X-axis accuracy in two axis machine tools

Abstract

A machine tool, comprising: a worktable assembly slidably carried by the machine frame for reciprocal movement along a work axis and which is configured to carry a workpiece. A worktool assembly is slidably carried by said machine frame for reciprocal movement along a worktool axis at a predetermined angle with respect to said work axis and so as to intersect same. A reference straight edge is carried by said worktable assembly and has a reference surface. Reference sensing means is carried by said machine frame for coaction with said reference straight edge reference surface, to measure reference spacing between said reference surface and said reference sensing means and to provide a reference output indictive of said reference spacing. Control means is provided to facilitate movement of said worktool towards and away from said work axis, which is responsive to said reference output to further facilitate worktool movement towards said work axis. The reference sensing means includes a fixed electrode that forms with said reference surface a capacitance gauge. The control means includes a look-up table storing information relative to initial dispositions of said reference surface and said reference sensing means, to provide an initial disposition output indicative thereof to further modify and facilitate worktool movement towards said work axis. The look-up table initial disposition output is indicative of the flatness of said reference surface.