Re: [CAD_CAM_EDM_DRO] Re: How do you compare steppers to servos

Glenn,
Your more than welcome.
I did make one mistake, as Mariss in his guidelines indicates the
design for servo motors should be at 80% rated speed not rated speed.
So you should base the example on 80% of 3000 or 2400 rpm.

Art

AKA Country bubba


At 01:37 PM 2/25/2011, you wrote:

>Thank you Art.
>That is very useful information and is just what I was looking for.
>
>Glenn
>
>--- In CAD_CAM_EDM_DRO@yahoogroups.com, Art Eckstein <art.eckstein@...> wrote:
> >
> > IF you want to match the torque speed characteristics of the stepper
> > system, find the torque curve for that stepper motor.
> > At the max rpm of the stepper, note the torque it will produce at
> > this working point. The holding torque is relatively useless for
> > figuring useable torque at speed.
> >
> > Now, you have the basic information you need. It is a balance of
> > tradeoffs between torque and speed with the servo. Let us assume the
> > max speed of the stepper is 750 rpm. Most servo motors are rated at
> > relatively high rpm say 3000. To match the rpm of the stepper, you
> > will need a reduction of 3000/750 or 4:1. No take the torque rating
> > of the stepper (at speed, not the holding torque) and divide by this
> > ration (4) and this will give you the minimum CONTINIOUS torque
> > rating you want from your new servo.
> > From this, I hope you get the idea and proceed from there.
> >
> >
> > Art
> > AKA Country Bubba
> >
> >
> >
> > At 12:01 PM 2/25/2011, you wrote:
> > >Suppose a system is advertised using nema23 steppers of some size,
> > >say 260 oz-in.
> > >
> > >You want to build the same system but instead use servos.
> > >
> > >How do you compare the compare power of the the steppers to the servos
> > >
> > >thanks
> > >Glenn
> >
>