Inspection Probe Tooling

GM reduces probe tooling design and manufacture time by 40 percent

GM Casting Engine and Transmission Center had been successfully inspecting parts with ZEISS CMMs (coordinate measuring machines) for several years and was now looking to accelerate and globalize the design and manufacture of the custom probe tooling to be used on the CMMs for a new project spanning across their facilities in North America. Using the Stylus System Creator and the new ThermoFit Pro components from Carl Zeiss, GM entered into the era of advanced probe tooling using flexible stylus systems and stylus simulations.

The challenge: more control needed over tooling design

The CMM and gage engineering group of the GM Casting Engine and Transmission Center is a centralized team of about 10 CMM programmers and engineers responsible for supporting all of the North American quality inspection labs for their next generation of 4 cylinder V8 engines. There are nearly 150 ZEISS CMMs dedicated to this project, mostly ACCURAs and PRISMOs, at various production facilities in the US, Mexico and Canada. This team designs CMM probe tooling and writes inspection programs for this new project and wanted more control over the reproducibility of components at all locations, reduced design and manufacturing time for tooling, and simple and quick tooling modifications for product changes.

Solution: flexible stylus systems and stylus simulations

Carl Zeiss 3D Automation, part of the metrology division of Carl Zeiss, first visited the GM Casting Engine and Transmission Center in 2010 and introduced new probe extensions with rotary joint systems. GM liked the thermal stability and carbon tube design, but was looking for fixed machined extensions for more control at their remote inspection labs. They also wanted some interchangeability if a probe configuration change was needed. For this next generation project, the CMMs they purchased were specific to the lifecycle of a particular component. Since the lifecycle could be 5, 10 or more years depending on the product line, they also wanted durable probe systems that would last and that could potentially be reused at the end of the project. After collaborating and testing probe tooling samples with GM, Carl Zeiss 3D Automation completed development of and launched their next generation probe tooling, called ThermoFit Pro, in 2011.

The GM Casting Engine and Transmission Center started using their first ThermoFit Pro modules in June of 2011. The new product line enables GM to build up even the most complex stylus system using the CALYPSO stylus simulator without the need for typical custom designing in CAD. Generic angle blocks can be modified in the software to the desired angle by simply choosing the according angle values. The real angle blocks are then quickly manufactured from semi-finished parts. The finished angle blocks can be machined either by Carl Zeiss or if desired by their own tool shop, as the semi-finished parts are available from stock. Each piece gets a ZEISS part number for easy documentation and reordering.

No CAD engineer or drawing is needed and everything can be done by their own application engineer within the Stylus System Creator. “I'm very impressed with the development of the CALYPSO simulation and Stylus System Creator using ThermoFit Pro modules,” says Craig Wegienka, senior manufacturing engineer at GM Casting Engine & Transmission Center. “I was able to use the Stylus System Creator to create the entire set of block and head tooling for our project. I simulated each individual probe configuration in CALYPSO to verify the tooling. The simulation proved that all tooling would work correctly.”

Benefit: decreased tooling design and manufacturing time

“All of these options and the ease of use reduce our probe tooling design and manufacture time by about 40 percent,” states Craig. “It saves us not only time, but also money because we don’t have to scrap probe components when there are changes.”

The task for GM to guarantee reproducibility of their products by having the same quality results—regardless if the parts come from a plant in Bangalore, Shanghai, Detroit or Sao Paolo— is a big challenge as varying employee skill levels or the availability of spare parts can cause production delays. And product design changes require program and probe tool modifications along with documentation changes. GM can now rely on the ThermoFit Pro modules and the CALYPSO Stylus System Creator to globalize quality control programs, reduce product launch time, while also quickly adapting to any product changes.

About the company

GM Casting Engine and Transmission Center, located in Pontiac, Michigan, inspects parts with ZEISS CMMs (coordinate measuring machines) and globalized the design and manufacture of custom probe tooling used on the CMMs for a project spanning across their facilities in North America.