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Boney
(@boney)
Active Member
Filament Pulling Towards Nozzle Mid Print

Hello! I am new to the community and to the print world. I received my first MK3s+ kit a little over two months ago. A couple weeks in to printing PLA successfully, I was overconfident and sold on getting a second printer, so I ordered the second. I also ordered PETG at this time as I had plans to print some more durable things. This is when I hit the wall of confusion.

I have been wrestling with PETG ever since jumping down the rabbit hole, and I can NOT GET THIS STUFF TO PRINT. I'm able to print simple shapes, but when it comes to more complex prints, overhangs are my mortal enemy. Super jelly of all those folks who absolutely love PETG, I WANT TO AS WELL DANG IT ALL.

I had a catastrophic meltdown on my second printer a week ago, printing PLA. Blob of death. Down to one printer for now. I wanted to keep one machine on PETG and one on PLA for the time being. Death blob compromised my cooling duct on my extruder, so I must print another. Right now I am using transparent filament for testing purposes. I plan on using black filament once I am able to successfully print the fan duct. I feel like ordering a duct from Prusa defeats the purpose of owning a printer. I SHOULD BE ABLE TO DO THIS!!! Okay, back to topic....

I was having trouble getting PETG to stick to the print bed, but I made some slicer tweaks that allow me to print to the textured bed without using adhesive, which was a wonderful hurdle to jump. Then I run in to this current problem. Notice the pulling of the layers of the support material in the attached pictures. I can not get this to stop pulling, if this is even the correct term. I have searched countless posts, blogs, the interwebs, and I am lost. This is my last hope. Praise be Josef.

I have tried nozzle temps of 230-250. Obviously this isnt the fix. I have tried reducing movement speeds. I have disabled and enabled fans. Maybe my fans are set too low? I have read of poor layer adhesion with ramped fans and PETG. I have also tried to print this at .15mm, .1mm, and .05mm with no avail.

I'm kind of lost. Please somebody. Please....

This topic was modified 3 years ago by Boney
Posted : 03/06/2021 2:57 pm
ssill2
(@ssill2)
Noble Member
RE: Filament Pulling Towards Nozzle Mid Print

if you're printing the duct, I believe that needs to be printed in ABS and not PETG otherwise it will melt.   PETG isn't bad.   you do have to left the zOffset a bit higher than PLA on the same sheet.

You could try getting someone to print you one in ABS.  Otherwise you might have to order one.

Posted : 03/06/2021 7:18 pm
FoxRun3D
(@foxrun3d)
Famed Member
RE: Filament Pulling Towards Nozzle Mid Print

Not sure I understand what you mean by "pulling", I do see some stringing, maybe that's what you meant. I love PETG, but some stringing seems inevitable. There are plenty of threads on stringing in the Prusa forums, and quite a few parameters you can try to change to minimize it. Google for bobstro notebook and you'll find a lot of good advice in Bob's write ups. 

Unless I do the rare high volume production run I don't tend to worry much about it and just take the heat gun to it. Intellectually not as satisfying.  Way faster. 

Regarding the fan shroud, as @ssill2 said, you'll need to print it in ABS or similar (I use PC Blend). If you use PC Blend, don't forget to put glue stick on your sheet or you'd better order a new one right away...

Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...

Posted : 03/06/2021 8:49 pm
Boney
(@boney)
Active Member
Topic starter answered:
RE: Filament Pulling Towards Nozzle Mid Print

@fuchsr

Yes, I see the stringing, and it's easily managed. I have had one successful PETG print and it was a wine bottle bird feeder, very simple angles.

I guess what I'll do is order a heat shroud. I'm not ready to try printing ABS just yet.

I'm gonna use red circles in the pictures, around where this "pulling" is occurring. The nozzle seems to pull the filament towards it as it moves around overhangs, eventually bunches up and curls up.

Posted : 03/06/2021 10:44 pm
Boney
(@boney)
Active Member
Topic starter answered:
RE: Filament Pulling Towards Nozzle Mid Print

As the nozzle moves by those points, the filament pulls towards the nozzle and causes that vertical curl. I have watched it happen time and time again.

Posted : 03/06/2021 10:51 pm
Boney
(@boney)
Active Member
Topic starter answered:
RE: Filament Pulling Towards Nozzle Mid Print

I'm also in the process of building heat enclosures. Gonna try to print the parts. Just got my acrylic sheet cut. I'm not sure it that will help or not but I was willing to give it a shot and I wanted heat enclosures anyway.

Posted : 03/06/2021 10:55 pm
FoxRun3D
(@foxrun3d)
Famed Member
RE: Filament Pulling Towards Nozzle Mid Print

Is your nozzle and the heater block squeaky clean? PETG likes to curl up to itself, if it can. I use nickel-coated copper nozzles and heater blocks, which seem to do better. I guess a silicon block may help too, I'm just not using them.

Could also be some of your print parameters. If you follow these instructions to save the project as a 3mf file, zip it, and upload it, I'm sure some ot the friendly folks here will be happy to chime in and offer suggestions for optimizing the parameters. 

Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...

Posted : 03/06/2021 11:01 pm
Swiss_Cheese
(@swiss_cheese)
Noble Member
RE: Filament Pulling Towards Nozzle Mid Print

post your Dot three MF project file so we can see the settings your trying to print with, as well as any pertinent information about the specific brand of filament your using. and if your printing in an enclosure.

 

Good Luck

 

Swiss_Cheese

The Filament Whisperer

Posted : 06/06/2021 5:12 am
Boney
(@boney)
Active Member
Topic starter answered:
RE: Filament Pulling Towards Nozzle Mid Print

@swiss_cheese

I will try to get the .3mf posted today, no promises though. Been busy all week. Definitely gonna do it though.

I am using Overture3D PETG. I really enjoyed printing with their PLA, as it was buttery smooth to print with.
As for enclosures, I am currently not printing in an enclosure, but I am in the process of building them. I have my Ikea Lack tables and Polycarb sheet cut for it, just gotta print the pieces and gather the last bit of hardware.

Posted : 06/06/2021 2:18 pm
Swiss_Cheese
(@swiss_cheese)
Noble Member
RE: Filament Pulling Towards Nozzle Mid Print

@boney

 

No worries, and I have clear Overture3D PETG sitting right here next to me. I like that brand they are a very good middle of the road filament I have some of everything they sell, even there Nylon, they make a fine ABS also.

 

post it when you get around to it, till then enjoy

 

Swiss_Cheese

The Filament Whisperer

Posted : 06/06/2021 6:32 pm
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