US Patent 7845257 Ultra-precision machine tool

A five axis motion controlled ultra-precision machine tool is provided in which major portions are composed as a structure completely symmetric about the machining point and errors due to thermal displacement can be minimized. A pair of Y axis guide members (41,41) are secured to the top face of a base (i) at both sides of an X axis slider (3) interposed therebetween for X direction so as to movably guide Y axis sliders (4,4) in horizontal Y direction perpendicular to X axis. Y axis linear motors (42,42) and the Y axis guide members (41,41) are disposed substantially at the center of mass of the Y axis sliders (4,4) respectively, so that the Y axis sliders (4,4) can be driven in Y direction with vibration and errors in alignment minimized.