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

Alan,
I don't know what it senses to decide to reverse the cut. But it usually
happens at the end of the toolpath when the normal cut condition suddenly
changes as the scrap drops and the cut current disappears or shorts.
I suppose a timeout for this is taken if nothing returns to normal quickly
and halts the prog.
This may happen just as the last block is read and the machine has not quite
reached the commanded position. Also, dirty material and gaps between
sandwiched stacked pieces can cause backups and breaks.
This machine is servo driven x-y 15 x 15" and u-v 5 x 5" (upper axis')
Once you get the fastest optimum cut speed set, after well into the material,
the speed is fairly constant, but still being watched by the controller for
shorts, breaks and anything that cannot support the set speed (condition).
The video display shows a dynamic bar meter of the voltage, cut speed in
"/min and several other parametrs. There are many other "pages" that show the
program progression, files, internal computer settings, back plot (with a dot
following the actual cut progress) and machine home and fixture offset coordinates.
Just a look at these screen shots are good to glean info from.
The O/S is DOS. No hard drive.
I will select a few shots & send them on direct. Anyone else?
RichD

Alan Marconett KM6VV wrote:

>
> Hi Rich,
>
> Yes! I'd like to see a few pictures. Probably not a project I'm ready
> to undertake, but still an interesting technology.
>
> Does it NOT need to "auto backup" that often? As I've mentioned, it
> sounds like a "short circuit" condition could be sensed, and the logic
> level change detected by the controller program, much like a probe or
> limit switch. Then, an immediate stop (no need for deceleration) and a
> short reversal of travel (like a backlash routine) before continuing
> would be simple to implement. Does the speed of cut change dynamically?
>
> Would you describe it as having an XY pair of axis, with a corresponding
> UV pair above? I don't have a good mental image of what it would look
> like. the foam cutters I've seen pictures have not been of a lot of
> help, and are probably an over simplification.
>
> Doesn't sound like it can cut arcs, if only "G01" and X Y are accepted.
> For simple "square" cuts, UV probably just follows XY, assuming the wire
> is vertical (do you call it a "vertical WEDM"?).
>
> Alan KM6VV
>