Re: Home-built EDM

I don't think most EDMs are very aggressive. The sparks won't be
concentrated either, they will simply jump over the shortest
distance. Eventually the gap will be such that no sparks are
produced and the tool can then be lowered again.

I have plans for an EDM and a very good Russian book but it will be a
while till I can have a go making one proper. Definate wish list
though.

Good luck with it

Graham

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Rich" <rmancini@h...> wrote:
> I just completed construction of a home-built EDM from an article
by
> Arnold Gregrich in Home Shop Machinist (October/November 2002).
> The initial test results were disappointing to say the least. Using
> plain tap water, I could hardly get any sparking at all. When it
did
> spark, there didn't seem to be enough power to start a hole, much
> less burn clean through a piece of 1/16" thick steel. I changed
over
> to deionized water with no real improvement. The sparks seem to
> wander and not concentrate in one area.
> These are the specs: Used two 3600 uf caps, a 400V rectifier and
200
> watt light bulbs in both sockets. The electrodes I tried were .062"
> mild steel welding rod, ¼" copper tubing and a piece of a
telescoping
> car antenna (chrome plated brass which didn't work at all).
> If anyone is familiar with this machine, I sure could use some tips
> on increasing performance. I need more aggressive sparking, but how
> to achieve it is the question.
> Rich