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

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


RichD wrote:

>
> Alan & Jon,
> I have used the Hitachi WEDM (1994 model) many times at school. It is old
> and does not have all the bells & whistles that the new ones have (thankyou!).
> We use a plain g-code prog (no g0, z, or tool calls). Only coordinate positioning.
> It is 4 axis, but we have not learned how to use the U-V as yet.
> It does auto backup when a problem with the cut is sensed to retry for a good
> cut. This happens sometimes at the end of a cut when the scrap drops and fouls the wire.
> Auto tracing to retract or retrace/restart a cut is a feature.
> It cuts thru any metallic or conductive material. The fastest I have seen is about
> .2"/min. thru steel. We use plain tap water flush as Atlanta water is almost
> mineral free. Cuts are very smooth and predictable.
> Wire is hard brass .010" dia. fed continuously thru tensioning rollers and saffire guides.
> Power is applied to the wire via graphite rubbing blocks.
> If anyone would like info or pics to help design a home built, just ask.
> There is no internal documentation available, but a user manual 4" thick!
> We have been repairing it ourselves, so know a little of the guts of it.
> RichD
>