Mill-turn centre counters threat from Eastern Europe

Citation

(2007), "Mill-turn centre counters threat from Eastern Europe", Aircraft Engineering and Aerospace Technology, Vol. 79 No. 6. https://doi.org/10.1108/aeat.2007.12779fab.014

Mill-turn centre counters threat from Eastern Europe

Mill-turn centre counters threat from Eastern Europe

The purchase by Surrey subcontractor, T&G Engineering, of an Okuma B-axis mill-turn centre in April 2007 was, according to director Peter Huntley, a direct result of downward pressure on prices mainly due to fierce competition from Romania and the Czech Republic.

He stated what most people in manufacturing today already know – that it is essential to produce components in one hit rather than in two or three operations, as it is the only way to quote competitive rates and still make a reasonable margin.

“Our prices are comparable with those of other western European subcontractors, so we rarely lose out to those countries,” commented Mr Huntley.

“In our experience, the old Eastern- bloc countries are the real threat at the moment. They can produce reasonable quality parts at low prices, so subcontractors like us in the UK are having to invest in multi-function, multi-axis CMC plant to help level the playing field”.

At the time he was interviewed, T&G had only produced a handful of components on its new, 7-axis Okuma Multus B300-W, supplied by UK agent, NCMT (Figures 7-9). It has 15kW of main- and opposed-spindle power and an 11kW, 225-degree B-axis milling spindle that performs both the prismatic metal cutting and, when locked in position, the turning operations as well. Automatic exchange of HSK A- 63 tools is from a 20-station magazine outside the machining area.

Figure 7 The 7-axis Okuma Multus B300-W mill-turn centre in use at T&G Engineering, West Byfleet

Figure 8 The machining area of the Multus B300-W

Figure 9 The first components machined by T&G on its Multus B300-W

Production of one recent component was ideally suited to the machine's capabilities, as the part included an off-centre slot that needed the ^80mm Y-axis movement of the milling spindle to machine it to the required 102m total tolerance. To produce the component on T & G's other machines would have required three operations, despite many of the other eight lathes on site (all Okumas) having driven tool capability.

“It is early days, but I would say that the Multus is cutting floor-to-floor time by around 15 per cent for this type of component up to the machine's capacity – 630mm diameter by 900mm long,” advised Mr Huntley.

A wide range of materials is machined at T & G's West Byfleet factory, from aluminium and brass to titanium and high-grade tool steels including those made from powder alloys, such as Vanadis 6. Tight-tolerance machining of tooling for the can making industry is a particular specialism. Other industries regularly served include aerospace, F1, and the connector and fibre optic sectors.

The company now has on order another Okuma lathe – a Space Turn LB3000 – specifically to replace grinding with hard-turning of tool steel parts up to 63 Re and of carbide components in excess of 70 Re. It will double the company's hard-turning capacity and lead to economies by allowing one operator to man both machines for a majority of the time.

Programming of new parts at T & G is mainly off-line, using a Unigraphics CAD/CAM system working from customers' electronic data. Post- processed programs are downloaded directly to the machines on the shop floor.

For repeat work, the operator normally calls up the program directly from the OSP-P200 control fitted to the Multus B300-W. It runs the Okuma operating system and also Windows XP, allowing Excel files to display machining instructions, tooling, offsets and cycle time.

Another feature of the control is comprehensive collision prediction and avoidance software that monitors in real time the position of the spindle, tool holder and tool relative not only to the work piece and fixture, but also to the entire machining area.

Details available from: NCMT Limited; Tel: +44 (0) 2083 984277; Fax: +44 (0) 2083 983631; E-mail: daveburlev@ncmt.co.uk