Machining of large components Wire EDM catapults German manufacturer into XXL machining
Small, delicate parts can be processed with high precision on large EDM machines, but not vice versa. What was already possible in EDM drilling, bes Funkenerosion from Fluorn-Winzeln also wanted to realise in wire cutting.
German manufacturer bes Funkenerosion has had to turn down orders in the past because their wire-cut EDM machines did not have these travel distances. ”With our more than 500 active customers, it's naturally difficult when you can't accept an order just because the size of the machines doesn't allow it”, explains Managing Director Markus Langenbacher.
And yet the machine park equipped with Sodick EDM machines was already quite impressive with one ALC400G, one SLC400G, one AG400L and one AQ750LH. The wire cutting services in contract production hardly left any customer wishes unfulfilled, only in the XXL range they had to turn down orders now and then.
“We used wire cutting right from the start, and we soon added die sinking as well,” says Jörg Roming, who is responsible for the wire erosion division. When contract orders started to increase, new EDMs had to be purchased. The choice fell on Sodick. “Sodick made us an attractive all-inclusive offer for three machines, which also convinced us of their quality and precision,” says Jörg Roming. Of the first three machines, only one is still running; two have been replaced over time. “We also rough a great deal of aluminium, which puts a lot of stress on the machines. Today we know that if we cut aluminium on a machine all day, we have to grab a cleaning rag every now and then when the door is open and spend five minutes washing everything down, otherwise it will affect the lifetime of the machine.”
Broadly positioned as a contract manufacturer in erosion
As a contract manufacturer, bes Funkenerosion masters all erosion processes from EDM to drilling and wire erosion. Customers also purchase accessories and consumables such as drilling and threading electrodes in almost all lengths and diameters directly from the company in Fluorn-Winzeln. The main customers include tool manufacturers, mould makers, medical technology companies as well as the aerospace industry. “Consumables are one of our major pillars, the stock assortment is extensive, so that we can always guarantee short delivery times”, assures Markus Langenbacher.
The electrode material is tested in terms of performance by the trials department to guarantee the customer the best possible results during EDM drills; this approach means that even special customer requests present no problem for the company. Just recently a customer ordered 20,000 electrodes from the company after successful trials.
When the company founders decided to retire at the beginning of 2021, a new managing director was needed. In the summer, Markus Langenbacher took over the management of bes Funkenerosion. Of course, this was a stroke of luck, because it is not always possible to find a suitable successor for a manufacturing company. It is not uncommon for foreign investors who know neither erosion nor the customer environment to take over. After a few years, such companies are sometimes sold off again in “individual parts” and are ruined. With Markus Langenbacher, however, a very experienced employee took over the helm. Having been with the company for 21 years, he not only knows the business and the processes in and out, but also the customers like no one else.
Markus Langenbacher was well aware of the concerns of his customers: “The customers reacted by waiting for the last two to three years before placing orders. After all, they didn't know what would happen to the company after the founders retired. Their relief could be felt when demand picked up again.
The constellation is interesting because the employees have known each other for 20 years and now the former colleague is suddenly the boss. Jörg Roming, who has been with the company for 18 years, sees this as a very positive thing: “We talk to each other much more frankly because we have known each other for so long. That is a tremendous advantage. When problems arise, we can talk with each other and find solutions together.”
Ultimately, suppliers like Sodick also benefit from the overall positive development in EDM. After a smaller ALC400G was delivered to the company in Fluorn-Winzeln as a replacement machine at the beginning of 2021, its large counterpart, an ALC800GH, followed in late summer. “We have taken the first step towards further expanding our wire EDM contract business to XXL parts with a significantly larger wire EDM machine. This enables us to serve this market specifically and we no longer need to turn down orders,” explains Managing Director Markus Langenbacher. New orders are to be generated by providing information to the broad customer base. “With our machine park, we also try to specifically address certain customers that we already have in EDM drilling. The customer wants complete machining of their XXL components from a single source, and we can now provide that.”
Getting “bigger” with wire EDM
For many years, bes Funkenerosion has had a unique selling point in the field of wire-cut EDM: with traverse paths of 1460 x 600 x 1,020 mm, components weighing up to 6 t can be drilled. The applications are also quite challenging. In a recent machining case, around 3,000 holes were drilled on one component in 145 eroding hours. “We have also handled components with 14,000 bores — a one-and-a-half-metre-long pipe that just barely fit on our machine,” recalls the bes Managing Director. With an electrode changer, the machining then ran day and night until the tube was completely perforated. “These are typical contract manufacturing orders for us. However, our know-how in wire cutting goes back much further. This is where we started as a manufacturing company in 1983.”
