The sizes of turning lathes are given as 10", 12", etc. These figures
denote the diameter, or size, of the largest piece of work that can be
turned on them. The measurement is taken from the center point of the
live center to the bed of the lathe (usually 5" or 6") and is one-half
the diameter of the entire circle. The length of a lathe is determined
by the length of a piece of work that can be turned. This measurement is
taken from the points of the live and dead centers when the tail stock
is drawn back the full extent of the lathe bed. Fig. 1 shows a turning
lathe with sixteen principal parts named. The student should learn the
names of these parts and familiarize himself with the particular
function of each.


CARE OF THE LATHE

The lathe should be oiled every day before starting. At the end of the
period the lathe should be brushed clean of all chips and shavings,
after which it should be rubbed off with a piece of waste or cloth to
remove all surplus oil. All tools should be wiped clean and put in their
proper places. If a student finds that his lathe is not running as it
should, he should first call the attention of the instructor to that
fact before attempting to adjust it; and then only such adjustments
should be made as the instructor directs.


SPEED OF THE LATHE

The speed of the lathe should range from 2400 to 3000 revolutions per
minute when the belt is on the smallest step of the cone pulley. At this