Simplify3D Skirt/Brim plus pressure advance = Stutter



  • For some reason when I turn on skirt/brim and pressure advance, I get a lot of stutter. The rest of the print is fine, I guess s3d spits out lots of small segments when generating a brim. Has anyone found a solution to stop this?



  • Note, I don't use pressure advance, but when I switched to RRF (from other firmwares like Reptier, Marlin, and Sailfish), I definitely noted more stuttering during the skirts/brims. Never put much though to it (since while slightly annoying, seemed harmless), but figured I'd put it out there.



  • I'm seeing similar issues, but not just for the skirt/brim.

    https://www.duet3d.com/forum/thread.php?id=3745


  • administrators

    It is normal for skirts generated by S3D to stutter when printed. It's because S3D generates a sequence of normal printing moves interspersed with short non-printing moves. I've no idea why it does that. Fortunately, it doesn't do that in the print itself.



  • @dc42:

    It is normal for skirts generated by S3D to stutter when printed. It's because S3D generates a sequence of normal printing moves interspersed with short non-printing moves. I've no idea why it does that. Fortunately, it doesn't do that in the print itself.

    That's what I suspected. Might have a play with the post processing and see if I can move the pressure advance code to after the skirt



  • Using S3D as well and see the same. Wondered why, nice to know now



  • Came up with this post processing command

    [[language]]
    {REPLACE "perimeter\nG" "perimeter\nM572 D0 S0.1; Pressure advance\nG"}
    {REPLACE "; solid layer\n" "; solid layer\nM572 D0 S0.1; Pressure advance\n"}
    {REPLACE "fill\n" "fill\nM572 D0 S0; Pressure advance\n"}
    {REPLACE "; skirt\n" "; skirt\nM572 D0 S0; Pressure advance\n"}
    {REPLACE "; bridge\n" "; bridge\nM572 D0 S0.1; Pressure advance\n"}
    
    

    Basically is disables pressure advance for the skirt and infill. Change the [c]S[/c] value to suit your needs



  • dc42 once M572 D0 S0 is set, do we have to redefine M376 again? or can we just do it just the once?

    EG,

    M572 D0 S0.1; Pressure advance
    M376 H10; fade compensation
    ….
    M572 D0 S0; Pressure advance
    ....
    M572 D0 S0.1; Pressure advance
    M376 H10; fade compensation (required again?????)



  • @nikker:

    Using S3D as well and see the same. Wondered why, nice to know now

    G1 X114.400 Y60.353 E0.0145
    G1 X114.412 Y60.348 E0.0006 <–
    G1 X119.159 Y58.485 E0.2369
    G1 X119.172 Y58.481 E0.0006 <–
    G1 X119.466 Y58.375 E0.0145

    because of the marked G-Code, that S3D generates for skirt.


  • administrators

    That's right. The ratio of extrusion to movement is different in the lines indicated compared to the surrounding lines, which is what causes the problem.



  • It seems to be that S3D generates the skirt by duplicating every vertex and connecting the duplicate vertexes to draw the outline… making a segment that is a function of the skirt offset distance. In theory, by choosing a larger offset you may be able to mitigate this... but that seems like a bad solution to a silly problem.


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