Mt 2 me8462- lab manual

Manufacturing Technology-II
Department of Mechanical Engineering Page 1
PARK COLLEGE OF ENGINEERING AND
TECHNOLOGY
DEPARTMENT OF MECHANICAL ENGINEERING
.
MANUFACTURING TECHNOLOGY LABORATORY - II

MANUAL
Second Year – Fourth Semester
B.E. Mechanical Engineering
Academic Year 2020-21
(Even Semester)

TABLE OF CONTENTS
SL.NO EXPERIMENTS PAGE
1 An overview about Milling machine 1
2 Contour milling operation on a work piece using a milling machine 6
3 Spur Gear cutting in Milling machine 8
4 Helical Gear cutting in Milling machine 10
5 Study of Gear Hobbing machine 12
6 Gear Generation in Gear Hobbing machine 14
7 Gear Generation in Gear Shaping machine 16
8 An overview about Grinding 18
9 Machining a workpiece using Surface Grinding machine 24
10 Machining a workpiece using centre type cylindrical grinding machine 26
11 Tool angle grinding using Tool and Cutter grinder 28
12 Measurement of cutting forces in Milling machine 30
13 Measurement of cutting forces in Turning Process 32
14 Study of CNC machine 33
15 Manual part programming for step turning 42
16
Component Drawing, Manual Part Programming and Execution on
CNC Milling Machine
45

SL.NO DATE EXERCISE SIGN

LAB INSTRUCTIONS

 The student should enter the lab with proper uniform and
formal shoes.
 The items likely to cause accidents like hanging chains, rings,
wrist-watches etc., are to be avoided.
 Always wear tight fit clothing.
 Never carry any sharp tools in the pocket.
 Keep the sharp tool always in its proper place as soon as
finishing the work with it.
 Tools which are not used always be kept at their respective
places.
 Never operate the machine which you do not fully aware of its
control.
 Try to keep the oil, grease away from the shop floor;
sometimes unknowingly a man may slip and meet with
accident.
 The students should operate only the prescribed machines/
equipments for that particular lab session and should refrain
from using any other machines and equipments.
 The power supply to the test table should be obtained only
through the lab technician.
 The students should carefully return any tools, gauges and
other accessories before moving out of the lab.
 The students should always get their observations approved
by the faculty in charge before writing the record.

 The student should avoid unnecessary discussions during
work time and should concentrate on his work.

EX.NO: DATE:
AN OVERVIEW ABOUT MILLING MACHINE
AIM: To study an overview about Milling machine.
A milling machine is a power driven machine that cuts by means of a multi-tooth rotating
cutter. The mill is constructed in such a manner that the fixed workpiece is fed into the
rotating cutter. Varieties of cutters and holding devices allow a wide rage of cutting
possibilities.
The basic function of milling machines is to produce flat surfaces in any orientation as well
as surfaces of revolution, helical surfaces and contoured surfaces of various configurations.
Such functions are accomplished by slowly feeding the work piece into the equi-spaced
multi-edge circular cutting tool rotating at moderately high speed.
Milling machines of various types are widely used for the following purposes using proper
cutting tools called milling cutters:
 Flat surface in vertical, horizontal and inclined planes
 Making slots or ribs of various sections
 Slitting or parting
 Often producing surfaces of revolution
 Making helical grooves like flutes of the drills
 Long thread milling on large lead screws, power screws, worms etc and short thread
milling for small size fastening screws, bolts etc.
 2-D contouring like cam profiles, clutches etc and 3-D contouring like die or mould
cavities
 Cutting teeth in piece or batch production of spur gears, straight toothed bevel gears,
worm wheels, sprockets, clutches etc.
 Producing some salient features like grooves, flutes, gushing and profiles in various
cutting tools, e.g., drills, taps, reamers, hobs, gear shaping cutters etc.
Milling machines are classified on the basis of the position of their spindle. The spindle
operates in either a vertical or horizontal position. The amount of horsepower the mill is
able to supply to the cutter is also often important.

Milling machines are generally classified into the following types:
 Column-and-knee milling machines;
 Bed type milling machines;
 Machining centers.
The column-and-knee milling machines are the basic machine tool for milling. The name
comes from the fact that this machine has two principal components, a column that supports
the spindle, and a knee that supports the work table. There are two different types of
column-and-knee milling machines according to position of the spindle axis:
 Horizontal
 Vertical
Vertical spindle type
In this machine, typically shown in the below figure, the only spindle
vertical and works using end mill type and face milling cutters; the table may or may
not have swiveling features.

