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:

pulley_t_ht = 10
no_of_nuts = 2
retainer_ht = 1.5
m3_nut_hex = 1
idler = 1.5
idler_ht = 1.5
nut_shaft_distance = 1.2
pulley_b_ht = 8
additional_tooth_width = 0.2
pulley_b_dia = 25
teeth = 50
nut_angle = 90
m3_nut_flats = 5.7
additional_tooth_depth = 0.2
retainer = 2
m3_dia = 3.2
m3_nut_depth = 2.7
profile = 9
motor_shaft = 8.2