Customized version of http://www.thingiverse.com/thing:299663

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=299663

Using the following options:

outer_diameter = 30
diameter_top = 11.4
articulation_thickness = 1.5
nut_diameter = 7.95
opening_width = 2.5
height = 30
bolt_diameter = 4,2
diameter_bottom = 5
pressure_point_thickness = 4.5
washer_diameter = 7.1