MACHINE CONSTRUCTION:
Machine parts :
1. Column
2. Head
3. Work Table
4. Saddle
5. Knee
6. Base
Table feed motions:
a. longitudinal feed
b. cross feed
c. vertical feed
The vertical milling machine is made up of five major groups: base and column, knee,
saddle, table, and head, (see figure). The base and column are one piece that forms the
major structural component of the milling machine. They are cast integrally, and provide
the mill with its stability and rigidity. The front of the column has a machined face which
provides the ways for the vertical movement of the knee. The knee supports the saddle and
table. It contains the controls for raising and lowering the saddle. Sitting a top the knee is
the saddle which supports the table. The saddle slides in dovetailed grooves into and away
from the machine, providing the mill with its Y-axis movement. On top of the saddle sits
the table. Being moved side-to-side, left-right, over the saddle furnishes the mill with its X-
axis movement. The workpiece is secured to the table through the use of various types of
holding devices.
The head is the most complex assembly in the major parts groups. This contains
the following components:
1. The drive motor and on/off switch.
2. Drive belt, gear train, and range lever selector.
3. Quill, spindle, and draw bar.
4. Quill feed, lock, and digital depth read out (Z-axis).

Types of milling
There are two basic types of milling, as shown in the figure:
Down (climb) milling, when the cutter rotation is in the same direction as the motion
of the work piece being fed
Up (conventional) milling, in which the work piece is moving towards the cutter, opposing
the cutter direction of rotation:
In down milling, the cutting force is directed into the work table, which allows thinner work
parts to be machined. Better surface finish is obtained but the stress load on the teeth is
abrupt, which may damage the cutter.
In up milling, the cutting force tends to lift the work piece. The work conditions for the
cutter are more favorable. Because the cutter does not start to cut when it makes contact
(cutting at zero cut is impossible), the surface has a natural waviness.
MILLING CUTTERS :
1. Face milling cutters
The shape, geometry and typical use of face milling cutters are shown in the below Fig.
The main features are:
 usually large in diameter (80 to 800 mm) and heavy
 used only for machining flat surfaces in different orientations
 mounted directly in the vertical and / or horizontal spindles
 coated or uncoated carbide inserts are clamped at the outer edge of the
carbon steel body as shown
 generally used for high production machining of large jobs.

2. End milling cutters or End mills
The shape and the common applications of end milling cutters (profile sharpened type) are
shown in the below figure. The common features and characteristics of such cutters are :
 mostly made of HSS
 4 to 12 straight or helical teeth on the periphery and face
 diameter ranges from about 1 mm to 40 mm
 very versatile and widely used in vertical spindle type milling machines
 end milling cutters requiring larger diameter are made as a separate
cutter body which is fitted in the spindle through a taper shank arbour as
shown in the same figure.
Face milling cutters End milling cutters or End mills
When using an end mill, there are certain general rules that should be followed when
making cuts.
1. The greatest depth of cut should never be more than 1/2 the diameter of the end mill.
2. Do not plunge an end mill more then 1-1/2 times its diameter. This is also true for
slotting. Do not, in a single pass, cut a slot deeper than 1-1/2 its width.
3. Do not edge mill to a depth of more than 1-1/2 times the diameter of the cutter.
RESULT:
Thus the study of milling machines and its operation were studied.

EX.NO: DATE:
CONTOUR MILLING OPERATION ON A WORK PIECE
USING A MILLING MACHINE
AIM:
To perform contour milling operation on the given work piece using a milling
machine.
MATERIALS REQUIRED:
Square aluminum plate-100x80x10
TOOLS REQUIRED:
1. Vertical Milling machine
2. Contour milling cutter
3. Outside Caliper
4. Steel Rule
5. Vernier Caliper
FIG - 2.1 GIVEN WORK PIECE
100
80

FIG – 2.2 FINISHED WORK PIECE
PROCEDURE:
1. The given work piece is fixed in a table.
2. The form milling cutters are used for contoured milling.
3. The machine is switched on to revolve the cutter at the selected speed.
4. By giving cross feed and longitudinal feed to the work table, the contour operations
are done respectively. The profile of the cutter coincides with that of the work piece.
5. After the work piece is milled as per the given drawing machine is switched off.
6. The work piece is removed from the work table and all the dimensions are measured
and checked.
RESULT:
The contour milling operation was done on the given work piece as per the given
drawing.
100
100
40
30
30
9.5
26
7
30 20 20
5 5

