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:

height = 30
pressure_point_thickness = 4.5
outer_diameter = 20
opening_width = 2
bolt_diameter = 3
articulation_thickness = 1.5
nut_diameter = 6.25
washer_diameter = 5.5
diameter_top = 8
diameter_bottom = 5