Harry Roth, a supplier of turned and milled parts, focuses mainly on the aviation sector, in which high-strength materials are machined to make special components of the highest quality. The company in Waldkirch is a specialist in this field, and has decades of experience. Customers appreciate the supplier's fast response time and flexibility, even for small batch sizes. "Product quality is the top priority for our customers, especially as many parts are safety-relevant components," explains Klaus Ganter, Production Management, Planning and Control at Harry Roth. "For us, this means ensuring maximum stability and reliability in the machining processes," emphasizes the production manager. At the same time, Harry Roth must also master the current challenges facing the machining industry – such as the demands for sustainability, resource conservation, profitability, and competitiveness. The shortage of skilled workers is also an issue here. "We are actively tackling the fields of automation and digitalization in production because they can help us to design more reliable and precise machining processes," assures Ganter.
SCHUNK has been able to make a significant contribution to achieving these goals with the iTENDO² sensory toolholder. It records vibrations directly on the workpiece via a piezo acceleration sensor on the tool's axis of rotation and visualizes them in real time on the tablet PC. "As part of a campaign at AMB 2022 to mark the iTENDO² launch, SCHUNK provided us with an iTENDO² test system," remembers Anton Bachmann, Production Supervisor at Harry Roth. "We wanted to work proactively on process improvements and became aware of the new toolholder," says Bachmann. Production manager and production supervisor agreed that the topics of processing optimization, quality improvement, scrap avoidance, and cost reduction should be tackled head-on. "These must not remain empty words," emphasizes Bachmann, "because it's about component safety for the customer and ultimately about competitiveness for us." Bachmann's team was able to identify more than a dozen specific applications with the iTENDO² test system. The decision was made immediately to adopt the intelligent tool for daily production.
Vibrations occur during the cutting process because the tool and workpiece move relative to each other during cutting and drilling. These radial vibrations on the tool's axis of rotation – also known as "chatter" – can take on different forms and are undesirable in any case. This is because they impose a particularly high degree of wear on the tool, leading to premature breakage, and thus to unwanted machine downtime. They also have a direct negative effect on the processing quality of the workpiece; poor surface quality results in poorer dimensional accuracy of the component and, in the worst case, rejects and waste of raw materials. With the iTENDO² intelligent toolholder, metalworkers can now detect these unwanted vibrations at an early stage and reduce or even avoid them by adjusting the cutting data, speed, or feed rate accordingly.
The sensory tool records the vibration data directly at the metal cutting location "closest-to-the-part" and visualizes it on the tablet as a "chatter index", which describes the radial amplitude deviation of the tool rotation axis from the mean value. "The iTENDO² toolholder is an ideal tool for us to get started with digitalization in metal cutting," confirms Anton Bachmann. "The practical application is very simple: We look at the first trial run before starting a series with the iTENDO² and immediately see what is happening in the process," explains the master worker. "We can see directly on the tablet PC where the vibrations occur on the tool and how strong they are. We respond to this by manually adjusting the cutting strategy, the cutting data, or other machining parameters. We can follow how the vibrations change directly on the screen. In this way, we gradually achieve process optimization in the machining of the specific component and can then start a series with the best possible settings."
With the iTENDO², the manufacturer SCHUNK has succeeded in combining the excellent features of TENDO hydraulic expansion technology with the possibilities of digital monitoring and optimization of processes in one toolholder. "With the iTENDO², we gain process transparency and can detect vibration peaks," says Bachmann, describing the benefits of the smart toolholder. "During the first pass, we see what happens between the tool and the workpiece. A corresponding cutting data correction immediately shows the effects." The production supervisor is enthusiastic about this new approach. "We can take an intensive look at the step-by-step process improvement for specific components and move on to reliable series production with an ideal tool behavior." With the tool package provided by SCHUNK, this can be done easily and without further instruction, confirms Bachmann, emphasizing the improved component quality in terms of surface flatness, precision, and dimensional accuracy. He continues with the observation that the possibility of cyclical condition monitoring of the spindle also makes an important contribution to practical condition monitoring.
"Our applications are all about maximizing the quality of our CNC parts. But with small batch sizes, the processes can be difficult to monitor," says Production Manager Klaus Ganter. "That has now changed. We have noticed a significantly longer tool life, which means fewer machine interruptions and enables us to run an unattended third shift at night. For us, iTENDO² is also an important building block for increasing automation in operations. Overall, we benefit from reduced tool costs, lower raw material consumption and lower personnel requirements due to increased process efficiency. The advantages of using iTENDO² and the uncomplicated partnership and cooperation with SCHUNK are an important aspect of our company's future viability," emphasizes the production manager.