SoliForum - 3D Printing Community — the impossible clogged extruder

Re: the impossible clogged extruder

null@example.com (chuey) — Wed, 23 Jan 2013 21:35:21 +0000

I had a similar situation. I ended up buying another hot-end though.

Then I started messing with the settings and it seems that for some reason my printer doesn't like printing at the higher speeds and flowrate. Still don't know why.

I set my speeds (SLic3r) to 30 for all movements and the filament multiplier to 0.7. It seemed to help but I am still have problems with my new hot-end.

I am starting to suspect that the reported temperature of the hot-end is incorrect.

Re: the impossible clogged extruder

null@example.com (Kuon) — Tue, 08 Jan 2013 21:47:25 +0000

i think it has leaked from the start else it would not get this bad and get clogged up within 2 days
i tried unscrewing it when it was still hot but then it broke there was just no moving it, it was completley stuck

i will now be requesting a new extruder hopefully they wont "lose" my email this time like my last 2

Re: the impossible clogged extruder

null@example.com (IanJohnson) — Tue, 08 Jan 2013 18:41:17 +0000

That looks like burnt ABS up in the PEEK. I think it is likely that the whole thing got too hot due to the compromised thermal connection between the heat core and the nozzle (and thermistor) they should send you a whole new hot end including the PEEK. I wouldn't trust the PEEK at this point because it can put pressure on the filament and cause skipping on its own.

Re: the impossible clogged extruder

null@example.com (danny) — Tue, 08 Jan 2013 18:17:37 +0000

The crap between the nozzle and heat core is probably leaked plastic.
After replacing my heat core I lightly tightened the nozzle on and since have found this leaking to be a problem. (Though I'd rather deal with leaks than break the barrel).

If yours has leaked since the start it sounds like it wasn't put together properly in the factory.

Re: the impossible clogged extruder

null@example.com (pcpoirier) — Tue, 08 Jan 2013 17:46:04 +0000

Plug the heater and sensor and heat it up again (don't bolt it up). Put pliers on the threads and a small adjustable wrench on the nozzle to unscrew when hot( don't us the flat that has the sensor.) once it starts to unscrew, quickly disconnect the wires and finish unscrewing before it cools down.
I bought a 6mm tap and die to clean up the threads after disassembly.

Re: the impossible clogged extruder

null@example.com (Kuon) — Tue, 08 Jan 2013 17:18:18 +0000

no the heat core and nozzle feel pretty much sealed together
if i take a look inside the peek i can see no damage in the middle but there is a weird yellow brown supstance
and the black stuff looks really like it got squeezed out from the nozzle it cant come from somewhere else because it had the kapton tape over it and it is all around it, there is no spot between the heat core and nozzle that doesnt have this black stuff stuck

i added 2 more attachments

the first one is a close up on the inside of the peek and the second one at the black stuff between the core and the nozzle

Re: the impossible clogged extruder

null@example.com (IanJohnson) — Tue, 08 Jan 2013 15:24:41 +0000

Can you unscrew the heat core, or is it stuck to the nozzle? There shouldn't be anything there. I wonder if plastic leaked from the nozzle, and got between it and the heat core. Then the heat core might have needed to get a little hotter to get the nozzle up to temp, which means more heat also going up to the PEEK, possibly damaging the PEEK. There shouldn't be anything in the threads of the barrel at the top either. Do the threads inside the PEEK look like they've been scraped up or damaged? What is the stuff in the barrel threads like? From the picture it almost looks like heat core cement, but maybe PEEK that has been torn away might do that.

If the failure was caused by plastic leaking from the nozzle, I would call that a manufacturing defect and demand a replacement. They have a way of losing emails, so send several and stalk them on IRC http://webchat.freenode.net/?channels=s … xMT0xOTU1d #solidoodle

Re: the impossible clogged extruder

null@example.com (Kuon) — Tue, 08 Jan 2013 12:47:14 +0000

i took a better look at the extruder and noticed a lot of black stuff between the heat core and the nozzle
should that be there???

please take a look at the attachment

Re: the impossible clogged extruder

null@example.com (Kuon) — Tue, 08 Jan 2013 12:32:31 +0000

thanks danny

but well this is the end of my extruder

after heating it i had no problem getting the peek off but when i tried to get the nozzle and the heat core of the barrel snapped in half....

so now i am at a loss

should i contact solidoodle?

almost 2 months ago i send them 2 e-mails with questions and never got a reply from them
now those questions are obsolete but how should i contact them now then?

Re: the impossible clogged extruder

null@example.com (danny) — Tue, 08 Jan 2013 12:00:51 +0000

It's probably stuck because plastic has squished into the threads on the nozzle and basically glue it.

You will need to take off the thermistor to remove the nozzle so getting reliable how hot is this information will be difficult. But I'd shoot for around 170 and the plastic is really soft and should "unglue" at that temp

Re: the impossible clogged extruder

null@example.com (Kuon) — Tue, 08 Jan 2013 00:11:24 +0000

@DePartedPrinter: i got it from solidoodle with my printer
its the natural colour

@IanJohnson
thank you for the tips

so first i need to heat the extruder a little (how much would you suggest?)

Re: the impossible clogged extruder

null@example.com (IanJohnson) — Mon, 07 Jan 2013 23:40:48 +0000

Replace the alcohol a few times so it doesn't get too hot.

You can hold the PEEK (black part) with pliers while you try to unscrew the nozzle. The nozzle will either unscrew from the brass barrel, or the nozzle and barrel will unscrew from the PEEK. You don't need to do any of it with bare hands, just use two pliers. Just be sure not to try to tighten too much when screwing the barrel back onto the PEEK.

If you can't get the barrel/nozzle off of the PEEK even when using two pliers, then it might have gotten too hot and the plastic melted into the barrel threads.

If the nozzle unscrewed from the barrel, and the barrel is still in the PEEK and you want to get it out, jam two nuts on the barrel and hold them with the pliers. Be careful not to hold the threads with the pliers .

Re: the impossible clogged extruder

null@example.com (DePartedPrinter) — Mon, 07 Jan 2013 23:20:16 +0000

Where did you get your filament from?

Re: the impossible clogged extruder

null@example.com (Kuon) — Mon, 07 Jan 2013 23:18:15 +0000

thank you both for your quick answers

@elmoret: no i tried but it dit not work

@pcpoirier i have not tried that yet thank you, i will get a pair of gloves tommorow and give it a other try

oh and one little question about cleaning:

in the "Cleaning ABS/PLA out of RepRap nozzle using blow torch" video the guy uses rubbing alcohol to cool and clean the parts after using the torch, what should i avoid so i wont get that big ball of fire near the end of the video
or are there better cleaning ways?

Re: the impossible clogged extruder

null@example.com (pcpoirier) — Mon, 07 Jan 2013 21:42:07 +0000

unscrew while it's hot.