Re: stepper vs servo

Hi,

Wonder if this describe the difference between a stepper and a servo:

Stepper: A ship where the OPTIMIST captain set a course, and doen't
touch the steering wheel thereafter, assuming everything will be
perfect. Everything OK as long as there are no unsurmountable
obstacles, otherwise course will be off by an offset caused by the
obstacle. Therefore a straight line will be a straight as long as
there are no insurmountable obstacles

A _______________________ B no obstacle

A _________
\_____________ B obstacle


Servo: A ship with a PERFECTIONIST captain always trying to maintain
a theoritically correct course, making macro/micro (more likely
micro) adjustments to the steering wheel continuously. (anyone has
compared steering a car and an ocean going liner?)
_ ___
A ___/ \ /\ / \_____ B
\/ \/

Final destination alway exactly, +- micron, at where it should be,
course corrections may be very micro, but path will ALWAYS be wavy
due to numerous course (micro) corrections.

Theoritically then, as long as steppers are sufficiently powerful,
maybe with very generous margins, the path cut will be more true to
planned cut, whereas servos will alway be (microscopically) cutting
a "wavy" path because of continuous (micron) course corrections.

Therefore, as long as there is sufficient margin on torque, a stepper
more precise (pathwise) than a servo?

Hair splitter.