Customized version of http://www.thingiverse.com/thing:811733

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=811733

Using the following options:

build_plate_manual_y = 300
build_plate_manual_x = 300
circle_resolution = 50
Spacing = 3
Rows = 2
Columns = 15
HoleDiameter = 6.4
BottomThickness = 3
build_plate_selector = 3
StepSize = 5
Roundness = 6