Customized version of http://www.thingiverse.com/thing:912248

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=912248

Using the following options:

bridge_width = 3
show_XY_test = yes
hub_diameter = 24
max_bridge_length = 100
bridge_z_gap = 0.2
number_of_bridges = 18
bridge_height = 0.8
min_bridge_length = 10
wall_thickness = 1