SHAPING MACHINE

• Introduction
• 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. James Nasmith, an
Englishman designed a shaping machine to produce flat
surfaces in the year 1836.
Shaping operation
 Method of machining
• The work is held firmly on the table and the ram is allowed to
reciprocate over it. A single point cutting tool is attached to
the ram. When the ram moves horizontally in the forward
direction, the tool removes metal from the work.
• On the return stroke, metal is not removed. The ram moves
at a slow speed during forward stroke. But during return
stroke, the ram moves at a faster speed.
• Though the distances of ram movement during the forward
and return stroke remain the same, the time taken by the
return stroke is less as it is faster. It is possible by ‘Quick return
mechanism’.
• In a shaping machine, a flat horizontal surface is machined by
moving the work mounted on the table in a cross direction to
the tool movement. When vertical surfaces are machined, the
feed is given to the tool.
• When a inclined surface is machined, the vertical slide of the
toolhead is swiveled to the required angle and the feed is
given to the tool by rotating the downfeed hand wheel.
 Main parts of a shaping machine
• Base
• The base is hollow and is made of cast iron. It provides the
necessary support for all the other parts of the machine. It is
rigidly bolted to the floor of the workshop.
• Column
• It is a box like casting mounted vertically on top of the base.
Two accurate guideways are machined on the top of the
column. The ram reciprocates on these guideways. The front
face of the column is provided with two vertical guideways.
They act as guideways for the crossrail. Crossrail moves
vertically along these guideways. The column encloses the
ram reciprocating mechanism and the mechanism for
strokelength adjustment.
• Crossrail
• It is mounted on the front vertical guideways of the column.
The table may be raised or lowered by adjusting the crossrail
vertically. A horizontal cross feed screw is fitted within the
crossrail.
• Table
• It is an important part useful in holding the work firmly on it.
It is mounted on the saddle which is located above the
crossrail. The top and sides of the table are
accuratelymachined and have T-slots. Workpieces are held on
the table with the help of shaper vise, clamps and straps.
• Ram
• Ram supports the toolhead on its front. It reciprocates on the
accurately machined guideways on the top of the column. It is
connected to the reciprocating mechanism placed inside the
column. The position of ram reciprocation may be adjusted
according to the location of the work on the table.
• Toolhead
• The toolhead is fitted on the face of the ram and holds the
tool rigidly. It provides vertical and angular feed movement of
the tool. The swivel toolhead can be positioned at any
required angle and the vertical slide can be moved vertically
or at any desired angle to machine vertical or inclined
surfaces.
Shaping machine
 Types of shaping machine
The shaping machines are classified as follows :
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
• 1 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.
• 2 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 the piston, the ram reciprocates.
Hydraulic shapers are high power machines and are used for
heavy duty work.
• 3 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 utilised in
precision workshops.
 Quick return mechanism
• The ram moves at a comparatively slower speed during the
forward cutting stroke. During the return stroke, the
mechanism is so designed to make the tool move at a faster
rate to reduce the idle return time. This mechanism is known
as quick return mechanism.
• As the ram moves at a faster rate during return stroke, the
time taken becomes less. The total machining time decreases
and the rate of production increases.
• The following mechanisms are used for quick return of the
ram.
1. Crank and slotted link mechanism
2. Hydraulic mechanism
3. Whitworth mechanism
1 Crank and slotted link mechanism
• An electrical motor runs the driving pinion(S) at a uniform
speed. This pinion makes the bull gear(M) to rotate at a
uniform speed. Bull gear is a large gear fitted inside the
column. The point ‘O’ is the centre of the bull gear. A slotted
link having a long slot along its length is pivoted about the
point ‘K’. A sliding block ‘N’ is fitted inside the slot and slides
along the length of the slotted link. ‘P’ is the crank pin and
‘OP’ can be considered as a crank.
• When the bull gear rotates, the sliding block also rotates in
the crank pin circle. This arrangement provides a rocking
movement to the rocker arm. As the top of the slotted link is
connected to the ram, the ram reciprocates horizontally. So,
bull gear rotation is converted into the reciprocating
movement of the ram.
 Quick return mechanism
• As shown in the diagram, ‘KA’ indicates the starting point of
the forward cutting stroke and ‘KB’ the end of the cutting
stroke. The rotation of the crank ‘OP’ in clockwise direction
through the angle P1RP2 refers to the forward cutting stroke.
The rotation of the crank in the same direction through the
angle P2LP1 refers to the return stroke. As the angle P2LP1 is
smaller than the angle P1RP2, the time taken for the return
stroke is less than that of forward stroke. So, it is evident that
the speed at which the ram travels during return stroke is
more.
