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:

retainer_ht = 1.5
idler = 1
motor_shaft = 6
pulley_t_ht = 12
additional_tooth_depth = 0
no_of_nuts = 2
m3_nut_flats = 5.7
m3_dia = 3.2
nut_angle = 180
profile = 5
retainer = 1
idler_ht = 1.5
m3_nut_depth = 2.7
nut_shaft_distance = 4
pulley_b_ht = 8
m3_nut_hex = 1
teeth = 54
additional_tooth_width = 0.2
pulley_b_dia = 35