EX.NO: DATE:
SPUR GEAR CUTTING IN MILLING MACHINE
AIM :
To cut spur gear in the given workpiece using Milling machine.
TOOLS / EQUIPMENT REQUIRED:
1. Milling machine,
2. Vernier caliper,
3. Mandrel.
4. Milling Cutter
PROCEDURE :
1. The dividing head and the tail stock are bolted on the machine table. Their axis must
be set parallel to the machine table.
2. The gear blank is held between the dividing head and tailstock using a mandrel. The
mandrel is connected with the spindle of dividing head by a carrier and catch plate.
3. The cutter is mounted on the arbor. The cutter is centred accurately with the gear
blank.
4. Set the speed and feed for machining.
5. For giving depth of cut, the table is raised till the periphery of the gear blank just
touches the cutter.
6. The micrometer dial of vertical feed screw is set to zero in this position.
7. Then the table is raised further to give the required depth of cut.
8. The machine is started and feed is given to the table to cut the first groove of the
blank.
9. After the cut, the table is brought back to the starting position.
10. Then the gear blank is indexed for the next tooth space.
11. This is continued till all the gear teeth are cut.

DIAGRAM :
Fig – 3.1 SPUR GEAR GENERATION
RESULT:
Thus the given workpiece is cut into spur gear using Milling machine.

EX.NO: DATE:
HELICAL GEAR CUTTING IN MILLING MACHINE
AIM :
To cut Helical gear in the given workpiece using Milling machine.
TOOLS AND EQUIPMENTS REQUIRED :
1. Horizontal Milling machine
2. Vernier caliper
3. Mandrel
4. Milling Cutter
5. Bevel Protractor
HELICAL GEAR MILLING:
1. Helical parts most commonly cut on the milling machine include helical gears,
spiral flute milling cutters, twist drills. and helical cam grooves.
2. When milling a helix. a universal index head is used to rotate the workpiece at the
proper rate of speed while the piece is fed against the cutter.
3. A train of gears between the table feed screw and the index head serves to rotate the
workpiece the required amount for a given longitudinal movement of the table.
4. Milling helical parts requires the use of special formed milling cutters and double-
angle milling cutters.
DIAGRAM:
Fig – 4.1 TOOL FEED IN HELICAL MILLING

PROCEDURE:
1. Milling cutter is mounted on a horizontal arbor.
2. Indexing is done to cut each tooth.
3. Indexing is the process of dividing the periphery of the workpiece into any number
of equal divisions.
4. Gear blank is done for indexing the workpiece.
5. It is also used for rotating workpiece at a ratio to the table feed rate to produce
helical grooves on gears.
6. In helical gear milling, only direct and simple indexing can be used .
7. Change gears for helical milling.
8. The workpiece is held in a dividing head parallel to the milling table.
9. The teeth was cut using a brown and Sharpe type gear cutter held on an horizontal
arbor to confirm the cutter directly above the workpiece.
10. Doing this means the cutter is directly above the workpiece.
11. But if the milling table is at right angles to the horizontal arbor the cutter is going to
make cuts along the axis of the workpiece.
12. Clearly for a helical gear the cut needs to be made at an angle.
13. The way to do this is the make the table capable of swivelling round to the required
angle.
14. Usually this would be done using some sort of power feed.
15. A universal milling machine is one with a table that swivels.
16. A purely horizontal machine can only cut helical gears if it has a table that swivels.
17. Suppose the dividing head is to the left. The cutter is to the right of the workpiece.
The dividing head is set to zero. The sector arms are set to the number of spaces that
represents one tooth (or rather the gap between two teeth).
18. The cutter is set to the depth required.
19. The table moves to the right. This can be done by hand or by means of a motor. As
the table moves right it will rotate the workpiece.
20. After the cutter has cleared the workpiece and cut one gap, the milling table is
lowered so the cut will not touch the workpiece when the table is rewound back.
21. Once the cutter is to the right of the workpiece the table can be raised.
22. The workpiece is rotated to the cutting position of the next “tooth” by moving the
pin on the dividing head through the spaces as defined by the sector arms.
23. Then the sector arms are rotated. Then the next cut can start.
RESULT:
Thus the given workpiece is cut into Helical Gear using Milling machine.

