Dealing with stringing issue on Lulzbot Mini

Help with printing with specific plastic filaments.
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SomeKittens
Posts: 3
Joined: Tue Feb 27, 2018 11:41 am

Dealing with stringing issue on Lulzbot Mini

Post by SomeKittens » Tue Feb 27, 2018 11:44 am

Spent the weekend trying to figure out this stringing issue I'm having. I use my printer for mostly minis and other tabletop gaming, so this is getting quite annoying. Used goblins as a test print because you can never have enough goblins.

Photos of prints (along with print-specific settings): https://imgur.com/a/tWtJy

* Printer: Lulzbot Mini
* Supports: Meshmixer
* Slicer: Cura (Lulzbot edition) 2.6.63
* Filament: eSun PLA+ Black

Settings across all prints:

* Layer height: 0.05mm
* Print speed: 60mm/s
* Travel Speed: 175mm/s
* Cooling: enabled
* Fan Speed: 100%
* Retraction Distance 1.75mm
* Retraction Speed: 10mm/s

STL (for the curious): https://www.shapeways.com/product/DT5S6 ... d=56485557

kcchen_00
Posts: 1701
Joined: Thu Feb 19, 2015 12:42 am

Re: Dealing with stringing issue on Lulzbot Mini

Post by kcchen_00 » Tue Feb 27, 2018 4:07 pm

Hmm... .05 layer height is very ambitious. I think people have gone that low, but sticking to a minimum of .1 is probably a good idea for FDM machines. SLA and other resin based machines would be better for optically clear or completely smooth results.

Stringing can also be a sign of extrusion temps being too high, but PLA+ operating temps are 205-225C according to eSUN's site. So 190C is even below the operating range suggestion... which is okay because part of this is depending on the hotend.

Try these tips:
- A little less flow rate, 95-95%.
- Make sure the fan is at 100% for PLA... or at the very least, always on.
- Your slicer (it looks like Slic3r) should have a retract head setting, try that as a last resort. With your retraction settings, this could reduce the stringing to just strands upward.

I suspect the flow rate will probably solve the issues. Otherwise, a little post processing (sanding) should get rid of the stringing.

SomeKittens
Posts: 3
Joined: Tue Feb 27, 2018 11:41 am

Re: Dealing with stringing issue on Lulzbot Mini

Post by SomeKittens » Tue Feb 27, 2018 4:13 pm

Huh, hadn't thought it would be the layer height. That would explain why it's been getting worse - I just thought it was because I was tackling more challenging prints.

I'll try bumping the layer height up to .1 and see what that changes. Otherwise, I'll take flow rate down another notch.

Thanks!

jnielsen
Posts: 2
Joined: Tue Apr 30, 2019 11:41 am

Re: Dealing with stringing issue on Lulzbot Mini

Post by jnielsen » Tue Apr 30, 2019 11:46 am

Did this work when you changed the layer height? We are also struggling with this here at the high school I teach at. We are trying to make miniatures for our school D&D club and having little success. Here is a copy of the two that we printed thus far.
Attachments
Lorcan (1) (1).zip
(2.53 MiB) Downloaded 20 times
Lorcan Stringy.jpg
Lorcan Stringy 2.jpg

SomeKittens
Posts: 3
Joined: Tue Feb 27, 2018 11:41 am

Re: Dealing with stringing issue on Lulzbot Mini

Post by SomeKittens » Tue Apr 30, 2019 12:15 pm

Yes, adjusting the layer height fixed it. It seems to me that with a tiny layer height and all the small fiddly bits of a mini, the nozzle couldn't squeeze out a small enough amount, leading to all the stringing.

I haven't experimented with a narrower nozzle, but have seen that recommended.

Also it's super cool that your school has a D&D club, wish that existed when I was a kid.

jnielsen
Posts: 2
Joined: Tue Apr 30, 2019 11:41 am

Re: Dealing with stringing issue on Lulzbot Mini

Post by jnielsen » Tue Apr 30, 2019 3:50 pm

Could you possibly upload a picture of your final product of your goblin?

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