Germany’s Komet Group, a leading supplier of precision cutting tools, is reported to be using metal Additive Manufacturing technology from Renishaw to produce new ranges of innovative cutting tools. As well as allowing special cutters to be produced more quickly, the use of Additive Manufacturing is said to enables more complex shapes to be generated, both for the external shape of the tooling and for the internal cooling channels.
Komet, which has its headquarters in Besigheim, employs more than 1,500 people, including its subsidiaries, and is represented in around fifty countries. In addition to developing, manufacturing and distributing a range of products, the company is said to use its technical know-how to analyse customers’ production processes, right down to the smallest detail, and then develop tailored solutions to help them achieve greater efficiency for all stages of their machining.
Additive Manufacturing was identified by the company as a potential production process to enable tooling designs that were too expensive, or even impossible, to make with conventional manufacturing methods.
Dr Reinhard Durst, Research and Development Manager for hard metal tools at Komet Group, has been investigating Additive Manufacturing for tooling production and the equipment available on the market for several years. He has been working with Renishaw for the last year, “because its offer has convinced us from a technical as well as an application point of view.”
“We are aiming for a win-win situation,” explained Ralph Mayer, the manager responsible for Additive Manufacturing services at Renishaw GmbH. “With our support, the customer shortens their learning curve and reduces the number of potential mistakes to a minimum. We only raise the question of purchasing a system when the customer is clear that it will provide added value for them. At the same time, we gather valuable information about the needs of the industry, which we can use to develop our machines and technology further.”
“Parts produced with Additive Manufacturing can reach an up to 99.9% consistent structure, just like rolled or cast metal components,” explained Mayer. “However, the correct strategy must be applied for every component. Our strength lies in our skill in analysing the technical challenges of our customers’ components and working with our customers to find the most effective solution.”
Komet stated that Renishaw has contributed a wealth of knowledge to help it find the parameters that are needed to produce a good tool. “The new design freedom from AM technology and the cooperation with Renishaw is helping us to develop even more innovative tool solutions.”
A new range of PCD screw-in milling cutters
The first of the projects handled jointly between Komet and Renishaw was the development of a new range of PCD (Poly-Crystalline Diamond) screw-in milling cutters. The main bodies of the cutters are manufactured on a Renishaw metal AM system, with multiple bodies produced during each cycle of the machine, and then fitted with PCD blades and screwed onto their tool holders. The use of the Renishaw technology to manufacture the tools allows geometries to be produced that would be almost impossible by conventional means. “Thanks to the additive process we have been able to place many more PCD blades on each tool,” explained Dr Durst.
“We have changed the arrangement of the blades and achieved a substantially greater axis angle. Compared to conventional milled tools, we have greatly shortened the grooves. These changes mean that the tool is a lot more productive for the user.” For example, with a 32 mm screw-in head, the number of grooves and blades has been increased from six to ten, achieving a feed rate that can be up to 50% higher.
In addition, the ability to optimise the paths of the coolant channels ensures that each cutting edge is supplied precisely with coolant through a separate channel, while the external design of the bodies helps to ensure that chips are removed reliably from the face of the tool.
AM also offers the potential to reduce component weight since material can be used only where it is necessary for the optimum functionality in the component. It also outperforms conventional production methods in terms of delivery time for any special or experimental tools needed by Komet’s customers.
“The ability to freely design the internal and external tool geometry alone means that excluding this additive process from our future plans would be inconceivable,” commented Dr Durst. “It gives us the ability to increase tool performance and productivity to such a great extent that it creates considerable added value for our customers.”