EX.NO: DATE:
5. STUDY OF GEAR HOBBING MACHINE
AIM: To study about Gear Hobbing machine.
THEORY:
Gear Hobbing is a technique that is employed to create gear teeth configurations that are
ideal for use in a wide range of machinery components. In cases where the gear hobbing
takes place in a mass producing environment, gear hobbing is accomplished through the use
of precision gear hobbing machines that ensure that the cut of each tooth on each gear
produced meets the specifications set by the producer.
Generally, a gear hobbing machine will make use of a series of customized bits that help to
create the specific types of cutting and shaping necessary to create gears that posses exactly
the right pitch and circle to work in various types of equipment. A customized bit is used
for a particular size and type of gear hobbing, which helps to ensure that the cuts that are
made into the blank surface of the circle of metal are relatively smooth and uniform.
Hobbing uses a hobbing machine with two skew spindles, one mounted with a blank
workpiece and the other with the hob. The angle between the hob's spindle and the work
piece's spindle varies, depending on the type of product being produced. For example, if a
spur gear is being produced, then the hob is angled equal to the helix angle of the hob; if a
helical gear is being produced then the angle must be increased by the same amount as the
helix angle of the helical gear. The two shafts are rotated at a proportional ratio, which
determines the number of teeth on the blank;
WORKING PRINCIPLE OF GEAR HOBBING
Hobbing is a process of generating a gear by means of a rotating cutter called hob.
The hob has helical threads. Grooves are cut in the threads parallel to the axis. This will
provide the cutting edges. Proper rake and clearance angles are ground on these cutting
edges. The rotating hob acts like a continuously moving rack as it cuts.
The gear blank is mounted on a vertical arbor. The hob is mounted in a rotating
arbor. The hob axis is tilted through the hob lead angle α so that its teeth are parallel to the
axis of the gear blank.
Then α = (900
– α1)
Where α1 = helix angle of the hob thread.
The hob axis is inclined at α0
with the horizontal as shown in the figure.
(Note: hob lead angle = 900
- hob helix angle)
The hob is rotated at suitable cutting speed. It is fed across the blank face. The hob
and blank are made to rotate in correct relationship to each other ie, they rotate like a worm
and worm gear in mesh. For one rotation of the hob, the blank rotates by one tooth. (In case
of single start hob).
For cutting helical gears, the axis of the hob is inclined to horizontal by α0
where

α = θ + (900 – α1) (If the helix of the hob and the helix of the gear to be cut are
different ie. One is right handed and another is left handed)
α = θ - (900 - α1) (If the helix of hob and the helix of gear to be cut are both right
handed or both left handed)
Where θ - Helix angle of the helical gear to be cut
α1 - Helix angle of the hob.
Fig – 5.1. Generation of external gear teeth (Straight tooth) by Hobbing
APPLICATION
Hobbing is used for generating spur, helical and worm gears.
ADVANTAGES
1. A single hob with the given module can be used for generating gear with any
number of teeth of the same module.
2. The same hob can be used for spur and helical gears.
3. Operation is continuous. So very fast rate of production.
4. Perfect tooth shape is obtained.
5. Process is automatic and so less skilled operator is sufficient.
6. Worm gears are generated only by hobbing.
7. Multiple blanks can be cut at a time. Hence high rate of production.
LIMITATIONS
1. Internal gears cannot be generated.
2. Hobbing cannot be used for producing gear teeth very near to shoulders.
RESULT:
Thus the Gear Hobbing Machine is studied in detail.

EX.NO: DATE:
GEAR GENERATION IN GEAR HOBBING MACHINE
AIM:
To cut Spur Gear using a Gear Hobbing machine.
MATERIALS REQUIRED:
Cast iron blank -  86 X 25 X 20 mm
TOOLS REQUIRED:
1. Gear Hobbing machine
2. Gear Hob
3. Gear tooth vernier
4. Spanner set
Fig – 6.1 GIVEN WORKPIECE

Fig – 6.2 FINISHED WORK PIECE
PROCEDURE:
1. The given work piece is held firmly on the spindle of the gear hobbing machine.
2. The Hob is set at an angle to the hob helix angle for cutting spur gear.
3. The change gears are set for the desired speed of work piece and Hob and feed of
the Hob.
4. The machine is switched on.
5. The work piece and Hob are allowed to rotate at the desired speed.
6. The hob or work piece is given full depth of cut equals to the tooth depth.
7. The cutter is given feed for the full width of the work.
8. After machining all gear teeth on the blank the machine is switched off.
9. The gear teeth are checked using a gear tooth vernier.
RESULT:
Thus the given workpiece is cut into spur gear using Gear Hobbing machine.

EX.NO: DATE:
GEAR GENERATION IN GEAR SHAPING MACHINE
AIM:
To generate gear using gear shaping machine.
TOOLS REQUIRED:
1. Cast Iron workpiece
2. Gear shaper with attachment
3. Vernier Caliper
4. Spanner set
5. Bevel Protractor
GEAR SHAPER:
1. A gear shaper is a machine tool for cutting the teeth of internal or external gears.
2. The name shaper relates to the fact that the cutter engages the part on the forward
stroke and pulls away from the part on the return stroke, just like the clapper box on
a planer shaper.
3. The cutting tool is also gear shaped having the same pitch as the gear to be cut.
4. However number of cutting teeth must be less than that of the gear to be cut for
internal gears.
5. For external gears the number of teeth on the cutter is limited only by the size of the
shaping machine.
6. For larger gears the blank is sometimes gashed to the rough shape to make shaping
easier.
The principal motions involved in rotary gear shaper cutting are as following:
1. Cutting Motion: The downward linear motion of the cutter spindle together with
the cutter .
2. Return Stroke: The upward linear travel of the spindle and cutter to withdraw the
latter to its starting position.
3. Indexing Motion: Slow speed continuous rotation of the cutter spindle and work
spindle to provide circular feed, the two speeds being regulated through the change
gears .
4. Completion of Cutting Operation: The indexing and reciprocating motions
continue until the required number of teeth to the required depth are cut all along the
periphery of the gear blank

