Customized version of http://www.thingiverse.com/thing:16627

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=16627

Using the following options:

m3_nut_hex = 1
pulley_b_ht = 12
idler_ht = 1.5
nut_angle = 90
m3_nut_flats = 8
m3_dia = 5.1
additional_tooth_depth = 2
pulley_b_dia = 30
teeth = 12
m3_nut_depth = 4
additional_tooth_width = 2
nut_shaft_distance = 1.01
motor_shaft = 5.2
retainer_ht = 1.5
profile = 4
no_of_nuts = 1
pulley_t_ht = 6
retainer = 0
idler = 0