Arachne Generating different wall thicknesses
This is a part with even thickness walls in each direction. I've tried a bunch of different settings in the arachne permieter generator and can't stop it from being sliced with different width extrusions on different layers. This is happening on both the X and the Y direction. Wall thickness of the model is 0.861mm, Printing with 0.4mm nozzle, extrusion width set to 0.41mm.
Vertical walls under 2mm thick always cause problems. Arachne is able to vary extrusion width to accommodate finer positioning but it needs something to work with. If you want sub millimetre thick sheets then the best tactic is to lay them flat on the build sheet and assemble post printing.
0.3mm layers, 0.41 extrusion width, 0.4mm nozzle and 0.861mm wall thickness - not much vertical 'squish' so reduced layer adhesion, only room for two extrusions that don't quite meet in the middle so relying on vertical 'squish' to push the sides out and provide lateral adhesion but nothing to prevent lateral evasion because everything is an outer perimeter. 0.41 extrusion so very little extra available for the 'squish' to work on...
I imagine Arachne is alternating trying to meet the required width and closing extrusions together to maintain squish.
Rework with 2mm thick walls and 0.45mm extrusion width and you should be OK.
Cheerio,
RE: Arachne Generating different wall thicknesses
@jason-20
Can you post the PrusaSlicer generated .3mf project file? so that we might explore the settings. You'll need to zip the file before the file server will accept it.
Regards
RE: Arachne Generating different wall thicknesses
@Diem - Yes I understand all of this. with respect to the actual print, it's fine. Good layer adhesion, wall thicknesses of the print match the model. Unfortunately I cannot make these walls any thicker and a multi-part, assembled part isn't an option. I would expect the arachne generator to adjust to make the sliced part match the model, however I would expect a consistent result across the height of the part.
I've attached a zip of the 3MF file here so people can have a look.
Just to be clear, I'm not having any particular issues with printing this part. I'm just trying to develop more of an understanding of what the slicer is doing. If I understand why this is happening I can potentially change my modelling processes to ensure a more consistent result in the slicer.
RE: Arachne Generating different wall thicknesses
@jason-20
This appears to be an Ender-3 profile issue, and may be worth reporting on GitHub, I don't refer users to GitHub often, however I sliced this project using MK3 profiles and Ender-3 profiles in PrusaSlicer and the MK3 profiles sliced perfectly with all extrusion widths looking as expected, the ender-3 profiles rendered as you displayed regardless of settings.
Regards
RE: Arachne Generating different wall thicknesses
I think what you are seeing there is the difference between the prime line defaults on the Prusa vs Ender3. if you comment out your prime line in the start G-Code, the slice results with the MK3 will be the same as my original attached image. I've tested this with a Voron 0.1 profile as well as a Prusa Mini and all give largely the same G-Code with different thickness perimeters up the part.