I've just stumbled over this Instructable: http://www.instructables.com/id/Which-3D-software-should-I-learn-for-3D-printing/ I wonder why Sketchup has such a bad reputation. I haven't really used it a lot, but just playing around it feels a lot more natural than most other CAD systems.
Hi, Balu, I've been using Sketchup on and off for several years now and plan to use it for 3D printable designs in the future (my 3D printer design/build is not finalized). Your post grabbed my attention for just this reason. I wasn't aware of any problems using it for 3D printing so I did some digging around and found this article. http://www.mastersketchup.com/8-tips-for-3d-printing-with-sketchup/ It describes the pitfalls one may encounter in using Sketchup for designing 3D printable models and how to avoid them. It appears the guy even wrote a book on the subject. https://www.packtpub.com/hardware-and-creative/3d-printing-sketchup Hope this helps. -Nugz