Learning from the Master of Mill-turn centers in the aerospace industry: Vol.1
“How does Yuki Precision achieve trusted quality in the aerospace industry? “

Yuki Precision is located in Chigasaki City, Kanagawa Prefecture, close to the Shonan beach. The company manufactures precision parts with several-μm tolerances, which are often used for space exploration equipment. The R&D-oriented small factory has been repeatedly covered in mediums, attracting attentions from global enterprises and establishing a position as an industrial pioneer.

(From left) Mr. Masahiro Ueno, General Manager of Manufacturing and Mr. Taizo Yagi, Head of Machining Technology Laboratory, in front of NTX 100 2nd Generation.

Aiming for high and leveled machining quality

Yuki Precision’s sound quality management system, certified by JIS Q 9100 (an international standard for quality management system in the aerospace/defense industries) in 2010, has gained trust in the company. Even in the competitive and hard-to-enter aerospace industry, some customers went far as to say, “we talk first to Yuki Precision whenever a problem occurs.” The company is active in promotion activities, including the ones in overseas aerospace shows, through which it has secured an increasing volume of design requests and orders for several-μm-level precise parts.

The company now produces components for prominent aerospace companies/organizations like Japan Aerospace eXploration Agency (JAXA), but it had long been a typical subcontracting company since its foundation in 1950. It undertook low-mix high-volume production, such as cutting machining of screws for electric equipment.

The company prospered with a high demand for public telephones’ parts in 1990s, but the business volume shrunk with the penetration of cell phones. The dot-com crash devastated the company and the bankruptcy seemed just around the corner. That was when Mr. Masato Otsubo, the third president, joined the company and drastically changed the management strategy.

“A survey showed that our customers chose us for the ‘quality’ and ‘trust.’ We decided to target the areas where the strengths can be fully utilized, which turned out to be the aerospace and medical equipment industries” says Mr. Otsubo, recalling the strategic turning point. He switched the business model from the low-mix high-volume production to the opposite. With the technical skill that covers from design through production, as well as the cultivated trust in the high and stable quality, the company started navigating through new fields.

NTX1000 2nd Generation for stable quality and process integration

A several-μm-level precision was a standard in the aerospace industry, and a boosting demand for implants in the medical industry called for a continuous and high-accuracy machining. Therefore, the company needed a machine that does not rely on human skills in setup operations, that can produce complicated parts with stable accuracy, and that is suitable for process integration.
NTX1000 2nd Generation (herein after referred to as NTX1000), DMG MORI’s highly accurate and efficient turn-mill machine, was installed to fulfill the requirement in 2016.

“Since we had long used lathes as main production equipment, we preferred a lathe-based machine with 5-axis machining function and a powerful tool spindle. When machining a robot engine’s injector, for example, two oblique holes from the front and back sides should be perfectly linked in the middle, which requires high positioning accuracy. NTX1000 is an optimal mill-turn machine equipped with B-axis, lower turret and 2nd spindle for high-level process integration. DMG MORI’s expertise in European technology was also appealing” explains Mr. Otsubo.

Process integration and stable accuracy for “Machining Technology Laboratory”

NTX1000 is a space-saving machine with a large machining area. The Direct Drive Motor (DDM) mounted on B-axis allows simultaneous 5-axis machining of different workpieces and high-level process integration.

As Yuki Precision’s NTX1000 mounts a tool spindle which runs up to 20,000 min-1 (option specification), it can perform small-diameter drilling, which used to be only possible with machining centers. The efficient circulation of machine-body cooling oil to minimize thermal displacement is another selling point of NTX1000, especially since smallest temperature change can have a significant impact when pursuing μm-level accuracy.