• -----------------------------------------------------------------------------
Crank and slotted link mechanism
Quick return mechanism of the ram
• The strokelength of a ram is the distance the ram
moves forward or backward. It depends upon the
distance between the centre of the bull gear and the
centre of the sliding block. it is adjusted according to
the length of the work.
 The size of a shaper
• The size of a shaper is determined by the maximum length of
stroke it can make. Shapers with maximum strokelength of
175mm to 900mm are available. Machines with maximum
strokelength of 300mm, 450mm and 600mm are used widely.
To specify the machine further, the following points are to be
provided.
1. The type of drive
a. Individual motor b. Belt driven
2. The method of obtaining different speeds
a. Gear box b. Step cone pulley
3. Horse power of the motor
4. Cutting to return stroke ratio
5. Number and range of speed arrangement
6. The type of the table
 Strokelength calculation and adjustment
• The length of the stroke is calculated to be nearly 30mm
longer than the work. The position of stroke is so adjusted
that the tool starts to move from a distance of 25mm before
the beginning of the cut and continues to move 5mm after
the end of the cut. The length of the work is 100mm. The
strokelength of the ram is calculated to be 130mm.
(25+100+5).
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 Adjusting the strokelength
• The crank pin fastened to the sliding block can be adjusted by
a lever placed outside the column. Through the bevel gears
placed at the centre of the bull gear, the radial slide lead
screw can be rotated.
• This rotation of leadscrew changes the position of the sliding
block to move towards or away from the bull gear centre. The
strokelength of the ram is adjusted by placing the sliding
block at a required position from the centre of the bull gear.
Note : The strokelength of the ram and its position should not
be adjusted when the machine is in operation. The machine
should be stopped before these adjustments are made.
 Method of table movement
• 1. The table moves in a cross direction when the crossfeed
screw is rotated.
• 2. A crank handle is provided to rotate the the crossfeed
screw manually.
• 3. When the crossfeed screw is rotated in clockwise direction,
the table will move towards left.
• 4. When the elevating screw is rotated, the table slides up and
down on the face of the column.
• 5. As the handles meant for crossfeed screw rotation and
elevating screw rotation are placed side by side, it is not
possible to operate both of them at the same time.
• 6. The work mounted on the table is provided with required
feed only during the end of the return stroke.
 Ratchet and Pawl mechanism (Automatic feed
mechanism for the table)

• The table of a shaping machine travels in a cross direction

when the crossfeed screw is rotated. The cross feed screw is
attached to the ratchet wheel. A spring loaded ‘pawl’ is
positioned to be placed between the teeth of the ratchet
wheel. The pawl is housed within a frame known as rocker
arm. The bull gear placed inside the column of the shaping
machine drives
• There is a diametric slot provided on the face of the gear B. A
crank pin is attached to a slider placed in the slot. The bottom
of the rocker arm and the crank pin are connected by a
connecting rod. The rotation of the gear B makes the crank
pin to rotate.the gear B through the gear A.
• This movement makes the rocker arm to rock about the
centre of the ratchet wheel. The pawl makes the ratchet to
rotate by a small amount in one direction only. As the cross
feed screw is attached to the ratchet wheel, the rotation of
the ratchet wheel will make the table to move in a cross
direction.
• If the direction of the table feed is to be reversed, the pawl is
turned about 180° from its position. The ratchet wheel and
the crossfeed screw will rotate in the opposite direction
resulting in the table movement in the opposite direction.
• When power feed is not necessary for the table, the pawl is
disengaged from the ratchet wheel.
Ratchet and Pawl mechanism
 Swivel toolhead
• The toolhead of a shaper holds the cutting tool rigidly. It is
fitted on the face of the ram. The vertical slide of the toolhead
can be moved vertically or at a particular angle to provide
vertical and angular feed movement to the tool. It allows the
tool to have an automatic relief during the return stroke of
the ram.
• The toolhead has a swivel base attached to the circular seat
on the ram. The swivel base has angular graduations marked
on it. As the vertical slide is mounted on the swivel base of
the toolhead, it may be set and moved at any desired angle to
machine angular surfaces like ‘V’ grooves and dove tail
grooves.
• The downfeed screw handle is rotated to move the vertical
slide up and down.
• A graduated dial is placed on the top of down feed screw to control
the amount of depth of cut or feed accurately.
