Cura is filling holes while slicing

[MBee 0]

I have a part that has a hole in the middle:

Note that it is generated by a program that does not render directions of triangles properly, but generally works, especially in Slic3r, but I need to use Cura.

 

So when I slice it, I want it to look like this (screenshot taken in Slic3r):

 

 

....but Cura closes that hole. What can I do?

I'm attaching the .stl file.

 

EX1.stl

[DivingDuck 104]

Look for Mesh Fixes -->Remove All Holes

Uncheck it if it is checked

 

[MBee 0]

(deleted)

Edited June 25, 2022 by MBee
Accidently stated false information

[MBee 0]

(deleted)

Edited June 25, 2022 by MBee
Accidently stated false information

[MBee 0]

1 hour ago, DivingDuck said:

Look for Mesh Fixes -->Remove All Holes

Uncheck it if it is checked

 

It's unchecked - my Mesh fixes settings are on the screenshots.
I uncheked "Union overlapping volumes" and got the hole to show up when the object is left alone.

However, once I inserted a yellow cube inside the object - it gets filled up again

This appears to look like it should - The yellow cube is not overlapping....

 

...buit if we go just 2 layers down, we can see that the closer red object is still getting closed!

 

 

[DivingDuck 104]

How did you create these models?

Check how much bodies Cura recognize as imported objects. It looks like your meshes are overlapping and/or have a much to close fit for individual bodies.

 

Take a look to Menu -->Extensions --> Mesh Tools. There are some additional options for checking your models.

 

[MBee 0]

39 minutes ago, DivingDuck said:

How did you create these models?

It's a hacky script I programmed in C++. Basically, it generates cubes and glues them together in a pre-defined way.
 

there are ~5 stl files, each containing a different model - they all have a different color

Quote

Check how much bodies Cura recognize as imported objects. It looks like your meshes are overlapping and/or have a much to close fit for individual bodies.

Not sure what you mean. They are supposed to touch each other's walls (they share coordinates), but nothing is supposed to intersect. I'm using RMB->"Merge Models" to put them in position.

Quote

Take a look to Menu -->Extensions --> Mesh Tools.

I installed the extension and messed around with it:

• The models are not watertight (Which, looking at my code, should be impossible - I guess It's because I ignored wrong-side vertices?)
• "Fix simple holes" responds with "The mesh needs more extensive repeair to become watertight"
• "Fix model normals" "randomizes" locations of red vertices, but does not remove them (picture):

Edited June 25, 2022 by MBee
typo

[DivingDuck 104]

You can try to use different tools for fixing the meshes like Meshmixer, Blender or 3d-Printer for Windows10 user but I think you should better build the objects with little space  like 0.1 mm between the individual bodies. You will need them anyway if you want to print your models.

Edited June 25, 2022 by DivingDuck