Master of measurement: The exterior master jig in quality assurance

33 years of working with the exterior master jig: Gerald Funk can look back on this time proudly. Because he has been accompanying measurement technology in quality assurance from the manual beginnings up into the virtual future. Audi blog author Charlotte Seybold has investigated whether his work has become easier during those years.

Funk’s eyes light up when he talks about the changes that have taken place in the Audi quality assurance during the last decade. The 54-year-old can look back on 33 years of exterior master jig development. The exterior master jig is used for measuring and checking all components that are visible from the outside in detail.

At the beginning of his time in the Audi quality assurance, he was responsible for measuring individual components and bodies manually with so-called feeler gauges and sliding cylinders. Shortly after, the tactile metrology was introduced. The associated offline programming marked a mini-revolution in Funk’s daily work: “Suddenly, it was possible to write programs on the computer, while the machine carried out other measurements. It saved a huge amount of time.” This didn’t make the work any easier, but it did make it significantly faster, more precise and less costly.

Gerald Funk has been a part of the development of the exterior master Jig for more than 33 years. In this interview, he explains how his work has changed over the course of time and how he imagines the future

In tactile metrology, CNC measuring machines record the data with measuring heads that come into contact with the sample. The data is then graphically integrated in CAD models.

Gerald Funk is one of those men who get in about things and embrace change. His aim is to establish optical processes and so-called reference body shells at all plants and thereby take another step into the future.

In one of the quality assurance steps, the experts equip reference bodies similar to a exterior master jig. Thus, the paint application can be considered in the final polish. Even though the paint is only 15 hundredths of a millimeter thick, it plays an important role in dimensional optimization.

Detail work with optical metrology

“The work we do with the exterior master jig on a current reference body shell already brings us a whole lot closer to the product delivered to our customers. And optical metrology can help us analyze and optimize components down to the tiniest detail,” explains Funk. To achieve this objective, Funk has also spent the last twelve years training international colleagues at several plants such as those in China and Mexico.

In optical metrology, CNC measuring machines use optical measuring heads to capture data without touching the sample. This means so-called photometry measurement cells can automatically digitize individual components and subassemblies, as well as body shells and even complete vehicles. Even data sets positioned and digitized separately can then be merged virtually afterward.

“In the near future, we’ll have reached the point of being able to virtually merge and examine components under the influence of simulated forces,” continues Funk. This significantly shortens the time spent measuring and manually setting up the components compared with taking tactile measurements on the exterior master jig. But doesn’t he find all these changes unnerving? “No,” says Funk emphatically. “I look forward to them.”

The digitalization opens new doors for measurement technologies: Optical measurement cells – compared to tactile measurement techniques – have the advantage that they can be done without touching the material. That’s how soft material, such as seats or seals, can be measured precisely.

Source: Audi Blog