PROCEDURE:
1. Attach the shaper cutter to the gear shaping machine.
2. Perform gear cutting in vertical direction from the upper to the down section and
back to the upper section (non-cutting) in reciprocal motion.
3. As cutting cannot be performed at the returning motion, cutting is not as efficient as
hobbing with continuous processing.
4. Remove the workpiece from the attachment after the gear generation operation is
performed.
Fig – 7.1 SPUR GEAR GENERATION USING GEAR SHAPER
RESULT:
Thus the Gear generation is done on the given work-piece using Gear shaper.

EX.NO: DATE:
AN OVERVIEW ABOUT GRINDING
AIM: To study an overview about Grinding machine.
THEORY:
Grinding is the most common form of abrasive machining. It is a material cutting process
which engages an abrasive tool whose cutting elements are grains of abrasive material
known as grit. These grits are characterized by sharp cutting points, high hot hardness,
chemical stability and wear resistance. The grits are held together by a suitable bonding
material to give shape of an abrasive tool.
Fig – 8.1 Cutting Action of Abrasive Grits of Disc Type Grinding Wheel
ADVANTAGES
 Dimensional accuracy
 Good surface finish
 Good form and locational accuracy
 Applicable to both hardened and unhardened material
APPLICATIONS
 Surface finishing
 Slitting and parting
 Descaling , deburring
 Stock removal (abrasive milling) finishing of flat as well as cylindrical surface •
 Grinding of tools and cutters and resharpening of the same.

GRINDING OPERATIONS
Grinding operations are carried out with a variety of wheel-workpart configurations. The
basic types of grinding are
 Surface grinding,
 Cylindrical grinding, and
 Centerless grinding.
HORIZONTAL-SPINDLE SURFACE GRINDER:
FIGURE 12.3 Schematic illustration of
Fig-8.1 Horizontal-spindle surface grinder.
Surface grinding is an abrasive machining process in which the grinding wheel removes
material from the plain flat surfaces of the work piece. The majority of grinding operations
are done on such machines.
In surface grinding, the spindle position is either horizontal or vertical, and the relative
motion of the workpiece is achieved either by reciprocating the workpiece past the wheel or
by rotating it.

The major parts of a Horizontal - spindle Surface Grinder are as follows
1. Wheel head
2. Column
3. Bed
4. Saddle
5. Work Table
6. Grinding wheel
7. wheel guard
SURFACE-GRINDING OPERATIONS
Fig - 8.2 Schematic Illustrations of Surface-Grinding Operations.
(a) Traverse grinding with a horizontal-spindle surface grinder.
(b) Plunge grinding with a horizontal-spindle surface grinder, producing a groove in the
work piece.
(c) Vertical-spindle rotary-table grinder (also known as the Blanchard-type grinder).
GRINDING WHEEL:
A grinding wheel consists of abrasive particles and bonding material. The bonding material
holds the particles in place and establishes the shape and structure of the wheel. Grinding
wheel consists of hard abrasive grains called grits, which perform the cutting or material
removal, held in the weak bonding matrix. A grinding wheel commonly identified by the
type of the abrasive material used. The conventional wheels include aluminium oxide and
silicon carbide wheels while diamond and CBN (cubic boron nitride) wheels fall in the
category of superabrasive wheel.

The way the abrasive grains, bonding material, and the air gaps are structured, determines
the parameters of the grinding wheel, which are
 Abrasive material,
 Grain size,
 Bonding material,
 Wheel grade, and
 Wheel structure.
To achieve the desired performance in a given application, each parameter must be
carefully selected.
ABRASIVE CUTTING TOOLS:
There are three principle types of abrasive cutting tools according to the degree to which
abrasive grains are constrained,
1. Bonded abrasive tools: Abrasive grains are closely packed into different shapes,
the most common is the abrasive wheel. Grains are held together by bonding
material. Abrasive machining process that use bonded abrasives include grinding,
honing, superfinishing.
2. Coated abrasive tools: Abrasive grains are glued onto a flexible cloth, paper or
resin backing. Coated abrasives are available in sheets, rolls, endless belts.
Processes include abrasive belt grinding, abrasive wire cutting.
3. Free abrasives: Abrasive grains are not bonded or glued. Instead, they are
introduced either in oil-based fluids (lapping, ultrasonic machining), or in water
(abrasive water jet cutting) or air (abrasive jet machining), or contained in a
semisoft binder (buffing).
CYLINDRICAL CENTRE- TYPE GRINDER:
Cylindrical centre- type grinders are intended primarily for grinding Plain
cylindrical parts, although they can also be used for grinding contoured cylinders, fillets
and even cams and crank shafts. The different parts of a cylindrical centre- type grinder are
shown in fig.
The principal parts of a cylindrical centre- type grinder are:
1. Base
2. Tables

