M.P- II-UNIT III-SHAPER, MILLING AND BROACHING MACHINES.ppt

UNIT -3
SHAPER, MILLING AND
BROACHING MACHINES

SHAPER
Shaping is a process of machining a flat surface which
may be horizontal, vertical, inclined, concave or
convex using a reciprocating single point tool.
A shaping machine is a reciprocating type of machine
tool.

Main parts of a shaping machine
• Base
• Column
• Cross rail
• Saddle
• Table
• Ram
• Tool head

SHAPER SPECIFICATION
• Maximum length of stroke
• Maximum crosswise movement of the table
• Maximum vertical adjustment of the table
• Type of driving mechanism
• Power of the motor
• Available speed and feed
• Type of shaper-plain or universal
• Floor space required
• Total weight of the shaper
• Ratio of cutting stroke time and return stroke time

Types of shaping machine
• A. According to the type of driving mechanism
1. Crank type
2. Hydraulic type
3. Geared type
• B. According to the design of the table
1. Plain shaper
2. Heavy duty shaper
3. Standard shaper
4. Universal shaper
• C. According to the position and travel of ram
1. Horizontal shaper
2. Vertical shaper
• D. According to the type of cutting stroke
1. Push cut shaper
2. Draw cut shaper

OTHER SHAPERS
Crank type shaper
Crank and slotted link mechanism of a crank type shaper converts the rotation of an electric motor
into reciprocating movement of the ram. Though the lengths of both the forward and return strokes
are equal, the ram travels at a faster speed during return stroke. This quick return is incorporated in
almost all types of shaper.
Hydraulic shaper
The ram of a hydraulic shaper is connected to a piston. Oil at high pressure is pumped to the
cylinder of the hydraulic system. As the oil pushes the piston, the ram reciprocates. Hydraulic
shapers are high power machines and are used for heavy duty work.
Universal shaper
The universal shaper has a special type of table which can be swiveled and positioned at any
angle about a horizontal axis. Apart from the cross and vertical travel, the table of a universal
shaper can be swiveled to any angle to machine inclined surfaces. In the process, the position of the
work in the table need not be changed. These machines are utilized in precision workshops

QUICK RETURN MECHANISMS
1. Hydraulic drive
2. Crank and slotted link mechanism
3. Whitworth mechanism

Crank and slotted link mechanism

FEED MECHANISM
• Hand feed
• Automatic table feed

Automatic table feed
- Paul and Ratchet Mechanism

Work Holding Devices – in
SHAPER

Method of Clamping
• Clamp in a vise
• Clamp on the table
• Clamping on V- Block
• Clamp on Angle Plate
• Fixture

Fixture
• To improve the machining accuracy , a
fixture is designed with T-Bolt, V-Blocks
and clamps for holding the work.
• So the total production and cost is reduced

TYPES OF TOOL
• According to shape –
straight tool ,
cranked tool
Goose necked tool
• According to direction of cutting
Left hand
Right hand
• According to the finishing required
Roughing tool
Finishing tool

.
• According to type of operation–
Down cutting tool
Parting off Tool
Squaring tool
Side recessing tool
• According to the shape of cutting
edge
Round Nose tool
Square nose tool

SHAPING OPERATIONS
1. Machining Horizontal surface
2. Machining Vertical surface
3. Machining Angular surface
4. Machining Slots , Grooves and Keyways surface
5. Machining Irregular surface

Machining Slots , Grooves and Keyways
surface

PRINCIPLE
It’s a process of
removing metal by
feeding the work
piece against the
rotating multi point
cutter

SPECIFICATION
1. Length and width of table
2. Max. longitudinal cross and vertical
travel of the table
3. Number of spindle speeds and feeds
4. Power of driving motor
5. Floor space and net weight
6. Spindle nose and taper size
7. Type of milling machine

CLASSIFICATION OF MILLING MACHINE
The milling machines are classified according to the general design
of the machine.
1. Column and knee type
a) Plain milling machine
b) Universal milling machine
c) Omniversal milling machine
d) Vertical milling machine
2. Table type milling machine
3. Planer type milling machine
4. Special type milling machine

