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:

additional_tooth_width = 0.2
nut_angle = 90
teeth = 12
idler_ht = 1.5
retainer_ht = 1.5
pulley_b_ht = 6
profile = 6
nut_shaft_distance = 2
pulley_t_ht = 7
additional_tooth_depth = 0
retainer = 0
m3_dia = 3.2
no_of_nuts = 1
m3_nut_hex = 1
motor_shaft = 8.2
pulley_b_dia = 25
m3_nut_flats = 5.7
m3_nut_depth = 2.7
idler = 0