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Author Topic: Filament Jamming  (Read 440 times)

JC_Unstoppable

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Filament Jamming
« on: January 07, 2013, 02:53:22 AM »
Hey guys,

   One of my hot ends is jamming.  I've monkeyed with it a whole bunch and I think I've found the problem.
Tell me if you agree.

I'll feed the filament in about 30mm and then I'll feed another 5mm and the feed gear starts stripping the filament.
When I pull the filament out I get this (as shown in pic filament_1)

It looks like the filament melted then flowed back up the filament and then hardened.

Pic filament 2 and 3 I think strengthen the case by showing that hardened piece that can be peeled off.

Any thoughts?
Is my hot end (or at least the piece that guides the filament) a little too big?

Thanks.


whosawhatsis

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Re: Filament Jamming
« Reply #1 on: January 07, 2013, 05:03:03 AM »
I've never seen one like that before. What's your filament diameter?

JC_Unstoppable

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Re: Filament Jamming
« Reply #2 on: January 07, 2013, 05:09:35 AM »
The filament is the stuff that came with the kit.  It measures 2.9mm to 3.2mm.  I tried the other filaments, which measured generally the same with the same results.

I did at one point pull the extruder apart and look at the funnel in the wooden piece.  There was some material that had beenscraped off the side of the funnel that I cleared away with an under sized (less than 3mm drill).  But the jamming was happening before that and consistent with the pictures I attached.


JC_Unstoppable

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Re: Filament Jamming
« Reply #3 on: January 07, 2013, 06:17:04 AM »
I tried feeding the filament again by hand and it looks like the nozzle is just clogged.  Nothing is coming out at all.

Any suggestions on how to clean it?
I'm worried about dipping the whole thing into acetone since there are plastic parts on the hot head itself.

Thanks.


whosawhatsis

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Re: Filament Jamming
« Reply #4 on: January 07, 2013, 06:30:52 AM »
PLA is not acetone-soluble, so that wouldn't help anyway. To remove PLA from the nozzle, heat it to 90-100C (too hot and the PLA will be liquid and won't lift out) with the filament in it, then slowly pull the plastic out. It should stretch into a thin string. Try not to break that string, and you might get it all (you'll be able to see a nozzle-shaped piece at the end if you're successful. If it doesn't work, you'll have to heat it up to extrusion temperature and try pushing the filament through for it to bond so you can try again, or you can remove the nozzle with a pair of wrenches (one on the nozzle, one on the block) while it is still at 100C. Have a paper towel or rag ready to hold the nozzle tweezers and a pin to dig the plastic out before it cools. When putting the nozzle back, make sure it tightens down hard against the barrel, not the heater block. There should be a small (less than 1mm) gap between the hex part of the nozzle and the heater block when it's tight.

ccox

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Re: Filament Jamming
« Reply #5 on: September 08, 2013, 07:05:35 AM »
It would be nice to post instructions or diagrams of the new hot end - for those of us dealing with a dreaded ABS clog.

 

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