Re: ECM, The poor man's EDM??

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Graham Stabler" <eexgs@n...>
wrote:

>
> I have kept trying but have still not come up with the electrode of my
> dreams. It is all down to the electrode in this simple gravity fed
> system. The small part that prevents shorting causes the tip to pause
> while enough material is undercut to release it, then it falls about a
> mm or so. This is not very good for the insulator but also means you
> end up with holes that have a sort of oscillating diameter. I want to
> come up with a porous insulating tip that will etch sideways freely
> just enough to allow the insulator to pass. Glass microspheres have
> been suggested, bonded to the tip. I have played with fibre glass
> cloths and braids as well and there is some promise.
>
> Not a dead duck by any means ad if the worst came to the worst a
> simple CNC control could be rigged up. Power off until a continuity
> test indicated the electrode had touched the part, back off a little,
> turn on ECM then repeat. Vary the time between feeds to try and
> maintain a specific gap. Or you could control the height simply by
> looking at the current. Either way it is easier than EDM.
>
> Graham

If I can envision what you are saying, the insulation prevents the
hole from being larger than the electrode, that is until the bottom is
cut deep enough that the sides start to be eroded.

What about a rotating electrode, with one point that is a conductor.
90% of the cut would be down, 10% sideways.

Easier than EDM ? what type of power are you using ?

Dave

>
>
> > Hi Graham,
> >
> > Have you done any more on this ?
> >
> > It is very intersting and I was wondering if you have pics ?
> >
> > Dave
> >