Customized version of http://www.thingiverse.com/thing:281520

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=281520

Using the following options:

geometry = 8
hole_diameter = 3
length = 40
turn_angle = 120
resolution = 50
width = 20
turn_diameter = 40
countersink_depth = 2
thickness = 4
hole2 = 20
hole1 = 0