Direct derivative of http://www.thingiverse.com/thing:23686 I split the STLs from the original thing into top and bottom parts using the provided SCAD scripts.

1. Print both parts at a given size
2. Glue them together
3. Spin !

I sliced the small one with Slic3r at 25%, rectilinear, 45° infill with 3 perimeters. Some layers were not adhering to the previous one on the layers with high overhang, it would be worth trying with 4 or 5 perimeters, or wider extrusion width.