Milling is one of most important machining operations
which employ a multipoint cutting tool is called milling
Milling is the process of machining using rotary cutters to
remove material by advancing a cutter into a work piece.
This may be done varying direction on one or several axes,
cutter head speed, and pressure.
Types of milling Machines
Column and Knee type
a) Hand milling Machine
b) Plain (horizontal) Milling Machine
c) Universal Milling Machine
d) Omniversal Milling Machine
e) Vertical Milling Machine
Fixed bed type Milling Machine
Planer type Milling Machine
Special purpose machines
a) Rotary table milling machine
b) Planetary milling machine
c) Cam milling machine
d) Profile milling machine
Size of Milling Machine
The sizes of working surface of the table
The maximum length of longitudinal, cross and vertical
travel of the table.
The power of driving motor
Number of feeds
Floor space required
HORIZONTAL MILLING MACHINE
In milling operation the metal is removed from the
work piece by rotating milling cutter
In horizontal milling machine the axis of milling
cutter is parallel to the surface of work piece.
The work piece mounted on a table can be removed
in three directions at right angles to each other.
a) longitudinal direction to provide length of cut
b) Vertical direction to provide depth of cut
c) Transverse direction to provide width of cut
In normal operation the machine is operated in
only one direction at a time.
The main parts of horizontal milling machine are:
The work table
The over arm
Base: The base is a grey cast iron which supports the
column at its one end.
Column: It is a large mounted vertically on the base. On
the front of the column guide ways are provided to support
the knee. A dovetail slide is also provided on the top to the
hold an over arm.
Saddle: The saddle is moved horizontally towards or away
from the face of the column by turning the cross feed.
Worktable: The work table provides the longitudinal
movement to the work by hand. The table is provided with
T-slots for direct mounting of the work pieces.
Over arm: The over arm is located in the sideway at the
top of the column.
Arbor support: the arbor support is positioned on the
under side of the over arm. It provides support for the
Spindle: The machine spindle is located in the upper
part of the column and receives power from the motor
through belts, gears and clutches.
Arbor: it is fixed in the taper of the spindle nose. It
locates the cutters in position, and is driven by the
HAND MILLING MACHINE
In Hand milling machine the cutter is mounted on a
horizontal arbor and is rotated by power. The work
mounted on table is fed manually against the cutter.
It is used for simple milling operations such as cutting
grooves, short key-ways and slotting.
PLAIN MILLING MACHINE
The plain milling machine with horizontal spindle is
called horizontal milling machine. The work fitted on
the table may be fed in three directions, longitudinal,
transverse, and vertical. The table movements are
provided by hand or power.
UNIVERSAL MILLING MACHINE
It is similar to a plain milling machine and differs in
respect of the table movements. It is capable of
handling a very wide range of jobs.
VERTICAL MILLING MACHINES
In vertical knee type milling machines, the position of the
cutter spindle is vertical. Though it has the same table
movements as in plain milling cutter, the spindle head
swivel . The tool head is attached to the end of the ram