Re: stepper EDM

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

>
> Graham,
>
> http://www.users.qwest.net/~kmaxon/page/side/control17_137.htm
>
> here's some work on stepper based EDM and a proportional gap input

circuit.

> This guy's site has been around for ages, & I just rediscovered it.
> It has most of the circuits, but the code for the executable are not

there.

>
> regards,
> TomP
>

I remember seeing this myself a while back, interestingly he seems to
have set up his software for profile cutting on a CNC sinker machine.

I'm working away with the propeller starting to get into the motion
control side of things to allow basic moves in three axis for rapids
and hopefully what I learn will be applicable to servo type controls.
I think I can control 3-axis with one processor as that is all it
has to do but time will tell as I work out the details.

I've been reading The EDM Handbook by E. Bud Guitrau and learning
about the benifits of CNC orbiting. I knew that conventional orbiting
helps with flushing as your electrode enhabits more space in the
workpiece than its own dimensions helping with flushing nut I hadn't
realized that CNC versions of this can in some cases allow roughing
and finishing with a single electrode.

You rough as normal with the orbiting action for good flushing, high
power/low frequency for low electrode wear, then after flushing you
lower the electrode into the cavity and erode sideways into the walls
of the cavity with finishing settings. You still have improved
flushing and the larger contact area allows higher powers to be used,
the orbiting action also means that the surface finish doesn't leave a
copy of itself in the side walls but is "sawn" off by the movement
improving finish. There is also no/less rounding of the leading edge
of the electrode as unlike a conventional finishing electrode it does
not have to sink through the whole height of the cavity, the large
side surfaces share the wear.

This could all get quite interesting in theory.

Cheers,

Graham