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MILLING MACHINE PPT 2: PARTS AND CLASSIFICATION OF MILLING MACHINES
1. LENDI INSTITUTE OF ENGINEERING
AND TECHNOLOGY
METAL CUTTING AND MACHINE TOOLS
COURSE CODE: C302
REGULATION: R16
3rd BTECH 1st SEM
PREPARED BY :
POLAYYA CHINTADA M.TECH,M.B.A,(PhD)
ASSISTANT PROFESSOR
TOPIC:
MILLING MACHINES
2. PARTS OF MILLINGMACHINES:
2
1. Base
ā¢It is a foundation member and it carries the column at its one end.
ā¢In some machines, the base is hollow and serves as a reservoir for cutting fluid.
2. Column
ā¢The column is the main supporting member mounted vertically on the base.
ā¢ It is box-shaped, heavily ribbed inside and houses all the driving mechanism for the spindle
and table feed.
ā¢The front vertical face of the column is accurately machined and is provided with a dovetail
guide way for supporting the knee.
3. Knee
ā¢The knee is a rigid grey iron casting which slides up and down on the vertical ways of the
column face.
ā¢ An elevating screw mounted on the base is used to adjust the height of the knee and it also
supports the knee.
4. Saddle
ā¢The saddle is placed on the top of the knee and it slides on guide ways set exactly at 90Ā° to
the column face.
ā¢The top of the saddle provides guide-ways for the table.
5. Table
ā¢The table rests on ways on the saddle and travels longitudinally.
ā¢A lead screw under the table engages a nut on the saddle to move the table horizontally by
hand or power.
ā¢In universal machines, the table may also be swiveled horizontally. For this purpose the
table is mounted on a circular base.
ā¢The top of the table is accurately finished and T -slots are provided for clamping the work
and other fixtures on it
3. PARTS OF MILLINGMACHINES:
3
6.Overhanging arm
It is mounted on the top of the column, which extends beyond the column face and serves
as a bearing support for the other end of the arbor.
7. Front brace
It is an extra support, which is fitted between the knee and the over-arm to ensure further
rigidity to the arbor and the knee.
8. Spindle
It is situated in the upper part of the column and receives power from the motor through
belts, gears, and clutches and transmit it to the arbor.
9. Arbor
It is like an extension of the machine spindle on which milling cutters are securely mounted
and rotated. The arbors are made with taper shanks for proper alignment with the machine
spindles having taper holes at their nose.
The arbor assembly consists of the following components.
1. Arbor
2. Spindle
3. Spacing collars
4. Bearing bush
5. Cutter
6. Draw bolt
7. Locknut
8. Key block
9. Set screw
4. CLASSIFICATIONOF MILLINGMACHINES:
4
Column and Knee Type Milling Machine
(a) Hand Milling Machines
(b) HORIZONTAL milling machine
(b) Vertical milling machine
(c) Universal milling machine
(d) Omniversal milling machine
Fixed Bed Type Milling Machine
(a) Simplex milling
(b) Duplex milling
(c) Triplex milling
(d) Rise and Fall type
Planner Type Milling Machine
Special purpose Milling Machine
a. Thread milling machine
b. Gear milling machine
c. Cam milling machine
d. Skin milling machine
e. Spar milling machine
f. Double end milling machine
Production type Milling Machine
(a) Rotary table milling
(b) Drum milling
(c) Tracer controlled milling
5. Column& knee type OF MILLINGMACHINES :
5
HORIZONTAL MILLING MACHINE
ā¢The horizontal milling machine has a
spindle that is parallel to the shop floor
and an over arm that extends over the
Work piece.
ā¢ The over arm supports the arbor, which
holds the milling cutter.
ā¢ On the horizontal mill, the arbor is the
component that rotates the milling cutter
7. 7
VERTICAL MILLING MACHINE
Spindle is vertical or perpendicular to the work
table.
It has all the movements of the table for proper
setting and feeding the work.
Spindle head may be swiveled at an angle,
permitting the milling cutter mounted on the spindle
to work on angular surfaces.
In some machines, spindle can also be adjusted
up or down relative to the work.
Adopted for machining grooves, slots and flat
surfaces.
ļ±Cutter is directly mounted in the spindle.
used for face and end milling operations
Column& knee type OF MILLINGMACHINES :
8. 8
Universal MILLING MACHINE
ļ±A universal milling machine is named so as it is used to do a
large variety of operations.
ļ± this milling machine is it table which is mounted on a circular
swiveling base which has degree graduations.
ļ±The table can be swiveled to any angle up to 45 degrees on
either side of normal position.
ļ± Helical milling operation is possible on universal milling
machine as its table can be fed to cutter at an angle.
ļ± Provision of large number of auxiliaries like dividing head,
vertical milling attachments, rotary table, etc. make it suitable for
wide variety of operations.
Column& knee type OF MILLINGMACHINES:
9. 9
Omni versal MILLING MACHINE
ļ± Omni-versal milling machine is like a universal milling
machine with additional feature that its table can be tilted in a
vertical plane by providing a swivel arrangement at the knee.
ļ±This enables it to make taper spiral grooves in reamers, bevel
gears, etc.
ļ±Used for tool room applications.
ļ±In additional to the movement of the universal milling
machine, its knee can be swiveled in a horizontal plane.
ļ± Suitable for cutting spiral grooves on angular jobs
ļ±Here the table also has four movements of the universal
milling machine. It can also be tilted in a vertical plane by
providing a swivel arrangement at the knee.
Column& knee type OF MILLINGMACHINES:
10. Fixedbed type MILLINGMACHINES:
10
Simplex head MILLING MACHINE
ļ± It is also known as manufacturing type milling machine.
ļ±Larger and more robust than column and knee type milling
machines.
ļ±Its table is mounted directly on the ways of fixed bed. Used
for tool room applications.
ļ±Table movement is restricted to reciprocation only. Cutter is
mounted on the spindle head which can move vertically on the
column. Suitable for cutting spiral grooves on angular jobs
ļ±Used for heavy production work.
13. PLANNERtype MILLINGMACHINES:
13
ļ± It is a heavy duty milling machine.
ļ± It consist of four spindles each with its own drive motor.
ļ± Table movement provides the feed.
ļ± Used where high MRR is the prime Concern.
ļ± it has a cross rail capable of being raised or lowered carrying the cutters, their
heads, and the saddles, all supported by rigid uprights.
ļ± There may be a number of independent spindles carrying cutters on the rail as
two heads on the uprights.
ļ± The use of the machine is limited to production work only and is considered
ultimate in metal re-moving capacity
14. PRODUCTIONtype MILLINGMACHINES:
14
DRUM TYPE MILLING MACHINE
ļ± It is a heavy duty production milling machine
ļ±It consist of two vertical columns mounted on sturdy base
ļ±Drum is mounted between the columns for holding the work
piece
ļ±Milling heads are mounted vertical columns, carrying
horizontal spindles and they are adjustable
ļ±All cutters in the spindle are face cutters, 2 are finishing
cutters and 2 more finishing cutters
ļ±Drum rotates continuously, work mounted on fixtures on the
rear side of the machine
ļ±First rough machining done at upper cutter and finishing
done at bottom cutter