Varied diet - machining centres tackle all comers

Freeform Technology (01280 820921) has installed its fifth 5-axis machining centre, a 650 by 650 by 560 mm (X, Y, Z) DMU65 monoBLOCK 5-axis universal machining centre from DMG/Mori Seiki (0247 651 6120). This is in support of its manufacture of patterns and moulds used in the manufacture of carbon fibre reinforced plastic (CFRP) body parts and other components on race cars, such as the engine cover and even the steering wheel. Also, the subcontractor produces some components directly, such as laminate under-floor planks for race cars, aluminium parts used in wind tunnel tests, and a variety of jigs and fixtures. The Buckingham-based company was set up in 2008 by two former production engineers at Formula One team, Red Bull Racing, Fred Hutton and Simon Burchett. Today, it supplies not only Red Bull Racing, but other F1 teams, such as Lotus, Mercedes GP, Williams, McLaren and Marussia. This latest DMG/Mori Seiki machine joins one from the same maker, this time a 5-axis machining centre configured with a B-axis spindle head and rotary table, which has been in use for a couple of years. The company also has three machines from an Italian firm that provide light machining within a large working envelope. SUCCESS DRIVES DIVERSIFICATION The company became a victim of its own success, finding itself with 14 employees working flat out from December to March, but with spare capacity during the rest of the year, after the F1 race season. This was the main reason for buying the latest 5-axis DMG/Mori Seiki machine. Unlike the Italian plant on site, the German-built machine has the power and rigidity to tackle any material, including the toughest of alloys. In addition to machining tooling block, aluminium mould tools can now be produced, allowing the subcontractor to widen its customer base. Particular targets are the aerospace, marine and automotive sectors, for which parts within a nominal half metre cube can be produced to tight tolerances on the DMU65 monoBLOCK. Mr Hutton comments: "It is not our intention to move into the manufacture of end-use metal components at the moment, even though we could, but to concentrate on what we know best and transfer our expertise in composite pattern-making across to other industries. "We have already produced front and rear bumper patterns for the Nissan RML Juke-R and the BMW WRC Mini. We see automotive as a growth area for us, as more and more CFRP parts are being incorporated into road cars, or at least offered as options. "We also intend to offer mould and pattern-making services to companies in the aerospace supply chain." The company selected the 18,000 rpm HSK-A63 spindle option to maximise productivity when machining aluminium and tooling block, the latter being cut dry. With a view to expanding into processing harder metals, an extra-large tank has been fitted to deliver through-tool coolant. Other options included are a 30-position tool magazine, Blum laser tool length measuring and breakage detection, and Renishaw spindle probing for setting workpiece datums. Mr Hutton adds that he likes the ± 120° swivelling trunnion design of the latest DMG/Mori Seiki machine, pointing out that, in his opinion, it is more versatile than a B-axis configuration, which cannot achieve such a large negative angle. At Telford-based Cobra Seats, £500,000 has been spent on upgrading the frame shop and replacing old manual machines. In their place are to be found four new CNC machine tools – a Hurco VMX30t vertical machining centre (01494 442222), an Amada press brake, a CMS tube bender and a Sirio cold saw. The investment was made at the end of 2011 and is already transforming the company's business. The well-known manufacturer of racing, sports and classic car seats has diversified into marine, stadium and office seating and is also increasing the amount of subcontract work that it undertakes. CONVERSATIONAL FAMILIARITY A second-generation family business run by Mark Dunsford, Cobra Seats employed Simon Baldwin as engineering manager to oversee the changes on the shopfloor. Mr Baldwin explains: "In my previous position working at a subcontract machinist, I was familiar with Hurco machines and their WinMax conversational CNC system. "As programming is so quick with the control, it is ideal for shopfloor use when small batches are to be machined. Thirty-off is a large run for us – we often machine ones and twos. "We previously drilled and countersunk holes in box section frame components by hand on a pillar drill, then part-assembled the seat and drilled smaller holes for the webbing. Each part would take four to five minutes to machine. "Now, machining is completed in one minute per frame section on the Hurco, including loading and unloading. Moreover, we know every feature will be reliably accurate to ± 0.1 mm, ten times better than the drawing states, saving time at the assembly stage." Previously, there was no milling capacity in the frame shop at Telford, so all such jobs were subcontracted. With the Hurco in place, milling the side mounts on custom seats, for example, and slot milling of runners so that they fit individual cars, can be carried out in-house. So, too, is much of the prototyping and pattern-making that was previously contracted out. The presence of the VMX30t means that some machining is performed that formerly would not have been undertaken at all. A case in point, involving the design of Cobra's stadium seating, is milling of holes into round tube, a procedure that would have been avoided, if machining them manually. Another example is the mechanism for a new superyacht seat, which will be produced in-house on the Hurco. Overall, the amount of production outsourced from Telford has halved from 20% to 10% since the CNC machinery was installed. Mr Baldwin predicts that the proportion will drop further to 5% by the end of 2013, so in the future only seat mechanisms and some very simple parts, such as forged, inserts will be purchased. A source of additional revenue