This is a beautiful mathematics generated shape where each fin is connected to the next and in the center of each there is a rounded ellipse cut hole - so light escapes differently from each fin.
Wall thickness: exactly 2mm
On the bottom there is a 10mm thick ring, inner radius: 6cm
(adjust as needed according to your bulb fixture)
I recommend 3D printing it with White Nylon
at ponoko.com or i.materialise.com
(with a personal 3d printer ABS or PLA will do too)
This design is licensed under the Attribution - Non-Commercial - Creative Commons license.
© 2012 by Dizingof