Tailstock

The tailstock is a movable support unit on a lathe, located opposite the headstock. Its primary function is to support the free end of the workpiece during turning, preventing deflection, chatter, and sagging, especially when the length-to-diameter ratio exceeds 3:1. It can also hold tooling like centers, drills, taps, and reamers for axial operations from the tailstock end.

In practical CNC machining, the tailstock is used to support long or slender workpieces during turning, preventing deflection, vibration, and chatter. The machinist advances the tailstock along the bed until the quill contacts the part, then locks it in place on the spindle axis. Alignment must be precise—vertical and horizontal—to avoid taper and tool damage. Clamping pressure is adjusted based on material and cut: excessive force can distort thin-wall parts, while insufficient force allows the free end to wobble. On production runs, programmable tailstocks move to preset positions and apply controlled pressure automatically, cutting setup time and ensuring consistency. Common applications include center-to-center turning of shafts, rollers, and barrels, and hole-making operations where drills, taps, or reamers are held in the quill while the workpiece rotates. This axial support improves roundness, straightness, and surface finish, especially on parts with length-to-diameter ratios above 3:1. Even in woodturning, tailstock use reduces chatter and out-of-round defects.