A Swiss lathe does not push the tool along the workpiece. It pushes the workpiece past the tool. That inversion is the whole invention. On a conventional lathe the bar is clamped in the chuck and the turret travels down its length, so the further the tool cuts from the jaws, the more the bar behaves like a diving board. Deflection under a given cutting force scales with the cube of unsupported length. Double the overhang and the part flexes eight times as much. Chatter follows. The Swiss solution is a sliding headstock and a guide bushing. The bar stock is gripped by a collet that slides on the Z axis, and it passes through a hardened bushing mounted a few millimetres from the cutting edge. The tool never moves along the bar. The bar feeds through the bushing into the tool, and the unsupported length at the point of cut stays at roughly one or two diameters no matter how long the finished component is. The consequences are considerable: - Slender parts with length to diameter ratio...