HORIZONTAL MILLING MACHINE
• Its one type of column
and knee type milling
machine

VERTICAL MILLING MACHINE
• Its one type of column
and knee type milling
machine
Mostly vertical milling machine
used to perform end milling and
face milling operations

UNIVERSAL MILLING MACHINE
• The basic difference between a universal horizontal milling machine and a
plain horizontal milling machine is the addition of a table swivel housing
between the table and the saddle of the universal machine.
• This permits the table to swing up to 45° in either direction for angular and
helical milling operations. The universal machine can be fitted with various
attachments such as the indexing fixture, rotary table, slotting and rack cutting
attachments, and various special fixtures

Possible motions in Universal
milling machine
• Vertical movement through the knee
• Cross movement through the saddle
• Longitudinal movement of the table
• Angular movement of the table by swiveling the table
on the swivel base

Omniversal milling machine
• This is a modified form of a horizontal milling
machine.
• It provided with two spindles, one of which is in the
horizontal plane while the other is carried by a
universal swiveling head

Duplex head fixed bed type
milling machine

Peripheral milling
The machining is performed by the cutting edges on the periphery
of the milling cutter.
It is classified under two headings
1. Up milling
2. Down milling

WORK HOLDING DEVICES
MILLING
• T – bolt and clamps
• Angle plates
• V-Blocks
• Machine vice
• Milling Fixture
• Dividing heads

3. Indexing
Head
• Its used for dividing the work piece periphery at the
work pieces into any number of equal divisions. The
process of dividing the periphery of work is called
indexing.
• Indexing is essential for cutting gears, splines, equally
spaced grooves, hexagonal heads etc.

Tool Holding Devices
1. Arbors
2. Adaptors
3. collets

1.Arbor
Spacing collars are used to set the cutter in the
required position

Stub arbor
Its similar to previous method , but smaller in size

2.Adaptor
If the size of the cutter shank is smaller than the hole of the
spindle nose, adaptors are used to hold the cutter

Milling cutters
1. Plain milling cutter
2. Side milling cutter
3. End milling cutter
4. Angle milling cutter
5. T-slot milling cutter
6. Slitting saws
7. Form milling cutter
8.Fly cutters
9. Woodruff key slot milling cutter

Woodruff key slot milling cutter

Milling Operations
• Plain or slab milling
• Face milling
• Angular milling
• Straddle milling
• Gang milling
• Form milling
• End milling
• T-slot milling
• Gear milling

Plain or slab milling
• It is the operation of
production of a flat
surface parallel to the axis
of rotation of the cutter. It
is also called as slab
milling. Plain milling
cutters and slab milling
cutters are used to perform
this operation.

Face milling
Operation where the front teeth of the tool are in engagement to
make a flat surface.

Angular milling
• Production of an angular
surface on a workpiece other
than at right angles to the axis
of the milling machine spindle
is known as angular milling.
Example of angular milling is
the production of the ‘V’
blocks

Straddle milling
• It is the operation of production of
two vertical surfaces on both sides
of the work by two side milling
cutters mounted on the same arbor.
By using suitable spacing collars,
the distance between the two
cutters is adjusted correctly.
• The straddle milling is commonly
used to produce square or
hexagonal surfaces.

Gang milling
• It is the operation of machining
several surfaces of work
simultaneously by feeding the
table against a number of cutters
(either of same type or of different
type) mounted on the arbor of the
machine.
• This method saves much of
machining time and mostly used in
production work.

Form milling
• The form milling is the
operation of production of
irregular contours by
using form cutters.
• Machining convex and
concave surfaces and gear
cutting are some
examples of form milling.

End milling
• It is the operation of
producing a flat surface
which may be vertical,
horizontal or at an angle to
the table surface.
• The end milling is
performed by a cutter known
as an end mill.
• End milling is mostly
performed in a vertical
milling machine.

