This object is part of a video series I created where I share my experience with OpenScad and SketchUp and when each of them are useful. In the series I show the differences between the two packages and how OpenScad is good for Component Modelling while SketchUp is better for System modelling.
The greatest overhang is 45 degrees which most printers can print without additional supports required.
The video series is available on Yourtube:
3D Modelling for 3D Printing #1: http://youtu.be/rUwoMPB4Lv8
3D Modelling for 3D Printing #2: http://youtu.be/hLOOyR4vBVs
3D Modelling for 3D Printing #3: http://youtu.be/dRlb7V7e7pw
3D Modelling for 3D Printing #4: http://youtu.be/ekfJ0XvZeNg