GF Agie Charmilles’
Form 20 and
Form 2000 feature
advanced high efficiency
generator technology
read more about
EDM
at www.mwponline.com
Case Studies
■ No margin for error
(keyword site search on
Sodick)
■ Sparks fly for finer
splines
(keyword site search on
GF AgieCharmilles)
january 2009
First and foremost, multipulsePro brings a clear
reduction in the response time of the processmonitoring
function. Before the development of this
technology, process monitoring involved the system
responding to an observation of each electricaldischarge
pulse once a statistical interpretation had
been completed. When discharges were determined to
be degrading, among the system reactions would be to
switch off the discharge generator. This resulted in
processing intermissions of much greater duration than
is the case with multipulsePro. The new OPS-Ingersoll
technology analyses each discharge pulse as it occurs
and reacts before the pulse concludes.
Control by multipulsePro results in noticeably less
electrode wear because of the synchronisation of its
process monitoring with the length of the spark
impulses and flushing parameters. Time is a significant
factor with regard to electrode wear behaviour, where
the longer the impulse duration, the less rapidly tool
wears occurs. Precision mould and die shops producing
filigree (complex and delicate) geometries in graphite
are the clear beneficiaries of this capability.
Higher speed is another advantage. OPS-Ingersoll
machines were formerly excellent for forming smaller
ribs, but now they cover a far wider application spectrum,
as highlighted by a recent trial. In the case of slot
geometry having a surface of up to 100mm 2 in cross
section, the highest speed achieved previously was
10m/min. However, with the help of the newly developed
technology, a cross-sectional surface of 250mm 2 can be
machined at the same speed. This is thanks largely to the
improved process monitoring of multipulsePro, where a
higher duty cycle of pulses can be attained, or in simpler
language, the periods of electrical discharge relative to the
length of pauses increase dramatically.
The greatest advantages will accrue to users with
critical manufacturing processes, or those with
workpiece cross-sectional surfaces as small as 1mm 2.
Shop-floor tests conducted by OPS-Ingersoll with
multipulsePro resulted in time savings of 17-40% for
sparking jobs involving difficult electrodes. Not content
with these gains, OPS-Ingersoll has now taken this
innovation to the next level by developing the first
spark generator with adaptive current shape, resulting
in dramatically reduced electrode wear.
Although developed for use with graphite electrodes,
the new Eagle Power TEC-Control can also be used with
copper and tungsten copper electrodes. The unit’s USP is
that each discharging impulse in the erosion gap has the
optimum current shape, which results in reduced
electrode wear. The company also says that the removal
rate for roughing with a graphite electrode can be
doubled, thanks to the extremely high process safeguards.
Power TEC-Technology, available in the company’s Eagle
die sink machines, only needs a maximum of two
electrodes, where several were required previously, while
electrode wear can be reduced to less than 0.01mm.
Furthermore, with Eagle Powerjump technology, a
significant reduction in processing time is possible as
‘jump-speeds’ can be increased up to 18m/min, not far
short of the ‘hallowed’ 20m/min seen by many EDM
vendors as the target over the course of the past few years.
‘Results from the Eagle are simply amazing for
mould and die makers using graphite,’ says Scott
Elsmere of HK Technologies. ‘A simple way to explain
this is to say that if a complex, detailed multiimpression
mould tool conventionally requires 6-8
electrodes, multipulsePro can reduce this to 4-6. Now
with the new Power TEC generator these highly
detailed and complex multi-impression tools can be
completed with 2-3 electrodes (one electrode for single
cavity), resulting in a massive reduction in yearly
graphite, milling, cutting tool and EDM costs.’
Swiss know-how
GF AgieCharmilles has also been active in this field
and has recently introduced a range of standard, highperformance
die-sink EDM machines with advanced,
high efficiency generator technology. For instance,
important features of the generator used on the new
Form 20 include high energy efficiency, low energy
consumption (37kW/h at full power) and reduced
thermal growth. GF Agie Charmilles says that the
technology also optimises the EDM process, delivering
low electrode wear and homogenous surface finishes.
The company’s high performance Form 2000,
meanwhile, makes use of the new ISPF (Intelligent
Speed Power) generator.Through its ability to create
digitally shaped pulses (DSPs), the ISPF improves
machining performance (especially in finishing
operations), and delivers exceptional surface finish
thanks to the virtual elimination of the recast layer and
reduced electrode wear. High resolution parameters for
controlling current and voltage, plus an extremely
sensitive servo system optimise machine responsiveness
and enable difficult and small internal radii cuts
(0.005mm) to be machined. The Form 2000 is targeted at
precision toolmakers and manufacturers making high
precision, complex parts for industries that include
micro-electronics, telecommunications, medical devices,
electrical connectors and optical systems.
www.sodi-techedm.co.uk
www.hktechnologies.com
www.gfac.com/uk
MWP
41
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