Clogged extruder block

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masada012
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Clogged extruder block

Post by masada012 » Thu Nov 13, 2014 8:15 pm

Does anyone out there have any advice for a clogged extruder block (not nozzle). I had gone through about 3kg of ABS filament (Octave) without any trouble until the last couple of weeks, when my extruder started extruding unevenly (gaps in extrusion) on the first initial layers, and then would stop feeding completely and proceed to air print. At first I though the filament was slipping, but I did not hear any kind of clicking noise that a lot of other people with the same symptoms would report.

I have tried removing and cleaning the nozzle, as well as swapping out the nozzle for a new one, but the extruder still wouldn't feed. Upon heating up the extruder and removing the nozzle, I found the shaft (not sure exactly what it's called) inside of the extruder block to be clogged with melted ABS plastic. I've seen a lot of advice for clogged nozzles, but if the clog is even further inside what's the proper way to go about fixing this? Any help at all would be greatly appreciated.
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Clog (Large).jpg
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stormychel
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Re: Clogged extruder block

Post by stormychel » Fri Nov 14, 2014 8:03 am

Hi,

I had a very bad clog in the first week I had the printer.

I took off the nozzle, put it in acetone, took apart the extruder assembly (actually not that hard, loosen the 2 screws on the side of the fan and take it apart), then went with a 1.5mm drill bit trough the feeder tube, all the way up.

Never had any more clogs since then, don't ask me why...
@stormychel

chang
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Joined: Thu Aug 14, 2014 3:13 am

Re: Clogged extruder block

Post by chang » Fri Nov 14, 2014 1:26 pm

I had the same problem 2 weeks ago.
I think it was caused by nozzle distance too close.

Anyway, I cleaned the nozzle in acetone and the extruder gear with a toothbrush. It didn't help.

I brought the whole extruder head to the dealer. The gear teeth had still some hard filament between. He cleaned the gear teeth with a steel brush and scratched it clean with some sharp tools.
A toothbrush is too soft for cleaning.

After this everything was ok.

He said, the feeder tube (or shaft) doesn't need to be cleaned. It will always melt the filament inside.
Let me know how it works
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amd-tec
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Re: Clogged extruder block

Post by amd-tec » Fri Nov 14, 2014 3:12 pm

You can also try this,

Take the nozzle away
Heat the block with withdraw
Take a drill and gently drill the jam out with hands when it`s enought warm
Extrude without nozzle and check does the extruded plastic look ok, if not just repeat.
Cut the melted plastic away
Put the nozzle back
Extrude again

Thanks,

amd-tec
"3D design with intelligent printing"
http://www.amd-tec.com

masada012
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Joined: Sat Jan 18, 2014 2:23 am

Re: Clogged extruder block

Post by masada012 » Fri Nov 14, 2014 7:33 pm

chang wrote: I brought the whole extruder head to the dealer. The gear teeth had still some hard filament between. He cleaned the gear teeth with a steel brush and scratched it clean with some sharp tools.
A toothbrush is too soft for cleaning.
Thank you for THIS! After going through 2 new nozzles and still getting air prints, I did a complete teardown of the extruder assembly, and just like you had experienced, my extruder gear teeth were gunked up with all different colors of filament. I ended up having to go to town on it with some wood cutting tools, and would have been too scared to try it if I didn't hear about how your dealer cleaned yours. Reassembled the extruder head and after some stupid mistakes (like forgetting to re-attach the temperature mod switch), my baby is printing beautifully (for now).

I'm not 100% sure, but I also figured that the gunk caught in the gears is not just ABS filament and added some open-celled foam like suggested here:

http://www.pp3dp.com/forum/viewtopic.ph ... onge#p6774

Thank you all for your advice, and I've got my fingers crossed that I won't have to come crawling back after another extrusion issue.

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josejuako
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Re: Clogged extruder block

Post by josejuako » Fri Nov 14, 2014 8:59 pm

Good , is verry important always have a ABS filament clean , for the nozzly and print object .

I also put some high temperature grease to the threads and inside the nozzle to remove without problems , long wihtdraw when I work in the heater to clean .


J
Last edited by josejuako on Sat Nov 15, 2014 3:16 pm, edited 1 time in total.

roller
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Location: Brisbane, Australia

Re: Clogged extruder block

Post by roller » Sat Nov 15, 2014 12:17 am

Greasing is a bad idea... no grease should ever get put into your extruder.

