Customized version of http://www.thingiverse.com/thing:54395

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=54395

Using the following options:

internal_diameter = 25
cogs = 12
build_plate_selector = 0
build_plate_manual_y = 189
build_plate_manual_x = 100
cog_base_width = 10
cog_length = 10
cog_base_height = 12
res = 50
height = 12
cog_tip_width = 3
hole_diameter = 5
no_angle = 10
tip_height = 12