Re: Harrison Lathe and Gecko's

Hi Terry,



the transfromers you are talking about, having multiple inputs... Are
there also multiple outputs ? often when you get such a unit they
offer a +10 or -10 or some such to allow you to tweek the output to
match your incomming voltages.

also, check any coils or relays powered by the unit. make sure all
the components can handle the reduced voltage.

I think the Gecko is a great option and would be my first choice.
I can only assume that since we get a poster who wants to use a Gecko
at something out of spec, Mariss just wanted you to go down a road
that would be successful.

as you noted, when a question is asked, the responses are extreemly
accurate and helpful. customer service is there too.

Dave






--- In CAD_CAM_EDM_DRO@yahoogroups.com, "James Owens"
<wotisname@l...> wrote:

> Hi Doug,
>
> Thank you for your suggestions below. My machine is three-phase and

I don't

> want to go down the route of tinkering with it unless I decide to

do a

> complete retrofit. I can't afford the time to do this at the moment

because

> there is a job waiting. The machine has all the functions of a CNC

lathe on

> the front panel and most of this works fine.
>
> The power supplies are many with four different transformers. The

one that

> we are concerned with here only feeds the stepper motors. The

transformer

> has two outputs of 61 volts AC @ 20 amps and also a 19 volt AC @ 5

amp (I

> think this is to feed the logic on the drives because they appear

to have

> switch-mode supplies). The input side of the transformer is tapped

for

> various voltage supplies. 220, 240, 415, 440. I have a three-phase

supply @

> 415 volts if I used the tap @ 440 instead of the 415 wouldn't this

reduce

> the output voltage enough to use the Gecko's without affecting the

other

> driver too much.
>
> As the supply for both steppers is fused @ 10 amp I wouldn't have

thought

> the Z motor needs more than 6 amps, but I'm checking the motor
> specifications with the manufacturer tomorrow.
>
> I was hoping to use Gecko's because Mariss gives so much help on

this list,

> there are probably other drivers that could be used. Although with

the curt

> reply to my post I'm not so sure now.
>
> Regards,
>
> Terry
>
>
> > Hi James:
> >
> > I make 1KW 75VDC power supply kits (specially for the 80VDC max

Geckos).

> > The toroid is qualified for 50 Hz & 240VAC, as I expect you have

in

> Britain.
> >
> > If you have stepper motors on your Harrison (we have a Harrison,

but alas

> > it is only manual!), what are the voltage & current ratings on

it? (I

> expect
> > around 4-10VDC & 3-6 amps range)... in which case the G201/G210

will work

> fine
> > (as long as your motors are 2 phase input steppers).
> >
> > I am taking delivery of my third cnc lathe (with blown controls)

on

> Friday,
> > and it will have G201 (Gecko stepper drivers). My cnc mill

already has

> G201's
> > but my first cnc lathe uses G340 servo drivers, all powered by my

power

> supplies.
> >
> > However, I haven't sold any supplies to Great Britain (yet),

although my

> > first lathe supply is wired for 240VAC input (just as it would be

wired

> > for GB).
> >
> > I do highly recommend the Geckos, on both the mill and this

upcoming

> stepper
> > motor driven lathe, the Geckos allow twice the speed (up to 2

inch/sec) at

> > 5 times the resolution (1/10 thou vs 1/2 thou) compared to when

they were

> new
> > from the factory. The servo version is the same speed (2

inch/sec) but

> the
> > resolution has gone up to 1/40 thou vs 1/10 thou as compared to

factory

> new.
> >
> > Another solution is http://www.rutex.com from Australia, but I

have no

> > experience with those.
> >
> > regards and good luck
> > Doug Fortune
> > http://www.cncKITS.com