Quality Magazine

Case Studies: CMM Precision Proves Essential to Success

May 1, 2006


Running five shifts, supporting four different product lines and processing more than 20,000 parts per month requires not only detailed planning, but also reliable inspection technology. For Dietmar Ingensiep, group leader of the common rail division at Robert Bosch Corp. (Charleston, SC), consistent output of accurate data is essential for ensuring uninterrupted manufacturing processes and producing high-quality products.

In 2001, when Ingensiep took over the department, one of the major bottlenecks he noticed was the extensive time needed to develop new coordinate measuring machine (CMM) programs. Today, with the help of dependable CMM technology and user-friendly software, this is no longer a concern.

Robert Bosch Corp., part of the Bosch Group automotive technology business, manufactures OEM components for customers such as Ford, GM and DaimlerChrysler. This includes anti-lock braking systems, fuel injection and diesel injection systems such as common rail and unit injector. At Bosch's plant in Charleston, SC, eight CMMs from Carl Zeiss IMT Corp. (Maple Grove, MN) work nonstop to keep the production running.

Bosch purchased a UC 550 and an Eclipse CMM from Carl Zeiss in 1989 to support the anti-lock braking systems production. Over the years, as more product lines were added, they also increased their inspection capacity by adding two Contura and four Prismo CMMs-equipped with Vast sensor technology and Calypso CAD-based software. Vast sensor technology allows high-speed multipoint measurement of size, form and position, an important factor when inspecting a wide range of parts. The key benefits of Calypso include its off-line programming capability and easy creation of measuring programs.

Almost 7,000 to 9,000 jobs are processed per month in two metrology labs. With a standard job consisting of three components, Bosch inspects about 21,000 to 27,000 parts. That kind of volume requires not only quick turnaround time, but also machine reliability. "The CMMs are essential to our success," Ingensiep says. "Certain production areas rely on CMM data to adjust their machines. If the data is incorrect, it would not be noticed until it hits the assembly line, which would be too late and could cause production to shut down. So for me, reliability and speed are a must."

Bosch is 100% dedicated to meeting customer requirements. But when it comes to metrology, the customer is not the driving force. "There is nobody that has more influence than our internal customers," Ingensiep says. "We are constantly challenged, for example, by our product development department. It is not only the accuracy, it is the fact that the parts are getting smaller and smaller. We are always pushing the envelope in all aspects of product design and therefore each of the CMMs. Our customers expect a product that works flawlessly and it is our job to design, measure and produce it." For Bosch, this also implies investing in the latest technologies.

With several product lines manufacturing the same products at different locations worldwide, accurate and correlating part quality is a priority. Bosch solved this problem by establishing compatible manufacturing conditions in each facility. This means that not only the same measuring equipment has to be purchased, but also the same production machines.

Before installing Calypso CAD-based software from Carl Zeiss, Bosch's in-house programming resources were limited due to the lengthy process of learning the programming language. They mostly depended on external companies to write programs. Because of their lack of product knowledge, several iterations were necessary before programs were ready. This was not only time consuming, but also resulted in high costs driven by an ever-changing environment requiring frequent program modifications.

With Calypso, programs can now be written off-line, while the CMMs continue measuring production parts. The short learning curve of the software also allowed Bosch to train several of its quality personnel within just a couple of months. By increasing its on-site knowledge pool, Bosch is now able to implement software program modifications immediately, making parts inspection a more efficient process.



Benefits

The key benefits of Calypso include its off-line programming capability and easy creation of measuring programs.

With the software, programs can be written off-line, while the CMMs continue measuring production parts.

The short learning curve of the software allowed Bosch to train several of its quality personnel within just a couple of months.

By increasing their on-site knowledge pool, Bosch is able to implement software program modifications immediately, making parts inspection a more efficient process.