Abstract: A turning machine is provided for machining a workpiece with respect to a longitudinal axis (14) of the machine. The machine comprises a base (2), a headstock (10) and a tailstock (12) supported by the base for mounting respective ends of the workpiece (8) such that it is rotatable about said longitudinal axis, and a carriage (4) for carrying a tool (24) to engage with the io workpiece. The carriage is moveable parallel to said longitudinal axis along two guideways on the base, wherein the guideways are located in use on either side of and spaced horizontally from said longitudinal axis. The machine configuration seeks to reduce roll and/or pitch errors occurring as the carriage moves along the workpiece.

Abstract: A method of monitoring the wear of a grinding wheel measures the force exerted between the wheel and a workpiece, and generates a warning signal when the measured force exceeds a predetermined threshold value. A signal proportional to the normal grinding force is obtained by measuring the electrical power drawn by the wheelfeed drive motor during grinding. The value of the force proportional signal is compared with corresponding values obtained during the grinding of one or more preceding similar workpieces. Where the grinding wheel includes an annular ridge for grinding an undercut in a workpiece, the ridge portion of the wheel will normally perform more work than the remainder of the wheel, will be liable to the greatest wear, and the force signals will be measured while such portions of the wheel are performing work. The method may be used with electroplated CBN grinding wheels.

Abstract: In a method of grinding a component, a reduction in the finish grinding time is achieved by rotating the component through only a single revolution during a final grinding step and controlling the depth of cut and the component speed of rotation during that single revolution, so as to maintain a substantially constant specific metal removal rate during the final grinding step. The headstock velocity can vary between 2 and 20 rpm during a single revolution of the cam during the final grinding step. Using a grinding machine having 17.5 kw of available power for rotating the wheel, and cutting with a grinding wheel in the range 80–120 mm diameter typically the depth of cut lies in the range of 0.25 to 0.5 mm.