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Taking Quality Assurance to New Heights

By Starrag Group Contributed Article
“Speed and accuracy were always a contradiction for us before we installed the new generation of ZEISS PRISMO fortis,” says Roland Ziltener, head of quality management, Starrag Group. (All images provided by Zeiss and Starrag)

Nowhere is precision more important than in the aerospace industry. And accuracy requirements are rightfully growing stricter every year, as new technologies and regulations are introduced, and there is a greater focus on performance and quality metrics. As such, aerospace parts manufacturers must concern themselves not only with efficiency but with fidelity in mind.

The Starrag Group, based in Switzerland, understands this well. The company manufactures machining centers for production systems that handle turbine blades and blisks, with a focus on aerospace applications. It provides machines tools for CNC milling, turning, boring and grinding workpieces of metallic, composite and ceramic materials under the product brands Berthiez, Bumotec, Dörries, Droop+Rein, Ecospeed, Heckert, Scharmann, SIP, Starrag, TTL and WMW.

With customers around the world, the company operates five manufacturing plants in Europe. To meet demanding customer and regulatory requirements, it must perform high-efficiency measurements that deliver fast, precise and easily reproducible results.

To that end, Starrag partnered with Zeiss AG on a pilot project, teaming the latter’s PRISMO 7/12/7 fortis and CMM Acceleration Mode for Aerospace Applications. Combining productivity and accuracy, the results included an 80% reduction in the rotary table axis definition time.

“In the field of measuring technology, accuracy is usually slow,” notes Roland Ziltener, Starrag’s head of quality management. But the opposite was the case with the Zeiss system.

The ZEISS Acceleration Mode for Aerospace Applications package features two rotary table measurement options: ZEISS VAST Rotary Table (ZVR) and ZEISS VAST Rotary Table Axis (ZVRA). One boosts the rotary table positioning speed, while the other boosts the axis definition speed.

Turning the Tables

The package features two rotary table measurement options: VAST Rotary Table (ZVR) and VAST Rotary Table Axis (ZVRA). The former boosts the rotary table positioning speed, while the latter increases axis-definition speed.

ZVRA defines the axis of the rotary table, providing a crucial foundation for accurate measurements, according to the supplier. Previously, defining the axis involved six single-point measurements. ZVRA achieves this through a continuous single movement that takes considerably less time.

What sets this method apart is the sensor’s movement along a consistent track at an even height, ensuring a smooth process with no unnecessary travel.

The time savings offered by ZVRA encourage a more frequent definition of the axis, leading to improved accuracy, safety and productivity. ZVRA reduces the axis-definition time from 60 to 12 seconds—an 80% time saving for each workpiece at Starrag, according to the partners. Additionally, the faster positioning speed reduces the need for multiple styli, making measurements faster and more flexible, Zeiss says.

ZVR enables faster movement of the rotary table, which in turn means faster measurement times. As workpieces are measured on different levels, the higher rotation speed supported by ZVR results in significant efficiency gains.

ZEISS CALYPSO software interacts completely with the ZEISS PRISMO 7/12/7, and Ziltener reports that it was “not at all difficult” for his team to get up to date with the latest version and the upgrades featured in the new fortis.

Customization, Support and Piloting

The Aerospace mode also includes an application support package for further customization. Detection parameters and machine parameters may be adjusted, such as the acceleration ramp of the individual X, Y, Z and RT axes. Such parameters are customized to specific customer measurement and application needs.

Operating requirements for the Acceleration Mode include the VAST gold active scanning head, the controller C99m, safety laser scanners, the rotary table RT-AB-600, and 315-mm or 400-mm face plates featuring a triple reference with three rolls. These new face plates harmonize the radial distances and the rotational pattern of the screw holes, according to Zeiss. The company also supplies clamping systems and a customized automated loading system to support productivity and efficiency.

In the pilot project, Zeiss and Starrag collaborated with shared geometry data to identify contour-checking solutions that are more effective at handling complex geometries. Application support also included significant efforts by Zeiss to provide Starrag with real-world training. With the PRISMO 7/12/7 fortis and CMM Acceleration Mode for Aerospace Applications in hand, Starrag is setup for continued long-term success in precision and accuracy.

With years of experience using Zeiss’ CALYPSO software, the pilot project was implemented smoothly onto Starrag’s site. The CMM software interacts completely with PRISMO 7/12/7, and Ziltener reports that it was “not at all difficult” for his team to get up to date with the latest version and the upgrades featured in the new fortis.

“We must be able to interpret the results and data and discuss these with our internal and external partners,” he explains.

A streamlined control panel with a designated holder improves workpiece handling.

Speed and Precision

Starrag can now measure more parts in less time “with the same accuracy we had before,” Ziltener says, thanks to the pilot project with Zeiss.

One area in which the increased productivity is plain to see is in the company’s standard turbine blade measurement program. Starrag reports a 74% reduction in the time it takes to return precise and reproducible results, down to 70 seconds from a process that once took 4 minutes and 30 seconds.

Now, the company can be more adaptable when it comes to what it’s measuring on which workpieces. An increase in speed rarely corresponds with an increase in accuracy, but PRISMO offers advantages in both and “never fails to amaze,” Ziltener asserts.

Meanwhile, the ZEISS PowerSaver feature contributes to energy conservation and sustainability at Starrag, a particularly important advantage given the increased prices in the oil, gas and electricity markets. PowerSaver brings energy consumption down to zero during user-defined downtime periods and operates discreetly in the background, according to the supplier.

In terms of safety, the laser-based system automatically reduces speeds in response to hazards. This not only enables secure loading and operation but also does not present a distraction to the user. Lastly, several ergonomic improvements, such as a streamlined control panel with a designated holder, improve workpiece handling. 

For more information about Starrag, visit  or call 859-534-5201. For more information about Zeiss, visit or call 800-327-9735.

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