FEATURE ON EDM

Making tools and fixtures on an ad hoc basis

Before vehicles are produced in large series, automotive manufacturers test and check the
properties and functions of all components under different conditions. All-Forming GmbH in
Kappel-Grafenhausen specialises in the production of the required prototypes and pilot
series. With innovative ideas and in-depth expertise, the team develops and fabricates the
necessary tools and fixtures. This is where the company appreciates the huge potential of
wire EDM technology.

To produce its punching and forming tools, the specialists at All-Forming have been using
the wire erosion process for many years. The company invested in a Mitsubishi MV2400R
Connect wire EDM machine in the middle of 2022 because the previous machine was
outdated in terms of programming and operation.
Production manager Sebastian Singler says All-Forming decided in favour of the wire EDM
machine from Mitsubishi Electric for several reasons. “First of all, the MV2400R Connect
comes with a cutting-edge and future-proof programming and operating approach. We
benefit from state-of-the-art touchscreen operation. In addition, interfaces to current CAM
systems are readily available. We also the like very large workspace which provides easy
access to the machine operator. This is particularly important for us as we frequently
machine one-off parts.”
All-Forming programs the components to be cut at a CADCAM workstation using the 3D CAD
workpiece data. The data for the NC program for wire EDM gets sent to the MV2400R
Connect via a direct data line. There, the company retrieves the current production orders
and NC programs and loads the machine with sheet metal accordingly.
The advantage is that the company can position several different pieces of sheet in the large
workspace. All-Forming’s MV2400R Connect can therefore cut several workpieces
overnight, unsupervised. This goes a long way towards producing stamping and forming
tools at short notice.
For further information www.mitsubishielectric-edm.eu

Vollmer set to unveil two eroding machines

At the GrindingHub 2024 exhibition in Stuttgart this May, Vollmer will give premieres to a
number of innovations. For instance, the company will unveil its QS 860 and QSF 860 eroding machines, which can machine PCD-tipped circular saws. Although the machines will not be on show in Stuttgart,
Vollmer will be providing information about them both digitally and in face-to-face
meetings. Another innovation from Vollmer will be the VFS 400 filtration system, seen for the first
time at GrindingHub. Visitors to the trade fair can experience live how the space-saving
system carries out ultra-fine filtration of cooling oil or dielectric during the sharpening
process. Depending on the machine type, up to two Vollmer sharpening machines can
connect to the VFS 400. At the show, these machines will be CHX 840 and CS 860 grinding
machines, which sharpen carbide-tipped circular saws. The VHybrid 260 grinding and eroding machine and the VLaser 370 laser machine will also be live on the Vollmer stand. Among further new technology will be a feature for the VGrind 360S grinding machine. Thanks to an optional dressing unit for the grinding wheel, tools with the ultra-hard cutting material PcBN can now also be ground in two machining steps: roughing and high-precision finishing. PcBN machining is possible with the VGrind 360S because the machine has very high system rigidity on one hand, and X, Y and Z axes driven by linear induction motors on the other, which implements oscillating tool machining. Vollmer will also showcase products and services from its subsidiaries Loroch and ultraTEC innovation.
For further information www.vollmer-group.com

Toolmaker gets right tool for the job




As a small subcontract toolmaking and machining business, Precision Engineering Services (Buxton) Ltd has carved a niche in the production of press and mould tools for the construction and DIY sectors. As part of these activities, the business undertakes a significant amount of wire EDM work, which is why it has just invested in a Mitsubishi MV1200S wire EDM machine from the Engineering Technology Group (ETG).

The Buxton-based manufacturer has a selection of manual and CNC machine tools as well as a die-sink EDM machine and a wire EDM. However, with the company’s 12-year-old Mitsubishi BA8 wire EDM being the busiest machine, its precision levels were sadly diminishing after more than a decade of non-stop operation.

“After more than 10 years of non-stop running, the ball screws on our existing Mitsubishi BA8 wire EDM were deteriorating and maintaining precision was becoming more of a challenge,” explains managing director Chris Barlow.“We knew that a new machine would be the best route forward. With linear drive technology and tubular shaft motors instead of ball screws, the new MV1200S has a 12-year accuracy warranty and an optical drive system that provides circular accuracy within 1μm, so we won’t have this concern in the future.”

With regard to overall cutting time, Barlowsays: “The speed of cutting is always restricted by the wire. However, features that would take four passes to finish on the BA8 are now possible in three or sometimes two passes with our new MV1200S. This improves our productivity by 25% and even 50% in some cases.”

This impressive productivity improvement is credit to the new V350 generator, which has a significantly higher effective clock rate.
For further information www.engtechgroup.com

Vollmer penetrates micro-tool market




Micro-tools are drills and milling cutters with diameters below 0.5 mm. Here, sharpening specialist Vollmer is successfully eroding these delicate PCD tools in a highly precise and cost-efficient way with its VHybrid 260 grinding and erosion machine.

Progress in areas such as medical implants and wearables means that electronic components are becoming increasingly fine and delicate, demanding the use ofever-smaller tools in the manufacturing processes. PCD micro-tools with diameters of 0.45 mm and below are in particular demand for the production of microchips.

The Vollmer VHybrid 260 grinding and erosion machine features Vpulse EDM generator technology, which achieves a surface finish of up to 0.05 Ra when eroding, corresponding to an average roughness of up to 0.24 Rz. In addition, it is possible to produce a cutting edge radius of up to 1.5 µm with the VHybrid 260. This capability eliminates the need for any subsequent grinding or polishing of functional tool areas.

To ensure optimum concentricity of 2 µmmaximum when machining micro-tools, the VHybrid 260 features an insulated tool steady rest, which also makes it suitable for eroding. Furthermore, due to the integrated‘Laser Check’measuring system, required tolerances of ±2 µm are achievable during fully automatic circular machining in a closed-loop process.

The VHybrid 260 is based on multi-layer machining, implemented through two vertically configured spindles. The lower spindle is forboth grinding and eroding. Moreover, the machine can switch up to eight grinding and eroding wheels, including coolant supply, fully automatically. Various automation options are available to enable unmanned operation around the clock.
For further information www.vollmer-group.com

New wire offers contamination-free erosion




To increase efficiency in the EDM production of contamination-free components, bedra has developed the confreecut ONE EDM wire.

In wire EDM, it is particularly important that component surfaces are free of contamination from foreign materials after production. In conventional wire erosion, the surfaces of the cut component may show residues of copper and zinc, requiring subsequent chemical cleaning. The additional cleaning process increases throughput times and production costs enormously. In the case of component surfaces that are difficult to access, the cleaning effect is also limited or insufficient.

Currently, most machine shops specify EDM wires made of molybdenum or tungsten for such applications. However, these wires carry a high material price. In addition, the wire guides are subject to heavy wear and automatic threading can be problematic, reports bedra.

To increase efficiency in the EDM production of contamination-free components, the company is introducing the confreecut ONE EDM wire, whichbedra says stands for contamination-free and fast machining with low wire guide wear and reduced wire costs. The wire has a high-purity outer nickel coating with optimal layer thickness. Run lengths of up to 60,000 metres per spool permit significantly more autonomous production compared with the usual fabrication of molybdenum and tungsten wires.

Notably, bedra was able to prove in numerous tests that confreecut ONE reduces the copper and zinc contamination, with zinc reduced to almost zero during processing with 2-4 trim cuts. In the process, bedra examined the components for these residues using highly sensitive analysis technology. The companyis happy to advise potential customers on specific erosion applications.
For further information www.bedra.com