Benefits sink in - EDM technology in action

In what was another strong year for machine tool investment, Sodi-Tech EDM (02476 511677) is the latest supplier to announce record UK results for 2012 – up 10% on 2011. Among those recently joining the Sodick order book was Banbury-based toolmaker Hanley Precision Tools, which is located side by side with moulding specialist Glazpart – both companies were founded by owner Ken Hanley. "We are seeing many customers bringing work back from China, fed up with the logistical challenge of having cash tied up in transit and the poor lead times," states Glazpart's operations director, Mark O'Mahoney. "Most mould shops cannot afford to operate their own in-house toolroom, which is one of Glazpart's differentiating benefits. Customers love the fact we have Hanley Precision next door, offering a one-stop shop." As part of a new investment programme, Hanley's latest EDM arrivals are Sodick AG600L wire and AG60L die-sink models. Both have System 3R (02476 538653) technology for rapid set-up. "Programming times are at least 50-60% faster than the machines they replaced, due to integrated default features that help accelerate program generation," says Mr O'Mahoney. "Furthermore, on the die-sink machine we've found that we no longer need to pre-rough cut cavity forms, making the process much faster, while finishing is now more refined. "The machines have made us more efficient; more competitive," he continues. "For instance, we can now run thinner wire, making us more cost effective, without any loss of performance. The automatic wire threading capability is also faster and more reliable, which, along with a 6-station toolchanger on the die-sinker, means the machines better support our 24-hour operation." ROUND-THE-CLOCK BENEFITS There is no doubt that 24/7 capability offers genuine market differentiation. Birmingham-based GB Precision is another tooling specialist that has invested in round-the-clock technology, in the shape of an automated 5-axis CNC machining and die-sink EDM cell, complete with System 3R WorkMaster robot. A Röders RXP500DS high speed milling machine for graphite machining (supplied by Hurco Europe – 01494 442222) and a Hyperspark Exact die sink EDM from Agie Charmilles (02476 538666) are served by the WorkMaster, which loads workpieces on to both machines. Over Christmas 2012, the cell ran unattended for 112 hours at a time, ensuring no interruption to customer deliveries. Agie Charmilles, in fact, celebrated its 60-year anniversary in 2012, along the way claiming some impressive leaps in technology. For instance, in the past 12 years, the company says it has reduced form tolerance in wire EDM by 50%, reduced surface roughness by 66% and decreased internal radii by 40%. On the die-sink side, it has reduced the spark gap from 20 to 5 micron, decreased surface roughness by 75%, achieved a 75% reduction in internal radii, and virtually eliminated wear on copper and graphite electrodes. Among the latest to benefit is Portsmouth-based subcontractor Di-Spark, which has recently acquired three new Agie Charmilles machines – two CUT 300 wire EDM models and a FORM 2000 die-sink EDM with integrated System 3R WorkPartner. Says managing director David Light: "Our existing wire EDM machines, while still performing satisfactorily, had a finite capacity. Owing to us winning new contracts and having existing contracts extended, we needed to address the situation." The large capacity FORM 2000 is one of Agie Charmilles' most advanced and most productive spark erosion machines. It is equipped with IQ 'Zero Electrode Wear' technology, an integrated workpiece pallet changer and automatic (electrode) tool changer, and Vision 5 control. Di-Spark operates the technology as a self-contained manufacturing cell for an aerospace OEM customer. The cell also features a 5-axis milling machine and a wire EDM. The aerospace industry was again the impetus for an order completed recently by EDM Plus (02476 678888), which was able to deliver CHMER AH53C and AH64C machines with extended W-axis movement. The subcontract customer required full CNC component manipulation, able to accommodate complex component geometry. As a result, EDM Plus added a CNC tilt and turn table to the machines. The first CHMER machine was installed in July 2012 and trials were conducted immediately, with samples submitted for laboratory pass-off. The parts produced exceeded the inspection criteria and were subsequently sent to the client for their approval, which has since been received. Of course, not all applications in this technology area are wire- or die-sink-based. In what is believed to be a UK-first, a recently installed Sodick EBM (Electron Beam Machine) at the University of Nottingham's Precision Manufacturing Centre (PMC) is now available as a subcontract resource for manufacturers looking to enhance or alter the surface properties of machined components. Sodick's EBM is based on new polishing technology that re-melts the surface of machined metal to achieve high speed, mirror-smooth surfaces in a short period of time. The technology can be used to enhance or change surface properties to provide, for instance, greater wear/friction resistance, better corrosion protection and/or water repellence, or the ability to stay clean for longer. Elsewhere, Huddersfield-based VTL Group has seen the first UK installation of a PEMTec Electro Chemical Machining (ECM) system from Ellesco (01202 499400). The ECM process works by dissolving excess material, utilising the principle of anodic solution of the workpiece in an electrically conductive medium (electrolyte). Of particular interest to VTL is the potential for cycle time reduction by using PECM on certain automotive components. Time is saved by the fact that roughing, smoothing and polishing operations are carried out in the same cycle, and the finished component is completely free of burrs, eliminating any secondary operations. Feed rates up to 2 mm/min can be achieved, depending on the material being processed. Box item Inspired by wire Mitsubishi EDM's next generation of MV Series wire cut machines, which are available in the UK from HK Technologies (01788 577288), feature a host of engineering improvements, many of which are claimed to be industry firsts. Arguably the most significant is the cylindrical drive technology, which Mitsubishi says removes many of the pitfalls associated with linear drive motors. At the core of this breakthrough are innovative tubular shaft motors that are deployed to move a number of axes. These motors prevent 'cogging' and ensure smooth and controllable movements. The new design also prevents other issues that Mitsubishi EDM says are associated with traditional linear drive systems, which trap heat behind the iron back-plate on the magnetic mount. This can cause geometric issues or lead to high electricity consumption, due to cooling requirements. Furthermore, there can be problems aligning the linear drive motors together on the driveways without generating a 'crabbing' effect. According to Makino, speed is the decisive factor in wire EDM. In just three passes, the company says that its new U3 model achieves a surface finish quality (Ra 0.4, at a cutting height of 100 mm) that other machines can only attain in four (www.machinery.co.uk/45251). Available in the UK from NCMT (0208 398 4277), Makino's new HyperCut technology claims to shorten machining times, reduce wire and power consumption, and prolong the service life of the energising plate and filter. Also new to the UK is the range of wire EDMs from Excetek Technologies – available from Warwick Machine Tools (01676 533073). Excetek develops much of its technology in-house, including the software and CNC. Programming can be done using standard ISO G-code or Excetek's Icon Assistant conversational software, which uses the control's database of cutting technologies. The automatic wire feed and threading system is also produced in-house. First published in Machinery, January 2013