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Topic: clogged extrusion tip?

I was having problems last night with ABS not feeding into the hot end.  The gear was stripping the filament and it was not extruding.

I thought maybe it was just too much dust, so I cleaned everything and it was still not extruding.  I was running the end at 200C.

I cleaned it again and tried to switch to PLA instead of ABS,  After messing with the end for 20 minutes and feeding a thin wire (not thin enough to go all the way throug) up and down the inside of the hot end, it started to work, but not very well.  The PLA was coming out in a VERY VERY thin extrusion and curling up on itself.  Like it was extruding at an angle.

Any tips on how to remedy this problem?

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Re: clogged extrusion tip?

You've most likely got a clog. Check out the clog resolution section of our troubleshooting section:
Clogged nozzles are exceedingly rare, but when they happen they can be very frustrating. The first thing to do is to see if you can clear the jam by hitting the "extrude" button on Pronterface. In many cases, the hot filament will be able to melt the more solid clog.

If this doesn't work, the next thing to do is to release the thumb screw on the side of the extruder. You should be able to pry open the acrylic slats and get to any offending clogs.

You may have a "cold jam" where the filament is stuck in the Black plastic barrel. In this case it might be advisable to remove all filament, then try and clear the jam with the 2mm Hex wrench.

If the jam is down in the nozzle, you could take a bit of Cat5, wire, or a needle and try to clear out the jam.

Let me know if you make any progress.

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Re: clogged extrusion tip?

How safe is acetone to use on the extruder?

This will obviously dissolve ABS but will it negatively impact on any of the other plastics in the assembly?

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Re: clogged extrusion tip?

solidoodlesupport wrote:

Let me know if you make any progress.

no luck so far.  I think the jam is down in the nozzle.  I've tried to switch back  to ABS, and back to PLA... I'm manually fed the filament into the extruder, it comes out, and acts like it's trying to curl, and it's MUCH thinner than how this worked when I first got it.

Cat 5 cable was too thick for me to push into the nozzle.  I found some magnet wire that I was able to feed in, but I couldn't get it far enough to floss the nozzle, I could only get in about one inch.

I tried a needle and a pin that were also both too big.  I tried forcing the filament in with a lot of pressure, same results a very thin hair of plastic extruding.

I'm thinking about finding either a guitar string or a fine piano wire or some other very stiff wire and feeding it in from the bottom, but I guess I'd like to know if there is a better way to do this.  If I go looking to buy some stiff wire is there a gauge I should be looking for?

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Re: clogged extrusion tip?

As I've posted above, soaking the metal tip of the nozzle in acetone will disolve any ABS. Not sure how it will react with PEEK, so only let it touch the metal parts.

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Re: clogged extrusion tip?

You can try taking the nozzle off and cleaning it out with a torch.  This will involve taking the thermistor off, so you will need some Kapton to tape it back on.  If you bought a roll to use on the bed you could cut a strip of that.  I recommend keeping a roll of 1/4" kapton around, it comes in handy a lot.

Heat the extruder up until the plastic is able to come out.  Shut off the power and unplug the connectors for the heater and thermistor, and pull off (without using bare fingers) the black insulating sleeves from the nozzle.  Very carefully try to unscrew the nozzle, taking care not to crush the thermistor.  You can cut the kapton and take the thermistor off now to make it easier, but you don't want to give the plastic too much time to freeze up again.  You might need to do something to secure the black insulator barrel if it keeps spinning.

If the whole barrel unscrewed from the insulator, then that's fine, you can clean that out too.  Carefully unscrew the heat core from the barrel, which should be easy.  If you need to unscrew the nozzle from the barrel, don't hold the barrel directly with pliers because you could crush the threads.  Run two nuts down the barrel and tighten them against each other.  Hold the nuts with the pliers while you unscrew the nozzle using a socket wrench.  You might need to warm it with the torch to soften the plastic inside.

Warm the nozzle and barrel enough to soften the plastic just enough that you can pull it out and it will stretch and pull more filament along with it.  Then go outside and start torching the nozzle and barrel (separately) in earnest.  When you start to see smoke and flames, you know the stuff is starting to burn out.  That's why you are outside.  Keep a small cup of alcohol handy and drop them in to cool off after they have been flaming a bit so you don't get the brass too hot.

Once the nozzle is cleaned out you can try shining a flashlight through it onto a piece of paper, as if you were viewing an eclipse.  I'm not sure how useful it is, but you can see if the edge of the opening is clear.  You might also see a couple lines that seem like a blockage, but are actually the filaments in the bulb.

