Model get empty part after slicing where 2 meshes intersect

[BenRQ 0]

Hi,

 

I tried to modify an existing mesh by adding a simple rectangle box, that intersect with the model and fill some empty parts for 5mm.

 

 

The model looks good in Fusion 360 and in Cura.

Only when I slice it I see that some part are missing.

 

 

 

What did I do wrong ?

Is there a way to fix this in Cura or Fusion 360?

 

Please note I also have the same problem with a cylinder on this model: you can see the hole on the left side of the model.

 

I tried all "Mesh fixes" option without success.

 

 

Ben

 

[geert_2 557]

I always thought that this alternating was the desired behaviour? When the slicer encounters the first edge it turns the material on. At the second edge = material off. Third edge = on, fourth edge = off, etc...?

 

Otherwise I think it has no way to know whether it has to fill a model or not, since the STL-file only consists of triangles, if I understood that well? Maybe software-engineers like smartavionics or ahoeben could shine a light on this?

 

Anyway, I use this feature to make hollow text and watermarks inside a model. I design the watermark separately, outside of the model, and then I just move it inside the model. After export to STL it is automatically sliced correctly, thus Cura automatically hollows-out the text.

 

Like here in this example, where I have copyright notices, a ruler, and some decorations as watermarks inside the model, a keychain. Or in the transparent testblock below. (For reference: text caps height = 3.5mm; text legs are 0.5mm.)

 

 

 

[BenRQ 0]

4 hours ago, geert_2 said:

I always thought that this alternating was the desired behaviour? When the slicer encounters the first edge it turns the material on. At the second edge = material off. Third edge = on, fourth edge = off, etc...? 

 

Thanks for the answer and the example @geert_2, it makes sense now that you say it.

 

But I'm surprised this is not an option to setup somewhere and even more why this would be the default option.

I mean you can just cut the intersection out of the model in your editor, I don't see why this would managed in the slicer.

 

I tried this : Union overlapping volumes ( https://ultimaker.com/en/resources/20424-mesh-fixes ), but it does not change the behaviour for me.

I'm a beginner, so I may miss something obvious here but for me it would make more sense to edit the model in the 3D editor.

 

[BenRQ 0]

I found what was causing the issue.

I'm using a support blocker on one part of the model, to slow down the print speed on this specific part.

 

If I remove this support blocker, it works fine: no more empty part !

It seems like using a support blocker inhibit the " Union overlapping volumes" features. This may be a bug.

I'm using 4.0.0-BETA-2

 

This support blocker does not touch the part with the issue, and I changed only the print speed.

 

 

[BenRQ 0]

If it can help someone, issue has been answered here : https://github.com/Ultimaker/Cura/issues/5461

It seems it's because my model was not watertight.

I will try to fix this.