3. Head stock
4. Tailstock
5. Wheel head
6. Cross-feed
1. BASE
The base or bed is the main casting that rests on the floor and supports the parts
mounted on it. On the top of the base are precision horizontal ways set at right angles for
the table to slide on. The base also houses the table- drive mechanism.
2. TABLES
There are two tables – lower table and upper table. The lower table slides on ways
on the bed provides traverse of the work past the grinding wheel. It can be moved by hand
or power within desired limits.
The upper table that is provided at its center is mounted on the top of the sliding
table. It has T- Slots for securing the headstock and tailstock and can be positioned along
the table to suit the length of the work. The upper table can be swiveled and clamped in
position to provide adjustment for grinding straight or tapered work as desired.
3. HEADSTOCK
The headstock supports the work piece by means of a dead center and drives
it by means of a dog, or it may hold and drive the work piece in a chuck.
4. TAILSTOCK
The tailstock can be adjusted and clamped in various positions to
accommodate different lengths of work pieces.
5. WHEEL HEAD
The wheel head carries a grinding wheel and its driving motor is mounted on a slide
at the top and rear of the base. The wheel head may be moved perpendicularly to the table
ways, by hand or power, to feed the wheel to the work.
6. CROSS-FEED
The grinding wheel is fed to the work by hand or power as determined by the
engagement of the cross – feed control lever.

Fig – 8.3 Cylindrical Centre-Type Grinder
RESULT:
Thus the overview of Grinding machine is studied.

EX.NO: DATE:
MACHINING A WORK PIECE USING A SURFACE GRINDING MACHINE
AIM:
To grind the given workpiece using a surface grinding machine.
MATERIALS REQUIRED:
Mild steel Flat - 80 X 50 X 10 mm
TOOLS REQUIRED:
1. Surface grinding machine
2. Vernier Caliper
Fig -9.1 GIVEN WORKPIECE

Fig -9.2 FINISHED WORKPIECE
PROCEDURE:
1. The given work piece is held firmly on a magnetic chuck of a surface grinder.
2. The machine is started and the grinding wheel is allowed to revolve at a selected
speed.
3. After giving a depth of cut, the work piece is made to reciprocate under the grinding
wheel.
4. The table is fed axially between passes to produce a fine flat surface.
5. The process is repeated for grinding another side until the desired dimension is
achieved.
6. The dimensions are checked for its given dimensions using a vernier caliper.
RESULT:
Thus the Grinding operation is performed on the given workpiece.

EX.NO: DATE:
MACHINING A WORK PIECE USING A CENTRE TYPE
CYLINDRICAL GRINDING MACHINE
AIM:
To grind a work piece using a cylindrical grinding machine.
MATERIALS REQUIRED:
Mild steel polished round rod -  25 x 150 mm
TOOLS REQUIRED:
1. Centre type cylindrical grinder
2. Vernier Caliper
3. Spanners
Fig – 10.1 GIVEN WORKPIECE
PROCEDURE:
1. The given work piece is held between centers.
2. The machine is switched on and the grinding wheel is allowed to revolve at a
selected speed.
3. By giving longitudinal and cross feeds the work piece is ground for the required
dimensions.
4. The work piece is removed from the machine and is checked for the given
dimensions.

Fig – 10.2 FINISHED WORK PIECE
RESULT:
Thus the grinding operation is performed on the given workpiece using cylindrical
Grinding machine.

