Slightly gloppy edges (PLA)

Just made my very first print today with my newly operational KITTAZ!

I printed up a herringbone gear that I want to use to help a friend with his art project. Overall I think it came out decently. Modeled with OpenSCAD, sliced with Cura.

  • 0.1mm layer height
  • Lulzbot silver PLA
  • 180º nozzle, 60º bed
  • fan on (stock shroud)
  • UHU glue stick directly on glass (no PET)
  • 50mm / sec speed

For a sense of scale, the gear is about 12mm thick. Interestingly the first half of the print is definitely worse than the second. Attached are some detail photos of trouble area. I had quite a hard time getting it off of the bed, but some water and a cheese slicer did the trick.

EDIT I forgot to mention: I did an extruder calibration test by extruding 100mm of filament and measuring the actual length extruded and it was so close (within 1 or 2mm) that I didn’t even bother to adjust the steps in the firmware.

I would love feedback on how I might improve my quality. Thanks!

More fan should help with this. If you can freeze the PLA as soon as it comes out of the nozzle, it will retain it’s dimensional accuracy better. Are you using the recommended configs from ?

You can control the fan speed with M106 Sfoo where foo is a number between 0 (off) to 255 (full on). Just type that into the input line in the bottom right of the pronter-like window.

Thanks for the reply. I am using the standard Lulzbot TAZ profiles for Cura. Looking at the gcode that cura generated for my models, I can see M106 commands sprinkled throughout with different values for each layer. Most are high (between 230 and 255) but some early on are lower (below 50). I remember reading at one point that less fan can help the first layers adhere better to the heated bed.

This morning I held my finger in front of the small fan duct pointed at the head of the nozzle and couldn’t feel any air moving. I can feel plenty of air escaping around the back of the fan. Could there be something wrong with my fan mount / shroud / fan? I am now printing out the recommended dual duct fan ( but I guess this will actually reduce airflow to the nozzle.

I also noticed this morning that some PLA had flowed out of the heater block of the nozzle and onto the nozzle itself. I’ve read in a few other posts here about the same phenomenon so I heated up the extruder, removed the nozzle and put some teflon tape in there before replacing it. Hopefully that will protect against that issue.

Overall, pretty good results, though, from my first few prints. I printed some smaller parts last night that came out great.

FYI- you don’t want to print directly on the glass bed, as it can potentially flake off during part removal. If that happens it’s not covered under the warranty. If you’d like to use something other than the PET surface, look at PEI:

Thanks for the advice. For the record, the new fan shroud seems to have improved airflow around the nozzle and my prints are looking better. I also stuck some PET film on my glass bed and that is working pretty well although I see more lifted corners than I did without. I’m going to try a little bit of glue stick.

After making those changes I splurged on Simplify3D and it has been giving me really good results.