CMMs Brake Metrology Limits

Knorr-Bremse Rail UK, a member of the global Knorr-Bremse Rail Division, are leaders in braking systems for all types of rail vehicles, from trams to very high-speed trains. In addition to braking systems, the Knorr-Bremse Rail Division offer a wide portfolio of innovative sub-systems to the world’s train builders including air conditioning, auxiliary power, door, monitoring and advisory systems.

Knorr-Bremse Rail UK operate four facilities in the UK; at their Corsham site precision machining is performed by a specialist team. The components produced at are all destined for use in the company’s advanced mechatronic EP2002 Distributed Brake Control (DBC) system, manufactured at the nearby Knorr-Bremse facility at Melksham. EP2002 is an ‘intelligent’ brake control system which self-compensates, in real time, to address the variable operating conditions the train finds itself in, including passenger loading, wheel spin and slide and variations in friction brake performance. The system has, and continues to be, an outstanding export success for Knorr-Bremse. Over 75,000 EP2002 units have been produced and sold to train builders globally with the Middle East and China being key markets.

Knorr-Bremse demand the very highest possible quality assurance in manufacturing. The Rail Division holds a wide variety of certifications and accreditations, including ISO 9001 and IRIS ISO/TS 22163, which goes beyond the ISO9001 standard to include requirements specific for application in the rail industry.

Due to the continuing global demand for EP2002, and the newly introduced EP2002 3.0, further investment was approved to support increased production efficiencies without any compromise to quality. CMM inspection was identified as essential in improving production efficiencies and highlighted as an area needing investment.

Research was conducted by Knorr-Bremse Rail UK into the available CMMs on the market. The company already had good experience with the performance of the Aberlink Axiom too HS CMM installed at the Melksham manufacturing site and an Aberlink Zenith too CMM in use at Corsham and when strengthening its CMM resource again chose Aberlink as supplier of choice.

Knorr-Bremse Quality Manager at Corsham, Aaron Rens, commented, “We produce safety critical parts where consistency of quality is absolutely paramount. We, of course, considered many CMM machines to deliver this consistent quality we need and chose the Zenith 3 CMM due to good standardization, ease of programming, even when machining the most complex of parts, and good value for money. Service support also influenced our decision; with Aberlink we’re able to phone and speak to support engineers and even software developers with any queries or feature requests and we receive a solution almost immediately.”

Purchased with the PH10M motorised probe head, SP25 scanning probe and Aberlink’s Programming from CAD software module, Aaron, commenting on the Knorr-Bremse setup said, “The Aberlink Zenith 3 was bought for the evolution of features that we needed to allow us to measure in the quickest time possible. The Zenith 3 with SP25 and Programming from CAD has hugely reduced inspection times, by up to 66% in fact. Our most complex part has over 600 unique features and the CAD software module saves weeks of work due to our ability to create inspection programs before the parts are even machined. We’ve also taken the additional steps of creating simplified versions of our part programs to allow our shop floor staff to perform in-process checks on key features.”

In addition to using the Zenith 3 for accurate measurement of new parts, Knorr-Bremse uses the machine’s SP25 tactile scanning probe to good effect for lifetime wear analysis of critical features, enabling inspectors to detect any potential issues early on.

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