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

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