Others
2022.12.20
A workpiece being bent by machining force or its own weight can be supported not only by a chuck but also by a tailstock equipped with a center from the opposite side.
Fig. 1 Tailstock position
The three typical types of tailstocks are explained below.
How to apply thrust to a workpiece (force of pressing the center against the workpiece) is different for each type.
Manual tailstock
The quill is moved in and out by turning the handle.
This type is used as standard in TAKISAWA’s manual lathes.
Fig. 2 Manual tailstock
Hydraulic tailstock
The quill is moved forward and backward by hydraulic pressure.
This type is used in many TAKISAWA NC lathes.
Fig. 3 Hydraulic tailstock
NC servo tailstock
The tailstock is moved by the servomotor.
Forward/backward positions and thrust are commandable in a program.
Fig. 4 NC servo tailstock
The tailstock is used with a center attached.
Fig. 5 Tailstock and center
The center attached to the tailstock needs to be selected according to the shape and weight of the workpiece, and the machining method.
The three typical types of centers are explained below.
Fixed center
・For large and heavy workpieces
・For machining with large cutting resistance
Fig. 6 Fixed center
Live center
・For small and lightweight workpieces
・For machining with small cutting resistance
・Incorporates a bearing and rotates together with a workpiece
⇒No friction at the core of the center
⇒Suppressing thermal distortion
Fig. 7 Live center
Umbrella live center
・For hollow workpieces
Fig. 8 Umbrella live center
The center angle is normally 60°. However, 75° or 90° type may be used for large and heavy workpieces.
Fig. 9 Center angle
How was that?
A tailstock, which is very helpful for machining a long workpiece, is one of the important components of a lathe. The shape of the center and quill thrust are also included in the conditions for good cutting.