• Apron consisting of clapper box, clapper block and tool post is
clamped on the vertical slide by a screw. By releasing the clamping
screw, the apron can be swiveled either towards left or towards
right with respect to the vertical slide. The clapper box has two
vertical walls within which the clapper block is housed. It is
connected to the clapper box with the help of a hinge pin. This
arrangement provides relief to the tool while machining vertical or
angular surfaces. The tool post is mounted upon the clapper block.
The tool post is provided with a slot to accommodate the tool and
a screw to hold the tool rigidly on the tool post.
• The clapper block fits securely inside the clapper box to provide a
rigid tool support during forward stroke. On the return stroke, a
slight frictional drag of the tool on the work lifts the block out of
the clapper box and prevents the tool cutting edge from dragging
on the work surface.
Swivel toolhead
 Work holding devices
• Workpieces can be held and supported on the shaper table
directly or by having some special devices. Depending on
the size and shape of the work, it may be supported on the
table by any one of the following methods.
• 1. Shaper vise
• 2. Clamps and stop pins
• 3. T-bolts and step blocks
• 4. Angle plate
• 5. V – Block
• 6. Special fixtures
 Vise
• Vise is the most common and simple work
holding device used in a shaper. Different
types of vises are used in a shaping machine
according to the need and they are :
 Clamps and stop pins
• T – bolts are fitted into the T - slots of the table. The
work is placed on the table.The work is supported by
a rectangular strip at one end and by a stop pin at
the other side. The screw is tightened to secure the
work properly on the machine table.
 T-bolts and step blocks
• The step blocks are used in combination with T-bolts and
clamps to hold the work directly on the machine table. T-bolts
are fitted in the T-slots of the machine table. One side of the
clamp holds the work and the other side rests on a step of the
step block. The different steps of the block are useful in
levelling the clamp when holding works of different heights. A
nut on the top of the clamp holds the work rigidly.
 Angle plate
• Angle plate resembles the English alphabet ‘L’. It is accurately
machined to have two sides at right angles. Slots are provided
on both the sides. One of the sides is bolted to the machine
table and the workpieces are held on the other side.
 V – block
• V – block is a metal block having a ‘V’ shaped groove on it. It is
used for holding cylindrical workpieces. Operations like
keyway cutting, slot cutting and machining flat surfaces can be
performed on the cylindrical workpieces held on a ‘V’ block.
• Special fixtures
• When internal keyways are to be machined on the
holes, the work is held with a special fixture. The
fixture has a V-block attached to it and the cylindrical
work is mounted on it.
 Tools used in a shaping machine
• The material of the cutting tool used in a shaping
machine should have more hardness and temper
when compared to the material of the workpiece. So,
the shaper tools are made of the following materials
1.High Carbon Steel
2. High Speed Steel
3. Carbide tipped tool
4. Stellite tool
 Types of shaper tools
According to the type of work and the type of operation, various
tools are used in a shaper. They are
• Right hand ( R. H ) tool
This is a tool used for machining by moving the job from right to the
left.
• Left hand ( L. H ) tool
This is a tool used for machining by moving the job from left to right.
• Roughing tool
When it is required to remove a good amount of material from the
workpiece, roughing tools are used. The cutting edge will be very
thick, sharp and strong to withstand the cutting pressure and to
dissipate the heat generated at the cutting point. The surface
obtained will be very rough.
Shaper tools
• Finishing tool
After the rough machining is performed, the finishing
tool is used to obtain a very high quality of surface
finish. The cutting edge will be either flat or slightly
convex.
• Goose neck tool
This is a special type of tool used for finish machining.
Very good surface finish will be obtained. The cutting
edge of goose neck tool has a springy action. The tip
of the cutting edge lies in the same line with the rear
side of the shank.
• Slot cutting tool
Wide rectangular or square grooves are known as slots.
Rough machining of the slot is carried out using round
nose tool. After that, a slot cutting tool is used for finish
machining work.
• T-slot cutting tool
The central rectangular (or square) slot is first machined
using rough machining tool and then by using parting tool
(or slot cutting tool).After that, a T-slot cutting tool is used
to machine underneath the rectangular groove.
• Form tool
Form tools are made to suit some specific requirements for
machining V shaped grooves or similar special shaped
grooves in concave or convex form.
Setting of shaper table, vise and toolhead

• The machining accuracy will not be perfect if the

machine table and toolhead are not set properly.
When the sides are perpendicular, it is referred as
squareness. Parallelism means the two sides are
absolutely parallel to each other.
• Alignment is an arrangement in which the relative
positions of the table, the jaws of the vise, the
toolhead and the ram are perfect. The above setting
of the table, work and the tool are done with the
help of test bars and feeler gauges.
