Motor Sizing

Power equals torque times angular velocity; torque equals mass moment of inertia times angular acceleration, therefore, power equals mass moment of inertia times angular acceleration times angular velocity. Additional power is needed for frictional forces, and throw in a little power for future increases in friction and a little more to keep from working your motor at near 100% power. You'll have to look up your own conversion factors and keep your measurement units straight, but at least now you know how to size a motor.

Thanks for the equation. Can you recomend any literature on the subject? I have some projects coming up requiring motors that I'll need to research.

Electrocraft Corporation published an engineering handbook: DC Motors, Speed Controls, Servo Systems,which is a very good reference in that it explains, in good ol' plain english, motor theory and control systems, whereas college courses I took on the subject were taught from a mathematical perspective 'cause my professors didn't actually have hands-on experience with motors or servo-control systems, and in retrospect, didn't even do a very good job of teaching that way.