Customized version of http://www.thingiverse.com/thing:116807

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=116807

Using the following options:

pin_radius = 0
ring_width = 5
pin_cap_width = 0
clearance = .1
pin_hole_radius = 0
ring_height = 6
element = C
ring_spacing = 2.5
mesh_resolution = 70
ring_height_step = .5
center_radius = 12
Build_Plate_Manual_Width = 140
Build_Plate_Type = 0
pin_cap_gap = 0
Build_Plate_Manual_Length = 141