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:

nut_shaft_distance = 4
pulley_t_ht = 6
pulley_b_ht = 8
nut_angle = 180
idler = 0
additional_tooth_depth = 0
teeth = 18
profile = 6
retainer = 3
m3_nut_hex = 1
idler_ht = 1.5
m3_nut_depth = 2.7
retainer_ht = 3
no_of_nuts = 2
pulley_b_dia = 35
additional_tooth_width = 0.2
m3_nut_flats = 5.7
motor_shaft = 5.2
m3_dia = 3.2