Customized version of http://www.thingiverse.com/thing:454702

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=454702

Using the following options:

tubing_wall_thickness = 0.5
allowed_overhang = 0.75
nTwist = 1
approximate_number_of_teeth_on_sun = 9
number_of_teeth_on_planets = 7
w = 6.7
P = 45
T = 15
D = 51.7
number_of_planets = 3
tubing_squish_ratio = 0.5
tol = 0.15
tubing_od = 4.0