XYZ Machine Tools delivers 2op portable VMC for reconfigurable cells; maximises spindle up-time and labour productivity

Cellular manufacturing, where a single operator can load/unload and monitor several machines simultaneously, maximises the number of minutes spindles are running and reduces labour costs. (Note: Video shows the machine in its Southwestern Industries guise - XYZ Machine Tools is owned by Southwestern Industries, which is also the originator of the ProtoTRAK control system) However, for smaller subcontractors, cellular manufacturing tends to be impractical. The result is that components get made across several machining operations on a variety of machines dotted around the factory. The answer is XYZ Machine Tools' 2op, portable CNC machining centre. "For smaller businesses, the logistics of moving parts around a factory becomes a problem, while quality control is also an issue, due to the potential of damage to machined surfaces as they are transported around a factory," says Nigel Atherton, managing director, XYZ Machine Tools. "Additionally, maintaining production control requires that each job has to be planned, scheduled, set-up, and monitored across all of these machines. All of which adds time and cost. The biggest cost factor is the fact that each machine has its own operator who sometimes has no option other than to stand idly by while the cycle completes. A case of the tail wagging the dog, as expensive labour is watching a relatively inexpensive spindle turning, resulting in an adverse ratio of spindle minutes to labour minutes." In developing the XYZ 2op, which comes with its own pallet truck to support easy relocation, XYZ Machine Tools has addressed the need for additional capacity for operations such as datum face machining, while maintaining the flexibility that subcontractors need on a day-to-day basis. Previously, subcontractors were faced with two choices: either to perform these primary/secondary operations on the same machine used for main production; or use an old manual machine tucked in the corner of the factory. The first option reduces the machine hours for more productive, value-added work, while the latter is labour intensive and adds risk to process security. Single or three-phase powered, the compact XYZ 2op has a footprint of just 1,219 by 762 mm and weighs in at just 1,000 kg, and comes with its own pallet truck, so can be moved as required. "Having the ability to locate a machine where you need it, when you need it, freeing up spindle time on more expensive machines, while making full use of the available skills and manpower, is a major advantage in the competitive world of subcontract machining," Mr Atherton stresses. In addition to filling the need for pre- and secondary operations, the XYZ 2op can also carry out more complex light machining operations. Equipped with a 5000 rpm, 3 hp spindle, it has an 8-position toolchanger and axis travels of 355, 305 and 431 mm in X, Y and Z, respectively. Control is provided by the easy-to-use ProtoTRAK TMX CNC unit that provides simultaneous three-axis movement. Workpieces and fixtures can be accurately and securely held in place through use of the Jergens Ball Lock system or users can employ the four tee slots. Says Mr Atherton: "The compact and portable nature of the XYZ 2op means that users can organise their main machine tools to leave just enough space to slot in this portable machine as and where it is needed. This additional capacity will help to maximise productivity and the option is there to add extra machines to balance any spare time that operators may have and balance it against the longest cycle time. This ability to reposition a machine tool simply by unplugging it also works to reduce capital costs, as fewer machines are needed. And every minute that the spindle is running, whether performing pre- or secondary operations, or fully machining components, those parts are virtually free of charge, as the operator could have been stood idle otherwise. "If you amortise the cost of a typical machine tool over seven years, the hourly rate for that machine is probably in the region of £4 -£6 per hour, an operator on the other hand will be costing £24 per hour, typically, with all the costs of employing him taken into account. Therefore, by spreading the operator's costs over more spindles dramatically reduces the labour content per component and, therefore, has an immediate impact on the profitability of his employer. A second benefit of this strategy is that fewer machinists are required for any given level of work - a major factor, given the shortage of quality skilled people. Thirdly, by freeing up availability of more expensive machine tools there is less pressure to add similar capacity, reducing capital expenditure along the way."