Wire EDM Machine Operation Chapter 1
Copyright November, 98 Page 1-7 Sodick Inc.
“ON” stands for on time. This parameter controls the length of time that electricity is
applied to the wire (per spark). There is a series of numbers that specify the various on
times available. The lower the number, the shorter the on time will be.
On time is a factor that can add power to the wire. As you increase the on time, the
machine will cut faster but the surface finish gets more porous and accuracy may
decrease because of the increased cutting speed. Usually, the on time for roughing is
higher than the on time for finishing.
If the on time is too great, the wire will be prone to breakage.
OFF
Parameter Range: (0-32)
“OFF” stands for off time. This parameter controls the length of time that the electricity
applied to the wire is turned off between each spark.
Off time is very important since it is during the off time that the particles are flushed out
of the gap. Without off time the EDM process could not take place and the wire would
eventually short out against the workpiece or break.
Off time is a factor that takes away power from the wire. Increasing the off time will
generally mean slower cutting, increased stability and less wire breakage.
Usually on time and off time are considered together for their effects. Off time cannot be
lower than ON time.
MA
Parameter Range: (M: 0-9) (A: 0-9)
“MA” affects the adaptive control. It controls the sensitivity and the amount of adaptive
control. When the machine’s adaptive control circuitry determines that something is
wrong with the cutting (hard spot in material, poor flushing, etc.), it looks to the MA
value. MA is a two digit number.
The first digit M controls the sensitivity, The lower the first digit, the lower the
sensitivity of the adaptive control system. The higher the number, the more sensitivity.
This means that a low first digit for MA (1 for example) would tell the control not to be
very sensitive to “problems” in the work zone. A setting of 9 would make it very
sensitive. A setting of 1 is desired when rough cutting with good flushing.
The second digit A controls the multiplier for the off time. When the control senses that
something is wrong (based on the M), it will multiply the off time by the value specified
in the second digit of MA until the problem is cleared. Then it goes back to its normal
setting. We must point out that you don’t actually see the off parameter change, it does
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