Originally, a Sodick VL600QH was to be purchased as a replacement machine. But since the ALC800GH was available at short notice, Markus Langenbacher and Jörg Roming took a look at it and eventually decided in favour of it. “Also in combination with our used drilling EDM machines, where we already have the traverse paths, the ALC800GH fits perfectly to close the circle between 800 mm start hole drilling (maximum possible is 1,000 mm) and 800 mm wire EDM”, Jörg Roming is also satisfied with the new EDM machine in this respect.
It was a seamless transition: the old machine was dismantled, the flat-bed trailer with the XXL machine arrived, then the old machine was exchanged for the new one and transport costs were saved accordingly. “We worked together optimally on both sides,” confirms Jörg Roming. When the machine was in the hall, he tested it with a granite angle calibrated to 2 my, with a length of 800 mm. Packed onto the machine in all directions and tested, even the smallest machine and angle faults become visible. Since every Sodick machine undergoes a quality test with generator calibration and geometry measurement before delivery, the granite angle showed no deviations, of course.
Incidentally, a job that was started with the old machine and now continued seamlessly on the new one: cutting height 358 mm. “We noticed the difference in quality immediately. Another enormous advantage for us is that the control system is almost identical, except for a few enhancements. We carried on with the ALC800GH straight away,” recalls Jörg Roming. He was also able to transfer the programmes to the new machine immediately. “We only had to make minor changes to the postprocessor, otherwise the transition was completely seamless.”
For threading, the new EDM signifies a quantum leap, and the fact that the operating instructions are integrated in digital form on the control system is an enormous advantage, he says. Leafing through and searching in user and programming manuals is no longer necessary. Drawings, maintenance instructions with illustrations, everything is listed item by item. Even part numbers can be found immediately via the search function. “The temperature compensation of the ALC800GH naturally has an effect on precision, so that even the XXL components are eroded with high precision,” Jörg Roming is visibly satisfied.
New CAM features 3D
Our wire EDM machines run series of up to 500 pieces. “For us as EDM specialists, that is a large volume,” Jörg Roming explains. The average for series production is between two and 20 items, but a large proportion constitutes of individual parts. The situation is different with drilling, where series of 1,000 items per week are not uncommon. “These are mostly coming from manufacturers of precision tools, for whom we use EDM to drill cooling channels as an extended workbench, for example,” says Markus Langenbacher.
The customer enquiries are received in different ways: one customer sends the enquiry by e-mail and expects a quotation, another sends the component straight away in a package with a drawing, 3D data and delivery date, a third visits us in person. “Many of the jobs are also repairs of tools such as die punches, which are needed yesterday if possible,” Markus Langenbacher says with a smile. And he has good reason to laugh, because his machine is so flexible that it can handle most orders. Especially in the case of wire cutting, the enquiries often come by e-mail or by special mail with the component and are discussed with the customer on the phone. The exemplary customers deliver a data set that is 100 percent worked out and reliable. For the last 30 years, one employee was responsible only for the CAM programming of the wire-cutting machines, but she retired at the beginning of 2021. The company has therefore replaced the CAM system for wire-cutting along with the new Sodick machines. Since the old CAM is not being updated and can only display 2D, it is to be gradually replaced by the new CAM. Jörg Roming now runs the CAM using the 3D data supplied by the customers and then already gets quite good simulation parameters as to which sides have to be machined and how. “The entire commissioning process including post-processors went like clockwork with the new CAM,” the EDM professional is simply thrilled.
Focus on maintenance and customer service
Although a free telephone hotline is available with every newly delivered machine for the entire lifetime of the machine, Jörg Roming has hardly used it so far. “Our hotline is much more direct here,” he says with an amused smile directed at Daniel Günzel. “If you maintain your machines well, you almost never have to dial the hotline.”
Due to the design of the sink without painted parts, only stainless steel and full ceramics, as well as the intelligent head design, maintenance and cleaning are easily done in a few minutes. When the machine has been running all day and has had a good workload, it is usually sufficient to spray the sink and heads with the water gun supplied. Nevertheless, the team at bes Funkenerosion takes maintenance seriously. Markus Langenbacher explains: “We have recently drawn up a checklist that is specifically tailored to each machine in terms of cleaning and maintenance. Jörg Roming adds: “It is extremely important to me that my EDM machines run reliably. If we do a thorough maintenance once a year, that goes a long way and I am confident that when I want to start a job on a machine, I can start immediately and without trouble.”