Sierpinski Tetrahedron

thingiverse

A simple Sierpinski tetrahedron cannot be printed because pyramids touch each other only in a single point, and because there are a lot of overhanging geometries (printing support is a nightmare in a fractal structure). 1) The "single point" issue can be easily solved with a 1.15 enlarging factor applied to the drawinf of the basic pyramid shape. 2) The "overhangings" issue can be solved adding a fourth pyramid to the Sierpinski fractal, just under the top one but pointing down. 3) Due to the enlarging factor, the fourth reverse pyramids extendes below model base ("negative Z coordinate"), so a clipping cube is necessary. 4) The reverse pyramids laying on Z=0 plane have a very tiny base, whose sticking to printing support is not sufficient, so a base frame is necessary. EDIT (20190120) : Due to finite-precision math, the valid SCAD model resulted in STL with tiny errors (intersecting faces and non-manifold edges). Just rotating the basic shape by 0.1 degrees solves issues (hack by HOPHEAD from openscad community forum). Files have been updated.