The XPI common rail fuel system is manufactured by Cummins-Scania XPI Manufacturing LLP, a 50-50 joint venture company located at the Cummins Fuel Systems facility in Columbus, Indiana, and at the Cummins plant in Juarez, Mexico.
“Our work in progress is reduced because we are able to measure in real-time and more frequently than we did in the past,” said Spencer Wilkison, XPI Quality Manager at Cummins. For Wilkison, the accuracy and frequency of the measurements is key to Cummins which designs and manufactures leading-edge fuel systems for diesel engines.
In the fall of 2006, Cummins was in the process of deciding which brand and machine to select for its measuring needs. Evaluation first started out in the lab to establish a baseline from past measurement practices and environment. After calibrations on products from selected providers, specific trials were conducted on artifacts. The machines had to pass the litmus test in production. "We had to be sure that there wasn’t any degradation due to changes in cleanliness and vibration," adds Wilkison. Based on the measurement results, service, support and some of the intangible support that Carl Zeiss offered, Cummins decided to purchase three Rondcom and five Surfcom machines. As part of its capacity expansion starting in the spring of 2008, the company phased in an additional five machines, including one GageMax coordinate measuring machine from Carl Zeiss.
Wilkison stressed the importance of the grinding process. "Precision grinding is required for our components. Multiple grind operations are necessary, which produce final print features or critical in-process features." After each operation, the operators perform all of their own measurements. After the measurement process, all of the data is sent to SPC to control processes and review monthly production capability.”