Re: [CAD_CAM_EDM_DRO] Commercial EDM capacitance ranges

I just bought a power supply that's supposed to weigh around 600 pounds.
Just so I can
take it apart and learn how it works. Being older technology I figure I can
replace a lot of the
control circuits with a microcontroller or two. Or maybe a single TI DSP.

thanks,
Larry Edington

----- Original Message -----
From: "RichD" <cmsteam@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, February 10, 2003 9:51 AM
Subject: Re: [CAD_CAM_EDM_DRO] Commercial EDM capacitance ranges


> Larry,
> I will try to answer best as I can.
> Industrial machines are huge. I have repaired wire and plunge units.
> The manufacturers **refuse** to supply any internal docs.
> Opening one of these up reveals an enormouse array of electronics.
> Which capacitor?. There are many. I have never gotten to the level of
> knowlege (or needed to) to discover the output circuits.
> All is computer controlled, in any case.
> The water for the flushing thru the cut in the wire EDM is just tap water
> recirculated and filtered for use as the local water is very mineral free.
> It splashes about the work area and drains back into the 'dirty' tank.
> The plunge EDM is another matter and an entirely different operation.
> This must be submerged to control the intense sparking on electrodes
having
> much larger surface areas than wire (.011" dia). Quenching fire and smoke
> as well as flushing movements are the usual method. A type of orderless
oil
> is pumped into the well on startup and automatically drained on stop.
> Even so, a lot of fire is seen to erupt from under an electrode.
> An occasional puff will make it to the surface.
> RichD
>
> Larry Edington wrote:
> >
> > Anybody know the range of capacitance found in a typical commercial wire
and sinker EDM?
> >
> > What about the adjustability of the capacitance? How many different
steps are usually available?
> >
> > What about voltage? I've read 80 volts max is typical.
> >
> > I assume if you are doing active spark control, you just put in enough
capacitance to supply your longest
> > spark time and limit down from there. I'm trying to determine what those
ranges are for spark time and max
> > voltages.
> >
> > One more question ( for now ). Why is deionized water used in wire EDM
when an oil product is used for sinker EDM?
> >
> > thanks,
> > Larry E.
>
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