best way to unclog the extruder (HELP!!!)

Hi. My first post on the forum...so be patient

I think i have a clog on the extruder. It's (i think) a wade gearer extruder (clogged with PLA).
So i would like unclog it cause now i can't extrude or print with the machine.
But i would like someone point me on the right direction cause i think i could make a several error here, and things getting worse.

An extruder image is attached.

Thanks.

If the jam is in the hot-end, then you will probably have to remove it from the printer, disassemble it and clean it out.
Depending on how bad the jam is, you may have to replace the PTFE sleeve inside the hot-end.

so i have to disassemble this entire part? unscrew the servo and so on until get the piece that appears on this video?

cleaning PLA

Sometimes you can clear the blockage by heating it up a little above the point where the blockage occurred and feeding filament through, IME if you're running PLA without a fan it's probably blocked higher up in the hot-end and you won't be able to clean it out this way. Perhaps others can chime in if they have a better way to do this.

You can probably get away without removing the stepper from the extruder, it depends how it's mounted and how accessible the mounting hardware is.

You need to
Get the Hot-end up to temperature and remove what filament you can by pulling it out.
Unplug the wiring to the extruder.
Remove the "cold end" and "hot end" from the X-Carriage
remove the "hot-end" from the cold end (be careful with the wiring)
disassemble the hot end
Assuming the blockage is in the PTFE part and not the Brass part, clean out or replace the PTFE tubing
If it's in the Brass part you can use the blow torch trick

Put everything back together.

After you've done this 3 or 4 times, you'll probably realize that having a connector close to the hot-end to allow easy removal of the wiring is a godsend, and probably try fitting a fan.

The one hot-end I had jamming issues with would always jam in the PTFE part almost 1/4 inch from the nozzle as heat soaked up the hot-end on long prints, since I fitted a fan it has not jammed since. Some people have issues where the plastic get's between the Brass nozzle and the PTFE, in this case you have to clean-out both parts.

I've been able to unclog a nozzle that got left overnight at 220-230C without extruding/printing by sticking a syringe needle into it.

buffff
i tried to clean it with a long safety pin, and i think was ok.
I did it with the four screws that support the filament gone away.

I am not sure, but i think that the problem is that extruder really can not drops down the PLA, i mean i think if a push down the filament (forced) sometimes extrude material just for a bit. But quickly go quiet, and does not work, again.

I got 245 temp. Then, i pass through the extruder the safety pin. After that, i could push down the filament while executing "run extruder" (i use RepSnapper) and i could see filament extruded (i think) normally.

But when i closed the piece (putted on the screws again), the behavoir was the same that before: no extrusion. When i get the target temp and run extruder...nothing...maybe a little tiny filament....

So, i am going to try the "easy way" again before fight with Polygonhell (think about procedure he posted gave me headache) and pray...

I haven't found a pin small enough to fit all the way through the nozzle (0.5mm or smaller). Did your pin go all the way through? BTW, when I used a syringe needle (30 gauge, 0.31 mm), the extruder was still together and the nozzle was hot. I pushed the needle into the tip of the nozzle as far as I can go and then extruded. I repeated this a few times until the extruded filament looked good.

What kind of hot end are you using? Your problem might not be a clogged nozzle if it extrudes at the beginning and then jams. If you have a teflon lining, there might be a gap where the lining meets the nozzle. This is know to cause the filament to get stuck.

A lot of hotends will not print PLA reliably without a fan blowing at the Hupper part of the otend.
PLA get's soft and gummy before it melts and if the hot area in the nozzle is too long, it expands inside the Hotend as the filament is forced down by the extruder and jams.
ABS doesn't do this, but requires a heated bed to print.
If you are getting relatively normal flow when pushing filament into the extruder by hand I'd look at whether the wades is stripping the filament first. If the nozzle is jammed no amount of feeding will extrude normally.

It's extruding now, but i don't know why, cause i did this morning the same operation than yesterday (clean it with a pin that was not enough small to go through the nozzle; anyway i passed it through PTFE. And i bought a syringe needle that don't pass through either, but i used it on the same way).

Anyway, it's extruding a little bit better than before.

B letter printed (PLA - 238 temp) i got today is attached.


I would like ask you a few questions (i'am a newbie)

i) Is ABS o PLA better to start and familiarize with 3d printing? (what temp will i need for each other?)
ii) Is there some maintenance tasks normally made to get the printer ready and well-working?
iii) What is the normal operation on a printing operation? I mean,....got the temp, wait 10 minutes, examples extruding operations....print...and...any way to follow good operations so avoid further errors? For exmaple, what's the better way to replace the PLA? (run the extrude on reverse, open the 4 screws??..)

iv) Polygonhell, how could i know if i need a fan on the extruder?. Do you told if i'm gonna print regulary with PLA i surely would need a fan?
How could i get the design to attach a fan on the extruder and how i could properly mount it?

Thanks!!

Hi definitively pla is the best to begin with. Abs has warping issues you don't want when you just start to calibrate and have fun :-)

I have a hotend with a ptfe liner and it clogs quite often. The liner ends to break between brass nozzle and ptfe thermal barrier if i don't change it after a clog, so i suspect a gap between the two parts....

I'll try to adjust the two parts but if it keeps happen i'll have to change. Maybe for a jhead if as soon as I can afford it :p

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Generation 1 : RepStrap "Prusa air" en MDF 10mm, moteurs d'imprimantes epson, bowden 50cm. // 9 machines filles.
Generation 2 : Prusa i2 poulies alu, lm8uu // 1 machine fille.
Pronterface + Marlin + slic3r

Quote
guille
I got 245 temp. Then, i pass through the extruder the safety pin. After that, i could push down the filament while executing "run extruder" (i use RepSnapper) and i could see filament extruded (i think) normally.

But when i closed the piece (putted on the screws again), the behavoir was the same that before: no extrusion. When i get the target temp and run extruder...nothing...maybe a little tiny filament....

When this happened to me, it turned out that my screws were too tight. Before you disassemble your hot end, try loosening the screws. Too little pressure against the filament makes the teeth of the hobbed bolt not catch. Too much pressure prevents movement. It is, unfortunately, a very fine line between the two, and varies with your plastic.

Also 238 C is WAY too hot for PLA. You should be extruding happily at around 180 C. 230 C is the temp for ABS.

EDIT: Just saw how long ago your last post was, guille. I hope that by now you've got it fixed!

Edited 1 time(s). Last edit at 11/19/2012 12:34AM by PomeroyB.