Re: I'm curious

And what if there is noise on the line, and the Gecko ignores a step
or steps when it shouldn't? That isn't closed loop! You can look
all you want with an oscilloscope, but you'll never account for all
possibilities. True closed loop won't either, but it will result in
fewer mistakes.

Your new system works 30-40% better than what it replaced? Well,
well. New technology works better than outdated technology. What a
suprise.

Mark

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Erie Patsellis <erie@s...>
wrote:

> And I contend, a properly tuned (o'scope, critically damped) Gecko

when

> run within the power limits of the attached motor will exhibit far

less

> than 128 counts of following error, and even then, only on rapids.

I

> typically see about 4-5 counts error (~ 1/2 thou) or so, far less

than

> the allowable following error for rapids on the "name brand"

closed loop

> controllers. IF I get a following error with a Gecko, I'm either
> accelerating too fast or otherwise have exceeded the capabilities

of the

> motor. On a typical system, 128 counts is somewhere in the areo of

12.8

> thou following error, did I mention on rapids? If you are getting
> greater than 128 counts of error on a G1 move, there is something
> seriously wrong with your tuning or you're using too small of a

motor.

> The geckos are closed loop, a pulse received indicates to the

drive that

> it has to move one count, it corrects the position. Gecko's work,

and

> quite well, most of the machines I retrofit have 'conventional'

closed

> loop controls, against common logic, a Mach2/Gecko system

typically

> rapids 30-40% faster, cuts smoother, and is about twice as

productive

> versus pre retrofit. and these particular routers are not small,

the

> smallest I work on is a 6x10, my personal test bed is an 8'x12'

router.

> The argument is mostly semantics, as I, you, and many others on

the

> list, work within the performance envelope and get qute good

results. I

> do on the other hand, have no hesitation in moving up to the

larger AC

> servos, if the budget and performance needs justify it.
>
>
> erie
>
>