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:

height = 100
baseThickness = 0
Distance = 8
twistCycles = 0.4
isHypotrochoid = 0
wallWidth = 0.4
Segments = 1000
turns = 300
Radius_of_fixed_ring = 7
layerHeight = 2
Radius_of_rotating_ring = 2