Page 73 - EDM Today Winter 2025

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The Seibu control also provides the ability to
display maintenance and service history. By
entering consumable unit pricing, the control
will return costs incurred – See Figure 4.

Andrew Yee
Applications Engineer
Seibu America
224-250-3786
https://seibu-america.com
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Q: When I try to drill a hole, why does the electrode approach the part, make
contact, then immediately retract the W-axis? It does not drill and will continue to
retract until stopped, or the upper limit is reached.
A: The most likely culprit is a combination of the LV setting and the GAP setting. There are three LV settings avail-
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able (1-3). Each LV setting utilizes a different “open gap” (no load) voltage. This is the voltage measured before
current begins to fl ow between the electrode and the workpiece, i.e., when the electrode is above the part and dis-
charge is turned on. This value can be observed on the analog voltmeter when discharge is initiated. – See Figure 1.
Open gap voltage for each LV setting is as follows:
Figure 1 shows an open gap voltage, on the analog voltmeter (LV
LV/HV Setting
Open Gap Voltage
setting 2—open gap voltage=60 volts).
If the GAP value exceeds that of the open gap voltage for the active
1
40
Though the GAP setting may always be set from 1-100, its value
2
cannot exceed open gap voltage. Therefore, when using LV setting 1,
80
3 60 LV setting, the W-axis will retract after initial contact with the part.
the maximum GAP setting would be 40. When set to 2, the maxi-
mum GAP value is 60. When set to 3, it would be 80. – See Figure 2.
EDM Today Magazine EDM Today Magazine LV setting is 1. GAP
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setting is 50, which
exceeds the maximum
allowable setting for
LV setting 1. The W-axis
will retract upon initial
contact with the part.
Analog Voltmeter
Adjust GAP value to be
<40, or change LV setting
EDM Today Magazine EDM Today Magazine during machining.
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to 2. *NOTE: Do not
change the LV setting
When changing the
LV setting, adjust when
the machine is idle.

Figure 2
Chad Rivers | Applications | Titan International Sales
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chad@titanedm.com | https://titanedm.com
Figure 1
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EDM Today, Winter 2025 Issue