Filament "curling" out of nozzle?

[ihackstuff 5]

I’m not sure what causes this, but my filament doesn’t come out of the nozzle “straight”, but it comes off the side, and curls back up until it sticks to the nozzle. This usually happens after a bad print when the nozzle drags through wet material.

Is this because of the notches on the filament from the feeder?

This is stumping me, but a consistent problem.

THANKS!

I’m using Ultimaker PLA.

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[SandervG 948]

If I am not mistaken this usually happens when there is some dirt inside your nozzle.

Are you already familiar with the 'Atomic Method'?

Here in the knowledgebase you can find more useful information, and this guide too.

For this particular thing, I think a good ol' Atomic Method should help you!

[SandervG 948]

Looking at your first layer, it looks like your bed could be adjusted slightly higher.

As a reference I usually have a screwdriver or something that I hold between 2 or 3 fingers and slide it gently over the first layer. If the filament moves it is not good, if it sticks and doesn't come off it is right.

[nallath 530]

The curling usually happens if there isn't enough filament coming from the nozzle to 'beat' the fans & shrinking properties of the material (eg; if enough material is extruded, gravity pulls it down enough).

[SandervG 948]

With the risk of making a stupid comment before checking it IRL, but this curling usually happens while it is priming, which is at the start of a print, which is when the fans are off?

[ihackstuff 5]

With the risk of making a stupid comment before checking it IRL, but this curling usually happens while it is priming, which is at the start of a print, which is when the fans are off?

 

Thanks! Yes, while it is priming. Thanks! I'll try an atomic clean. I did that many many times when I used some "bad" ABS (still under investigation, non-Ultimaker filament).

[ihackstuff 5]

Looking at your first layer, it looks like your bed could be adjusted slightly higher.

As a reference I usually have a screwdriver or something that I hold between 2 or 3 fingers and slide it gently over the first layer. If the filament moves it is not good, if it sticks and doesn't come off it is right.

 

Thanks for this info, but could you clarify a bit? So if I'm reading right, you drag the screwdriver over the first layer of a print after the first layer prints, and I've paused? And I see if the layer slides across the bed? Sorry I'm new at this. :-)

[yellowshark 123]

Yup it is normally a dirty nozzle but the filament should lay down OK once it has settled; i.e. the first few centimetres may not stick; but some judicious splatting and scrapping with a long screw driver should see you off and running.

[ihackstuff 5]

Edit: (I'm marking this as the best answer because of the pictures, but it was SandervG that got me this idea.)

I just wanted to follow up and let everyone know how this turned out, in case it helps someone else. Atomic Cleaning (http://support.3dverkstan.se/article/10-the) did wonders. But even though I'm printing PLA, I had to crank the temperature up to 260 degrees, because some really tough junk had accumulated inside the nozzle. The high heat burned it off. Finally.

You can see in the pictures that even after 4 passes at 220, the "cone" on my removed filament was incomplete. This was where the junk was hiding. Towards the end, 260 degrees was my magic number.

First pass at 220 degrees. Lots and lots of junk on the filament and the tip:

Second pass at 220, more junk, but notice the deformed cone. This told me there was more stuck in the nozzle that wasn't coming up. It's like a cool reverse image "Xray" of what's inside the nozzle:

Third pass at 220. Looks better, but the cone is still deformed:

Another pass at 220. Relatively clean, but that cone is unacceptable:

Last pass at 220. Clean, and deformed, but that filament strand and the deformity tells me there's still crap in there:

You can see here that at 250 degrees, finally, some of that black junk came out. Notice it's in the exact same place as the hole in the cone in the previous steps. Finally, that spot is loosening up because of the higher temps:

And finally, a pass at 260 degrees. Clean, and really nice looking. There's still some crud on the wall, though:

The last pass at 260 came out clean as a whistle. The filament is stretchy because of the heat, and the fact that I didn't pull it out sharply. I got lazy. :-)

Thanks for the help everyone! It's good to be back in action! And the filament isn't "curling" anymore. It comes straight down. For months I've had to tease the filament out to keep it from curling up. I should have realized it was a problem sooner.

Edited October 29, 2015 by Guest
Attribution to SandervG

[DidierKlein 635]

Thanks for the feedback!

Can you select the answer that you found the most usefull to guide others?

The black junk comes probably from burned ABS or something like that? That's why you had to increase the temp higher than 220°c to get rid of it!

[SandervG 948]

Thank you for your great write up, I am sure it will be helpful for other users!

[IRobertI 428]

Yes, very nice series of pictures. I have saved it as a reference to use when telling customers that it might not always be enough to just do an Atomic _once_. Some customers don't seem to want to accept that sometimes

[DidierKlein 635]

Why it's so much fun to do more than one atomics! (NOT)

[ihackstuff 5]

Yes, definitely that old ABS, which makes this clog MONTHS old! :-O

I marked mine as the best answer because of the pictures, but gave credit to SandervG for the awesome idea!

Thanks everyone!

Thanks for the feedback!

Can you select the answer that you found the most usefull to guide others?

The black junk comes probably from burned ABS or something like that? That's why you had to increase the temp higher than 220°c to get rid of it!

[SandervG 948]

Thank you @iHackstuff for writing this nice blog! It was a pleasure to read, with kind words for @IRobertI (dear I say.. a genius?) and the entire community!

[SandervG 948]

Oh, and if your nozzle ever gets stuck again by a power cut, you can just manually push the Zstage down to free it up, or leave it there. Next time when you start a print heat up the nozzle and it will automatically free it self