EX.NO: DATE:
TOOL ANGLE GRINDING USING TOOL AND CUTTER GRINDER
AIM:
To sharpen all kinds of cutting tools like milling cutter, hobs, gear cutter using Tool and
Cutter Grinder.
TOOLS REQUIRED:
1. Hss Tool bit
2. Carbide Tip tool
3. Spanner set
4. Bevel Protractor
5. End mill cuttert
PROCEDURE:
GRINDING MILLING CUTTERS:
 Milling cutters must be sharpened occasionally to keep them in good operating
condition.
 When grinding milling cutters, care must be exercised to maintain the proper angles
and clearances of the cutter.
 Improper grinding can result in poor cutting edges, lack of concentricity, and loss of
form in the case of formed tooth cutters.
 Milling cutters cannot be sharpened by offhand grinding. A tool and cutter grinding
machine must be used.
BENCH-TYPE TOOL AND CUTTER GRINDING MACHINE:
1. The bench-type tool and cutter grinding machine described here is typical of most
tool and cutter grinding machines.
2. It is designed for precision sharpening of milling cutters, spot facers and
counterbores, reamers, and saw blades.
3. The grinding machine contains a l/4-HP electric motor mounted to a swivel-type
support bracket which can be adjusted vertically and radically on the grinder
column.
4. The column is fixed to the grinder base which contains T-slots for attaching grinder
fixtures used to support the tools that are to be ground.
5. The motor shaft or wheel spindle accepts grinding wheels on each end.
6. One end of the spindle contains a wheel guard and tool rest for offhand grinding of
lathe tools.

7. Cup, straight, and 15º bevel taper abrasive grinding wheels are used with this
machine.
8. Fixtures used for grinding tools and cutters include a center fixture for mounting
reamers, taps, and so forth between centers;
9. The grinding wheel should be set up so that the wheel traverse is aligned with the
face of one tooth (Figure 5-18).
10. The alignment should be checked by moving the grinding wheel away from the
cutter, rotating the cutter, and rechecking the traverse on another tooth.
11. After this alignment is accomplished, the depth of cut, is regulated by rotating the
cutter slightly, thus maintaining the same rake angle on the sharpened cutter.
12. The depth of cut should never be obtained by moving the cutter or grinding wheel in
a direction parallel to the wheel spindle.
NOTE: A positive rake angle is a rake angle that increases the keenness of the cutting
edge. A negative rake angle is one that decreases or makes the cutting edge more blunt.
RESULT:
Thus the grinding operation is performed on the given tool using tool and cutter grinder.

EX.NO: DATE:
MEASUREMENT OF CUTTING FORCE IN MILLING PROCESS
AIM:
To measure cutting force in Milling machine using Milling Tool Dynamometer.
TOOLS REQUIRED:
1. Milling Tool Dynamometer
2. Dividing head
3. 7/8” Arbor
PROCEDURE:
1. This is a simple and easy to understand set up to study the behavior of cutting forces
during milling operation in three directions.
2. With this unit we can evaluate cutting forces for varying cutting depth, speed and
feed.
3. The unit works on standard method of Octagonal ring with strain gauges.
4. It is in two parts one mechanical set up consisting a set of octagonal rings
sandwiched between two M.S. plates with strain gauges fixed on it.
5. This set of octagonal rings transmits the relevant data to the force indicator during
milling operation.
6. Milling tool dynamometer is a Rigid in construction, Compact Unit, Easy in
handling and Assessment of cutting forces by giving due consideration to various
parameters like depth of cut, material, speed and feed.
7. It has Digital force indicators to measure three forces simultaneously.
SCPOE OF EXPERIMENTATION :
1. To measure force values in three directions.
2. To study the change in these forces by varying speed cut and feed.
UTILITY REQUIRED :
 Necessary Milling Machine with automatic feed arrangement and tooling and 230
Volts, Single phase, 50 Hz stabilized power supply.
TECHNICAL DETAILS :
1. Mechanical sensing unit with set of octagonal rings and strain gauges.
2. Three channel Digital Force Indicator with balancing potentiometers and
polycarbonate front plate.
3. Range of force measurement in coordinate direction – 0 to 500 Kg.
4. Overall size of mechanical unit – 300 x 300 mm

Fig – 12.1 Milling Tool Dynamometer
RESULT:
Thus the cutting force is measured using Milling Tool Dynamometer.

EX.NO: DATE:
MEASUREMENT OF CUTTING FORCE IN TURNING PROCESS
AIM:
To measure cutting force in Turning operation using Lathe Tool Dynamometer.
TOOLS REQUIRED:
1. Lathe tool Dynamometer
2. Sensor
3. Single Point cutting tool
PROCEDURE:
1. Lathe Tool Dynamometer is a cutting force measuring instrument used to measure
the cutting forces coming on the tool tip on the Lathe Machine.
2. The sensor is designed in such a way that it can be rigidly mounted on the tool post,
and the cutting tool can be fixed to the sensor directly.
3. This feature will help to measure the forces accurately without lose of the force.
4. The sensor is made of single element with three different wheat stones strain gauge
bridge.
5. Provision is made to fix 1/2" size Tool bit at the front side of the sensor.
6. The tool tip of the tool bit can be grind to any angle required.
Forces in X - Y - Z directions will be shown individually & simultaneously in three
Digital Indicators Supplied.
TECHNICAL DETAILS:
CAPACITY : X,Y,Z – Force
500Kg
EXCITATION : 10V DC
LINEARITY : 2%
ACCURACY : 2%
CROSS-SENSITIVITY : 5%
MAX. OVER LOAD : 150 %
Fig – 13.1 Lathe Tool
Dynamometer
RESULT:
Thus the cutting force is measured using Lathe Tool Dynamometer.

