That is, the thickness of the walls around the hole becomes equal to one, as I need. But additional walls appear inside the model, where the modifier passes.
Is there any way to do what I want? I need 6 lines for the outside walls, and 1 line for the wall around the hole, and I don’t need any other lines inside the model.
The outer square of the part and the inner circle of the part are both outer walls, they are both on the outside of the part. The outer wall is always one wall followed by inner walls numbering #walls - 1.
Notice from the first picture of the slicing, orange is outer wall, yellow is inner wall. Using the panel in the upper right you can determine the line type by color.
It may be possible to get what you are after by reducing that modifier diameter until its just the right size, not sure what that would be.
Also, not sure why you are after this, one wall is very few walls and i would imagine that inside hole coming out all dusty looking (one wall for all of that infill to attach to might not work so well).
I tried to reduce the modifier size to the size of the hole, but somehow it always creates more walls than I want. Maybe there are other ways to get what I want?
The screenshots are just a simplified example of the task of what I want to get. In general, my task is to get the lightest part possible. And I don’t need a thick wall on the inner hole, extra lines on this wall only increase the weight of the part, but do not carry any functionality, and in my project every extra gram plays a huge role(
One could design that part such that it is hollow rather than solid with 6 x 0.4mm outside wall thickness and 1 x 0.4mm inside wall thickness, even lighter but much less strength. Due to that you could add necessary support geometry on the inside. Then the slicer will not have much choice when you enter 6 walls, it will have room for 6 on the outside so it will get 6 and the inside will only have room for what you have designed.
Caveat: 1 wall is not really a thing one should design to, two is the minimum the slicer likes to see so you may want to do a 2 x 0.4mm inner wall, unless you’re keen on dropping to a 0.2mm nozzle.