Re: stepper vs. servo

To choose to design and build a servo drive rather than shelling out
$114 for a gecko is beyond description.


--- In CAD_CAM_EDM_DRO@yahoogroups.com, Albee Tang <educom@t...>
wrote:

> Hi guys,
>
> Talking about Gecko G320 servo driver. Are they fit for any type of

DC Servo

> motor? I have a National Servo motor but I could not find the

Electrical

> specification.
>
> By the way, instead of buying Gecko G320, can we just build one

using some

> Power MOSFET construct it in H-Bridge? Wouldn't that be cheaper

than buying

> a Gecko driver?
>
> Regards,
> Albee
> ----- Original Message -----
> From: "bull2003winkle" <bull2003winkle@y...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Tuesday, February 10, 2004 11:48
> Subject: [CAD_CAM_EDM_DRO] Re: stepper vs. servo
>
>
> > Scott:
> >
> > What you say is correct, and either will work subject to some
> > limitations. The main advantage of servo's is speed. The main
> > advantage of steppers is simplicity. If steppers can meet your

speed

> > requirements then there is no significant advantage to servos.
> >
> > There are other differences, of course. Steppers are great for

high

> > torque at low speed and servos provide the most power at high

speed.

> > The speed/torque curves for steppers show that they are constant

power

> > devices with torque decreasing with speed.
> >
> > BTW, the Gecko G320 is a servo drive, the G201 is a stepper drive.
> > They both look the same to Mach2.
> >
> > Regards;
> >
> > Ken
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "plastiguy"

<plastiguy@a...>

> > wrote:
> > > Group -
> > > I'm going to go ahead and open up this can of worms (though I'm
> > > certain it's been done many times before my time in this

forum). The

> > > age old question has popped up again. For a 4x8 CNC router with
> > > pretty standard mechanics I can effectively use either steppers

or

> > > servos, each of which I can readily find within the torque

range I

> > > need (400 to 600 in-oz, about 200 watts max), and each of which

I can

> > > use with my driver of choice (Gecko G320) and each of which fit
> > > comfortably into my budget and each of which are addressable

with my

> > > software of choice Mach 2 AND each of which offer the resolution
> > > (depending on manufacturer) I desire. So, I'm finding it more

and

> > > more difficult to commit one way or the other. Given these

equalities

> > > for my specific application, I'm beginning to think that in the

end,

> > > from a performance and features standpoint, there'll be no
> > > significant difference. Oh sure, I know the stepper-advocates

will

> > > point to the consumable brushes on the servos, and the servo-

camp

> > > counters with...well, something equally relatively minor, but

are

> > > there big glaring pitfalls and upshots for these different

means of

> > > moving junk around that I'm missing? I'm a believer in "You

get what

> > > you pay for" so I don't want to sacrifice anything important

just to

> > > save a few bucks and go with steppers, whle I also don't want to
> > > throw money away by integrating servos when, once the covers

are put

> > > on the machine, I'll never even detect the difference in having

put

> > > the servos on instead of the steppers.
> > > Hope I'm missing something so I can GET ON WITH IT!
> > > Scott
> >
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
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