I got the idea for this part from this website: http://oliviervanherpt.com/functional-3d-printed-ceramics/. I have no idea how Olivier designs his products, but I used two 2D 8-pointed star shaped curves as control curves for a single Loft surface. This eliminated any overlapping shells which tend to confuse slicing software. This part printed in slightly less than 27 1/2 hours using a print speed of 80 mm/sec and a 0.200 mm layer height.