LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
headstock transmit power from the drive shaft to the spindle through an
intermediate shaft. Use the speed-change levers to shift the sliding gears
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
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
(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.
(a) The primary purpose of the tailstock is to hold the dead center to
support one end of the work