[CAD_CAM_EDM_DRO] Wire edm specs

Some one ask what the specs were on a wire edm power supply. I dug through
several manuals and some class notes. The edms I found info on were close to
each other, most were mits machines.

All of this is for .010 wire cutting steel:

Open volts: Machines had settings from 25 to 150

Stable / Start 120-125 volts
Ruff 145-150 volts
Finish 80-120 volts

Gap volts:
Stable / Start 55 volts
Ruff 40 volts
Finish 40-100 volts

The gap volts controls speed and gap distance:
Lower number and machine runs faster trying to get the wire close enough
to bring the open volts down to the gap volt setting:
To low and wire makes contact / breaks
Higher number (can't be as high as open or machine will not move) moves
slow and leaves a larger gap with a ruffer finish

Liquid Resistivity 1.8 to 2.8 milli amps per sqr cent

4-6 liters per min flushing on ruff burns 1.5-2 on finish burns (150 - 300
psi)

flush cups .004 to .018 from work

Having the flush cups around .006 away from the work gives us 2 to 4
times the cut speed that we get when gutting a part hanging free between the
flush cups. Also the finishes aren't as good when the flushing is further
away

A note I haven't seen brought up, several wire machines have the UV axes
on top of the XY axes so that when you are doing 2D moves the UV axis screws
don't have to move, so slight missmatch between XY and UV movements aren't
there and you only have to move UV a little when doing 4 axes moves....