Nozzle diameter does not affect extrusion width - why? (2.8.0)
My printer is a tuned up Ender 3 with 0.6mm nozzle. I am trying to migrate from SuperSlicer to PrusaSlicer. After carefully trying to move all the settings, the test prints still look "sparse" and I can visually see uneven strings of filament being extruded, clearly too little volume coming out.
I am puzzled about the following behavior: no matter which nozzle diameter i set in my extruder settings, I will always get the same count of extrusions in the bottom layer (on other layers too but bottom layer is easy to inspect). Comparing the density of extrusion paths per mm to SuperSlicer, SS creates extrusion paths with approximate width of the nozzle size used (0.6mm). PrusaSlicer creates much higher density, looks like what I would expect with a 0.4mm nozzle configuration. In SuperSlicer, i see a clear change in the bottom layer path count if I configure e.g. 1.0mm nozzle size. In PrusaSlicer nothing in the slicing seems to change. Gcode changes a little but not as much as I would expect.
In both slicers I have configured the extrusion width to be 110% overall.
Gcode files generated with 0.5mm and 1.0mm nozzle configs are available in my google drive. Both files say ";WIDTH:0.352" on line 47 when starting the perimeter.
The config files were exported from SuperSlicer and I made some automatic and manual corrections to make them accepted in PrusaSlicer. I haven't tried doing a full new manual configuration value by value. Another symptom I see is PrusaSlicer using only 66% of filament grams in comparison to SuperSlicer.
Please let me know if there is some real explanation why doubling/halving the nozzle size would not affect bottom layer gcode significantly?
Best Answer by Lassi Niemistö:
found an old issue: https://github.com/prusa3d/PrusaSlicer/issues/5894
oh, in PrusaSlicer, it is calculated over layer height 🤣 read the docs
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
Good morning Lassi.
Extrusion width is set in the 'PrintSettings, Advanced' sub menu
As you can see, the extrusion width settings can either be in fixed metric units (0,4mm nozzle, 0.45mm extrusion width for most settings) or Percentages.
so if the same profile is used with a 0.6mm nozzle, you will be under extruding, however if you change the value to a percentage ( (0.45/0.4) x 100) = 112.5% )
then when you change the nozzle to 0.6 the 112.5% setting will automatically increase the extrusion width ( ( 0.6mm x 112.5%) /100) = 0.675mm ) extrusion width.
If you change to a 0.8mm nozzle, 112.5% extrusion width will automatically give an extrusion width of 0.9mm
in your case percentages may be the way to go...
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
@joantabb thanks for the suggestion. Maybe my comment above was unclear - I have used 110% all over those extrusion width settings in both SuperSlicer and PrusaSlicer
I can try to play with those settings though to see if it gives any clarity how the width gets calculated. Or if I can work around the issue with metric settings if the percentage calc does not work.
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
Tested with nozzle=0.8 and extrusion width 110% vs 0.8 and here is the result.. clearly the percentage input is not calculated correctly
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
Prusa use Metric settings in their profiles for prusa printers... maybe there is a bug with percentages...
I have never used percentages, myself.
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE:
I can also confirm giving the widths in metric fixed my print quality. Maybe I am confident enough to send a bug report.
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
Send change requests to prusa slicer for hub.
But do a search first to see if it has already been reported.
Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
found an old issue: https://github.com/prusa3d/PrusaSlicer/issues/5894
oh, in PrusaSlicer, it is calculated over layer height 🤣 read the docs
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
You have no idea just how many of those closed issues there are regarding this on github lol.
Also you could also have found here in this forum
https://forum.prusa3d.com/forum/prusaslicer/prusa-slicer-extrusion-width-unexpected-behaviour/
https://forum.prusa3d.com/forum/prusaslicer/odd-slicing-behavior/
https://forum.prusa3d.com/forum/prusaslicer/first-layer-extrusion-widths-too-small-with-0-8mm-nozzle-and-prusaslicer-2-5-0/
etc etc. Going back years.
RE: Nozzle diameter does not affect extrusion width - why? (2.8.0)
Yeah, somehow it would be nice to get an alert if one tries to configure extrusion width e.g. < 70% of nozzle size which would often be an error in the configuration.