About This File
I modeled these with the Grayscale Model Maker in 3D Slicer (see tutorial pt. 1), hollowed with Meshlab, fixed for printing with Meshmixer.
"ABD010_PS_M18_1mm.stl" has a wall thickness of 1mm to minimize material volume for printing through Shapeways--I would recommend white "strong and flexible plastic."
"ABD010_PS_M18_closed.stl" is hollow with filled holes--this is what I would use for filament printers, but you could use this to print a solid model through Shapeways.
I haven't printed this model yet, but I will post pics when I do!