No chain is stronger than its weakest link.

"A high-precision, repeatable result can only be achieved in interaction with all relevant components. This is why clamping devices are an extremely exciting topic for us," emphasizes Thomas Bader, Managing Director of the high-tech grinding machine manufacturer Haas from Trossingen in the Black Forest region. "After all, the clamping device is the direct interface between the blank and the grinding machine and no chain is stronger than its weakest link".

The optimal clamping device, which is aligned to the workpiece, not only guarantees the highest holding forces and an exact form or force closure, the perfect clamping device is mainly responsible for the transmission of many other requirements in today's grinding operation. Automated production in particular is driven by cost optimization while simultaneously increasing quality and process reliability. The desire for speed, precision and cost efficiency requires that all reserves are exhausted in order to be able to exploit further potential.

Minimum set-up costs, maximum flexibility and extreme precision

Especially in the precision tool grinding of indexable inserts, cutting inserts, drills, milling cutters, threading tools or reamers, we have observed two developments for years:

First: The automated manufacturing of ever smaller batch sizes

The times when tool grinders could produce the same standard product for years are a thing of the past. Today, production processes are required that are extremely flexible and efficient in mastering new tasks faster and faster. This results in significantly higher process reliability, lower control costs and consistently high precision. Ergo: Safe, fast, economical and repeatable. Special tasks have become standard.

Second: Automated large-scale production

Over large quantities, extremely precise, reproducible production results must be delivered. Here, too, process reliability, cost-effectiveness and repeatability are mandatory. Here, too, complex tasks and requirements change much faster than in the past.

Conclusion: The customers demand significantly more flexibility and more efficiency in the entire production chain.

Up to the last µm

In view of the uncompromisingly high requirements in tool manufacture, a few thousandths of a millimeter are decisive for the quality of the finished product. Best surface results, highest reproducibility, increased tool life, good accessibility to the workpiece and significantly higher grinding speed can only be achieved with a perfect clamping device. The individual clamping device, as the link between the machine and the workpiece, has a decisive influence on the entire process sequence. Here Haas Schleifmaschinen works hand in hand with the renowned clamping device specialists.

Special clamping devices from Haas made to measure

However, there are always specific customer requirements that require special solutions. These special clamping devices are made-to-measure products, adapted to a customer-specific production of very special workpieces. Here the Haas designers leave nothing to chance. They develop the suitable clamping device for the respective task themselves, adapted to the production sequence in the Multigrind® grinding machine and to the respective customer requirements.    

"With our engineering know-how, we are part of the solution and therefore always at eye level with the growing needs of our customers. Haas Schleifmaschinen is known to its customers as a system supplier and not just as a machine manufacturer.  This is the only way we can finally get the valuable impulses from the rapidly developing market. These impulses demand top performance from us and thus consolidate our outstanding position in the market," emphasizes Thomas Bader.

An example from practice

The customer's wish list for the perfect clamping device for the fast production of inserts is demanding and long: outstanding quality, repeatable clamping with a few µm and a high rigidity of the clamping device without compromises. Good accessibility, especially with deep contours, and the use of the largest possible grinding wheel diameter are also required.  Cost-effectiveness is expected due to low retooling costs and, of course, complete machining in a single clamping operation. But that's not all: in the future, it should also be possible to clamp other workpieces with the same basic holder in conjunction with interchangeable parts. The result: maximum flexibility, because the next order for multi-bladed indexable inserts or internal extractors will definitely follow.

With the PV-holder, Haas has a special clamping device at the start which fulfils all these wishes. The workpiece is clamped or pulled onto the reference surfaces in a safe and repeatable vertical position with pull-down clamping jaws. Before series production starts, the application engineers at Haas Schleifmaschinen simulated the entire grinding process using their own Multigrind® Horizon software and checked each individual step - this ensures process reliability.

Haas Schleifmaschinen has all components under control. From the Multigrind® high-tech grinding machine to the Multigrind® Horizon software to perfectly matched and tested clamping devices. The big advantage for the customer: one system provider for the best possible grinding results.

The perfect drive for the perfect clamping device

With the Haas Multigrind® series, Haas has real all-rounders at the start, which is already derived from the name. But the fact that these Multigrind® all-rounders are really specialists is often only discovered by customers at second glance. Timo Zepf, Product Manager for Clamping Devices at Haas Schleifmaschinen, comments: "We are resolving a contradiction that has not existed for a long time. Haas Schleifmaschinen is responding to the demands of many customers for more flexibility and production conditions that could previously only be achieved with several different standard grinding machines".

The future of tool grinding

Particularly in the leading discipline of tool grinding, a great deal has changed over the past 5 years. Haas started in 2015 to develop the perfect tool grinding machine for the future. With the extremely compact Haas Multigrind® CU with integrated tool changer, production is extremely economical, repeatable, precise and fast. Due to the short set-up times, even smaller special orders pay off. As a production unit with three, four or more grinding machines in series, an automated mass production can be organized that deserves its name.

Consistently eliminating risks before the start of production

Best concentricity accuracy is mandatory and can only be achieved with high-precision clamping devices. A stable design of the clamping device and its high rigidity prevent vibrations that could lead to a wobble in extreme cases. The extreme stress caused by the grinding of carbide tools bears risks which are often only recognised in continuous use. Standard clamping devices, but also many high-quality multi-range chucks, repeatedly reach their limits in continuous operation with fatal consequences in the production process. Complex maintenance, constant monitoring and cumbersome readjustment are the result, and in extreme cases quality suffers.

Thomas Bader therefore advises: "The combination of perfect clamping technology, intelligent machine control and state-of-the-art high-tech grinding machines can realise the required potentials, and this is the only way we can turn our customers into real winners".