Wire EDM Machine Operation Chapter 1
Copyright November, 98 Page 1-9 Sodick Inc.
If the machine is equipped with EF2, then the IP setting of 117 or 116 (one hundred
value) place the machine into the AC mode during cutting (Electrolysis Free).
V
Parameter Range: (0-3) EF2 (0-9)
“V” Voltage is a factor that adds power to the wire. You can think of voltage as being a
crude setting for the power range and “on time” as a way of fine tuning the actual power
to the wire. The higher the number, the greater the voltage. As you can probably already
see, you should always consider voltage and “on time” together.
Voltage is a function of workpiece thickness. The thicker the workpiece, the greater the
voltage can be without fear of wire breakage. This is because a thick part allows the
power in the wire to be dispersed over a greater area. Picture the wire pulled tight. If you
took a (thin) sharp knife, it would be easy to cut the wire. But now picture taking a (thick)
baseball bat. It would not be as easy to cut the wire. This analogy shows the relationship
of voltage to the cut. Thin workpieces require a lower voltage, while thick workpieces
allow a greater voltage.
While cutting, this parameter is usually not adjusted. The cutting condition file will set
the value according to which pass is being made. Usually for the first pass it will be set at
3, and the following skim cuts will use 0 or 1 when not using the EF2 circuit.
For machines with EF2, the rough-cut will also be set to 3, but the final skim passes will
use a larger value. This is because the EF2 machine uses a fine finish circuit during the
final skims, and the voltage level needs more than 3 possible settings.
SV
Parameter Range: (00-31) EF2 (000-255)
“SV” stands for servo voltage. This sets the gap voltage between the wire and the
workpiece. Lowering this setting makes this gap smaller. Too low makes the cut unstable
because the particles are trapped in the gap. The voltage can be read by the voltmeter on
the control. This parameter controls the cutting performance and overburn. Think of this
setting as the gas pedal on your car. Pushing the pedal to the floor (smaller sv) causes the
machine to try to cut faster, but the engine size has not increased. So this parameter
actually doesn’t add power to the wire, but will make the machine try to cut faster when
lowered. If set too high, it will slow down the cutting speed.
For machines with EF2, the value set is an actual voltage target the machine will try to
achieve. If it is set at 25, then the machine will maintain a gap voltage of 25 volts. This
method of setting the gap voltage directly allows for finer settings. This is required for
fine surface finish cutting.
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