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blackomega

Ultimaker 2 Extruder nozzle blocked

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Got a bit of a problem.

Left a model to print last night but it failed half way through (PLA stopped extruding) but now I can't get any of it to come out. I've tried heating the nozzle to 260C as the manual suggests and still nothing. I've even removed and reloaded the filament as that used to work in the past but again, nothing. The nozzle does get hot and the temp sensor does seem to be reporting the correct temperature.

Any other suggestions?

 

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also if you have a medical needle .. that can work great... or a syringe ... or a acupuncture needle !!

then take the print bed right down.. so you have lots of space for your hands.. then heat up the hot end without any PLA loaded in... and carefully slide in your sharp instrument in and out of the nozzle... that will normally get all the little ol gunk out and get you back printer... plus its a thousand times faster than taking your hotend apart and trying to clean the head out that way... :-)

just becareful of your fingers with the hot hotend !!

Ian :-)

 

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Thank you all for the suggestions. I had thought of that but don't have such thin wire that would be rigid enough to be useful.

I've managed to unblock it now by repeatedly loading and unloading the filament.

I was using the clear filament and have noticed it seems to be more sensitive to a higher temperature than the coloured ones. At the default 220C then the filament seems to burn if there is an extruder jam resulting in a black blob.

Incidentally, is it a simple process to replace the nozzle if need be in the future?

 

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is it a simple process to replace the nozzle if need be in the future?

Not really. The nozzle and the heater block are a single piece in the um2 and you have to remove the heater and the thermocouple - both of which can potentially be stuck and either could be damaged if removed too roughly. However your UM2 is still new and they might come out easy.

Much easier to do is to take the head all apart and clean out the hot end from the "top". I suggest you order some acupuncture needles now so you will have one for the next time.

 

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yes it is !!

get yourself a good strong .3mm syringe needle to clean out the hot nozzle from below...

worst case scenario....taking the hot end of a um2 takes about 3 minutes and the nozzle pops out no problem... just be careful when you are putting back together the housing.. that you dont pinch any of the fan cables !!

Ian

 

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yes it is !!

get yourself a good strong .3mm syringe needle to clean out the hot nozzle from below...

worst case scenario....taking the hot end of a um2 takes about 3 minutes and the nozzle pops out no problem... just be careful when you are putting back together the housing.. that you dont pinch any of the fan cables !!

Ian

I took off the two side fans mount assembly exposing the single piece nozzle and heat block. It seemed pretty well fixed in place with no obvious way of removing it without disassembling the entire print head.

 

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I had exactly this problem last week.I tried to the heating to 260c a few times but that did not work. I couldn't get any material to feed. So I figured that whatever was blocking the nozzle was bigger than 0.4mm so would never feed out.

so here is how I solved it (without taking the whole nozzle apart):

Follow the change material process, except do not feed any material back in, just press the dial to follow the process.

then remove the bowden tube from the hot end.

Heat the nozzle to 220 deg C.

Take a piece of filament and feed it by hand into the top of the PEEK as far as you can.

now set the temperature to around 90 deg C and whilst it is cooling gently push a pin/needle/0.35mm drill etc up the business end of the nozzle.

after the nozzle has cooled to 90deg C wait a couple of minutes and carefully pull the filament back out of the top of the head.

I found that the filament came out almost exactly the internal shape of the nozzle and brown bits could be seen in the filament.

repeat a couple of times, until the filament comes out perfectly clean.

re-assemble your bowden tube and reload the material.

This worked a treat for me. next time this happens i will take photos for reference.

Bob

 

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One more piece of advice - loosen the 4 screws on the print head a few turns before removing the bowden tube - you have to remove the blue clip and push down on that outer ring while lifting on the bowden.

Sometimes the blades that hold the bowden in scrape a little bit off the outside of the bowden when you remove it and if you do this too many times then it tends to not stay inside the print head and pops out during prints. If that happens you probably need to get a new bowden.

But don't worry about that too much - just go for it.

 

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I've used this method many times, and so have others. Someone said the other day, the method should be named after the person who first suggested it, but couldn't recall who it was, or what thread it was in... and I just saw it again here.

Sooo... this should be known as the "Atomic" Nozzle clearing method.

 

 

I had exactly this problem last week.I tried to the heating to 260c a few times but that did not work. I couldn't get any material to feed. So I figured that whatever was blocking the nozzle was bigger than 0.4mm so would never feed out.

so here is how I solved it (without taking the whole nozzle apart):

Follow the change material process, except do not feed any material back in, just press the dial to follow the process.

then remove the bowden tube from the hot end.

Heat the nozzle to 220 deg C.

Take a piece of filament and feed it by hand into the top of the PEEK as far as you can.

now set the temperature to around 90 deg C and whilst it is cooling gently push a pin/needle/0.35mm drill etc up the business end of the nozzle.

after the nozzle has cooled to 90deg C wait a couple of minutes and carefully pull the filament back out of the top of the head.

I found that the filament came out almost exactly the internal shape of the nozzle and brown bits could be seen in the filament.

repeat a couple of times, until the filament comes out perfectly clean.

re-assemble your bowden tube and reload the material.

This worked a treat for me. next time this happens i will take photos for reference.

Bob

 

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Update, I tried to remove again but this time I pulled from the back to give it some help and the filament came out the back.

Now how to do I pull this bowden off? I removed the blue choker but the white plug isnt budging and I am afraid of just ripping the tube out and breaking something.

ANy tips?

 

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Ok, so I was hot n frustrated so I just went for it and pulled the sucker out.

I pressed some filament in by hand and pushed a thing amount out of the print head

cooled the head to 90c with some filament in there, had to give it a nice tug. wasnt satisfied with the little bump on the end. Was hoping for a bigger booger

I put it all back together, put the white 4 prong piece for the bowden into the print head assembly first, then the tube, then the blue horseshoe clamp. I reloaded the filament, it came out strong, now I am going to make a test print!

O YEAH!!!

 

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You just press down on the white '4 prong' collet, while pulling up on the Bowden Tube. If you yank it out, you run a real risk of damaging the collet, and also of scraping plastic off the outside of the Bowden which a) could fall into the nozzle, and b) means that there isn't enough for the collet to grab next time - so that the Bowden won't stay tightly in place. (If that happens, cut 2 or 3 mm off the end of the tube, so that the collet gets some fresh plastic to bite into next time.

And here's how to reinsert the Bowden to ensure it stays tightly in place in the right spot:

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/?p=40399

 

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Don't feel bad. I couldn't figure it out either until I read about it. But afterwards it's obvious. I mean what is that clip for if not to hold up something. And after removing the clip maybe I should un-hold-it-up. Should be obvious but it wasn't.

 

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