Tailstock

Lathe Operations
Page Navigation
11

on the drive shaft and the intermediate shaft to line up the gears in

different combinations. This produces the gear ratios needed to obtain the

various spindle speeds. Note that the back gear lever has a high and low

speed for each combination of the other gears.

(d) The headstock casing is filled with oil to lubricate the gears and

the shifting mechanism contained within it. The parts not immersed in the

oil are lubricated by either the splash produced by the revolving gears or

by an oil pump. Be sure to keep the oil to the full level as indicated on

the oil gage, and drain and replace the oil when it becomes dirty or gummy.

(e) The headstock spindle is the main rotating element of the lathe and

is directly connected to the workpiece which revolves with it. The spindle

is supported in bearings at each end of the headstock through which it

projects.

The section of the spindle between the bearings carries the

pulleys or gears that turn the spindle. The nose of the spindle holds the

driving plate, the faceplate, or a chuck. The spindle is hollow throughout

its length so that bars or rods can be passed through it from the left and

held in a chuck at the nose. The chuck end of the spindle is bored to a

Morse taper to receive the solid center.

The hollow spindle also permits

the use of the draw-in collet chuck (to be discussed later in this lesson).

At the other end of the spindle is the gear by which the spindle drives the

feed and the screw-cutting mechanism through a gear train located on the

left end of the lathe.

A collar is used to adjust the end play of the

spindle.

(f) The spindle is subjected to considerable torque because it drives

the work against the resistance of the cutting tool, as well as driving the

carriage that feeds the tool into the work.

Because of the torque and

pressure applied to the spindle, adequate lubrication and accurately

adjusted bearings are absolutely necessary.

(4) Tailstock.

(a) The primary purpose of the tailstock is to hold the dead center to

support one end of the work