Gaps in narrow area in first layer, but only as part of larger print
After printing for a few months with my MK3S I've now run into a problem that I can't get my head around:
* If I print a first layer with a narrow horizontal area and an overall small footprint, everything seems to be fine.
* If I print the same narrow horizontal area as part of a larger print, things start to go awry: filament gaps start to show up in the narrow area.
The first picture shows the smaller print, printed in 3 different filaments:
* Fillamentum ExtraFill PLA mellow yellow
* Fillamentum ExtraFill PLA turquoise blue
* Made for Prusa PLA galaxy silver (which came with the printer)
No filament gap problems here:
The second picture shows the same area as part of a larger print, again printed using the same 3 different filaments:
Fillamentum turquoise blue prints fine, Prusa galaxy silver shows some gaps on the left and Fillementum yellow shows many gaps.
The print gets to the narrow area after the larger infill area and the print direction is the same in all cases. I stopped the print when the defects started to show up.
I've been using the default PrusaSlicer settings for these filaments. I've tried firmware 3.9.0 as well as 3.9.1 but both behave the same. I've tried different live-z adjust values, without obvious differences. The Fillamentum spools are brand new and the Prusa spool was kept in a dry box.
What I don't understand: why do these defects start to show up in this area in the larger print, while it prints fine if part of a smaller print? And secondary: why do these different filaments (in one case just a color difference) behave so differently here?
Thanks for your input!
RE: Gaps in narrow area in first layer, but only as part of larger print
Looks to me like under- extrusion, this can happen over time if your nozzle becomes partially clogged, or it can happen because of a change in the moisture content of the filament, or a change in the tension from the idler, or even filament not being to spec ( meaning it got thinner or thicker during production run), any of 100 reasons etc., etc.
First thing I would try would be to use some cleaning filament and do 2 or 3 cold pulls, then check the idler tension is proper. make sure your using the proper amount of heat for each different filament, they aren't created equal. If those things don't help clear you up we'll move on from there.
Also just out of curiosity have you tried orienting one of the models at 45 degrees and seeing what happens?
The Filament Whisperer
RE: Gaps in narrow area in first layer, but only as part of larger print
I would say it has to do with your print bed not being flat across the whole surface.
I would assume you are printing both small and large parts in the middle of the bed with the cutouts on the front?