True grit technology

Arguably the biggest news arrived late last year when NCMT (020 8398 4277), Makino's agent in the UK and Ireland, announced that a cell based on a robot-fed Makino machining centre configured for VIPER grinding had been installed at Trac Group's Crewe facility, following the award of a long-term contract to produce four types of large nickel-alloy turbine vane for a European power generation company. Image: Trac Group's Makino VIPER installation NCMT undertook turnkey responsibility for the supply of a Makino A99e machining centre and the process for producing the vanes. Included in the package were programs, grinding wheels, workpiece fixtures and a Fanuc M-900/A 6-axis robot for exchanging fixtured components automatically. According to Craig Barnes, the engineer in charge of the A99e cell, conventional grinders are slow to set up for a new job and tend to suffer from coolant leaks, valve problems and other issues, such as frequent alarm messages. It is claimed that none of these shortcomings applies to the VIPER process on Makino platforms. Trac is now migrating its existing blade and vane work across from conventional grinders to the Makino machines. The trend of automated grinding continues with a success story from Studer (+41 33 439 1111), which recently announced that it had passed the milestone of 100 grinding systems sold with the company's easyLoad handling system. The hundredth unit went to Josef Rees GmbH & Co KG of Wehingen, Germany – a sub-contract precision machine shop. The easyLoad system can be combined with Studer machine types S21, S31, S36, S40, and covers workpieces between 20 and 300 mm in length. Adjustable conveyor belts or easily interchangeable pallets account for high flexibility, while keeping set-up times short. Studer is currently further developing the easyLoad concept, so that additional machine types can be equipped for an increased workpiece spectrum. Another prominent manufacturer of grinding machines announcing sales success is Jones & Shipman (0116 201 3000), which says it has now sold a number of its recently introduced Ultragrind CNC cylindrical grinding machines – the first of which went to a precision component manufacturer, based in France. MODULAR WHEELHEAD UltraGrind features a new modular wheelhead design that not only offers multiple wheel spindles configured to suit customer requirements, but also provides more power, more accuracy and increased component weight handling. There is also a high degree of modularity in the way the machine can be configured from build, allowing customer- specific machines to be manufactured quickly and easily. "We have already received a number of orders for the UltraGrind, including one for two machines from a premium sub-contractor to the aerospace industry," says Mike Duignan, sales and marketing director. Another UK grinding machine specialist, Curtis Machine Tools (01206 230032), has received an order from Germany for two cells to manufacture turbocharger shafts. The cells will each include two CMT Vector twin-spindle cylindrical grinding machines, a burnisher, and units for deburring, superfinishing and washing, as well as incorporating a laser-based final inspection system. Gear grinding also continues to flourish, as Hemel Hempstead's Micro Precision Gear Technology, can testify, following its acquisition of a Hoefler Promat 400 gear grinder from Micronz (01352 758840). Supplying gears to the aerospace, medical and motorsport sectors, the machine was bought in response to the growing levels of customer demand for non-helical forms and spur gears. "Besides removing a potential, non-helical gear production bottleneck, our new Hoefler gear grinder has enabled us to offer a range of smaller gears between the sizes of 25-175 mm, opening up a lucrative new market for our output," explains the company's managing director, Terry Grubb. Image: Micro Precision Gear Technology's Hoeffler Major vendors in the tool and cutter grinder arena are also reporting good sales levels. Korber Schleifring UK (01926 485047), for example, says that Cajero's investment in its machine tools now tops £1 million over the course of the past four years. Cajero has to satisfy customer activity within the aerospace industry, particularly with clients whose constant quest is to harness the advantages of composites and who 'invent' new materials. "This has meant that almost 40 per cent of our business revolves around tool development projects," says Phil Harding, managing director. Playing the key role at the Isle of Sheppey site is a trio of Walter Helitronic Power multi-axis CNC tool grinders and a Walter Helicheck 4-axis, non-contact measuring centre, all supplied by Korber Schleifring UK. The Walter Helitronics are also used to grind ultrasonic knives for tape laying machines that cut glass fibre, Kevlar and carbon fibre, as well as for regrinding button bit drilling tools for rock mining. Cajero's latest Helitronic Power is fitted with a disc-loader pallet system that can accept 40, 56 or 90 tools for processing in a fully automatic cycle. Also part of the Korber Schleifring group is Ewag, which has just announced the launch of its Compact Line CNC grinding machine, designed for the manufacturing or sharpening of indexable inserts in all materials. The Compact Line features an integrated robot system, with everything inside the machine positioned close to the working B-axis; the travel ranges for axes and robots are therefore kept to a minimum, cycle and downtimes are shortened, and productivity is, therefore, increased. Elsewhere, Anca (024 7644 7000) is promoting its MX7 tool and cutter grinder, which can manufacture a variety of tools up to 16 mm in diameter. The inclusion of a standard wheel pack changer on this production machine increases the machine's throughput and flexibility, enabling a 10 second wheel-change time. Box item Blohm Jung raises its profile Changes in the profile achieved when grinding are often attributed to the wheel losing profile. However, this can be from plain diamond wear and is often seen as a slow deterioration in profile. Here, the diamond can wear unevenly, giving an unusual profile, and this is where the Blohm Jung GEOID system, available in the UK from JRA Bennett (01455 250400), comes into its own. According to Blohm Jung, even new dressing tools can have a deviation of a few microns. Additional deviations also occur from abrasion during the dressing process. No matter how small the deviation, the profile geometry of the grinding wheel is directly affected and thus also the workpiece. GEOID compensates automatically for any error on cutting radius. The advantages of GEOID are obvious. Errors in cutting geometry and abrasion are readily detected and compensated at the least deviation. As a result, diamonds with slight abrasion that had to be sorted out in the past can now be used for much longer. Even at 30 micron tool abrasion, profile accuracy of < 5 micron can be achieved. First published in Machinery, Feb 2010