I know this may be a duplication of other threads, but......
There have been many threads on the subject of how S3D behaves when dealing with thin walled sections....and I think its about time the designers took some time sooner rather than later to address the issues that have been discussed on the forum relating to thin walls. Here's a selection of recent threads:
There are two issues.
Firstly, the behavior that if a single filament will not fit, then its not generated. This results in complaints about the slicer not working correctly....the arguement against this being that the printer should only work within what it physically can do and by not printing, it's highlighting an error in the design. A simple solution would be to have a check box to allow working one way or the other.
The second issue relates mainly to the quality of top & bottom surfaces where the width of the wall section is not a multiple of 2 times the extruded filament width...resulting in gaps and holes on the surface. The "Allow gap fill where necessary" option should get rid of the gaps....but it doesn't seem to do so reliably....and it certainly doesn't show up as having much of an effect on the print preview. A more effective gap filling control is required...preferrably one that does not need adjustment of several other options as well.
Edit 26th Jan 16 - another thread: viewtopic.php?f=23&t=1838