The teeth is always the issue for me having airprints. In two years i have clogged a nozzle twice. One time due to dust that had gathered on my filament and once due to the plastic wrap on a filament still be stuck to it in parts and I didn't notice. I always prime (extruder) at least two times (usually 3) when changing between PLA and ABS or when changing to a higher temp filament (from non OEM back to OEM).

PLA is the worst culprit for clogging the gear. I always have to clean the gear after 4 or 5 PLA prints (the wear on my old extruder gear is part of that issue). The PLA is more brittle and tends to grind off in a jam ... jams which are caused by the nozzle being a bit too close (generating backpressure) on the first layer but I am happy with other print reliability at this start height so I leave it this way and live with the maintenance.

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josejuako
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Re: Clogged extruder block

Post by josejuako » Sat Nov 15, 2014 5:34 am

Roller you look like a bible!. Have you used or had experience?. I advise you because I see it useful to facilitate the removal of the nozzle. You also want to talk just like other people around here that we're stupid!.

Only the fat is placed in the thread of the nozzle at the location shown in the first image.

Easily remove and replace the extrusion nozzle to clean the nozzle if there was excess fat extrude 2 or 3 times .

I use this fat!.

Image



J

stormychel
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Re: Clogged extruder block

Post by stormychel » Sat Nov 15, 2014 10:34 am

I'm with roller here... who wants anti-friction grease in a place where you really need friction?

edit: ok should have read better, on the thread seems ok to me :) sorry
@stormychel

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josejuako
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Re: Clogged extruder block

Post by josejuako » Sat Nov 15, 2014 3:00 pm

First nozzle is hard to remove and second make experience, it is not empirical. I've learned that the internal cleaning of the nozzle is important to have a good quality. I use a lot ABS in different colors and there are times when I have not cleaned the nozzle for a long time, but my experience is clean. Now if I remove the nozzle easily that's very good for me and for anyone . I ever put here is the result of experience and make life easier . I wish explain it better but you only speak English and for you is a limit the same to me .
Always I do it in wihtdraw seting .



J

roller
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Re: Clogged extruder block

Post by roller » Fri Nov 21, 2014 2:48 pm

Josejuako, my advice is based on building lots and lots of printers from scratch and having been involved in reprap for years before adding an Up to my printers. I don't come here to tell people off but there are a number of people new to printing who come on to give other people poor advice based on their very limited experience and misinformation. Most of the time if they had read through the years of knowledge on this forum before they commented they would know they are wrong. I try to put sstop to this sometimes not because I want to shut them down but because they are speaking as if they are presenting facts rather than theories and this can mislead other new users that come here. Good 3D printing is about good engineering and science ... it means theories need to be tested before they are presented as fact. It's intersting on the one hand you come to us specifically for expert advice when you have a problem but when we try to protect the forum from bad advice you start getting insulting.

Even with all my reprap experience I read ALL of the previous forum posts first, then tested ideas with my own printer and then started throwing around theories about how we can make the printer better. I am not the last authority on these printers by far. I know a couple of users on this forum who have lots more useful gems of knowledge to offer than me and have contributed a lot more to the improvement of these printers than I. That said I have a pretty intimate of the mechanics of 3D printers and do what I can to help others work through problems they are having and try to save them from working with the misinformation shared by some others new starters. I probably wont be doing this much more in the future as I have to go back to real work in the real world but hope to finish up my contribution by wrapping all the good information that's been discussed over the years in a wiki so that new users will have answers to their FAQs that PP3DP fails to answer. If you think my info and the other "experts" who will be contributing is poor then don't bother reading - please beleive your own myths and continue to have your printer jam and have to fix it regularly.

If you are jamming so often you want to lube your nozzle I would be looking at why you jam so often. Common reasons are bad filament (contains contaminents), dust on your filament (store it when not in use or run it through a sponge to brush it clean) or you heat up your extruder too often without purging it. I have had two nozzle jams in 2 years and I know exactly why those two jams occurred - clearly I must be doing something right.

As for our comments against grease, your first post seemed to recommend greasing the extruder not just greasing the nozzle thread - you can see how such information in the mind of a new user may break their printer.

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