Extrusion problem

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DrRobot
Posts: 51
Joined: Wed Aug 19, 2015 5:27 pm

Extrusion problem

Post by DrRobot » Tue Oct 27, 2015 6:22 am

I was printing with a spool of black PETg without issues. Then, I changed to a spool of white PETg I used before without running though any cleaning filament. Now I have an extrusion problem: I have tried several 1-2 hours print, and the extrusion seems to stop when it gets to the top solid layers. I tried to reduce the filament drive tension screw to minimum and extrude a couple of 10mm, and then retract, I got uneven bite marks as shown in the attached picture. I thought this may because a clog somewhere in the extruder, so I tried to remove the extruder from the filament drive and then extrude a couple of 10mm and retract, I got perfectly even bite marks (10%-15%). So, does this mean it has a clog somewhere in the extruder? Thanks for any help!
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20151026_233637.jpg

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Jules
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Joined: Wed Jan 21, 2015 1:36 am

Re: Extrusion problem

Post by Jules » Tue Oct 27, 2015 1:14 pm

How fast are you printing it? If it is having trouble when it starts trying to push a lot of filament, but is otherwise okay, you might have a partial clog in the nozzle that is preventing even flow at normal extrusion rates. If that happens, the gear starts to kind of chew up the filament like that.

PETG needs to print at speeds of about 3200 mm/min. If yours is printing in that range, it might be time to take the nozzle off and check the interior for buildup. If you're printing faster than that, slow it down. The PETG needs time to melt in the nozzle. :D

DrRobot
Posts: 51
Joined: Wed Aug 19, 2015 5:27 pm

Re: Extrusion problem

Post by DrRobot » Tue Oct 27, 2015 4:15 pm

Hi Jules,

Thanks for the reply. I am using exactly the same setting as in your post: viewtopic.php?f=11&t=2593. The only difference is I used white color (which I used before without issues). Just as you said, I think it clogs when extruding faster (on solid layers), not when printing infill (I used 30%). Should I contact customer support before I disassemble the extruder? The machine is still under warranty, but I am afraid they won't help since I used eSUN brand filament.

Bratag
Posts: 438
Joined: Wed Jan 14, 2015 5:33 am

Re: Extrusion problem

Post by Bratag » Tue Oct 27, 2015 4:42 pm

DrRobot wrote:Hi Jules,

Thanks for the reply. I am using exactly the same setting as in your post: viewtopic.php?f=11&t=2593. The only difference is I used white color (which I used before without issues). Just as you said, I think it clogs when extruding faster (on solid layers), not when printing infill (I used 30%). Should I contact customer support before I disassemble the extruder? The machine is still under warranty, but I am afraid they won't help since I used eSUN brand filament.
White filaments tend to be strange. I have to run mine at 10-15 degrees hotter than any other filament. I think it has to do with the pigments they use in them. As far as using eSun filament negating support I do not believe that is the case. Makergear aren't like some companies that force you to use their filament.

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Jules
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Re: Extrusion problem

Post by Jules » Tue Oct 27, 2015 5:06 pm

Agree with Bratag, the whites are a bit fiddly. Your hot end is probably fine, I'd just retract it completely, try running the black through again, slowly, to clean it out and reduce the tension on the screw a bit more - not much, just a little, before you try the white. Then try it again, with a looser tension and a hotter temp.

You are going to experience a lot of jams and stripping - it's not something MakerGear needs to replace a hot end for. Cleaning out a jam is going to become very commonplace for you. (i don't even think about them any more - i just loosen the tension on the screw and reload.)

It might not even be jammed, just try increasing the temp a bit first. Not all of the PETGs are exactly alike, you might need to go up a few degrees or down a few, with different colors. One might need to be printed a little slower than others to give it time to melt.

All part of the process. :D

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insta
Posts: 2000
Joined: Tue Sep 16, 2014 3:59 am

Re: Extrusion problem

Post by insta » Tue Oct 27, 2015 6:17 pm

Bratag wrote:
DrRobot wrote:Hi Jules,

Thanks for the reply. I am using exactly the same setting as in your post: viewtopic.php?f=11&t=2593. The only difference is I used white color (which I used before without issues). Just as you said, I think it clogs when extruding faster (on solid layers), not when printing infill (I used 30%). Should I contact customer support before I disassemble the extruder? The machine is still under warranty, but I am afraid they won't help since I used eSUN brand filament.
White filaments tend to be strange. I have to run mine at 10-15 degrees hotter than any other filament. I think it has to do with the pigments they use in them. As far as using eSun filament negating support I do not believe that is the case. Makergear aren't like some companies that force you to use their filament.
They won't void their warranty for not using their filament*, but they can certainly require you to use their filament as a test to show its a problem with the machine before replacing parts. They may or may not, (and it might be situational), but that's perfectly reasonable IMO.



