Re: EDM troubles

Dave, I would bet you have serious positioning problems. I have used
my EDM with the dielectric being air, kerosene, or tap water,
successfully and never lost sparking action until the hole was
completed and the electrode comes out the bottom end.
Kerosene stinks, air is wild (sparks all over the place) and water
just hums along. Maybe I am lucky<G>. My power supply voltage max is
about 74 volts. You need 75 to jump 1 mil in air at sea level if I
remember my physics. I am normally running at around : 40 volts
across the gap and the electrode is driven toward the work, and at
about 20 volts the electrode moves away from the work. These values
are set via comparators which control the down/up direction of the
stepper drive. So I am working in a gap which averages about 0.5 mil.
That is small and touchy. Richard

Ps Hang in there!

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> Hi all,
>
> simple RC EDM unit. after test drilling some holes in steel with a
> copper electrode, I pulled the electrode out mid spark to inspect

the

> progress and now it does not start to spark easily.
>
> It went from full voltage to sparking voltage without a spark, then
> quickly went to a short.
>
> do the electrodes get dirty with carbon ?
>
> any suggestions ?
>
> Sparkless in New Jersey. (Dave)