Hi all,

My company builds a pretty large CNC machine and the new owner has begun to question whether we need to use servo motors rather than stepper motors. I have done quite a bit of searching on the web but can't seem to find any in-depth comparisons of servos vs. steppers with respect to application.

About the most relevant thing I have found so far comes from NetMotion.com's Application / Advisor where they wrote, regarding Positioning Applications, "Use stepper motor if torque is lower than 500 oz-in, less 2000 rpm, low to medium acceleration rates" and "Servo can handle effectively when load is mostly inertia instead of friction. The ability to overdrive servo motor in intermittent duty allows a smaller motor to be used. If positioning is critical in micron level use servo."

Well that is good information, but it is not enough for the boss. Does anybody have a link to more documentation I can use to explain when to use a servo and when to use a stepper? The more technical the better.

Thanks
Steve