 Operations performed in a shaping
machine
• Different types of operations are performed in
a shaping machine. They are broadly classified
as
• 1. Regular operations 2. Special operations
 Regular operations
1. Machining horizontal
surfaces

• A shaper is mostly used to machine a flat, true

surface on a workpiece. Horizontal surfaces are
machined by moving the work mounted on the
machine table at a cross direction with respect to the
ram movement.
• The clapper box can be set vertical or slightly
inclined towards the uncut surface. This arrangement
enables the tool to lift automatically during the
return stroke. The tool will not drag on the machined
surface.
Machining a horizontal surface
 Machining vertical surfaces
• A vertical cut is made while machining the end of a
workpiece, squaring up a block or machining a shoulder.
• The feed is given to the tool by rotating the downfeed screw
of the vertical slide. The table is not moved vertically for this
purpose. The apron is swiveled away from the vertical surface
being machined
 Machining angular surfaces
• If the surface to be machined is neither horizontal nor
perpendicular, the surface is called inclined surface.
Machining ‘V’ grooves and dovetail grooves are some
examples for angular machining. Machining the inclined
(angular) surfaces can be done in several ways. They are
a) Taper strip method
• The taper strip is positioned on the table and fixed. On the
taper strip, the job is fixed and machined. The angular surface
is obtained.
b) Layout method
• Slanting surface is marked on the work piece. The job is
positioned by suitable arrangement in such a way that the
marked line is either horizontal or vertical. If the machining is
carried out, the required angular surface is obtained.
c) Degree parallel method
• Degree parallel block is a wedge shaped precision block for a
particular angle. The degree parallel block is placed first on
the table. Over and above that, the workpiece is positioned
and the machining is done as usual to obtain the required
angular surface.
• d) Universal vice method
• The job may be fixed in the universal vice and then the vice is
swiveled to the required angular position. If the machining is
carried out, the required slanting (angular) surface will be
obtained.
• e) Universal table method
• If the universal table is available in the shaping machine, then
the table can be tilted to the required position and the work is
fitted on that. The machining is done as usual to obtain the
required angular surface.
• f) Swivel toolhead method
• An angular cut is made at any angle other than a right angle
to the horizontal or to the vertical plane. The work is set on
the table and the vertical slide of the toolhead is swiveled to
the required angle either towards left or towards right from
the vertical position. The apron is then further swiveled away
from the work to be machined.
• Special operations
• Apart from machining horizontal, vertical and vertical flat
surfaces, the shaping
• machine can do some special machining operations.e work to
be machined.
Machining a angular surface
Machining dove tail groove
• Dove tail joint is machined on two separate pieces of work
as male and female elements. The required shape is
marked on the face of the work and the unwanted metal
is first removed by the round nose tool. A special form
tool is used to finish the machining.
Machining a ‘V’ block
• The required shape of a ‘V’ block is marked on the face of
the work and machining is done by any suitable method
of angular machining.
Machining a tongue and groove joint
• The male and female elements of the tongue and groove
joint having vertical surfaces is machined after the exact
shape is marked on the face of the work.
Various shaper operations
 Machining external keyways
• Machining external keyways refers to the cutting of long slots
along the length of cylindrical rods. Initially a round nose tool
is used and then a square nose tool is used to finish the
operation. A hole of depth equal to the depth of the keyway is
made at the blind end to leave a clearance to the tool at the
end of the stroke. When a keyway is cut at the middle of the
shaft, holes are drilled at both ends of the keyway.
 Machining internal keyways
• Internal keyways are cut inside the holes of gears and pulleys.
It is done by holding the tool on a special tool holder called
‘snout bar’. The snout bar is directly fitted on the the clapper
block.
 T-slot machining
• The shape of the T-slot is marked on the face of the work. A
parting off tool is fitted on the toolpost and a rectangular slot
is machined at the middle for the required depth. The broad
base of the ‘T’ slot is machined by a T-slot cutting tool.
• Machining a rack gear
• Rack gear cutting is a process of cutting teeth
elements at linear pitch on a flat piece of work. Firstly,
the groove is machined with a square nose parting
tool. Then, the groove is further machined with a form
tool conforming the shape of the teeth.
• 11. Machining irregular surfaces
• A shaper can also produce a contoured surface using a
round nose tool. To produce a small contoured surface
a forming tool is used. If the curve is sufficiently large,
powered crossfeed along with manual down feed is so
adjusted that the tool will trace the required contour.
 Cutting speed, Depth of cut and Feed
• Cutting speed
• The distance an object travels in a particular period of time is
known as speed. In a shaper, the cutting speed is the speed at
which the metal is removed by the cutting tool in a period of one
minute. In a shaper, the cutting speed is considered only during the
forward cutting stroke.
