A polyhedron with hole and minimum number of vertexes greater than zero. Allready modeled at http://www.thingiverse.com/thing:29014/#files by cdsteinkuehler, published Aug 22, 2012. It is the dual of the Szilassi polyhedron: thingiverse.com/thing:12200It is already printed by cdsteinkuehler, published Aug 22, 2012. I dont own a 3d printer. I uploaded it just for the fun of csg preview of openscad program. I would like to learn that someone printed a working puzzle either of the hole and two halves as easy or of 7 tetrahedrons :) Needed TextGenerator.scad OpenSCAD 3D Text Generator by pgreenland, published Mar 10, 2013 at http://www.thingiverse.com/thing:59817/#files and maths.scad Contributed by: William A Adams at https://github.com/kweekly/sensezilla-hardware/blob/master/dust_environment_sensor/enclosures/bezier_test/maths.scad Top, bottom, left, right, front, back orthogonal views with or without annimation seems pretty to me. Thank you Exporting stl file of the main solid to blender and using UVmaping I marked seam the 17,14,45,52,62,51,74,73 edges, unwraped and printed (unfortunately to png) the unfold pattern. After painted and constructed the paper model i downloaded, i installed inkscape and realized it would be much easier by svg format. Unfortunately i didnt print the final cut of paper with extented paper that used for glue.