American/Swiss combo

Image: Click here for additional image For every high-end Swiss watch brand, there's a mass-market product that relies on suppliers, such as family-owned precision engineering firm, and Haas customer, Pierre Bercher SA. These relatively low-cost watches may not be as coveted as the Piquets or the Pateks of this world, but they trade on their Swiss-ness just as much as their pur sang cousins. Bercher SA makes plastic parts for some of Switzerland's best-known watch brands. "Seventy per cent of our work is for Swiss watch companies,' says Pierre Bercher. "Typically, these companies want fast turnaround and the peace of mind that comes from knowing that their suppliers know what they are doing. The other reason they continue to use local companies is that generally, people don't want a 'Swiss' watch that's made in China, even a low or mid-price brand. It's about provenance." The company's workshop, in Cernier, is divided in two by a wall of windows. On one side of the glass, there are 17 Arburg plastics injection-moulding machines. The other side contains a menagerie of manual and semi-automatic machine tools, as well as three Haas CNC machines (Haas Automation, 01603 760539). By the window, lit by the sunlight reflected from the deep fresh snow outside, are two 15,000 rpm Haas VF-2 vertical machining centres, both flanked by Agie Spirit die-sink EDM machines (GF AgieCharmilles, 024 7653 8666). Each pairing is a self-contained cell; the Haas units machine copper electrodes used by the Spirits to make the steel moulds that are used on the Arburg injection-moulding machines. Bercher SA is able to produce runs of up to one million plastic parts from a single steel mould. "The moulds we make on the Agie EDMs are complex," says Mr Bercher, "so we often need multiple electrodes to make the desired form. The shape of the electrode is, in part, that of the object to be moulded. Each electrode is machined in copper, which is why we chose the Haas VF-2s with 15,000 rpm: because the material is relatively soft, but we need to achieve and maintain high precision and excellent surface finish." Electrode walls are often machined to thicknesses of less than 0.5 mm and heights of 5-6 mm, which means they can easily burn or break up. "Over the course of a typical year, we may make as many as 40 moulds and produce up to 14 million finished parts. Runs of a million or less are small numbers for one or two of our customers, which is why they prefer to source them from outside." Forty moulds a year doesn't sound like much machining, but some moulds need more than a dozen copper electrodes to deliver the part complexity and some electrodes take hours to design, let alone to machine. "With die-sink EDM, there's an electrical impact on the electrode, but no contact with the workpiece,' says Mr Bercher, "so an electrode lasts quite a long time. Even so, it's rare that we'll reuse one. Our customers change designs frequently. Their products tend to be fashion accessories, rather than investments." OFFICE MILL, THE LATEST The other Haas machine in the Bercher workshop is an Office Mill OM-2, with 30,000 rpm, presided over and operated by Bercher senior's son, Dan. "This is our latest machine tool investment," says Bercher senior. "It's a great, small machine, with excellent accuracy and capabilities. We are using it to make even smaller electrodes having wall thicknesses of as little as 0.3 mm. "With its 30,000 rpm spindle, the Haas machines perfect surfaces. Why spend more? A Haas costs an awful lot less than some alternative machines, but it does the job just as well." Back in the UK and a product of a more practical nature, Hi-Force, a manufacturer of high pressure hydraulic bolting and lifting products, is using Mori Seiki technology (0844 800 7650). It has invested £850,000 with Mori Seiki at its Daventry factory - a turnkey solution for the company consisting of two NL3000 lathes with Y-axis, a Duraturn lathe and a NMV5000 DCG 5-axis machining centre. The NMV5000 DCG was purchased to manufacture Hi-Force's range of 10 torque wrenches, which vary in size and capacity from 1,700 Nm up to 48,000 Nm of torque output. The 5-axis capability of the machine enables the component parts to be completed in one hit. Mori Seiki has been providing an ongoing program of training and optimisation to enable the company to produce the complete range of wrenches and to swap between them rapidly as requirements change. The majority of Hi-Force's products are delivered within seven days, as it holds a significant amount of stock. However, the new Mori Seiki machines have cut typical turnaround times from eight to four weeks. "The shorter manufacturing times give us considerably more flexibility," underlines managing director Kevin Brown. "A condition of a recent major order was for delivery within two weeks. We were able to reschedule our production, thanks to the new machines, so that we could be sure of meeting the customer's demands." Shorter production cycles have also resulted in lower costs. "We are achieving savings of around 25 per cent on our manufacturing, cementing our commitment to Mori Seiki. "We are moving into a new purpose-built 50,000 ft2 facility in 2010 to meet our plans for growth and to continue our policy of 'Made in the UK'. We are anticipating that, as part of this expansion, we will be investing a further £400,000 in Mori Seiki equipment and services." New product launches in brief Three new twin-column, bridge-type machining centres have been introduced by Hurco Europe, High Wycombe (01494 442222). Designated DCX 22-40, DCX 22-50 and DCX 32, their construction has advantages over gantry-type and C-frame machines, in that it has superior thermal stability for higher accuracy machining, and allows heavier table loads (up to 11 tonnes) and larger Y-axis travels with no loss of rigidity. The Dugard Eagle 'V' series of vertical machining centres extends the already wide range and capacity of the existing range of standard 'C- frame' CNC vertical machines from C Dugard (01273 732286). The traverses of these large machines allow X, Y and Z movements up to 3,200, 1,066 and 750 mm, respectively; table loadings up to 4,500 kg, while table areas are up to 3,200 by 1,025 mm. XYZ Machine Tools (01823 674200) SMX 2500 CNC/manual bed mill joins three larger models in the SMX bed mill range, with all four models equipped with the latest generation ProtoTRAK SMX 3 3-axis control. The SMX 2500 is a 3 hp/2.25 kW variable spindle speed head machine – 70 to 4200 rpm in two speed ranges – with a 1,245 mm by 228 mm table able to hold components weighing up to 600 kg. X, Y and Z-axis travels are 812 mm, 406 mm and 685 mm, respectively, with 3.8 m/min rapid traverse in all three axes. Chiron Werke (Chiron Werke UK, 01926 818418) has introduced its Big Mill series of vertical machining centres. The new series has X-axis travels from 1,250 up to 6,000 mm, but larger machines can be supplied. The Y-axis features a stroke of up to 920 mm, while the Z-axis has up to 1,000 mm of travel. Axis acceleration is up to 0.7 G, reaching a top speed of 60 m/min. First published in Machinery July 2009