• This is expressed in metre per minute. The cutting speed differs to
suit different different machining conditions like work material, the
finish required, the type of the tool and the rigidity of the machine.
Depth of cut
• Depth of cut (t) is the thickness of metal that is removed during
machining. It is the perpendicular distance measured between the
machined surface and the uncut surface of the workpiece. It is
expressed in mm or in inches.
Feed
• Feed (S) is the relative movement of the work or tool in a
direction perpendicular to the axis of reciprocation of the ram
per double stroke. It is expressed in mm per stroke.
Coolant
• Due to the friction between the tool and the work surface
during machining, heat is generated. The tool loses its cutting
capacity and the machined surface is hardened. Coolant is
used on the surfaces to avoid damage to the cutting edge of
the tool as well as to the machined surface. Soluble oil is
mixed with water to be used as a suitable coolant. One part of
the oil is mixed with fifteen parts of water to be used as
coolant. Usage of water as coolant may result in rust
formation on the metal parts. Lubricants cannot be used as
coolants.
 Safety precautions
The following safety precautions should be observed while
working on a shaping machine.
Safety precautions regarding operators
• 1. No alteration or adjustment should be done on the
machine parts while the
• machine is functioning.
• 2. Clamps holding the work should not be adjusted while the
machine is in operation.
• 3. The machine is to be stopped before cleaning the metal
chips.
• 4. The sharp edges of the work should be handled with care.
5. The measuring of the work should be done only after the
machine is switched off.
6. The operator should not seek the assistance of others for
starting and stopping the machine.
7. Machining of precise parts and internal surfaces of the
workpiece are to be carried out with great care and attention.
8. The operator should stay away from direction of the ram
movement.
• Safety hints regarding the shaping machine
1. The workpiece is to be positioned in such a way that the ram
will not hit the workpiece while performing the forward
stroke.
2. Strokelength of the ram and the position of stroke are to be
set correctly before performing the operation.
3. Proper holding of the work should be ensured. Work holding
devices like clamps and vice jaws should not come in the way
of the reciprocating tool.
4. We have to ensure that the tool or the tool post or the ram
will not hit the job or the job holding clamps or the vise jaws.
5. The machine should be stopped before making any
adjustment to the strokelength, position of stroke, apron and
tool position.
 QUESTIONS
I. A. Choose the correct option
1. The shaping machine was developed by
a. Henry Maudslay b. Eli Whitney
c. Michael Faraday d. James Nasmith
2. The operation mainly done on a shaping machine is
a. Turning b. drilling
c. machining a flat surface d. thread cutting
3. The mechanism used to move the shaper table automatically is
a. back gear mechanism b. crank & slotted link mechanism
c. tumbler gear mechanism d. ratchet & pawl mechanism
4. The part involved in reciprocation by quick return is
a. Table b. ram c. Column d. crossrail
5. The ratio of forward stroke time to return stroke time is
a. 3 : 2 b. 5 : 3 c. 1 : 3 d. 1 : 2
I. B. Answer the following questions in one or two words
• 1. What type of surfaces are machined on a shaper?
• 2. Which stroke of the shaper is faster?
• 3. What is the use of ratchet & pawl mechanism?
• 4. What type of cutting tool is used in a shaper - a single point or a
multi-point?
• 5. Which part of the shaper is involved in automatic lifting of the tool
during return
• stroke of the ram?
II. Answer the following questions in one or two sentences
• 1. Name any four important parts of a shaping machine.
• 2. What is the use of crank & slotted link mechanism?
• 3. Define ‘feed’ in a shaping machine.
• 4. Name any two points in specifying the size of a shaping machine.
• 5. What is the use of a clapper box?
• 6. What is the use of swivel toolhead of a shaping machine?
III. Answer the following questions in about a page
• 1. List out the types shaping machines.
• 2. Write short notes on a. Changing the strokelength of the ram
• b. Position of the ram
• 3. Explain any two work holding devices used in a shaping machine with
diagrams.
• 4. List out the types of tools used in a shaping machine.
• 5. Explain any two operations performed in a shaping machine with
diagrams.
IV. Answer the following questions in detail
• 1. Draw a neat diagram of a shaping machine and explain its important
parts.
• 2. Explain the crank & slotted link mechanism of quick return of the ream
with a diagram.
• 3. Explain the ratchet & pawl mechnism with a diagram.
• 4. Explain any four work holding devices used in a shaping machine with
diagrams.
• 5. Explain any four operations performed in a shaping machine with
diagrams.