Customized version of http://www.thingiverse.com/thing:53916

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=53916

Using the following options:

layerHeight = 2
Distance = 8
Segments = 300
isHypotrochoid = 1
wallWidth = 0.8
baseThickness = 1
turns = 1
Radius_of_fixed_ring = 50
twistCycles = 0.1
height = 66
Radius_of_rotating_ring = 2