Re: emc for wire edm control

[Ray Henry <rehenry-at-up.net>]

Hey Thanks Michael.

The info about how folk do it is great.  I believe that I can use the old 
pots on the face of the Agie and set a level like you suggest to trigger a 
parport pin and from that do anything I want within the EMC code.  Things 
just get easier when you share!

Great stuff.

Ray

Michael wrote
>
> Not all Wire EDM's "back up" during a shorted condition.
> For example, most Japax wires go into feedhold during short,
> and then continues along the contour after the short is cleared,
> usually by flushing,
> Sensing the voltage at the gap is the best way to achieve this.
> A simple, yet precision comparator/opto circuit works nicely here.
> Setting the circuit to output at, say 20 gap volts, is a good starting
> point. Then tweak it for best performance...
> In my opinion I would get the machine up and burning using this
> approach, then delve into the more complex task of actually making the
> machine backup in a shorted condition.
>
>
> I am currently working on a retrofit for wire/sinking/hole popping EDM's
> Both servos and steppers.....
>
> I have several old 2-axis "blue" Andrew 330's and 630's with servos,
> these macines do backup during short, a DEC PDP8\a is the heart of the
> axis motion on this beauty.
> Does anyone know how to dis-assemble pdp8\a a code???
>
> and an old Japax 4-axis machine with steppers, this machine feedholds
> during short
>
> Hope this helps....
> Michael