Cura Wrong Slicing

[3dmuza 0]

I've made this cookie cutters with rhinoceros 6 and  checked the stl file with Meshmixer and they seem fine. However, when slicing it on Cura 4.8 it creates inner squares as a wall which are not inteded to be there at all. Does anyone know if it is  a problem of the modelling, the mesh or the way I'm setting Cura? Does it happen oftenly when modelling with Rhinoceros for 3D printing? 

To the post i attach the stl file and the pictures of what I 'm reffering to 

Thank you very much for your help

cortante flor capsula 1.stl

[GregValiant 1,330]

Cura shows the "Not Watertight" warning immediately upon opening the STL.  Cura is attempting to build two outer walls in that area.  Either a wall is flipped and faces the wrong way, or the model was created with the cross piece line-to-line with the peripheral piece.  The model is 4 pieces that almost connect together.  The picture below is the first layer with Initial Layer Horizontal Expansion set to -.10.  You can see numerous holes around the peripheral piece as well.  That's a bad model.  Cura's Mesh Tool is unable to fix it.

 

Here is the same model after being repaired at Service.Netfabb.com.  This will print, but I would set Initial Layer Horizontal Expansion to 0.  There are still some errors at higher layers.  Bad model.

 

 

Attached is the STL of the repaired model.

1609520774_cortanteflorcapsula1_fixed.stl

Edited May 1, 2021 by GregValiant