Optimize print with thin walls

[skewcrap 3]

Hi

 

I print a self made cover of a cable duct with PLA with my UMO. Printing basically works fine, but there is one feature I would like to optimize. I think the problem is that the slicing of cura is not ideal for the geometry. See the feature marked in yellow in the attached image. First, I printed without the inner whole in the corner. Since I had overextrusion in that part, i made the whole because i thaught that printing without infill would be possible. But now, the print quality in the corner suffers.

 

Are there advanced settigns in cura to change the way this feature is printed? Do I have to try another slicer? Maybe the feature of veriable extrusion offered by simply3D could help?

 

Thanks for any advice.