T- slot milling
• Its done on work
piece in two stages
• First using end
milling a plain slot is
made
• Then in second stage
T-slot cutter is used
to enlarge the slot as
shown in fig

Gear cutting
• Gear cutting operation
is performed in a
milling machine by
using a form cutter.
• The work is held
between centers on a
universal dividing
head.
• A proper gear cutter is
selected and the teeth is
produced on w/p

INDEXING OR DIVIDING HEADS
1. Plain or simple dividing head
2. Universal dividing head
3. Optical dividing head

Plain or simple dividing head
• The index plate having 12 or 24 slots
equally spaced on the periphery.
• The spindle is directly connected to
handle.
• The job is held between the centers
• The hand lever is used for locking
the spindle in position.

Universal dividing head
• Worm gear mechanism is
connected to main spindle.
• Worm is mounted on the shaft.
• The worm gear has 40 teeth and
the worm is single threaded.
• So 40 turns of crank will move
the spindle by one complete
revolution.
• A spring loaded pin of the crank
fits into the holes in the index
plate. If the pin moved from one
hole to the next in a 24 hole circle
of the index plate , the spindle
will revolve by 1/40 x 1/24 =
1/960 of a turn.

INDEXING METHOD
1. Direct or rapid indexing
2. Plain or simple indexing
3. Differential indexing
4. Compound indexing
5. Angular indexing

DRILLING
Drilling is the process of producing hole on the work piece by
using a rotating cutter called drill.
Drilling may be done in a lathe or vertical milling machine. It
can conveniently be done, quickly and at low cost in a drilling
machine.
Drilling machine can also used for boring, counter-boring,
counter-sinking, reaming, tapping and spot facing operations.
Drilling machines are used in machine assembly, repair shop,
tool room, maintenance work, agricultural machinery etc.

Types of drilling machine
1. Portable drilling machine (or) Hand drilling machine
2. Sensitive drilling machine (or) Bench drilling machine
3. Upright drilling machine
4. Radial drilling machine
5. Gang drilling machine
6. Multiple spindle drilling machine
7. Deep hole drilling machine

SPECIFICATIONS OF DRILLING
MACHINE
Weight of the machine.
Power of the machine in HP.
Max. spindle travel is in mm.
Max. size of the drill in mm.
Table size of max. dimensions of a job can
mount on a table.
The No. of spindle speed in rpm.
The No. of automatic spindle feeds mm/rev.
Floor space required.

Portable drilling machine
• It can be carried and
used anywhere in the
workshop. It is used for
drilling holes on work
pieces in any position,
which is not possible in
a standard drilling
machine.
• These machines can
accommodate drills
from 12mm to 18 mm
diameter.

Sensitive drilling machine (or)
Bench drilling machine
• The drill is fed into the work
purely by hand . The operator
can sense the progress of the
drill into the work because of
hand feed. The machine is
named so because of this
reason.
• It can handle drills upto
15.5mm of diameter

Upright drilling machine
Though it looks like a sensitive
drilling machine, it is larger and
heavier than a sensitive drilling
machine.
Holes of diameter upto 50mm
can be made with this type of
machine

Radial drilling machine
The radial drilling machine
is intended for drilling on
medium to large and heavy
work pieces. It has a heavy
round column mounted on
a large base. The column
supports a radial arm,
which can be raised or
lowered to enable the table
to accommodate work
pieces of different heights.

Gang drilling machine
• Gang drilling machine has a long common table and a base. Four to six drill
heads are placed side by side. The drill heads have separate driving motors. This
machine is used for production work. A series of operations like drilling,
reaming, counter boring and tapping may be performed on the work by simply
shifting the work from one position to the other on the work table. Each spindle
is set with different tools for different operations.

Multiple spindle drilling machine
This machine is used for
drilling a number of holes in
a work piece simultaneously
and for reproducing the
same pattern of holes in a
number of identical pieces.

Deep hole drilling machine
• Very deep holes of L/D ratio 6 to
even 30, required for rifle barrels,
long spindles, oil holes in shafts,
bearings, connecting rods etc, are
very difficult to make for
slenderness of the drills and
difficulties in cutting fluid
application and chip removal.
Such drilling cannot be done in
ordinary drilling machines and b
ordinary drills.

