So.... I thought up a very simple (likely conservative) method to estimate cutting forces so some of you can size your stepper motors accordingly.
This question has been posted time and time again, and when i was looking for the answer I found tons of conflicting results, equations and conclusions.
So here is a derived solution and equation to this problem that should be used only to ball park....
http://aimenshawki.com/?p=234
Let me know what you think!