MILLING MACHINE OPERATIONS - OD1644 - LESSON 1/TASK 1
(10)
Use a recommended cutting oil liberally.
(11)
Keep chips away from the workpiece; brush them out of the way by any
convenient means, but do not do so by hand or with waste.
(12)
Use good judgment and common sense in planning every job, and profit
by previous mistakes.
b.
Operations.
Milling operations may be classified under four general
headings as follows:
(1)
Face Milling - machining flat surfaces which are at right angles to
the axis of the cutter.
(2)
Plain or Slab Milling - machining flat surfaces which are parallel to
the axis of the cutter.
(3)
Angular Milling - machining flat surfaces which are at an inclination
to the axis of the cutter.
(4)
Form Milling - machining surfaces having an irregular outline.
c.
Speeds For Milling Cutters.
(1)
General. The speed of a milling cutter is the distance in feet per
minute that each tooth travels as it cuts its chips. The number of spindle
revolutions per minute necessary to give a desired peripheral speed on the
size of the milling cutter.
The best speed is determined by the type of
material being cut and the size and type of cutter used. The smoothness of
the finish desired and the power available are other factors relating to the
cutter speed.
(2)
Selecting Proper Cutting Speed.
(a)
The approximate values given in table 1 on the following page may be
used as a guide for selecting the proper cutting speed.
If the operator
finds that the machine, the milling cutter, or the workpiece cannot be
handled suitably at these speeds, immediate readjustment should be made.
(b)
Table 1 lists speeds for high-speed steel milling cutters.
If
carbon steel cutters are used,
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