Mitsui Seiki profiles micron accuracy and repeatability

The Mitsui Seiki product range is supplied and serviced in the UK by 2D CNC Machinery based in Hinckley with this 3-axis CNC (‘Mother Machine’) designated vertical jig mill type developed for processing highly demanding workpieces typical of optical, medical, aerospace and specialist mould and die sectors.

Capacity in X-axis is 1,200mm, Y 800mm and Z 500mm with a table working area of 1,200 mm by 800 mm. The mechanical design focus was on the planer-style symmetric construction to maximise rigidity to achieve super high-grade tolerance levels based on hardened and ground tool steel slideways. The machine also incorporates Mitsui Seiki’s latest ‘sliding mechanism’ development where contact slideway elements, not only to enhance levels of acceleration, but also to minimise stick-slip which enables claims for the Z-axis having some six-times greater static rigidity than more conventional Z-axis machine tool designs.

A thermal compensation system reduces any influence of temperature change or temperature-generated displacement by 60% on workpiece accuracy due to integrated sensors housed on the machine faceplate and within the spindle. Further gains are made with the MAMS multi-sensor system on the Z-axis, which reduces thermal growth and deflection by 30 per cent. In addition, to help maintain stable rates of axis feed within 0.0001 mm that contributes to the holding of high orders of surface finish, a centralised cooling system is incorporated within the sideway lubrication as well as the core of each ballscrew to stabilise the precise operation of axis feeds.

The Mitsui Seiki PJ812 has direct drive spindle options of 50 taper, 30kW, 10,000rpm up to an 18kW, 30,000rpm with 40 taper. Rapid traverse rate is 24m/min. Control is by Fanuc 31iM-B and a 40-tool magazine is standard.

www.2DCNC.co.uk