Manufacturers’ expectations for precision and process control never remain static: for processes like turning and grinding, machine operators and developers are always looking for something faster, with tighter control over operations and results, and of course for finishes that are closer to perfect. Add to those objectives the growing interest in “flexibility”: the way that a machine or a program allows a designer or a manufacturer to adjust capabilities to the particular requirements of a product or an operation.

This is the context for much of the technological development ongoing in machine tool design and processing.

A ready example is the QXD250 grinding machine that the Vollmer Group will introduce to North America next month. It is the product of “many years of research,” Vollmer explained, prompted by customers’ inquiries and experiences with earlier generations of the QXD series.

“The highlight is the new Vpulse erosion generator,” according to Vollmer, “which can finish PCD materials 30% faster than any of its predecessors, and is also capable of achieving finishes as smooth as 0.1μ Ra. The modular automation, six axes CNC controlled movement as well as the ability to grind, erode and polish in one machine setup create an optimized solution for PCD tool processing.”

The Vollmer Group introduced its QXD400 rotary erosion machine for finishing polycrystalline diamond (PCD) tools in 2005. It was the first model in the QXD series, with six CNC-controlled axes moving simultaneously to machine the required tool geometries.

In addition, it incorporated a six-position holder for electrodes and/or grinding wheels, coupled with the automated tool magazine, allowed operators to machine materials unattended — boosting operating efficiency.

The QXD400 was built atop a unitary, 17,000-lb pound concrete polymer base in order to ensure high accuracy in all movements. That design was capable of completing tools up to 400 mm in diameter, with cutting lengths to 400 mm too.

In Figure 1, it is easy to see how the QXD400 could address many of the dimensional concerns for toolmakers producing PCD saw blades and metalworking tools, and all PCD woodworking tools. It complemented other Vollmer machine models, such as the QWD, QM, and QR/QF machines, in particular for finishing larger saw blades and the longer PCD metalworking tools.