Prewi relies on Vollmer machines

Herford, Germany-based Prewi Schneidwerkzeuge GmbH develops tools for the wood and furniture industry, supplying its worldwide customers with milling cutters, drills and circular saws tipped with carbide or diamond. To manufacture these products, the company uses around 30 sharpening machines from Vollmer, including a recently installed QXD 250 disc erosion machine.

“With the QXD 250 we want to expand our range of diamond-tipped milling cutters and drills so that we can respond more precisely, quickly and flexibly to customer requirements,” explains Helmut Prekwinkel, founder and CEO.
Operating from its 18,000 sq m facility, Prewi produces cutting tools, machining units, exhaust ventilation systems, pressure pads and landing skids, as well as measuring devices for all areas of the wood processing industry. The toolmaker is a pioneer in the use of PCD for rotary tools.
“We were one of the first manufacturers to bring PCD-tipped tools to the market in order to efficiently machine highly abrasive materials,” says Prekwinkel. “To precisely sharpen our diamond tools to a high standard of quality, we have put our trust in Vollmer’s eroding machines for many decades now.”
Prewi is able to use the recently delivered QXD 250 to prepare PCD-tipped rotary tools around the clock. Thanks to the machine’s Vpulse EDM generator technology, the company says that the QXD 250 achieves an excellent surface finish quality at the maximum stock removal rate during tool machining.
“With Prewi, we combined a long-standing partnership with a lively exchange in order to develop new technologies and fields of application for our eroding machines,” says Dr Stefan Brand, CEO of the Vollmer Group.
For further information www.vollmer-group.com

High value machine order for GFMS

GF Machining Solutions (GFMS) has won an order to supply an AgieCharmilles FORM 300 EDM die-sink machine and an AgieCharmilles CUT E600 wire EDM machine to Bridgend-based Nemein Ltd. The machines will be delivered and installed at Nemein’s 11,000 sq ft facility later this year via a staged process.

Nemein’s new machines will be used, in the first instance, to manufacture components for self-powered tools used in the global oil and gas downhole sector. These tools, which incorporate energy harvesting technology from heat and vibration, are designed to effectively eliminate the sector’s (over) reliance on ‘potentially’ unreliable and unsafe primary lithium batteries, while removing run time limitations and increasing temperature ratings.
Commenting on placing the order with GF Machining Solutions, Nemeins’ CEO Suzannah Bourne says: “To better control our manufacturing processes we made the decision to develop and strengthen in our in-house machining capacity and capabilities by investing in high-performance machine tools. We undertook a comprehensive research programme to identify and select the machine tools we required, and were particularly impressed, not only with GF Machining Solutions’ technologies, but also by their customer-focused and partnership-based business approach. These are exciting times for Nemein and this investment in the machine tools will be instrumental in helping us achieve our ambitious business growth and expansion objectives.”
The importance of the order is also acknowledged by GF Machining Solutions’ area sales manager, Roger Mullard, who says: “Nemein is a company that’s going places. Their innovation, engineering and technical prowess are highly regarded and respected worldwide.”
For further information www.gfms.com

Wire EDM duo unveiled

Sodick used last month’s EMO exhibition in Germany to unveil two new wire-erosion machines, the Sodick ALC800G and VL600QH. The newly announced ALC800G incorporates all the features and benefits of Sodick’s Premium wire range, as well as offering
a three-sided automatic door and 1500 x 1040 mm work tank. A high-column (optional) version of the machine provides an extended Z-axis stoke of 800 mm.

Meanwhile, the new VL600QH, which incorporates an extended Z-axis stroke of 500 mm – making it suitable for tackling tall workpieces – is a development of the VL600Q linear motor driven wire-cut EDM. The latest machine retains all the features and benefits of the earlier model, including the FJ-type automatic wire threader with ‘pop-up’ functionality for increased reliability.
Other machines on the stand included a Sodick Premium ALC600L wire EDM, an AG60L die-sink EDM equipped with a robot and the entry-level AD55L die-sink EDM. The latter incorporates a plethora of Sodick innovations, including linear motors on X, Y, and Z axes, as well as the K-SMC Sodick Motion controller, 1 Gbit/sec communication technology, SGF nano-wear generator and ceramic work-zone.In addition, the symmetrical structure of the AD55L has been specifically designed to provide improved rigidity in order to help maximise machine performance. Sodick is represented in the UK by Sodi-Tech EDM.
For further information www.sodi-techedm.co.uk

EDM simplification through innovation

Innovative CAM technology can and should simplify the entire programming process. However, working with wire and water, instead of speeds and feeds, presents a challenge for CAM systems originally developed for conventional milling and turning applications. The concept of removing material with a cutter does not translate easily to the concept of eroding material with a thin wire.

Slicing through metal with an energised wire is a very efficient way to cut intricate shapes. These intricate part shapes have physical properties unique to the wire-cutting process, and include constant tapers, variable tapers, vertical land areas, sharp corners, radius corners, sharp corners that taper into radius corners, and more. A first step to simplifying the programming process is for a CAM system to recognise and retain knowledge of those unique properties so that wire programming can be automated.
Esprit is a feature-based CAM system that automatically recognises machinable features that are specific to wire machining. Choices include die (pocket), punch (boss), hole, open profile, and even turning profile features for wire machines equipped with a rotary table.
An emphasis is placed on fast and easy creation of machinable features for wire EDM. Detailed properties about XY and UV profiles, workpiece height, tapers and corner styles are associated with the EDM features so that, regardless of the type or number of operations applied to the feature, the integrity of the underlying data remains the same. When EDM properties are embedded in the feature, the entire programming process is streamlined because most of the data needed for programming is coming from a single, reliable source.
For further information
www.espritcam.com

Wire EDM can replace broaching for fir tree slots

As aerospace OEMs and supply chain companies face increasing pressure to produce more fuel-efficient aircraft, wire EDM (WEDM) is emerging as a key machining technology, reports GF Machining Solutions. According to a body of evidence generated by David Welling at the Laboratory for Machine Tools and Production Engineering (WZL) at RWTH Aachen University (Germany), WEDM has the potential to replace broaching as the technology of choice for the manufacture of fir tree slots for found in high-pressure compressor and turbine disks.

“Broaching tools have obvious limitations; one of these is the high tool wear that results from the increased toughness of aerospace materials,” says Welling. “Also, broaching machines require a lot of floor space, have a high initial investment cost and offer low flexibility.”
Until about 10 years ago, WEDM was not considered a viable process for full fir tree slot production due to the recast white layer left on components by earlier generator technology. But Welling’s research has shown that WEDM now, with the advent of sophisticated digital generator technology, compares well to broaching in terms of surface integrity and part tolerances – both important in fir tree slots.
So far, Welling’s research has shown through component high cycle fatigue studies that WEDM compares with broaching in terms of component fatigue life, and that WEDM is actually capable of machining fir tree slots with the required accuracy. In addition, Welling says that WEDM offers an advantage when it comes to automation since it offers the process monitoring capabilities necessary to ensure machining quality.
“Furthermore, WEDM does not present the tool wear challenges inherent in broaching,” he adds. “In WEDM, since the tool is the wire that is being unwound from the spool, there’s a new tool being used for every process second.”
For further information
www.gfms.com