Drilling operations
• . (a) Reaming
(b) Taping
(c) Counter-boring
(d) Countersinking
(e) Center drilling
(f) Spot facing

Drilling operations
.
Producing larger hole
on the previous
drilled hole upto
50mm dia
Enlarging the
hole using
single point
cutting tool
Enlarging hole
somewhere at its
end

Mounting the drill tool
1. Fitting directly in the spindle
2. By using sleeve
3. By using socket
4. By means of chuck

Fitting directly in the spindle
• The drill is directly held in the spindle by friction.
• To remove the drill from spindle, a tapered wedge called
drift is forced into the slotted hole in the spindle

By using a sleeve
If the shank of drill smaller than
the taper in the spindle hole, a
sleeve is used.
The sleeve with drill is fitted in
the hole of the spindle

By using a socket
• Its used when taper shank of the drill is
larger than taper hole of the spindle
• The body of the socket has taper hole
which is larger than the drill spindle
bore
• So the bigger drill can be fitted into the
socket

By using chucks
• Its suitable for holding any smaller
size drills, straight shank drills and
other tools not having taper at the
holding end.
• Drill chucks have tapered shanks
which fit into the machine spindle.
• The jaws used to hold the drills

Introduction
• One of the most versatile machine
tools; used to bore holes in large
and heavy parts as engine frames,
machine housings etc which are
practically impossible to hold and
rotate in an engine lathe or in a
drilling machine.
• Also drilling, milling and facing
can be preformed with equal
facility.
• Along with attachments screw
cutting, turning, grinding or gear
cutting can also be performed.

SPECIFICATIONS OF BORING
MACHINE
• Type of machine-floor, planer type, or multi spindle etc.
• Max. size of boring spindle diameter in mm.
• Max. spindle travel in horizontal and vertical direction in
mm.
• Max. travel of table in longitudinal and cross-wise
directions in mm.
• Range and number of spindle speeds in rpm.
• Range and number of spindle speeds in mm/rev.
• Floor-space required for the machine in m.
• Weight of machine in Tonnes.
• H.P of the machine motors.

Types of boring machine
1. Horizontal boring machine
a. Table type
b. Floor type
c. Planer type
d. Multiple head type
2. Vertical Boring Machine
a. Vertical boring mill
b. Vertical turret lathe boring machine
3. Precision Boring Machine
4. Jig Boring Machine

Types
1. Horizontal boring machine:
• The work is supported on a table which is stationary and tool
revolves in a horizontal axis.
• Can perform boring, reaming, turning, threading, facing,
milling , grooving and many other operations with suitable
tools.
• Work piece which are heavier and asymmetrical can be easily
held and machined.
• Different types has been designed to suit the different purpose.

Floor type –
Horizontal boring machine

Planer type –
horizontal boring machine

Multi spindle–
horizontal boring machine

Types
2. Vertical Boring Machine:
• The work rotates on a horizontal table about a vertical axis
and the tool is stationary except for feed.
• Machine may look like a vertical lathe.
• Larger diameter and heavy work pieces, can be set up more
quickly than in lathe.
• Multiple tooling may be adapted with its turret type tool
post, increasing the rate of production.

Vertical Turret lathe boring
Machine

Precision Boring Machine
• It uses a single point cutting tools to machine surfaces
rapidly and accurately.
• Cemented carbide and diamond tipped tools are
operated at a very high cutting speed to produce
accurately sized holes with fine surface.
• Jig boring machine is a precision boring machine,
resembles to vertical milling machine in construction.
• Accurate positioning of holes is achieved by Lead
screw method or Mechanical / Electrical Gauging
method or Optical measuring method.

Precision Boring Machine
Jig Boring Machine

Introduction
• Broaching is the process of removing metal with a
tool which has “teeth” arranged in a row. Each
tooth is successively higher than the previous tooth
and removes more material. In broaching, one
stroke or cycle of the machine produces a finished
part.
• Broaching is used to produce both internal and
external features. Production rates are high and
tolerances of +/- .0005” are possible.

