Machinery Repairman

to the table of the milling machine. The base of the
rotatable type is graduated in degrees. This feature
allows you to machine compound angles. The
toolmaker’s knee has a tilting surface with a built-in
protractor head graduated in degrees to set the table or
a vernier scale for more accurate settings.
CIRCULAR MILLING ATTACHMENT
The circular milling attachment, or rotary table
(fig. 7-11), is used to set up work that must be rotated
in a horizontal plane. The worktable is graduated
(1/2° to 360°) around its circumference. You can turn
the table by hand or by the table feed mechanism
through a gear train, as shown in figure 7-11. An 80
to 1 worm and gear drive contained in the rotary table
and index plate arrangement makes this device useful
for accurate indexing of horizontal surfaces.
INDEXING EQUIPMENT
Indexing equipment (fig. 7-12) is used to hold and
turn the workpiece so that a number of accurately
spaced cuts can be made (gear teeth for example).
Figure 7-11.—Circular milling attachment with power feed mechanism.
7-8