Newly I asked Sven to program a software which hollows out objects to help me to print the DAVID-Angel:
viewtopic.php?f=9&t=5461
And here it is for a free download. Thanks to Sven!

Two parameters must be set in the Hollow Maker software, the wall thickness (in mm) and the level for smoothing of the inner surface. Of course the outer surface will be the same as before. Good smoothing values will be 100-1000. But test it, this value depends on the state of the outer surface. A strongly structured one, like my example here of the Morpheus sculpture needs a higher value. I had set '500'. And as you can see on the attached image of the three slices the wall thickness varies. So don't set the thickness parameter too small, otherwise the inner skin will come to the outside.

This Morpheus bust was scanned by Mattia. The first image is a screen shot of the scan and the letters A, B an C indicate the cross sections of the next shown 3 layers (of 824 layers) after slicing, which was made by the B9C software of Michael Joyce.
How to use the Hollow Maker:
Download the zip file, unzip it into one folder and don't remove the 3 *.dll files. The Hollow Maker can only import and export OBJ files, therefore if you e.g. have a STL file use the free MeshLab software to convert it. Load the OBJ file which should be hollowed into the folder mentioned above. Move this OBJ file by drag and drop onto the Hollow Maker exe.
Set the 2 parameters on demand. The output result will be two OBJ files: One with the addition 'hollow' and the other one with the addition 'inner'. Latter can be used for checking. Don't try to upload an OBJ file to the B9C software, for me it didn't work. Convert it to STL before.
Give it a try!
Walter
PS. The white dot in layer A on the left side of the head is the tip of the (free) down hanging hair. Here it is necessary to set a supporting rod before 3D printing!
If you like to know how the bust was scanned, look here:
http://www.david-laserscanner.com/wiki/ ... els_by_hal
Edit: If you want to use the software for a XP pc, please download Sven's "Make Hollow", version 0.4. His post of Jan 18, same thread.