Looking for information on drawing sprockets...

Group,

i'm planning to attempt to mill the tooth profile of a small (6 mm
pitch) sprocket on my own blank using my maxnc 15cl. i know how to
draw the bottom of the tooth profile (part of a circle), and i know
the distance between these circles (pitch), but i'm wondering how
critical the top half of the tooth profile is. i could probably wing
it by trying to copy the one i have, but if anyone knows where to
find the "proper" info, i would appreciate it.

patrick