The new Mitsui Seiki PJ812 vertical-spindle profiling centre is a three-axis CNC vertical jig mill engineered to perform high-accuracy contour machining and precise boring of components with critical tolerances.

Aimed at the mould and die, optical, aerospace and medical industries, this machine is being launched into the UK market by sole agent Hinckley-based 2D CNC Machinery Ltd (www.2dcnc.co.uk).

According to Mitsui Seiki, the PJ812 combines jig borer levels of positional accuracy (±1µm) with the ability to contour at ultra-high accuracy, thanks to the use of the Mitsui Accurate Milling Support thermal-growth monitoring system.

This minimises the influence of temperature changes on workpiece accuracy and cuts temperature-generated displacement by up to 60%, says the company Compared with previous-generation technologies, it can improve compensation for thermal growth and deflection in the Z axis by some 30%.

The machine features a level of static rigidity that is said to be some six-times greater than a conventional vertical machining centre, while further contributing to high accuracy is its planer-style symmetric construction with hardened and ground steel slideways, plus special contact elements designed to enhance acceleration.

Meanwhile, Mitsui Seiki’s latest development — a ‘sliding mechanism’ that reduces ‘stick-slip’ — helps to achieve axis-feed accuracy within 0.1µm. The PJ812 also has centralised ballscrew cooling systems that help to maintain precision when performing axial feeds.

The Mitsui Seiki PJ812 has a work envelope of 1,200 x 800 x 500mm, and the 1,200 x 800mm table can accommodate loads up to 1.5 tonnes. In addition, the choice of direct-drive spindles includes 50 taper 30kW 10,000rev/min and 40 taper 18kW 30,000rev/min variants.

Rapid-traverse rates are 24m/min, a 40-tool magazine is supplied as standard, and control is by Fanuc 31iM-B.