Artifact lines in bottom layer (PLA)  

RE: Artifact lines in bottom layer (PLA)

Helle,

I have seen these lines when printing 0.2mm layer height (which is what the first layer defaults to regardless of layer height selection for the slicer) when the slicer cannot create the infill in one pass.  It seems that the gaps remaining are too narrow for the filament thread being extruded and so you end up with a raised ridge like this.  You did not specify which PLA you are using however if it the slicer parameters for the filament (diameter, extrusion multiplier) are not well calibrated for your particular filament there may be some over or under extrusion exacerbating the problem. 

I have personally just begun to work on the calibration issue using forum contributor Bobstro's notes (found here: http://projects.ttlexceeded.com/3dprinting_filament_topics.html ).  The good news is that when printing at 0.15mm layer height as you are subsequent layers will not show this anomaly as significantly and will largely cover over the "defect" in the first layer.

Bobstro or others with much more experience than I may weigh in with additional comments or suggestions.

Regards,

Steve

RE: Artifact lines in bottom layer (PLA)

Thanks Steve !

Great link too.

Without changing the print location/orientation I set print to 0.2mm and for some reason bottom layer was (almost) perfect. (Which doesn't make sense because the bottom layer was still 0.2mm)

I then found an option to set bottom layer to 0.15mm and sure anough, a perfect bottom layer.

Cheers

Helle

RE: Artifact lines in bottom layer (PLA)

(never mind, forum won't let me post pics today.)

RE: Artifact lines in bottom layer (PLA)

Here's what I tried to post yesterday:

Quick tests to show different solid infill results. Top-left: Cura using default 0.2mm layer heights. Bottom-left: Cura with top layer ironing enabled. Top-right: PrusaSlicer using default 0.2mm layer heights. Bottom-right: PrusaSlicer using variable layer height to create thinner top layer.

Using thinner solid infill extrusion widths can help as well. Calibrating your extrusion multiplier for each filament can help a lot.

(Parts flipped inadvertently, but not home to repeat prints.)