Help with zigzags on thin (single line) bridges

[aaaidan 0]

 

Not sure whether this is a bug, but I am trying to print a cylindrical "brush", where there are lots of single line bridges radiating from a central cylinder. Many of the bridges look great, but there are lot that are getting sliced into multiple lines, perhaps as though they're trying to get filled in like a top surface.

 

 

I've tried lots of settings, some thoughtful tweaks, and lots of flailing. I have successfully printed a very similar model in the past.

 

Attached screenshot, cura project, and here's an onshape link to the cad project.

 

Any idea what I'm doing wrong? 

CE-brushv3-2.3mf

Edited March 2, 2022 by aaaidan
fix title typo

[aaaidan 0]

Oh, I am using Cura 4.11.0

[GregValiant 1,287]

Look around here for Arachne Engine Beta and the Beta II release.  It is slated to become Cura 5.0 and is much better at models like this.  It uses variable line width and those thin spokes will slice.  As Cura progresses I think it is getting more accurate and consequently fussier about the model geometry.  Notice that the spokes are yellow.  That is the color for infill and you really want those spokes to be defined as having "Outer Walls" which would make them straight single passes which would show as red in the preview.

 

Depending on your dimensional requirements you could make the Outer Wall Inset -0.1 and the model will slice.

Another problem is that the features aren't very tall.  At a .28 layer height the nozzle is moving up past the features after only 1 layer.  Moving down to a 0.2 nozzle size may be an option as well.  There is a lot of bridging going on however you decide to print this.

 

I think your 160mm/sec print speed for a model like this with such fine features is iffy at best.

You should try putting together a profile for small delicate models.  Viewing the settings in the profile (in that 3mf) it seems they may work well for larger prints but on something small and essentially round, going with a less aggressive profile I think would help.  That has nothing to do with the slice of course, just sayin'.