Dealing with stringing issue on Lulzbot Mini

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/DT5S63LSL/goblin-melee?optionId=56485557

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.

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!

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.
Lorcan (1) (1).zip (2.53 MB)


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.

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