Re: edm

batwings@... wrote:

> From: batwings@...
>
> At 10:52 PM 10/19/99 -0500, you wrote:
> >GASP! DON'T look at that page! This guy is NUTS! He has hooked
> >directly from the power mains to his workpiece and electrode, with a few
> >lightbulbs and a rectifier diode in series! This is so dangerous, I just
> can't
> >believe he really did this. (Maybe it is a troll, or he's trying to kill
> us!)
>
> It sez so right on the site that this is not very safe, and it gives
> recomendations for making it safer. Believe me I wouldn't want anyone
> killed, even my two fave trolls. I only wanted to show how simple it is in
> principle.
>
> >I'm leaving the above URL unobliterated so that you can see what NOT to do.
>
> A much more positive thing to do is provide advice on how it should be done
> instead, no? Maybe you can describe your home-built edm? I haven't tried
> making anything toward that purpose yet but do have projects in mind.

Yes, I should have included the URL for my simple setup in the message.
I'll do it now, then : http://www.artsci.wustl.edu/~jmelson/edm.html
This has a step-down transformer, which isolates the rest of the EDM
power supply from the line, and reduces the voltage to about 30 Volts.
That is safe enough you are not even likely to get a shock if you touch
the work and the electrode at the same time, but I don't recommend
doing that, anyway.

Because it confused someone, that transformer with the arrow across it
looks like it is isolating the line, but a standard variac does not do so.
It is just the closest symbol I could get in the schematic package I used.

Jon