There are many reasons for the taper of the cylindrical surface of the turning, sometimes due to the poor positional accuracy of the spindle axis of the headstock relative to the bed rail. In the case of no-quantity and inspection tools, the following emergency methods can be used to solve the problem temporarily. When a positive cone appears on the outer cylindrical surface of the turning (ie, the end of the chuck is large), as shown in the figure, use the diagonal horn (or adjustable horn) 7 and 8 below the bed to raise the A of the lathe. Corner, and use 3, 4