It is its hardness that makes diamond the king of cutting. Circular saws tipped with PCD (polycrystalline diamond) not only achieve a long service life in wood and metal processing, but are also almost unrivaled when cutting highly abrasive composite materials. To ensure that PCD circular saws retain their sharpness, the Biberach-based sharpening specialist Vollmer has now launched two new disk erosion machines onto the market. With the QS 860 and QSF 860 twins, saw manufacturers can produce their PCD circular saws with different geometries and diameters from 80 to 860 millimeters. On the other hand, sharpening services, furniture manufacturers and insulation producers use the erosion machines to precisely resharpen circular PCD saws that have already been used. Vollmer ND handling systems, which automatically load up to three machines - with up to 650 PCD circular saw blades depending on the model and equipment - ensure unmanned machining around the clock.

The Vollmer Twins have a Lot in common

Both machines share a robust design, a complete CNC control system and measuring equipment for fully automatic set-up and work processes. They have measuring probes that record all relevant parameters and deliver precise 3D measuring accuracy. The sensor system detects newly inserted teeth and sharpens them to size. The feed pawls automatically detect broken teeth and determine the tooth pitch so that manual adjustment is not necessary. Thanks to Vollmer's tried-and-tested operation, users can control and program the QS 860 and QSF 860 via touchscreen or keyboard. As the machines have identical management of the erosion discs, once measured erosion electrodes do not need to be measured again after changing. In addition, erosion electrodes are automatically dressed after wear to restore the original quality.

In Saw Tooth Machining, each Twin is unique

The twins make a difference when eroding the PCD saw tooth - one sharpens its tooth flanks, the other its flank flanks. The QS 860 erodes flanks with different geometries and tooth shapes and automatically measures the clearance or bevel grinding angles. This increases ease of use when machining a profile and contributes significantly to error prevention. The machine is also capable of processing hollow back geometries, which results in particularly clean and precise cuts with PCD circular saws. A unique feature of the QS 860 to date is that a second machining spindle can be used, which can erode contours on the clearance surface such as concave radii or V-shapes using a peripheral electrode. This machining is carried out in one tool set-up together with the standard free surface machining. This significantly reduces set-up times and increases the quality of the PCD saws, as no reclamping is required.

Processing the Flank Faces

The QSF 860, on the other hand, is designed for processing the flank faces and uses an integrated measuring probe to record all relevant parameters such as cutting width or log thickness. The calibration of different saw types at different radial and tangential angles is also automated.

Digitalization increases the Efficiency of Erosion Machines

The twins exchange the operating and machine data collected via the standard IoT (Internet of Things) gateway, for example to determine machine utilization in real time. A data input station makes it possible to prepare new jobs at an external workstation during operation and thus use the machines even more productively. A DNC (Distributed Numerical Control) system, which is operated on the customer's own IT system, is available to centrally manage programs that have already been written and to use them across machines. The Vollmer dashboard visualizes machine data live and provides detailed machine status information - at any time and from any device, anywhere in the world.

New Vollmer Filtration System 400

“Our new Vollmer Filtration System 400 can also be connected to both eroding machines in order to clean the dielectric to a high standard using ultra-fine filtration,” says Thomas Wenger, Product Manager for the QS 860 and QSF 860 at the Vollmer Group. “Solids are separated from the liquid in the VFS 400 in a filter unit with small filter elements, which in turn leads to an improved surface quality during the eroding process and significantly increases both the quality and service life of the PCD circular saws.”

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