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
additional_tooth_width = 0.2
m3_nut_hex = 1
m3_nut_depth = 2.7
m3_nut_flats = 5.7
profile = 10
motor_shaft = 8.2
pulley_b_dia = 23
retainer = 2
pulley_b_ht = 10
pulley_t_ht = 10
idler = 2
nut_angle = 120
no_of_nuts = 2
nut_shaft_distance = 1.2
idler_ht = 1.5
additional_tooth_depth = 0.2
teeth = 40
m3_dia = 3.2