Re: EDM, was Re: Cheap Encoders

Hi Scott,

Do you have a circuit diagram for your EDM and, if so, could you post it
somewhere or let me have a copy with an email please? I built a simple
EDM a while back but could never get the electronics bit to work
consistently and I'd like to resurrect it from its resting place under
the bench! Your machine sounds to be very well designed.

Scott Acorn wrote:

> Pit falls and dangers
> use only edm oil in your mach. ------Fire
> only edm in a sumerged tank of oil with a min. of 1" oil covering part

I can second this from bitter experience! When I made my EDM and gave it
its first try out I knew very little about the workings of such things.
I had spoken to several people who used EDM at work but who seemed to
know little about its technicalities. However, I was advised by a couple
of them that the cutting fluid they used was White Spirit (Stoddarts
Solvent) and that it was sprayed on. So, when I fired my machine up, not
having equipped it with a coolant pump, I made a little dam of putty
around where the electrode would touch and filled this up with White
Spirit. As soon as the first spark was generated burning White Spirit
was flung in all directions and I spent a frantic few minutes stamping
out burning patches of carpet and trying to find hidden fires under the
mess on the workbench. Needless to say I quickly changed the electrolyte
and settled on another recommendation of 50% Antifreeze and 50% water
which seemed to work OK.

Best wishes

Ian

--

Ian W. Wright LBHI
Sheffield Branch Chairman of the British Horological Institute.
Bandmaster and Euphonium player of the Hathersage Brass Band. UK.
See our homepage at:- http://www.iw63.freeserve.co.uk or
http://www.iw63.demon.co.uk/ or
http://www.GeoCities.com/Hollywood/6067/index.html

'Music is the filling of regular time intervals with harmonious
oscillations.'