Re: [CAD_CAM_EDM_DRO] Re: stepper accuracy compared to servos...

At first read, the original post looked like B.S., however, if the servo
system in question is a G320/340 step/dir type drive, then yes, the dynamic
accuacy is going to be suspect. The one point I would disagree with is the
"you are guaranteed to have a dynamic accuracy of much better than one full
step" statement. Your accuracy is only going to be plus or minus one step,
never "better than". Factor in the angular inaccuracies of a typical stepper
motor, say +/-5% (and even worse when micro stepping) along with dynamic
errors, and steppers can not compete with TRUE servo systems.

True servo systems, either full analogue or digital SERCOS, will always have
better dynamic responses than any step/dir system. If steppers were really
that good, everyone would be using them.

Regards, Paul.

On Friday 30 January 2004 5:19 pm, cnczeus wrote:
> > (If you missed the whole post, it's worth reading IMO...)
>
> I believe you refer to the in motion accuracy of steppers to that of
> servos and I must agree that steppers are better, however once a
> single step is lost the remainder of the motion is far worse than the
> worst of the servo drive.

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