Re: stepper vs servo Chicken & Egg

Hi Jon,
You missed my point, Both systems work great! I like
how you bring in the best servo motors made to bolster your
position. In that case STEPPER are better because they are
cheaper, WAY cheaper.

Bob

--- In CAD_CAM_EDM_DRO@y..., Jon Elson <elson@p...> wrote:
> cncdxf@a... wrote:
>
> > Hi,
> > Not to burst anybodys bubble, But! DC motors have dead
> > spots with less torq.
>
> No, absolutely wrong! We're not talking about $3 toy-car motors,
> here. They do have LOTS of torque ripple. Any good servo motor
will
> have very little torque ripple. I could show you how LITTLE torque
> ripple there is in a relatively ho-hum tape drive motor, if you were
> closer.
>
> > The only difference between a great
> > stepper and a great servo is! Speed! DC motors also step!
> > They are not linear outputs like voltage. At slow speeds
> > they jump. How many POLES does the DC motor have? 8-16-32?
>
> A decent servo will have somewhere in the area of 30-50 armature
> poles.
>
> > Maybe 6? Servo Systems have just as many problems as
> > steppers. In the real world they both work great! The
> > answer is "The Rooster".
>
> No, I really hate to get pedantic, but you don't know what you are
> talking about. Several motors I have tested for servo applications
> had no noticable torque or velocity ripple down to .1 RPM or below.
> You can get these motors turning on 0.5 Volts or so, and they are
> still totally smooth!
>
> Jon