Re: Stepper Motor vs Servo Motor

Thanks Jon for the info. That does lead me to another question.

I am looking for Nema 34 servo motors, of all the various servo
motors out there what brands and models should I be looking for?

--- In CAD_CAM_EDM_DRO@y..., Jon Elson <elson@p...> wrote:
> zone_369 wrote:
>
> > I have three questions on this subject.
> >
> > What is the difference between the two motors?
>
> Stepper motors have discrete positions that they step to, servo
motors
> can move to any position. For open-loop control, steppers are the
only
> way. For closed loop, steppers have a number of disadvantages.
The
> biggest is that misalignment of the stepper and encoder can make it
> hard to reach certain positions, or cause endless hunting. Some
stepper
> drivers draw the most power at standstill. All stepper drivers
draw a lot
> of power at standstill, and provide motor torque that rapidly
falls off as speed
> increases. If you have a heavy machine to move, or want rapid
acceleration
> or high cutting forces, then you will find servo motors a better
deal. Small
> stepper systems are quite cheap, but when you get to large stepper
systems,
> they get VERY expensive. Servos can often be cheaper in the large
sizes
> (assuming you will buy surplus, not new.)
>
> > Which would be better for a closed loop system?
>
> My personal preference is always to servos for positioning
systems, as in
> mill/lathe/router machines.
>
> > Where do I get them for a reasonable price?
>
> There are a bunch of surplus sources. Herbach & Rademan, C&H
Sales,
> Surplus Center, Brigar, etc.
>
> http://www.herbach.com/
> http://www.aaaim.com/CandH/
> Surplus Center -- Tel. 1-800-488-3407, Fax 402-474-5198.
> http://brigarelectronics.com/
>
> Jon