Check out this video for a demonstration of the torching-

http://youtu.be/6bTfl35zlHE

When you put everything back together, make sure the heater core is screwed down as finger tight as you can get it against the nozzle.  When you tape the thermistor back on the nozzle, make sure it is covered completely with as little air surrounding it as possible.

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Re: clogged extrusion tip?

From a completely theoretical point of view (I don't even have a machine to get clogged up yet!)

If it's the actual tip that's blocked

according to the sales page, the tip is 0.35mm
that makes about a gauge 11 guitar string. (cuold blockages there be fixed with a sub melting heat (to soften the plastic slightly, (so around 100*c) and pushing plastic out with wire, (this temperature is obviously easily reached by dropping the part into a kettle.

I'm guessing that'd clear the very tip. the video seems to show cleaning the barrel. I've got two questions.

is burning really better than just dissolving the plastic in either acetone or petrol?
(for either the heater barrel or the actual tip.)

does the carbon residue left from that burning make the nozzle more likely to clog in future, or does a coating or carbon actually provide lubrication? (I'm guessing that it's going to lead to contamination of the plastic and sooner failures)

if there was such a vast clog, would if be better to use a drill to clear the clogs (adapter to have a very sharp tip, and blunt flutes to avoid damaging the brass, and use it as a hand held tool rather than a machine tool. (or if you have a lathe using that to properly centre and ordinary drill?) (only really useful for the barrel not the tip).

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Re: clogged extrusion tip?

The torching can be a last resort.  However if the clog is something other than ABS, the acetone may not do much.   You might have success with pushing a wire through the tip, but what ever clogged the nozzle would still be in there.

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Re: clogged extrusion tip?

I read somewhere that some tainted filament from China had small bearings in it. The bearings were small enough to be encompassed in the filament but large enough to clog the extruder.

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Re: clogged extrusion tip?

Gordym wrote:

I read somewhere that some tainted filament from China had small bearings in it. The bearings were small enough to be encompassed in the filament but large enough to clog the extruder.

Let's hope not, this filament was from solidoodle

I had knee surgery today I doubt I'll be well enought to try to clear the clog for a day or two.

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Re: clogged extrusion tip?

Okay, I got a guitar wire.  I heated up the nozzle and pushed the wire all the way through. 

This is a video of how my extrusion looks when running it away from the bed.

It didn't do this when I got it, and It was extruding slightly thicker based on what I've got left in my scrap bucket.

Is this a problem?

See how it doesn't drop straight down?  It curves off to the left right after exiting the tip of the extruder?

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Re: clogged extrusion tip?

Mine always curls up when it leaves the tip.

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Re: clogged extrusion tip?

I think I've cleared it well enough then, thanks

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Re: clogged extrusion tip?

I have the same issue.

heated up the hot end to 200c, stripped some wire from cat5, got it all gobbed up with ABS, then stripping it off with wire strippers, repeated.  8-10 times, until almost no ABS came out on the wire.  I gently worked it around in the barrel.

ramped it up to 210, and fed the fil in.  it curled for a second, then it started extruding straight as an arrow.

working like a charm running at 200c.

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Re: clogged extrusion tip?

I'm glad the clogging problems are being resolved. I want you all to know that this problem is on our minds, and that we are looking for easier solutions.

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Re: clogged extrusion tip?

Mine is still not 100% the way it was at first, and still curls to the left.  But it's extruding well enough right now

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Re: clogged extrusion tip?

Mid print I had some black stuff extrude into my print, a few small dots, but it kept on going.. disaster averted?

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Re: clogged extrusion tip?

Third print in with my printer and it clogged up so much no filament would come out at all. I now have raw fingers from turning a small drill bit to try remove as much of the plastic as possible. The good thing was that I didn't need to remove any tape to get the head apart. Just disconnected the two connectors and unscrewed it. I think I might have had a problem from the start, when I extruded filament before the clog it always curled up, now it goes straight down and it extrudes more evenly now.

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Re: clogged extrusion tip?

pretenda wrote:

Third print in with my printer and it clogged up so much no filament would come out at all. I now have raw fingers from turning a small drill bit to try remove as much of the plastic as possible. The good thing was that I didn't need to remove any tape to get the head apart. Just disconnected the two connectors and unscrewed it. I think I might have had a problem from the start, when I extruded filament before the clog it always curled up, now it goes straight down and it extrudes more evenly now.

Good to hear things are working better for you!