Sunflower Coaster
Inspired by Islamic art and mathematics

The STL model is easy to resize to fit most uses. I printed mine at 100 x 100 x 10 mm.

File 4 is the original. The 1mm drain holes weren't printing because they were too small and clogged while printing. The coaster was fine but no drains.
Version 6  I made the drainage bigger with 2mm feet.

You could also open the CAD model and play with the math. 
I have 36 clockwise blades and 24 counter-clockwise. You could also change the curve of each blade. Or the shape of each prism. I used triangles, but other shapes can work.

Designed using Onshape