Re: [CAD_CAM_EDM_DRO] Re: Monarch conversion to VFD

Hi Paul:
Thanks for the link to KB Electronics.
I will call them today.
By the way, the 10K is 10K CANADIAN--- it's actually 6K in real money.
Shipping into Vancouver Canada from New York is about $2000.00 USD and about
$2500.00 USD from Florida.($4165.00 CDN!!!!). These rates were quoted to me
on a freight weight of 3500 lbs.
I've seen some terrific deals that turn out unworkable once I figure in the
customs and freight.
Painful fact of life in the cold snowy wastes of Canada.
You can bet that I'm taking my tenths indicator to the dealership when the
machine gets here from Calgary though!!
Everything is going to have to be impeccable on the machine for it to be a
worthwhile deal, even at 6000 clams!!
Cheers

Marcus

----- Original Message -----
From: "Paul Amaranth" <paul@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, January 07, 2002 4:09 AM
Subject: Re: [CAD_CAM_EDM_DRO] Re: Monarch conversion to VFD


> >
> > Hi Paul:
> > I heard about the genuine Monarch replacement; the reports on prices
> > scared me off that notion!!!
> > I'm told to expect about the same money again to do the conversion by
this
> > route. OUCH!!!
> > An AC motor and VFD can't possibly cost 10 grand. Can it???
> > At 650 bucks a day charge out rate, I can afford to spend a couple of
weeks
> > on it and still come out ahead, but I don't want to.
>
> Yeah, I didn't say they were cheap. I heard they sell rebuilt 10ees for
> around 65K US.
>
> > Problem is, any Monarch that I buy has the same potential problem, which
is
> > a major Achilles heel on an otherwise almost perfect machine for my
needs.
> > The solid state DC controller that you mention is the route the
machinery
> > dealership has been struggling with for the last 4 months.
> > So far--- no bananas!!
>
> > With my nonexistent electronics expertise, I'm looking for a solution
that
> > involves only a simple hookup.
> > Jon Elson posted with the comments that it's not a big problem so I'm
> > hopeful, but then he's a whiz at this kind of stuff.
> > Thanks very much for your comments; I appreciate it!!
> > Cheers
>
> This really isn't that bad a problem. For the DC solution, talk to the
> tech folks at KB Electronics (www.kbelectronics.com); they've had a
> number of people do the DC conversion. I'm missing the original message,
> but it sounded like they couldn't get the top speed? They've probably
> don't know about field weakening on DC motors then.
>
> Control on the 10ee motor is handled in 2 stages. From bottom to
> some intermediate stage, the field voltage is constant and armature
> voltage is increased. Above that point, armature voltage is held
> constant and field voltage is _decreased_. If you don't do both
> right you won't get the full range on the motor speed. And if you
> don't have a safety cutout on the field supply, if it goes out
> you can have a very dangerous overspeed condition happen.
>
> The VFD conversion is electrically simpler (as Jon said, a couple of
> switches and a potentiometer and you're good to go), but some
> fabrication is necessary. More expensive if you buy everything new,
> but makes for a really nice machine.
>
> I'd do a VFD conversion myself, but I have a couple of the DC motors
> underfoot and I like to play with old tech. (I'm also cheap and I
> managed to get one of the KB controllers off of ebay a while ago)
>
> I'd still look around for other examples. Shipping isn't that
> bad; you ought to be able to find a really good one for a lot less
> than $10K.
>
> Paul
>
>
> --
> Paul Amaranth | Rochester MI, USA
> Aurora Group, Inc. | Systems & Software
> paul@... | Unix / Windows / NT
>