Sleek, Stylish Swiss Precision for Milling/Turning

July 11, 2019
A Geneva job shop is built on a foundation of precision, producing watchcases with accuracy and reliability suitable to its high-end location.

On one level, it’s a Lamborghini showroom, sleek, stylish, and powerful. One flight downstairs, it’s a precision machining operation. Together, it’s a “premium top-down concept” in keeping with the high-style neighborhood in Geneva, Switzerland. But somewhat surprisingly, it’s the Niru Swiss AG machine shop processing parts for jewelry and watchmaking that is home to the most exclusive equipment on display there — a Bumotec s191V five-axis machine from Starrag Group.

Of course, watchmaking is a Swiss specialty, and Niru Swiss (like the customers it serves) knows what that specialization requires.

"It is not possible to create the unusual case design with conventional production technology,” said Felix Baumgartner, founder of chronometer brand Urwerk.

Among luxury watchmakers there is much appreciation for the case for the new UR-111C wristwatch, which is just 15 mm high and 46 mm wide, and does not require a screw-on bottom plate. Instead, the case is cut as a single piece from an aluminum blank and includes a 20-mm-deep side compartment to accommodate the movement. All this is done at Niru Swiss thanks to the standard, high-quality performance of the Bumotec s191V 5-axis machining center delivering excellent and consistent accuracy down to the last micrometer.

Managing director Julien Ducommon and his four employees credit the Bumotec s191V vertical CNC high-performance machining center for producing such specialized products. This machining center is capable of precise and productive machining of highly complex components for the jewelry and watchmaking industries. The team in Geneva uses a total of four CNC machine tools, three of which had been in place already at a company that Niru acquired.

The Bumotec s191V mill/turn machine center combines Swiss mechanical functionality with state-of-the-art CNC control and drive technology, for precision, three- to five-axis cutting of complex components. The thermal stabilization unit almost eliminates warm-up cycles when starting or after machining interruptions, according to the developer.

Choosing Bumotec for its fourth machine was a deliberate step for Niru. The combination of linear motors, direct drives, nano interpolation, and a high measurement resolution of 1/100 µm, enable excellent contouring accuracy (e.g., a roundness of 1.4 μm with a radius of 50 mm.) The "excellent thermal stability" allows Ducommon and his team to turn and cut components continuously from early in the morning until late at night, without any loss of precision.

With the Bumotec technology, the Niru Swiss team can work across five axes simultaneously and components are machined using a single clamping operation.

As a result of the investment, Ducommon has set his sights on conquering new customer market. Now, the shop not only machines metals but also plastic materials, such as PEEK ("polyether ether ketone", an organic thermoplastic polymer used to form engineered parts, including bearings, piston parts, pumps, and valves, for example.)

It’s little wonder Ducommon already has started to plan a new workshop, which will provide more space for both staff and machines. And Starrag's Bumotec product range is contributing to this vision.

"For me, the most important requirements in this competitive field are the ability to deliver optimum productivity, precision and stability,” according to Ducommon.