BenRQ

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.

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.

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.

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