Toolmaker Moves Further Into 5-Axis Subcontract Machining

High Wycombe, UK - To fulfil an automotive contract, won against competition from an incumbent overseas supplier, to reverse engineer and machine a family of aluminium impellers, Waterford Tool has acquired a Roeders RFM600DS 5-axis vertical machining centre (VMC) from Hurco Europe, High Wycombe, the exclusive agent in Ireland and Britain for the German machine tool manufacturer. The VMC was supplied through Hurco's local Irish representative, Michael Gannon.

Despite its name, only 20 per cent of Waterford Tools' turnover is derived from tool and mould making these days, competition from China and Eastern Europe having eroded this side of the business over recent years. The concentration now is on front-end consultancy and design input followed by fast turnaround of plastic injection moulds, glass moulds and blister pack tooling for local customers in the south of Ireland. Precision subcontract machining accounts for 60 per cent of the business, and growing, the remainder being mechanical assembly and test.

Founded in 1973 by the present owner and Managing Director, Bill Curtin, the company is part of the Schivo group and employs more than 70 people in a 25,000 sq ft manufacturing facility on the IDA Industrial Park in Waterford city. Much work is done for the medical sector, while another specialism is the manufacture and supply of parts and assemblies for the laser-build market.

Waterford Tool learnt of the Roeders high-speed VMC range from Hurco when it installed one of its own VMX42 three-axis machining centres in July 2004. The contract machinist had been employing 3+2-axis machining on VMCs from other manufacturers for some years, mainly using 3-axis cutting with two axes positioned and fixed. Some fully interpolative, 5-axis work was undertaken, but it was cumbersome to program, slow in execution and limited in terms of the complexity of component that could be produced. It was certainly not suited to producing the impellers.

Consequently, the decision was made to invest in a purpose-built 5-axis machine with the capacity for exceptional high speed and accuracy. The Roeders RFM600D/S was installed during April 2005 in a temperature-controlled room at Waterford. According to Plant Manager, Jack Lyng, the Roeders was selected in preference to two other shortlisted machines, both Japanese, due to the excellent surface finish and superior accuracy – three to four microns total – achieved during trials on the German-built machining centre.

The seven tonne RFM600DS has a -2 / +92 degree swivelling trunnion carrying a 360 degree table. Thermal compensation is provided of the frame, ballscrew nuts and bearings, and a temperature sensor in the 14 kW / 42,000 rpm spindle compensates for growth, all of which allows for very high precision machining. It also means that the morning shift can start without the need for a warm-up period, maximising production.

The tool magazine holds 26 HSK-E40 cutters and laser-based tool measurement has been fitted. Roeders' own control system provides the requisite high speed processing of very large amounts of data.

Waterford Tool has invested in Open Mind's hyperMILL dedicated 5-axis CAM software to optimise the complex machining strategies, which in the case of the impellers are based on the customer's 3D component data, created in the Catia CAD environment, provided as STEP files and imported straight into a dedicated impeller CAM package.

The Hurco VMX42 was added to the general machine shop at Waterford to add up-to-date capacity and high metal removal capability for toolmaking as well as for production work in batches of typically 10- to 50-off. Touch probing is installed to speed setting of workpiece datums. Machine specification includes a working envelope of 1,066 x 610 x 610 mm, 10,000 rpm spindle, 40-station magazine for 40-taper tools and comprehensive swarf management.

The proprietary Ultimax control, which displays graphics on a second screen, allows both simple and relatively complex components to be programmed quickly at the machine, mainly from drawings. CAD data is supplied by some customers, which is conveniently downloaded in DXF format directly into the control.

SOURCE: Hurco Europe Ltd