>Curt controlled his spark discharge voltage by
>dynamically adjusting the electrode gap on the fly. I
>think that for pcb work this is not the correct
>approach because of the wire erosion problem, since
>one needs to KNOW the gap distance AND available
>discharge energy BEFORE discharge, which is why I am
>going for the touch down zeroing method, (slower but
>speed is not significant at the moment). The discharge
>
>
Don't you want to try changing every other variable first, to see if
you can eliminate the erosion problem first, then adjust everything else
to match? With the same distance everything else could be just as well
known with 1/4 the spark energy and 4x the rate for the same total,
seems you could simply be too close for the instantanious spark energy
you are using or something similar..
Only messed with EDM a few times, but I think I'd try everything under
the sun first before living with the electrode eating up, even to the
point of feeding blasting caps to the goats in the backyard before
giving up.. Keep them away from the back wall unless you want a mess.
And keep a camera handy, you will want a pic of the PETA girl's face.
Also start thinking now about two electrodes. Could cut both sides
with a 2 tooth tip, but independent control would be better. Raise one
while traveling to make an intersection. Change the width for different
traces or pads etc. And start routing everything with parallel traces
and you'll be cutting one edge of two traces at once, should cut the EDM
time about in half. Might even be nice for a third or fourth parallel
electrode for use while the board is already under control..
Alan