7/26/2019 Case Study Schweikert LY90

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British CMM used in Porsche body inspection

(Released on 1st March 2004)

German subcontract pressworking specialist, Schweikert GmbH, faced the problem that a newproduct it was making for Porsche – the side of a 911 Targa – was too large to be measured

accurately on any of its existing co-ordinate measuring machines (CMMs). So the companywent to UK manufacturer, LK, for an LY-90 CNC horizontal-arm, single-rail measuring machinewith a working capacity of 6,000 x 1,600 x 2,000 mm.

Explained managing director, Rainer Schweikert, "The LY-90 has an inherently robust andstable guide system, which means that large parts on jigs or smaller parts on an adjacentwork table can be placed immediately beside the machine at a convenient height. Of the fivestaff in our quality control department, two are exclusively concerned with inspecting parts onthe LK and ensure that geometric product specifications laid down by our customers aremet."

The LY-90, which is available with a measuring range up to 20 metres in X, has 15 + L/75

linear accuracy, 20 + L/50 volumetric accuracy and 0.001 mm resolution. This high precisionis ensured by stable cast construction of carriage and saddle, wide bearings, and direct, low-hysterisis drives. Low mass, carbon fibre composite construction of the column and a metalmatrix composite spindle lend themselves not only to high accuracy but also to rapidmeasurement, with vector positioning speeds up to 40 m/min. Control is by the latest LK2000 ACT controller, which optimises performance and incorporates remote monitoringfunctionality.

 An important aspect in the decision to purchase an LK machine was the manufacturer'sadvanced CAMIO 3D measuring and reporting software, which allows direct use of CAD datato program the CMM. Electronic data supplied by Porsche and other Schweikert customerswill be used not only in press tool manufacture but also to create precise measuring routinesquickly for subsequently inspecting the parts. This can be carried out ahead of the availability

of first prototypes, which in any case invariably contain slight inaccuracies and so are not anideal reference to work from.

 A feature within CAMIO is the reference point system (RPS) for rapid and reliable alignmentof components prior to measurement. The designer specifies a series of RPS features,typically three, each with six constraints applied across the three orthogonal axes, based onfactors such as how the part will be fixtured and mated with other components.

 Another key factor in opting for the LY-90 was the contact, dating back many years, betweenthe German LK sales agent, Märklen Messtechnik, and Schweikert, whose two othermeasuring machines Märklen upgraded and regularly maintains and calibrates.

Concluded one of Schweikert's quality engineers, Bernd Kolbus, "The LY-90 has fulfilled all ofour expectations. We use it for a wide variety of measuring tasks and have been able toincrease our metrology capacity considerably as a result. The LY-90 also offers us thepossibility of measuring larger components and establishing more ergonomic workingprocedures."