sloppy edges w/ PLA

Hi Everyone,

I’m not sure if this is a filament issue or a hardware issue. When I print with PLA on my TAZ 4.5 (hexagon hotend, PET bed), I’m getting sloppy/globby edges. I used to get really nice looking edges with PLA but after running some prints on ABS (needed for temp resistance) and going back to PLA, this is happening.



I am using CURA 17.10 with standard PLA (eSUN) settings switched to expert mode tp add a brim and improve cooling settings. 0.21mm layer heigh with retraction enabled. 205C extruder temp/50C bed temp

Does anyone know what could be causing this and what I can do to fix it and get clean edges again?

You indicate that you switched to expert mode. Are you also using the Lulzbot supplied Cura profiles as a starting point? https://www.lulzbot.com/taz-cura-profiles

I have had issues like what you are seeing when my fan speed is too slow (or off).

Try what geburges said, however it could also be over-extrusion

Not quite. I started in Quickprint and set it to eSun PLA. When I switch to expert it asks, “Copy the settings from quickprint to full settings?” and I click “yes”. From there, I changed the minimum fan speed from %75 to %100 and I changed the infill % from %20 to 25%

I have recently checked the eSteps on the printer and everything was correct but perhaps I will check again.

thanks!

I bet you have still some ABS inside you nozzle, I have simmilar issues when switching back from PETG. You have to be shure to flush out the ABS completely before starting a print with PLA again, especialy if you did no perfect cold pull after the last ABS print.
Try to flush it out, stay by your printer al the time!:

  1. Load PLA and heat up to 240°.
  2. As you pas about 220°, extrude 1mm of filament from time to time to prevent the PLA from burning inside the nozzle.
  3. At 240°, do some long extrusions at high speeds. For example 40mm @ 100mm/min.
  4. Repeat around 2-3 times.
  5. Cool down to print temperature, continue to extrude 1mm as in step 2.
  6. Print and check

This way all residues should be out of the nozzle.