SPECIFICATION
• Max. length of stroke in mm.
• Type of drive: Electro-Mechanical or Hydraulic drive.
• Power range.
• Speed and Feed.
• Weight of the machine.
• Floor space.

TYPES OF BROACHES
1. According to types of tool movement
(a) Horizontal type (b) Vertical type (c) Continuous type
2.According to the types of operation
(a) Push type (b) Pull type
3. According to the types of surface to be broached
(a) Internal type (b) External type
4. According to the construction of broach
(a) Solid type (b) Progressive cut type
5. According to the operation to be performed on the work piece
(a) Surface broach (b) Round hole broach (c) Keyway broach
(d) Spline broach (e)Burnishing broach

Broaching methods
Pull Broaching
Workpiece is clamped to the broaching machine in stationary position and the broach is
pulled through the work. Broaches are usually long and are held in a special head. Pull
broaching is mostly used for internal broaching.
Push Broaching
Workpiece is held in the broaching machine in stationary position and broach is pushed
through the portion of workpiece to the machined. Normally push broaching is done by
hand and arbor presses (hydraulic press). This method is also recommended for internal
broaching like for sizing and finishing the holes, cavities, and key ways.
Surface Broaching
Any one of two, either workpiece or the broach (tool) is kept moving and other is kept
stationary. The method is widely used as surface finishing operation. In case of surface
broaching, the broaching tool is specifically designed for the shape to be finished.
Continuous Broaching
In continuous broaching the broach is held stationary in the broaching machine and
workpiece is moved continuously. The teeth of movement of the workpiece may be either
straight, horizontal or circular. This is generally used for broaching a large number of
similar workpieces at a time.

Horizontal type internal broaching
machine

Horizontal type surface
broaching machine

Vertical broaching machine
- push down type

Vertical broaching machine
- pull down type

Continuous type
Broaching Machine

Rotary table continuous
Broaching Machine

Nomenclature
Pull End ---- Pull end is made to attach the broach to the broaching machine through the puller head.
Front Pilot -- This centres the broach in the hole to be finished just before start of processing.
Roughing Teeth --These are the cutting edges which remove larger amount of stocks during cutting. Larger amount
removal generates poor quality of surface finish but makes the operation faster.
Finishing Teeth --- These are cutting edges removing smaller stocks of material. These are used for final finishing of the
surfaces and their accurate sizing.
Rear Pilot and Follower Rest --This is a supporting device to the broach when it is likely to complete its operation of
broaching.
Land --It is the width of flank face of the broach normally it is kept slightly inclined to give relief angle to the flank face
of broach.
Pitch -- It is the distance between two corresponding points on two successive teeth of a broach. Normally pitch of
finishing teeth of a broach is kept comparatively smaller than the rough cutting teeth.
Height of the Teeth ---Height of the roughing and finishing teeth gradually increases from the shank to the finishing teeth.
This increment is called the cut per tooth, it depends on the material being machined. Normally the cut per tooth is
taken from 0.01 or 0.2 mm for the finishing teeth and it may go up 0.2 mm for the cutting teeth.

• Advantages and Limitations of Broaching
Major advantages
• Very high production rate (much higher than milling, planning, boring etc.)
• High dimensional and form accuracy and surface finish of theproduct
• Roughing and finishing in single stroke of the same cutter
• Needs only one motion (cutting), so design, construction,operation and control are
simpler
• Extremely suitable and economic for mass production
Limitations
• Only through holes and surfaces can be machined
• Usable only for light cuts, i.e. low chip load and unhard materials
• Cutting speed cannot be high
• Defects or damages in the broach (cutting edges) severelyaffect product quality
• Design, manufacture and restoration of the broaches are difficultand expensive
• Economic only when the production volume is large.

Disadvantages
(a) Its initial cost is quite high.
(b) Very large sized work pieces can not be subjected to broaching operation.
(c) Broaching is not possible for the surfaces having obstructions.
(d) Removal of larger stocks is not possible in broaching operation.
(e) Clamping devices require frequent maintenance and cost.

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