Toolmaking tales

Austrian toolmaker Haidlmair has been employing Blum-Novotest's measurement software FormControl V3 since 2005, becoming Austria Toolmaker of the year in 2006. The company measures tools used in die-casting and injection moulding on 5-axis milling machines. "Our CNC machines provide high precision milling; we more or less take it for granted that measurements are kept within set tolerances," explains Engelbert Gotthartsleitner, tool production manufacture manager at Haidlmair. "In the past, co-workers from the assembly department would turn up quite frequently to the toolmakers with defective components. Wasn't there a way to measure parts on the machine? There was a small measuring machine, but it was unsuitable for measuring randomly shaped surfaces and it was simply too small for tools with dimensions larger than 1 m." Following this, the company adopted Blum FormControl V3 software (01543 257111) and was able to utilise arbitrary probes to measure whole workpieces, directly on its 5-axis machine. A newly purchased 5-axis milling machine was equipped with a version of the software, with five additional licences for the measurement software then purchased, while, with the introduction of its new Hermle C50U machine tool, the number of licences increased to six by 2009. All new machining centres will now be equipped with FormControl from the outset, says the company. The measurement software will work with all workpiece probes, including those already installed on some of Haidlmair's machines. Image: On-machine probing using Blum's FormControl software, avoids after-the-event problems At present, 15 Haidlmair employees use Blum's FormControl software, with the decision when and where to use it left to their discretion. "The right moment for implementation of the software is decided by the system operator," explains toolmaker Harald Söllner. "We do not receive guidelines from our superiors as to whether we should measure or not." That said, complicated parts are always measured, with final measurements taking place only at the very end. Use of Blum's software means that, should any rework be required, the part is still on the machine and can be remachined quickly. Removing a part from the machine, measuring it and then finding that rework is necessary wastes time and delays projects. And, in addition to time-savings, Blum FormControl software also keeps a log, enabling retrospective tracing of critical points and machining steps. CONSUMER GOODS To give an example, production manager Mr Gotthartsleitner highlights a tool used to form synthetic parts for the consumer goods industry, which takes 10 to 15 hours to machine. Measurements are taken at the end, with particular interest paid to a preset diameter. "If problems occur later on during fitting, we can be certain that they are not due to an incorrect diameter." The operator looks for the relevant measuring points offline on the PC while the CNC program is running. To support this, CAD data in IGES format is exported to FormControl V3. The operator then uses the software to program probe travel. The measurement program is transferred to the machine, the probe automatically loaded into the spindle and measuring points then taken. For the consumer goods tool, measurement takes less than 5 minutes. In order to fully understand the potential of FormControl V3, Mr Söllner highlights that being a CNC milling operator or toolmaker is an advantage, saying that is important that the operator who has machined the workpiece also sets the measuring points. For he has knowledge of the machining tool path, critical sections on the workpiece and also the points that require more stringent tolerances. Ease of use of the measurement software is underlined by the fact that the arrival of five new licences was followed by a one-time training event. There is a steady exchange of knowledge between staff and, according to the toolmakers, it is possible to use the measurement software independently within a day. Even parts purchased from suppliers are taken from the assembly line to be measured on the company's machines, using Blum's FormControl V3 software, when they do not fit correctly. At Numatic International, manufacturer of the smiling Henry and Hetty vacuum cleaners (previous page), the firm's in-house toolroom is kept busy. The Chard, Somerset-based firm has subsequently standardised on the System 3R Macro reference system – chucks and electrode holders – to help make a significant percentage of the hundreds of injection mould tools. "We needed to find a more efficient system for the production of electrodes, and Macro has given us a 90 per cent saving in set-up time," explains Simon Adams, toolroom supervisor. The company used to machine copper for electrodes in a vice on mills and then put the workpieces into the spark erosion machines, using a different clamping system. This was time-consuming and also allowed positional errors to creep in, leading to a loss of accuracy. Numatic has now invested in a Macro chuck for its vertical mill. Once the electrode is set-up on the Macro holder, it is simply transferred to the EDM machine on the same holder. Once the machines have been programmed, there is no need to do it again or check the positioning, as repeatable accuracy is guaranteed. Typical tolerances at the company are 0.05 - 0.10 mm, which Macro takes in its stride. "Set-up on our spark erosion machines has gone down from 1 hour to minutes!" continues Mr Adams. "Macro gives us full interchangeability and flexibility – the electrodes also remain on the Macro holders, in case any rework is required. We don't always need to mill an electrode, so we are also producing a more accurate electrode just using the EDM process. Image: System 3R Macro chucks are saving time for the Henry vacuum maker "As a major innovator, we are constantly developing new products, and the efficiencies we have gained with Macro are vital when we need to produce prototype tooling in a quick time frame." Over the past year, Numatic's toolroom has been set up to produce injection mould tools and currently produces 10 tools, from single to six-impressions, and is looking to produce at least double that number over the next year. Italian firm Dynamic Srl operates in a number of industry sectors, ranging from heating, ventilating and air conditioning, through to automotive. However, Dynamic has also developed a reputation as experts in the development and production of compression and injection moulds for indoor and outdoor furniture. The company, based in Cazzago St Martin, Brescia, Lombardy, provides moulds for major brands such as Origlia, Casprini, Bonaldo and Miniform amongst others. Due to the higher mechanical strengths and excellent surface finish required for furniture, Dynamic specialise in the use of gas-assisted moulding with BMC (bulk moulding compound) and SMC (sheet moulding compound) glass fibre reinforced polymer resins. Furniture part thickness can vary greatly, so gas assisted moulding permits the use of thin and thick sections to ensure structural integrity of the product, without the risk of sink marks or unpredictable distortion and warping. SINK MARKS ELIMINATED The principle of gas-assisted moudling is that nitrogen gas is injected during the moulding cycle. The major benefits are the elimination of sink marks and the creation of cavity voids, without the need of a core insert. During the cooling phase of normal injection mould tools, the moulding will shrink away from the cavity and an extra pack of material has to be introduced to counteract the sink. When using gas-assisted moulding, this additional pack is replaced by nitrogen which helps eliminate sink marks and improves overall surface finish. Dynamic has been using the VISI product suite from Vero Software (01242 542040) for two years. "We expected a lot from the products and we haven't been disappointed" says Ivano Muratori, project manager. "We are able to create to complex prototype geometry using VISI Modelling, the plastic flow analysis using VISI Flow and the production tooling using VISI Mould and Vero's Machining Strategist. The integrated nature of the product ensures there are no data translation issues when moving between departments." Image: Vero Software's VISI range provides a complete solution for an Italian plastic furniture maker With the introduction of the Vero products at Dynamic, the technology processes have evolved. But, most importantly, the time frame from design conception through to final part production has been reduced by half. "We can now guarantee project completion within 6 months when previously it took us almost a year," explains Tiziano Perini, CEO. "We have halved our production time, which in the current economic climate has proved to be a major advantage."