Re: [CAD_CAM_EDM_DRO] Re: Software for wire EDM control?

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Alan Marconett KM6VV
> <KM6VV@a...> wrote:
>
> > It sounds like EDM is also done with a wire, like cutting foam
> wings?
>
> Yes the taper (or not) is programmed in as a difference in the linear
> axis locations between the top and bottom set of wire guides. In 4
> axis Wire edm the part is always stationary as the taper is not
> accomplished by tilting the part.
>
> Some machines (Agie) are programmed as R-theta, polar coordinates.
> Some simple machines use an angle setting and 2 axis coordinates.
> These usually are not useful for any complex shapes like a circle to
> a square transition. Common uses for the simple angular style are
> punch press Die and punch clearance cutting. These shapes are defined
> as a 2D contour with a draft angle all the way around (some have a
> straight section along the wall too) Another example would be the
> manufacture of simple Aluminum or plastic extrusion dies. Complex
> shapes usually require full 4 axis programming, as the entry and exit
> holes on an extrusion die may differ considerably more than just an
> angle off the exit hole.
>
> > Sounds like there is more to it then just "wiggling a little wire
> > around". And they do this X-Y U-V in a tank of water? ;>)
>
> The process is usually flood-flush today, not submerge. Also the
> wire is not fixed like in hotwire plastic cutting. It traverses at a
> precise rate across pulleys on either side of the guide eyelets.
> this helps with particle removal and the size of the cut does not
> change due to erosion of the wire. It is not unusual to have .0001-
> .0002 inch depth finish passes to make a precision flat surface (just
> a skim cut with no programmed move too). Also the internal corners
> are radiused at the same size as the wire. About .005 in or so.
> Just about as good as you can get with a broach, without the custom
> tooling for each part.
>
> Fred Smith - IMService