for Cobra Seats is the manufacture of products on a subcontract basis. Currently, production for outside organisations accounts for only 5% of turnover, but is expected to rise to 15% during 2013. ALREADY EARNING ITS KEEP Mr Baldwin concludes: "The VMX30t will play a major role in this growth, yet it is already paying for itself with the work we are putting on it. We purchased the machine as a 3-axis model, but with a view to adding a 2-axis indexing table to give us 5-axis capability in the future, as we gain experience. "Hurco gave us good advice during our acquisition of the VMC and has provided good service when needed, especially over their telephone helpline. Elsewhere, subcontract machinist Progress NC has taken delivery of a German-built Spinner U5-620, the first in the UK, supplied in January 2013 by recently appointed sales and service agent Whitehouse Machine Tools (01926 852725). The configuration of the 12,000 rpm vertical spindle machine sees all the linear slideways above the working area. Rotary axes are provided by a 360°, 650 mm diameter table mounted on a -90/+110° swivelling trunnion. Co-owner Andrew Russell says: "The Spinner specification far outweighed that of other 5-axis machines we considered. It was cutting metal on the first job within 48 hours of commissioning. "You normally expect a few teething troubles when a new machine is installed, but not a single thing has gone wrong with the Spinner. "We are holding very tight tolerances, due to the glass scales, which inherently allow better accuracy and repeatability than the other machines we looked at, which were fitted with rotary encoders. Co-owner Stephen Boocock adds: "Spinner machines are not that well known in the UK. I had not heard of them before Whitehouse took over the agency, after which I saw the spec of a larger 5-axis machine on their web site. "Andrew and I went over to see the Spinner factory, where the machine tool builder uses its own lathes and machining centres to make many of the constituent parts. We were very impressed with the rigidity and stability of construction. "The owner, Axel Spinner, took time out to meet us. We were accompanied to a nearby job shop that uses a U5-620 5-axis machine and we could see how well it would fit into our operation." Progress NC produces parts for aircraft, boats, guns, motorsport and a wide variety of other industries, with batch size ranging from one- to 100-off. Both partners comment on the rigidity of the Spinner U5-620. Where other machines can sound hollow when a tool is engaging the workpiece, the Spinner is audibly more solid in cut. It is already apparent that tool and insert longevity at Progress NC is increasing, due to lower vibration. Consumable costs are saved and the frequency of tool changes is reduced, leading to higher productivity. Moving to Leicester-based Air Time Products, a manufacturer of innovative after-market components tailored specifically for the freestyle and freeride jet ski specialist, and an XYZ Mini Mill 560 compact machining centre is supporting production, 95% of which is exported. Set up by Chris and Lisa Giles eight years ago, it was envisaged that ATP would design its own products, and then outsource machining of its aluminium and stainless steel components. But it was not long before production moved in-house, even though neither Chris nor Lisa, who is also an accomplished and enthusiastic jet skier, have any previous formal engineering qualifications or experience. "We have had to learn about every aspect of the machining process, from materials through to programming and operating a CNC machine," says Lisa Giles. This was, she adds, made easier by the training provided as part of the purchase, along with a tooling package and the reassurance of a three-year warranty. "The applications and training people from XYZ spent a lot of time with us when we were learning about CNC," says Chris Giles, "and they continue to help, the telephone help line being particularly useful when we need some advice or assistance." MORE TO FOLLOW The Mini Mill has since been followed by an XYZ ProTURN CNC/manual lathe and, most recently, by a 20 hp/8,000 rpm XYZ 710 VMC with 4th axis capability. This vertical machining centre's 760 mm by 430 mm table can hold workpieces weighing up to 500 kg and its 4th axis capability can be used either as an indexer for moving the part to a set angle or as a fully interpolated axis for spiral milling. The Siemens 828D conversational control, fitted as standard, can be programmed on the shopflooor without any G coding knowledge, courtesy of ShopMill sequence programming. Alternatively, programming can be done off-line, using CADCAM, as is the case at ATP. With 68 products currently available from ATP, the CNC machines are re-set for the next priority order, as they become available, with small, regular batches of 20 to 100 parts being the norm, rather than long production runs. The couple's son, Ollie, lends a hand, setting and running machines. Box item 1 of 1 Recent product launches in brief [] Real-time process monitoring and data management software, called MPmax, has been introduced for use with Makino machining centres, available from UK agent NCMT. www.machinery.co.uk/48378 [] RK International's Europa Milltech turret mills have been enhanced with the addition of manual and full CNC control of three axes. www.machinery.co.uk/48377 [] The new DIXI 210 P from DMG/Mori Seiki features a volumetric accuracy of 35 µm for the precise machining of large, heavy components. www.machinery.co.uk/48364 [] DMG/Mori Seiki has added a turning capability to its DMU 125 monoBLOCK vertical machining centre, naming the new machine the DMU 125 FD. www.machinery.co.uk/48357 [] UK agent Whitehouse Machine Tools suggests the Akari HS-630i horizontal machining centre fits the bill for businesses looking for a low-cost machine, capable of producing high precision components within a nominal 1 m cube machining envelope. www.machinery.co.uk/47534 First published in Machinery, April 2013