Infill strange behaviour?

[3dwim]

Hi,

I'm playing around with the Infill parameter, trying to reduce printing time for some proof-of-concepts and because the objects don't need the strength of filling in too much.

I found some strange behaviour. I have arrived at two easy files (SketchUp-created, exported to STL) of which one does produce the specified 10% Infill and the second doesn't. File 1 is a box with a rounded top which shows a nice sparse Infill, file 2 is a similar box, square and doesn't use it. When I look inside it looks more like 80% Infill. I can't explain. I tried seperate slicing and combined. I don't know why/how this behaviour occurs, can anyone help?

Attached three files: FL-1b.stl (the rounded top), FL-2b.stl (square) and the gcode produced. I added the SketchUp-files for someone wants to see these.

.... But alas, I can't upload the attachments, the board is refusing this for me. For who is interested, placed it zipped at: http://www.wimvd.nl/problems/KISSproblem.zip

Regards,
Wim.

[frozen.rabbit]

reduce skin thickness

[Dreide]

The infill is increased by KISSlicer as preparation/support for the top skin layers, so the object is not tall enough (or the skin is too thick) for any layer in between to have such a coarse infill.