Diverse machining centre applications (video)

Suffolk-based die casting specialist RD Castings is successfully using Brother high speed machining centres to diversify away from over-reliance on supplying the yellow goods sector, which saw large falls in demand during the recent downturn. The company used only to machine its own zinc and aluminium high pressure die castings, but, during the second half of 2009, it started a subcontract milling and turning service, producing components in a variety of materials for a much wider spread of industry sectors. Since the mid 90s, six Brother machining centres have been supplied by Whitehouse Machine Tools (01926 852725) to R D Castings' Mildenhall factory (01638 717 944). They systematically took over from manual milling, drilling and tapping, which was labour-intensive and subject to quality variation. All of the Brothers are fitted with twin APCs (automatic pallet change) and some are equipped with a Nikken fourth CNC axis. According to R D Castings' sales and marketing director, Anthony Pateman, the machines are ideally designed for machining castings. In particular, he cites fast feeds rates and tapping speeds, as well as sub-second tool change time, as key. Floor-to-floor times, he says, are twice as fast as machining centres without APCs, and their performance versus others won the company over when it installed its first in 1995, in fact. Latest to be installed at the company's Mildenhall site was a Brother TC-32BN QT 4-axis machining centre with 16,000 rpm spindle, 40-station BT30 tool magazine, 8,000 rpm rigid tapping, 70 m/min rapids, 20 m/min cutting feed rate and acceleration up to 1.5 g. This specification, it is claimed, makes it one of the quickest machines on the market and underscores why R D Castings has continued to invest in Brother machines. Image: Brother machining centres are making RD Castings competitive PUSHING THE BOUNDARIES "The Brother machines have pushed the boundaries, regarding the cutting tool technology we use; no longer is carbide tooling sufficient," explains Mr Pateman. "We are now fully committed to the use of polycrystalline diamond (PCD) inserts, which are clamped in dynamically balanced toolholders to achieve speeds and feeds that are not possible by conventional machining. "Coupled with the benefit of high pressure, through-tool coolant fitted to the Brother machines, the new tooling allows a level of productivity that a few years ago was beyond our imagination." Machine reliability is also crucial to an operation like R D Castings. "I can count on one hand the breakdowns across all our Brother machines over the last 16 years," Mr Pateman confirms. "Their reliability and speed, combined with the high level of support from Whitehouse, has been an unbeatable package for us." At Kontax Engineering, XYZ Machine Tools' Mini Mills (01823 674200) underpin its subcontracting business and its world- wide reputation in the manufacture and supply of the world's smallest commercially available Stirling engines (typically around 15 cm high). The Maidenhead, Berkshire-based company's step change to international status as a manufacturer actually began some 10 years ago, when Chris Guise joined the firm. An experienced CNC operator and programmer, his involvement prompted the first step into CNC milling and the company's move into Stirling engine manufacture. "It was during one of the slacker periods in our subcontracting activities that we began making these small model engines, almost as a hobby," recalls Steve Leversuch, Kontax Engineering's owner and managing director. "However, we found we could sell them relatively easily, especially if they could be priced so that enthusiasts would be buying from their 'back pocket money'. We began without a comprehensive business plan, but we were soon introducing new models and the demand, from as far afield as the USA, Australia and Japan, became such that Chris was saying we needed to invest in some new, higher performance CNC machine tools. The one that stood out at the time, and I haven't been tempted elsewhere since, was an XYZ compact VMC with Siemens ShopMill conversational control." The XYZ Mini Mill 560 vertical machining centre has a working envelope of 560 by 400 by 500 in X, Y and Z, respectively. Kontax Engineering now has two XYZ Mini Mill 560 VMCs, which machine the majority of the steel, aluminium and brass components needed for each model engine in batches up to 200-off. Image: It started as a sideline, but model Stirling engines now big business for Kontax Image: XYZ machining centres underpin Kontax' efforts Moving to Germany and Munich-based P+S Technik played an important roll in supporting the shooting of the award-winning film Slumdog Millionaire by providing the small digital cameras used in its production. In fact, Slumdog Millionaire was the first film shot mainly in digital to be awarded the Academy Award for Best Cinematography and the camera that helped support this achievement, through its ability to support discreet filming, was the SI-2K Mini from P+S Technik. HAAS PROVIDES THE WHEREWITHAL And key to the production of this small unit is Haas machining centre technology (01603 760539). The SI-2K Mini is a complete digital movie recording system that combines flexibility with efficiency in production and processing. It has interchangeable hard drives, giving up to four hours' data storage, different viewfinder solutions, battery mounts and a shoulder set option that provides photographers with an independent digital cine camera, ready for use in many sets or locations. However, the real beauty of the SI-2K Mini is that the lightweight camera head, which houses a 2/3" CMOS image sensor, can be separated from the rest of the camera body. In this way, the 'eye' of the camera can be used as a hand-held – or attached to any moving object, such as a helmet, the underside of a train or a car. Meanwhile the recording components can be hidden elsewhere. As Slumdog Millionaire director Danny Boyle noted at the time: "You can capture a bit of the life that's going on around you without people realising it and becoming self-conscious." In effect, the SI-2K Mini helped Dod Mantle to devise a unique visual style that perfectly suited the story. In order to make the SI-2K camera head as small and as light as possible, P+S's manufacturing division, P+S Technik Präzisionsteile GmbH, made it from aluminium on its latest Haas, a high speed VF-3SS mill with a TR160 trunnion table. As Richard Wagner, who heads the division, explains: "The Haas enables us to precision mill the parallel surfaces between the lens and the sensor location face to a tolerance of 0.01 mm. It also has a fine pitch thread of M2 X 0.25 and produces high quality surfaces (it is important that the parts look as good as they work). For machine finishing, we mount the part in a high precision clamp, using special gripping jaws." Image: High accuracy parts for P+S' high-tech cameras are made on Haas machine tools In fact, it is "the precision and reliability" of the Haas machines that Mr Wagner particularly likes. The firm now has five Haas mills – the original VF-1, bought in 1999, and four 5-axis models (a VF-2, VM-3, and two VF-3SS). "We currently make some 8,000 different parts for customers, with average batch sizes of 50-100 (although they can range from one prototype to 1,000 finished items)," he explains. "Some of these can only be machined on a 4 or 5-axis machine, because you have to be able to simultaneously mill angles and radii so they merge into each other. It is also very economical to produce free-formed surfaces on the VF-3SS using 3D copy milling." See P+S video below First published in Machinery, April 2011