Re: [CAD_CAM_EDM_DRO] EDM? Was: Phase Control of SCR's; Hi Curren t

dave engvall wrote:

> e.heritage@... wrote:
>
> > It appears to be so neglected by hobbyists who want to make their own
> > because it's quite a tricky thing to get going I've read. The second guy I
> > mentioned had to start it up, cut a tiny hole, stop, back it up, wash out
> > the dielectric, bring it back down, drill, stop, bring it back up.... etc.
> > I'm not sure how far you could take it as a hobbyist if you wanted to build
> > your own. I'm pretty sure it'd take about three minutes to solve the
> > problems with the dielectric from the talents I've seen on here so far. The
> > guy was saying he couldn't find any hollow electrode thin enough, so he
> > couldn't pump the fluid down it. I'd just try pumping it straight down the
> > sides of the electrode myself, you've seen the You Only Live Twice...
>
> Dave....just out of lurk mode:
> Unless you drill really small holes the hobby brass tubing should do the job. According to the liturature one does well to spin
> the rod AND inject dielectric thru the rod to flush. One article I read (either "EDM today" or 'MMS" was using really high pressure
> dielectric and it not only flushed but stabilized the rod in the hole for less wander of the wall. IIRC 1000 psi was in the right
> range. They also drilled deep holes very quickly; like 0.040 500 thou deep in a few minutes.

Yes, I was the guy who "couldn't find hollow electrodes", but that was late at night, digging
in my junk box. I needed to burn out a couple of broken taps in parts. The hollow tubing
in the K&S displays at the local hobby shop are just right for this.

Jon