Quality measures

NC Service, a Swedish machine tool calibration and maintenance company that works with key CNC machine users, was one of the first users worldwide to take delivery of Renishaw's QC20-W ballbar (01453 524524). The new cable-less design eliminates issues with the previous QC10 when used on large machines or where its data cable had to be fed through machine guarding. Peter Jönsson, managing director of NC Service, Gothenburg, Sweden, who has used the Renishaw QC10 ballbar (and Renishaw laser calibration systems) for years, is convinced of the benefits and happy to take delivery of the new QC20-W wireless ballbar. "QC10 has been one of our most important tools and 100 per cent reliable, since 2004 – we will continue to use it for some jobs. However, most machines must be run with the doors shut, while, with large test radii for bridge machines, the cable can become a problem – QC20 makes it much easier. I'm also looking forward to using the 'volumetric analysis' function," says the managing director. INITIAL IMPRESSIONS Following the first few weeks of the new device's use, Mr Jönsson explains his initial impressions: "We have used QC20 on customer machines for several jobs now and, for what might seem like a simple changeover, the move to wireless data transmission makes a significant difference. Previously, when we set up a test on a machine, using QC10, we often found problems routing the cable through the guarding – machines should always be run with the doors shut. QC20 has solved another problem we've always had when using QC10 on large bridge machines. In this case, we use the largest diameter test – a 600 mm radius – and, with QC10, it was very difficult to stop the cable tangling." Image: NC Service's Peter Jönsson (left) receives his QC20-W from Ben Taylor, Renishaw assistant chief executive (right) The change to QC20-W has been seamless, according to NC Service. "QC20 uses new Ballbar 20 software, which accepts data captured using both QC20 and QC10, so we can continue to compare the latest test with historical data. Support from the Renishaw engineers has been excellent, ever since we first purchased QC10 and the XL-80 laser calibration system. They are now setting up the new Bluetooth connection and training us in the use of the new software." Mr Jönsson reports that he is keen to start using the new 'volumetric diagnostics' function, which can only be used with data gathered with Ballbar 20 software. The user selects three test files from the X-Y, X-Z and Y-Z planes, which are displayed on a single page. The new analysis finds overall maximum and minimum circularity values to give 'sphericity' and also shows individual test circularity results. NC Service's typical annual machine testing service sees the QC20-W used as the final test, in fact. First, a machine is checked and corrected for any major mechanical issues; then Mr Jönsson uses the Renishaw XL-80 laser calibration system to map and compensate comprehensively for positioning errors, with this then followed by benchmark tests, using the QC20-W ballbar in all three planes. Staying with large machine tools, but this time for the measurement of parts that come off of them, and Gateshead-based Express Engineering has installed Romer Sigma Measuring Arm and Aberlink 3D software. A leading supplier to the oil and gas, aerospace, defence and power generation industries, it has, as part of a £3.5 million, three-year expansion programme, recently installed three large capacity machining centres and associated ancillary equipment. This will support the company's ambitions in the burgeoning renewable energy sector, with Express Engineering now able to machine a range of parts of up to 2 m in diameter and weighing up to 8 tonnes. "Having previously been operating at full capacity, the first phase of our ambitious expansion programme, an 18,000 ft2 factory extension, means that we now have room to grow. To ensure the quality of the output from our large capacity horizontal machining centre, having examined the alternatives, we have purchased a Romer Sigma Measuring Arm and Aberlink 3D software. Because of the size of the components to be measured, and their demanding tolerances, we consulted Northern Metrology (01294 821893 or Hexagon Metrology, 01952 681300). Image: Express Engineering is using Romer Sigma portable arm technology for large part inspection "After considering the range of large capacity measuring tasks to be performed, Tony Smith, the owner of Northern Metrology, suggested employing a combination of two complementary technologies, a 2.5 m Romer Sigma Measuring Arm, linked to Aberlink 3D measuring software. Now fully employed, our new measuring arm/software combination is proving both easy to use and able to meet our stringent geometric part accuracy specifications." HIGH PRESSURE MEASUREMENT High pressure fuel injection technology specialist Delphi's Stonehouse, Glos, site is using an Aberlink Axiom Too CMM (01453 884461) to support its production. The facility specialises in the high-precision manufacture of EUIs for heavy duty applications, helping vehicle and engine manufacturers around the world to meet increasingly demanding emissions legislation. In accordance with the company's philosophy of continuous improvement, an international truck manufacturer recently challenged Delphi Stonehouse to tighten the geometric tolerances on the interface between the EUIs from 100 micron to 30 micron. Exceeding drawing requirements, and beyond the inherent capability of the processes involved, the new tolerance demanded a re-evaluation of the manufacturing and inspection methods. A manufacturing and inspection strategy was initiated for the high volume injectors. An inspection bottleneck was identified as a major potential difficulty and, in consultation with Chris Gay, one of the Delphi Stonehouse's preferred inspection equipment suppliers, several potential gauging solutions were explored. Having deemed dedicated fixtures too inflexible, a solution was found in the Axiom Too. Image: Aberlink's Axiom Too is helping Delphi manufacture fuel injectors to new, more demanding tolerances "Having rejected several other measurement strategies, the in-depth understanding of our complex and tight tolerance measuring problem, shown by Aberlink on our initial approach to them, gave us the confidence to explore their suggested solution," explains Will Johnson, Delphi Stonehouse quality manager. "Within a two-week period, working closely with Delphi personnel, Aberlink ran injector measurement trials, made minor modifications to their software, successfully completed arduous R&R trials and installed two Axiom Too CNC CMMs within the Stonehouse facility. "And, because of the urgency of our requirements and to further expedite the procurement process, we took advantage of Aberlink's Lease Hire Scheme. As the Aberlink operator interface is relatively simple, we have enjoyed the benefits of a reduced training time, while the high speed of our new Aberlink CMMs will enable us to keep up with the current unit inspection volume of 2,000 per week and also our projected throughput of 3,000 units. It was enlightening to compare the Axiom Too with our existing CMM that cost five times more. We were astonished that our new, less expensive machines delivered similar levels of accuracy, while considerably outperforming the more expensive CMM, when it came to the speed of inspection routines." First published in Machinery, April 2010