature to full temp.

Be gentle, precise, and deliberate.

Re: Extruder completely stuck, heat didn't fix it

I personally unload filament like PLA at 170C. I call this "PLA holding temp". This should really be the "preheat" setting, but "preheat" as a term is already taken to mean "go to full temp".

There's no reason that I can tell to heat it all the way to full temp just to pull it out.

This, again, is like the probing temperature issue where there's no reason to be probing at full temp. There's no reason to be unloading at full temp either.

When I want to *load* the new filament in, that's when I boost the temperature to full temp.

Be gentle, precise, and deliberate.

Thanks for your answer, really appreciated 🙂 I'll change my routine procedures then.

So the unloading temp should be between the glass transition temperature and the full fluidity temperature.

What's your opinion when you are changing a filament rated for different temperatures ? like going from PLA (~210 °C) to Polycarbonate ( ~280 °C) and vice-versa ?

Re: Extruder completely stuck, heat didn't fix it

Christophe

When unloading filament, I generally take the opportunity to do a nozzle clean at the same time. That is (for PLA) temp to 95 degrees and pull out the filament with pliers.

Peter

Re: Extruder completely stuck, heat didn't fix it

Hi,

I upgraded my MK1 to MK2, with the old one I never once experienced clogged extruder. Now I have a blockage 2nd time in two days.... I was able now to run a metal wire through the extruder. Need to clean the nozzle in aceton again.

Some questions after reading all the treads here:

- Where do you specify the retraction parameter ? I am using Slic3 with settings file from latest 1.7.3 drivers for Mac
- I am running latest firmware 3.06
- What do you mean that the ptfe tube needs to be 'square' ? Do you mean straight cut at the bottom ?
- do you pull out PLA string from below or above at 170 deg ?

Sorry bit confused by all the info 😮

Re: Extruder completely stuck, heat didn't fix it

Hi Alain,

In Slic3r, the retractation is located on "Printer Settings" -> "Extruder 1" -> "Retractation" -> "Length". 0.8 mm should be fine for PLA, as recommended by E3D ( http://wiki.e3d-online.com/wiki/E3D-v6_Troubleshooting ).

E3D seems to prefer 0.6 mm for ABS, but sadly in Slic3r it's not a filament parameter but a global printer parameter.

Re: Extruder completely stuck, heat didn't fix it

Merci Christophe !

I did not look under extruder - my fault. It is set for 0.8mm, so that cannot be the problem. Continuing troubleshooting. The fan is cooling well too.

Re: Extruder completely stuck, heat didn't fix it

Thanks for your answer, really appreciated 🙂 I'll change my routine procedures then.

So the unloading temp should be between the glass transition temperature and the full fluidity temperature.

What's your opinion when you are changing a filament rated for different temperatures ? like going from PLA (~210 °C) to Polycarbonate ( ~280 °C) and vice-versa ?

I mostly switch between TPU, PLA, and PETG. Haven't tried polycarbonate yet.

The important things to me are: make sure to clear out all the old filament, and don't damage the hotend or any components.

From what I've seen, these plastics have a wider operating range than what we're specifically shooting for, mostly because we're trying to optimize print characteristics. But if all you want is for the filament to get out of the hotend, the plastics will extrude at lower temperatures, and can also survive higher temperatures for brief periods. Like, I know PETG extrudes at lower temperatures, but it doesn't stick right until I hit 250C.

So swapping from filaments of different temperatures so far, the process is the same. Unload at the holding temp of the old filament, load at the full temp of the new filament.

I haven't tried polycarbonate yet, but I suspect it won't be that different, and at worst, you'd need to use an "in between" filament if you really need to gradually step the temperature between filaments.

I have a bit of "cleaning filament" that I bought that supposedly has a wide temperature range as sort of a hedge, but truthfully haven't adequately tested it. (Haven't needed to... I've only had a few jams isolated to some dud filament, and all of them I could clear out just by unloading at "holding temp".)

Re: Extruder completely stuck, heat didn't fix it

Hello Guys,

Thanks for the tipps! I just hat my first clogged heatbreak and the tipt with cold pluging really help!

THANKS to gz.1 and PJR! 😛 😀 🙂 🙂 😀

This tips should be in the manual or help pages!

Re: Extruder completely stuck, heat didn't fix it

We had the same terrible issue with a coggled hotend on the first load. The front and rear fan's cables were swapped so it stopped extruding, after I pulled out a big part, the rest stuck inside.

So this post was very helpful for us and this video as well: so we could see the parts nearly separated and how we could take them apart. A vise is very important and a heat gun! Now it's 100% perfect.

Thanks for the online helpdesk and this forum! 🙂 😉

Re: Extruder completely stuck, heat didn't fix it

I experienced this same problem with MK2 and MK2S units. Once it happened during filament change, others due to users using a not so good Cura profile.

Symptom was the same as reported before. Somehow some plastic was blocking the way and heat won't help fuse it (at least using normal PLA temperatures).

Acupuncture needle showed the nozzle was clear and it was almost all the way in easily at PLA temperature.

My way of solving it is quick, simple and requires almost no disassembly:

1) Preheat hot end (my issue was always with PLA)
2) Release the extruder idler (so you can insert filament manually easily)
3) Insert filament manually all the way in.
4) Using the needle-nose pliers hold firmly the filament 6mm above the extruder top.
5) Take a screwdriver (I used the one that came with my printer kit) and hold it from the metal end with your (other hand). And using the handle as a hammer hit gently the pliers holding the filament.
6) After a few hits your should get some downward motion of the filament, move the pliers a few millimeters up and keep on hitting them (or pushing it if you already can) until you see some filament coming out of the nozzle.
7) Put the extruder idler screws back in and start using your printer again.

That would be it. The method brought back to life several of our printers.

Re: Extruder completely stuck, heat didn't fix it

We had the same terrible issue with a coggled hotend on the first load. The front and rear fan's cables were swapped so it stopped extruding, after I pulled out a big part, the rest stuck inside.

So this post was very helpful for us and this video as well: so we could see the parts nearly separated and how we could take them apart. A vise is very important and a heat gun! Now it's 100% perfect.

Thanks for the online helpdesk and this forum! 🙂 😉

guess you didn't follow the self-test wizard 🙂

Re: Extruder completely stuck, heat didn't fix it

In my case (MK3 MMU2), it turned out that the jam was in the PTFE tube going through the heatsink, so solution was to swap it out for another PTFE tube.