Re: stepper edm

--- In CAD_CAM_EDM_DRO@yahoogroups.com, tomp-tag <tomp-tag@...> wrote:

> The slightly smaller size is still like a 2.002" dia ball in a
>2.004" cavity, the interfacial area ( cutting area ) is small (in
>theory a point ), and whatever that area is, that is the 'leading
>edge' you speak of.
> You always have a 'leading edge'.

I am refering to CNC orbiting, i.e. in the finishing stage the
electrode is lowered into the cavity, the z is fixed and the electrode
moved in the x,y plane. The small amount of material still to be
removed is removed by the whole face, the wear is shared. In a simple
sinking operation the edges of the finisher does all the cutting. In
at least the example of a blind straight sided cavity I was thinking of.

> and electrodes ( tools) made inexpensively,
> then multiple electrode are faster due to a larger cutting area
> ( shell mills cut faster than engraving tools )

I really don't understand how an orbiting electrode could be
considered an engraving tool compared to a shell mill. Take a
cylindrical electrode made slightly undersize undersize, (to account
for the gap) then set it making a cavity, the surface area presented
to the work is that of the end of the electrode, it is not smaller
because it is orbiting, it is only slightly smaller because it is
well, slightly smaller. If it lets you up the power because of better
flushing then that's even better.

> The number is relative, and the problem of multiple electrode
> accuracy is a given element in the work equation.
> Standard technologies from manufacturers will suggest up to 7.
> ( ie: Mitsubishi & Agie, carbide < 1.2 um finishes )

I don't really get your point.

I think I've pretty much got basic 2-axis interpolated moves with
trapizoidal velocity profiles programmed up in the propeller. I'm
doing it with a single processor, it would be easier with multiple
ones but I think the speeds should be good enough. For gap control
use the code would need to be altered and effectively clocked by the
gap conditions rather than the processor clock, I think :)

Cheers,

Graham