Basdorf, Lampe & Partner in Berlin Köpenick manufactures casting tools for the automotive and railway industries. Each one of them later produces millions of brakes or engine blocks for the customer. It goes without saying that dimensional accuracy is very important. For two years now, the company has been supported by the ZEISS COMET 3D sensor.
The company was using optical measuring methods in quality assurance for final inspection even before the acquisition of the ZEISS COMET, but they did not measure by themselves. This was left to a service provider, but only for half a year. “Then we realized that we can only meet our requirements if we take care of quality assurance ourselves.“ At a trade fair, the head of the company specifically visited the ZEISS stand to find out more about the 3D sensor – and was immediately impressed. “The price-performance ratio was unrivalled“.
Upgrading the quality assurance system was unavoidable. “Customer demands for precision have risen and continue to rise,” says Felix Kricheldorff. This is understandable, because enormous costs depend on the company’s products. The most important service is the manufacturing of casting tools of metal parts for combustion engines, brakes and other components on cars and trains. Also tools for sheet metal forming and fibre-reinforced plastics are being manufactured. Millions of parts are cast later in Ingolstadt or Munich with a tool out of Berlin Köpenick. If the tool is not absolutely precise, it will produce tons of scrap and therefore high costs.
Four Hours Instead of One Week
These tools are partly large and heavy and, in some cases, bizarrely shaped. Every square centimeter of its surface must have the right height to within a few micrometers. Testing the complete surface of a complex tool with a coordinate measuring machine would be possible in principle but would take up to a week.
In case of deviations, the tool would have to be reworked and checked again. All in all a lengthy process and no practicable way given the high demands placed on customer adherence to delivery dates. On the contrary, an inspection with ZEISS COMET usually does not take longer than four hours and for smaller parts it can be considerably shorter. This significantly accelerates the processes.
But it was not like that right from the start. “It took us up to a year to be able to rely on the measurement results,” says Frank Heinzelmann, one of the two quality inspectors of the company. This was not caused by the measuring device, which worked reliably, it was because processes had to be adapted to it. For example, the hall has large glass windows under the roof and in summer the sunlight shines directly on some workplaces. If the 3D sensor was currently busy with a measurement there, the metal parts weighing many kilograms would expand and the measurement results would be falsified.
They learned from this, says Heinzelmann who has been working here as a CNC milling cutter for 25 years. They were setting up a parasol first but without any success. At the moment one corner of the hall is being darkened in such a way that light and heat can no longer influence the measurements. On the other hand, the familiarization with the ZEISS colin3D software was quickly done. “We received good training and the software is also very intuitive,” says Heinzelmann. “And if there were any questions, the ZEISS service team helped us immediately.”
Another advantage is the flexibility of the ZEISS COMET which is also evident when it comes to measuring larger, less mobile components in the production environment. Instead of rotating the component, ZEISS COMET can be moved around to measure all surfaces.
For the customers casting part to detach from the mold, it must consist of at least two, often several, tool parts. The construction of a tool or a mold requires a lot of experience and creativity – and good metrology. Because the cast part shrinks as it cools. So that it does not become too small, the tool must be somewhat larger from the outset. ZEISS COMET ensures that there are no unpleasant surprises when it comes to complex shaped components. The older coordinate measuring machine, which is still part of the workshop, is rarely used now, says Frank Heinzelmann. The customers demanded tolerances of 0.1 to 0.2 mm, “COMET achieves the necessary measuring accuracy for all parts.”
For more information: www.zeiss.com/metrology