(1) The workpiece rotates and the tool makes a feeding motion. Most of the holes are bored on lathes in this way. The roundness of the hole mainly depends on the rotary accuracy of the machine tool spindle, and the axial geometry error of the hole mainly depends on the position accuracy of the tool feed direction relative to the rotary axis of the workpiece. This boring method is suitable for machining holes with coaxiality requirements on the outer surface.
(2) Tool rotation and workpiece feeding motion The boring machine spindle drives the boring tool rotation and the table drives the workpiece feeding motion.
(3) Tool rotation and feed motion With this boring method, the overhang length of the boring bar varies, and so does the force deformation of the bar, with a large diameter near the spindle box and a small diameter away from the spindle box, forming a tapered hole. In addition, as the overhang of the boring bar increases, the bending deformation of the spindle due to its own weight increases, and the axis of the hole to be machined will be bent accordingly. This boring method is only suitable for short holes.
