Random infill throughout layers on thin wall model.

[iwantcake2 0]

Running into a strange issue when slicing a model with 2 mm walls. I've been trying to get the model to print only walls and I haven't had any luck doing so since theres random infill on some layers and only walls on other layers. This model is uniform throughout.

 

In the image below you can see that it slices with 4 walls on the other two sections but I'll have layers randomly with infill as it prints. For some reason when it does infill there is a lot of stringing and zitting on my prints (PETG). Prefer to have only walls since it makes the prints much quicker and less chance for stringing.

[GregValiant 1,351]

With the model loaded and Cura set up the way you want, use the "File | Save Project" command and then post the 3mf file here.

[iwantcake2 0]

Infill Troubleshooting.3mf

 

Didn't realize I had to do this. Thanks. 

[GregValiant 1,351]

Project files can tell a lot about what's going on, but unfortunately, nothing about what a person is really trying  to do.

 

As far as "What's going on"...

The vanes aren't all the same size.  In particular - the one at 12:00 is tapered from 2.01 at the tip to 2.16 at the root.  Cura notices that.

Here is a screenshot with the walls at 1.2mm (I changed the infill to grid also).  You can see the gap in the upper vane extends from the root to the tip but the other vanes only have a bit of space.  That is the inconsistent thickness having an effect.

Because the vanes are essentially 2mm wide and your line width is .4 they need 5 stripes to fill in.  So Cura will put 2 loops all around giving it 2 walls on each side and then use skin for the center gap that is left over.  That's where things really slow down.  The new Cura called Arachne would likely do a better job with your settings.

 

Below I have infill at 0% and 2 walls and "Fill gaps between walls" is turned off.  I put a blocker in the center configured to add more walls for the center post.  That's what is in the 3mf file and you can delete the blocker if you want.  If it is grouped with the model then CNTRL+left click will select it.

 

GV_InfillTroubleshooting.3mf

[iwantcake2 0]

Hmm.

 

This does solve the infill issue but now there are voids in the model where the infill used to be. My solution was to have everything as a wall even the infill. Is there any way to repair the mesh to fix that?

 

Tried remodeling it in fusion 360 instead of onshape which was the first program I used but still have that striated infill pattern that's been giving me issues.

Edited December 16, 2021 by iwantcake2

[iwantcake2 0]

Ideally it would be like this picture below which I get in some layers but other layers have striated infills.

 

 

Edited December 16, 2021 by iwantcake2

[iwantcake2 0]

Update to this problem. Downloaded arachne and sliced with 5 walls and it worked perfectly. No more random infill patterns within the walls throughout every layer. Will update this tomorrow to report if it has fixed my stringing problems upon printing.

Edited December 16, 2021 by iwantcake2

[GregValiant 1,351]

If the vanes were 2.4mm thick then you could have 3 walls up one side and 3 down the other.  I think you have it in mind that a wall means the whole vane...it does not.  A single wall would loop around the entire periphery and so there would be a wall up one side of a vane and then down the other.  The thickness of a vane needs to be divisible by an even number - not an odd number like 5.  Arachne can do it but previous versions of Cura do not.

If you were to make the wall width 1.2 (3 walls) in Arachne the vanes would look the same as with 5 but the center post might not be solid.

[nallath 1,124]

Could you also post this on the arachne discussion page on github? It helps us keeping track of what is going on.