Tc 9-524 fundamentals of machine tools

ANGULAR MILLING
General
Angular milling, or angle milling, is milling flat surfaces
which are neither parallel nor perpendicular to the axis of the
milling cutter. A single angle milling cutter is used for angular
surfaces, such as chamfers, serration’s, and grooves.
Milling dovetails (Figure 8-28) is a typical example of angular
milling.
each completed cut.
Setup
A typical setup for plain milling is illustrated in Figure 8-27.
Note that the milling cutter is positioned on the arbor with
sleeves so that it is as close as practical to the milling machine
spindle while maintaining sufficient clearance between the
vise and the milling machine column. This practice reduces
torque in the arbor and permits more rigid support for the
cutter.
8-22
Milling Dovetails
When milling dovetails, the usual angle of the cutter is 45°,
50°, 55°, or 60° based on common dovetail designs.
When cutting dovetails on the milling machine, the
workpiece may be held in a vise, clamped to the table, or
clamped to an angle plate. The tongue or groove is first
roughed out using a side milling cutter, after which the
angular sides and base are finished with an angle milling
cutter.
In general practice, the dovetail is laid out on the workpiece
surface before the milling operation is started. To do this, the
required outline should be inscribed and the line prick-
punched. These lines and punch marks may then be used as a
guide during the cutting operation.
STRADDLE MILLING
When two or more parallel vertical surfaces are machined at
a single cut, the operation is called straddle milling. Straddle
milling is accomplished by mounting two side milling cutters
on the same arbor, set apart at an exact spacing. Two sides of
the workpiece are machined simultaneously and final width
dimensions are exactly controlled.

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