Re: [CAD_CAM_EDM_DRO] Re: stepper vs servo Chicken & Egg

cncdxf@... 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