Case Study Tool shop finds size doesn't matter for EDM automation

Editor: Eric Culp

By integrating an OPS-Ingersoll EDM automation solution, a toolmaker has increased productivity and reduced electrode wear.

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Automating the EDM machine was hard to imagine when the toolmaker considered the extremely large workpiece dimensions.
Automating the EDM machine was hard to imagine when the toolmaker considered the extremely large workpiece dimensions.
(Source: OPS - Ingersoll Funkenerosion)

If investing in a new machine, one has to decide whether performance can be increased to achieve greater throughput. The tool construction team at Coko Werk, Bad-Salzuflen, Germany, faced this question when two old EDM machines had to be replaced by a new one.

One unit takes the place of two, and throughput rises

When the company wanted to replace two of its EDM machines, they turned to OPS-Ingersoll for an automated solution. With workpieces of 1,270 mm x 1,770 mm, and the small pallet sizes of 320 mm x 320 mm, automating the new Gantry Eagle 1200 machine was hard to imagine. Moreover, pallets, software, job management systems and external measurement systems had to be incorporated.

After weighing all the options, Steffen Bierbach, manager of tool production at Coko, chose to take the risk. “We compared isolated applications and linear systems, and then decided on the OPS-Ingersoll solution with an integrated robot system. We were sure we could achieve our objectives with this system.”

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One of the initial goals was increased machine capacity to eliminate bottlenecks for the production of several identical large tools. Since the company wanted uninterrupted production, the machine was delivered and ready to go within the same week. In addition, Bierbach noted that the machine up-time, flexibility and efficiency were higher than initially expected. “Today we have returned to typical batch-size-one production, though we are happy to say that there are positive results here, too,” Bierbach said. “To be precise, although we have reduced the number of EDM machines from four to three, throughput times have improved.

“In the past, spontaneous tasks required a large amount of organisation,” he added. “Modern automation, however, makes it possible to react fast. This is particularly important to Coko as a very large proportion of production involves plastics and changes have to be made almost hourly.”

Cutting electrode wear, but not staff numbers

EDM group leader Oliver Prohl agreed. “I quickly realised that the automation concept would enable us to achieve our objectives without problem." He added that the system has reduced electrode wear by 20% to 30% as the monitoring and control system is more responsive.

At Coko Werk, automation doesn’t mean less staff. To achieve a higher throughput rate, the electrode construction, production and programming departments were restructured and jobs shifted to the preparatory virtual field. “OPS-Ingersoll did a really good job,” said Bierbach. “It is important that you retain your employees when making such big changes. We managed this. We are now using the system so efficiently thanks to the interest and commitment of our employees."

Quick implementation confirms the decision

“You feel that the choice you made is the right one when you go from 0 to 60 without any preliminary work, and realise six months later that the performance thresholds have been almost constantly pushed to the limit,” Bierbach concluded. “By late 2011, we also integrated a new measuring machine with chip recognition into the system.”