Cura wall thickness issue/anomaly

[bob2345 0]

Hi there a new Cura user here,

so I'm trying to print a flange with a hollow vertical cylinder modeled in Fusion360 with a thickness of 1.2mm as seen here:

My issue is that despite a cylinder part thickness of exactly 3x line width (.4mm) I haven't been able to understand Cura's path choice and would love if someone could explain it.

As can be seen in the screen caps below, if I choose a 0.4mm wall thickness and 100% fill, the inner and outer walls are circular, but about 20% of the circumference the infill is zigzaged.

If I choose a double or triple line wall thickness (0.8 or 1.2mm) with 0% infill the middle path is short "dashes" and the print time is more than doubled (that's why started to look into this, namely the print was taking forever with the huge number of tiny movements).

Can anyone explain why this is not being pathed as 3 concentric paths, and why there is a difference in the paths (and printing time) between a 3 line width wall thickness with 0% infill and 1 line thickness and 100% infill.

thank you!

[gr5 2,167]

There may be other solutions but cura likes to make loops in "shell mode". So if nozzle is .4 then it wants to do .8 of the wall or 1.6. You are right between at 1.2mm. So try lying and saying you have a .3mm line width and want at least .6mm shell width and it should print it with a simpler path (4 passes)

I'm not sure how good the quality will be with a .4mm nozzle but .3mm line width. Also it will take a long time to print with a .3mm print spacing.

There may be another solution. There are lots of new features in cura that I haven't played with yet.