When industries such as the medical sector place stringent demands regarding the quality of a workpiece, then the machinery used in production must be able to satisfy such requirements. Bühler Metallbearbeitung GmbH handles this matter with multi-tasking INTEGREX i-150 machining centers from Mazak.
Founded by Gerhard Bühler and a partner in 1990 as a contract manufacturer for CNC milled parts, Bühler Metallbearbeitung focused for years on turning and milling steel and aluminium mechanical precision parts. These were for, amongst others, the automobile industry and aluminium die forging. Processing of aluminium parts and high-quality steel continues to this day. However, the primary focus is now on the medical industry. An in-house milling section was therefore set up specifically for such discerning clients. In 2020 they moved to newly erected premises with offices and a large production facility in Spaichingen, on the edge of the Swabian Jura, offering plenty of space.
breaking into the medical industry
However, the path there was anything but smooth. Managing directors Torsten and Rainer Bühler took over management of the company overnight in 2001 after the unexpected death of their father. With their rigorous focus on quality, continued improvements to technology within the machine pool, and a hint of fortune favouring the brave, both brothers succeeded in turning the company within a matter of years into one of the most reputable companies around in the contract production of small, extremely complex parts up to 65 mm in diameter.
Rainer Bühler, who is responsible for the technical side of the company, cast his mind back to the early days: “Early on, we always handled orders from other companies that were dealing with backlogs. The breakthrough for our company came in 2007 on a project with a very tight schedule, requiring 1.2 million windscreen wiper levers for the Mercedes C-Class. We fully satisfied client requirements, on schedule, with 20 staff on 3 shifts working with three second-hand 4-axis milling machines.”
Things have progressed rapidly since then. The company then entered the medical industry back in 2008, which has always been a key industry in the region. Once again, it was necessary to manufacture very large numbers of complex workpieces with the exceptional quality that customers had come to expect. Other, similar orders followed: As a result, Bühler obtained two 7-axis milling machines in 2012. “Essentially, we skipped 5-axis processing”, says Torsten Bühler, who is responsible for all matters relating to innovative milling and turning technology, processes, and quality assurance. “Due to the rapid increase in workpieces that are suitable for 7-axis processing, we made a direct transition from 4-axis processing to 7-axis processing”.
“Essentially, we skipped 5-axis processing… Due to the rapid increase in workpieces that are suitable for 7-axis processing, we made a direct transition from 4-axis processing to 7-axis processing”.
Torsten Bühler, Managing Director
DONE IN ONE, AUTOMATED 7-AXIS PROCESSING
Five automated 7-axis milling and turning stations, equipped with bar feeders, are at the production site, two of which are from Mazak. These INTEGREX i-150 multi-tasking machines were specifically developed for fully processing small, complex workpieces. They are equipped with traverse paths in X/Y/Z of 370/200 and 435 mm as well as a milling spindle with automatic tool changer that rotates in the B-axis, and a rotary table with direct drive motor that switches on the C-axis and enables simultaneous processing in 5 axes. The maximum turning length is 385 mm.
The “Done-in-One” full processing concept from Mazak integrates all processing procedures from supplying raw material, via processes such as turning, milling, drilling, and much more without a clamping process. This significantly reduces the production lead time of a workpiece whilst improving the accuracy of such work whilst also making work easier for the operator. All INTEGREX machines are ideally suited for automation.
Torsten Bühler is completely satisfied with the output from Mazak’s machines. “Although the configurations and performance parameters of our five 7-axis machines are pretty much the same, both Mazak machines provide superior performance in terms of accuracy and surface quality in some of the diameters.” Rainer Bühler also added: “For me as a user, it is fascinating to see how easily complex parts including the deburring of spheres can be done in one setting with the right machine. On top of that, the surface quality is outstanding, and finished parts only need to be washed after production.”
“For me as a user, it is fascinating to see how easily complex parts including the deburring of spheres can be done in one setting with the right machine. On top of that, the surface quality is outstanding, and finished parts only need to be washed after production.”
Rainer Bühler, Managing Director
POWERED BY SMOOTH TECHNOLOGY
With both INTEGREX i-150 machines, the tool magazine has space for 72 tools (standard is 36) with a max. tool length of 210 mm, a max. tool diameter of 125 mm and a max. weight of 5 kg. The magazine is loaded via a side door. During processing, a laser constantly monitors the exact position of the tool in the spindle during the tool change. Alongside rigorous automation of machinery, integration of superior measurement technology in the machine is a foundation of the company’s success.
The new INTEGREX i-150 is fitted with SmoothX CNC, which was specially developed by Mazak for 5-axis simultaneous milling with interpolating axes. SmoothX has software features that help support more complex processing procedures such as free-form surface milling, which has the Intelligent Pocket Milling (IPM) function for pocket milling. This automatically generates the tool path to ensure a constant tool pressure angle and therefore an even load on the tool as well as ideal cutting conditions – even on materials that are more difficult to handle. Compared to traditional programs with an offset tool path, the cycle time for pocket milling is reduced by up to 60%.
Many benefits of SmoothX such as the ease of operation and the touchscreen panel are not used at Bühler because Rainer Bühler programs all work processes externally via SolidCAM due to the myriad different controls and handling systems within production with four employees.
productivity improvements
At Bühler they are delighted with the machine uptime of Mazak machinery. “The machinery is extremely reliable across all three shifts, so practically 24/7”, says Rainer Bühler. “This is also shown by the downtime figures.” Mazak’s technical support is also available by phone if assistance is required. A required service is on site within two days. Operation in 3 shifts is very much the norm at Bühler. 30 well-trained employees now work around the clock to produce complex, fully processed milled parts as well as turned and milled parts, system components that are ready for installation with all surface and heat treatments, as well as installation of assemblies and systems. This is not just for medical equipment, but also for telecommunications, machinery and plant engineering, manufacturers of hydraulic and pneumatic tools, as well as for the rail sector and for connection technology.
The switch to the new building resulted in more space and therefore more flexibility as well as further optimization of processes. A ring duct for air conditioning the production hall and consistent temperature control of machinery is also part of the general renovations. The Mazak INTEGREX i-150 was obtained in 2021. It is equipped with an integrated heat plate exchanger and is connected to the cooling water ring. Waste heat from two redundant compressors is used to heat the office block. This is an exceptional form of climate and environmental protection which also lowers costs at the same time.
