A British-designed and built, heavy-duty chucking lathe, able to swing 2.5 tonne components in excess of one metre in diameter over the bed, has been added to the top end of the turning machine range built by the MHP division of Geo Kingsbury Machine Tools, Gosport. The first such machine, whose specification is described below, was delivered in March 2007 to a UK customer that prefers to remain anonymous.
Having a Meehanite cast iron, 45 degree construction, the 22 tonne MHP260/3000 has a 900mm turning diameter and can accommodate components up to three metres long between chuck and servo-driven, programmable tailstock, which features a hydraulic quill with 150 mm stroke.
The spindle is rated at 45 kW / 1,250 rpm and delivers 235 Nm of torque through a 1:4 ratio gearbox. Eight 60VDI tools are resident in the turret, all stations being powered by a 7.5 kW, 3,000 rpm motor. Control is by Siemens 840D CNC with integrated, double redundancy safety system and 'Shopturn' shop floor programming.
Each subsequent lathe will be built to order and can be tailored to the requirements of the user, including selection of the control. For example, the next machine has already been ordered and will have 1,100 mm swing over the bed, 1,000 mm turning diameter, 2,000 mm turning length, no tailstock and a 12-station, 60VDI turret.
Many different options may be selected including Heidenhain linear glass scales in X and Z for enhanced accuracy, a 3-roller steady rest for components ranging from 200 to 500 mm in diameter, a Renishaw infrared probe mounted in the turret for component measurement, vacuum chucking and interface, and hydraulic power chuck.