Re: Angle Iron Ways

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Neil Gillies" <neil@...> wrote:

>I'd appreciate some off-the-wall thoughts.

You asked for it! :)

Make a tool out of stainless steel that looks essentially like the
roller you will eventually use. Mount this on some basic form of
spindle, something like a cheap cordless screwdriver will do. You now
have a rotating electrode for Graham's patent pending ECM rail
finishing method. The rotation creates a centrifugal flushing action.

Basically you have the electrode spinning while being constantly
flooded with a solution of sodium chloride or better, sodium chlorate
(faster). Fairly low voltage (12v) is applied between the tool and
the angle iron, the angle being the positive and the tool the
negative. The angle iron is fed through guides to ensure a constant
distance between its bottom and the tool to ensure constant rail
height and also guided to keep the tool central on the rail.

The rail must be fed by some means that produces a constant current or
at the very least prevents shorting. More current leads to faster
machining (a small welder would probably kick ass but heat the
dielectric too much). It could be a gravity feed with a geared DC
motor set to lower it very slowly if the current (measured by resister
and comparator) drops below a certain level.

Cutting will be more effective if the parts not to be machined are
painted to insulate them.

In theory this should all work, in practise it might all get a bit wet
and wild. I'll leave it to you to decide, it was a fun thought
experiment at the very least :)

I'll say this though, one day effective home ECM will happen and it
will be cool!! I'll also reiterate an important point, the machining
electrode is not effected (other than by very mild plating) so the
accuracy of height will come down to process/current control.

Graham