* they may void your warranty on certain parts if you run the metal-infused filaments through and end up shredding mechanical parts from the abrasive
Custom 3D printing for you or your business -- quote [at] pingring.org

Bratag
Posts: 438
Joined: Wed Jan 14, 2015 5:33 am

Re: Extrusion problem

Post by Bratag » Tue Oct 27, 2015 6:37 pm

insta wrote:
Bratag wrote:
DrRobot wrote:Hi Jules,

Thanks for the reply. I am using exactly the same setting as in your post: viewtopic.php?f=11&t=2593. The only difference is I used white color (which I used before without issues). Just as you said, I think it clogs when extruding faster (on solid layers), not when printing infill (I used 30%). Should I contact customer support before I disassemble the extruder? The machine is still under warranty, but I am afraid they won't help since I used eSUN brand filament.
White filaments tend to be strange. I have to run mine at 10-15 degrees hotter than any other filament. I think it has to do with the pigments they use in them. As far as using eSun filament negating support I do not believe that is the case. Makergear aren't like some companies that force you to use their filament.
They won't void their warranty for not using their filament*, but they can certainly require you to use their filament as a test to show its a problem with the machine before replacing parts. They may or may not, (and it might be situational), but that's perfectly reasonable IMO.



* they may void your warranty on certain parts if you run the metal-infused filaments through and end up shredding mechanical parts from the abrasive

Funny you should mention that - I have just started printing with the proto-pasta stainless steel. Of course I have already replaced my hotend with an E3D and a hardened steel nozzle. I am a little worried about the hob on the extruder motor wearing if I print with it a lot. It is considerably harder and more abrasive that pla etc.

That being said - having a Millenium Falcon print and look like a diecast piece is pretty damn cool.

DrRobot
Posts: 51
Joined: Wed Aug 19, 2015 5:27 pm

Re: Extrusion problem

Post by DrRobot » Tue Oct 27, 2015 10:45 pm

Jules wrote:Agree with Bratag, the whites are a bit fiddly. Your hot end is probably fine, I'd just retract it completely, try running the black through again, slowly, to clean it out and reduce the tension on the screw a bit more - not much, just a little, before you try the white. Then try it again, with a looser tension and a hotter temp.

You are going to experience a lot of jams and stripping - it's not something MakerGear needs to replace a hot end for. Cleaning out a jam is going to become very commonplace for you. (i don't even think about them any more - i just loosen the tension on the screw and reload.)

It might not even be jammed, just try increasing the temp a bit first. Not all of the PETGs are exactly alike, you might need to go up a few degrees or down a few, with different colors. One might need to be printed a little slower than others to give it time to melt.

All part of the process. :D
Thanks for all the reply. Right now I don't have any black filament left, but I'll try to increase the temp and lower the speed a little. I found that the white PETg has rougher surface than PLA, which may cause more friction in the guide tube sometimes

DrRobot
Posts: 51
Joined: Wed Aug 19, 2015 5:27 pm

Re: Extrusion problem

Post by DrRobot » Wed Oct 28, 2015 4:33 am

I am able to disassemble the V3B hotend, and I think there is indeed a clog. I found some previous post that suggested paint stripper or torch to clean the barrel and nozzle. Will paint stripper also work on PETg? What's the best way to clean the filament inside the peek?
Attachments
20151027_220252.jpg
20151027_220229.jpg
20151027_220404.jpg

jsc
Posts: 1864
Joined: Thu Apr 10, 2014 4:00 am

Re: Extrusion problem

Post by jsc » Wed Oct 28, 2015 9:28 am

Methyl ethyl ketone (MEK), the active ingredient in paint stripper, should attack PETG, so it's worth a shot. I haven't seen anybody who has reported on it. As long as you have it apart. Although usually, just ramming the thinnest hex wrench that came with the printer down the barrel while it's installed and heated will clear out most clogs, along with maybe a sub-.35mm diameter guitar string going the other way, from the nozzle.

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