[object changes after importing into cura]

The more I use skethup, the more I like it, til I try to print, yesterday found the 24 segments circle bug, draw a circle, print a polygon... check the printer, draw a circle, print a polygon!!! Realy?? A polygon?? Just 24?? I go back to autocad...

[object changes after importing into cura]

Hi!

I installed several pluggins, inspector and solver and none worked, I readed something about sketchup doesn’t draw  watertight objects or something like this, so triyed fusion 360, unable to draw a simple square, ended installing stl exporter pluggin and do the job, seems that the problem is the .obj file 

[object changes after importing into cura]

I draw a piece I want to print, when opened with cura, the design changes, tried redrawing it many times, tried straight lines instead of arcs, allways wrong, autocad opens it correctly.

 

Better a few images...

 

Many thanks!!