EX.NO: DATE:
14. STUDY OF CNC MACHINES
AIM: To study about CNC machine’s and its codes.
COMPUTER NUMERICAL CONTROL:
Numerical Control(NC) is a form of programmable automation in which the processing
equipment is controlled by means of numbers, letters, and other symbols. The numbers,
letters, and symbols are coded in an appropriate format to define the program of
instructions for a particular job.
Computer Numerical Control (CNC) is a reprogrammable microprocessor based control
system that accepts a set of programmed instructions, processes and sends O/P control
information to a machine tool ,accepts feed back information to a machine tool from a
transducer and based on the instructions and feed back it assures that proper motion, speed
and operation occurs.
A CNC system may be characterized in terms of three major elements, hardware,
software and information.
HARDWARE :CNC hardware includes the microprocessors that effect control system
functions and peripheral devices for data communication, machine tool interfacing and
Fig – 14.1 BLOCK DIAGRAM OF CNC SYSTEM
ACTUATING DEVICES (SPINDLE
MOTOR, SERVO MOTOR AND
CONTROLLERS)
CNC CONTROLLER
MACHINE
TOOL
FEED BACK
TRANSDUCER
NC PROGRAMME

machine tool status monitoring . In addition to, certain elements of the machine tool like
transducers, actuators can be considered part of the CNC system
SOFTWARE : CNC software includes the programs that are executed by the system
microprocessors. These programs process input and output instructions and control
information ,make all necessary computations for machine functions, coordinate the
functions of these machines and accessories and provide the communication links with
other levels of manufacturing automation .The instructions that drive a CNC system are
frequently generated using special programming languages like APT based CNC
programming systems.
INFORMATION : CNC operation requires data such as cutter location data, machining
data information regarding the dynamic characteristics of the machine and many other
information pertaining to the process.
TYPES OF CNC MACHINES
1. Vertical Machining Centers (VMC)
2. Horizontal Machining Centers (HMC)
3. Multi-axis machining centers
4. Milling machines
5. Drilling machines
6. Surface Grinders
7. Cylindrical grinders
8. Tool and cutter grinders
9. Fixed RAM Electro Discharge machines (EDM)
10. Wire EDM
11. Punching and nibbling machines with plasma arc or laser beam machining
12. Forming machine
13. Gear cutting machines
14. Coordinate Measuring Machines (CMM)

FEATURES OF CNC TURNING MACHINES
1. High powered drives and wide speed range
2. Simultaneous 2 tool operation with 4 axis machines
3. High duty drums type turrets capable of accommodating internal as well as
external turning tools.
4. Automatic tool changer(ATC) facility
5. Off axis machining facility
6. Probes for work piece size monitoring, tool condition monitoring, inspection of
tools and setting of automatic tool offsets
7. Programmable tail stock
CNC PROGRAMMING
PART PROGRAMMING :
The part programming method include a variety of procedures ranging from highly manual
to highly automated . The types of part program are
1.Manual Part Programming
2.Computer assisted part programming
3.Computer automated part programming
4.NC programming using CAD/CAM
MANUAL PART PROGRAMMING:
In Manual Part Programming the programming instructions are documented on a
form called a part programming manuscript . The manuscript is a listing of the positions of
the tool relative to the work piece that the machine must follow in order to perform the
processing . The listing may include other commands such as speeds, feeds, tooling and so
on. A punched tape is then prepared from the manuscript.
COMPUTER ASSISTED PART PROGRAMMING:
In computer assisted part programming much of the tedious computational work
required in manual part programming is performed by computer. For complex work part
jobs with many processing steps, use of the computer results in significant savings time .
when computer assisted part programming is used the programmer prepares the set of
processing instructions in a higher level computer language. The high level language
commands are interpreted by the computer and the required data calculations and data
processing are accomplished to prepare the NC program.

NC PROGRAMMING USING CAD/CAM:
NC programming using CAD/CAM is an advanced form of computer assisted part
programming in which an interactive graphics system equipped with NC programming
software is used to facilitate the part programming task. In this method the programmer
works on a CAD/CAM workstation to enter the machining commands .The actions
indicated by the commands are displayed on the graphics monitor, which provides visual
feedback to the programmer .Also certain portions of the programming cycle are automated
by the NC programming software to reduce the total programming time required.
COMPUTER AUTOMATED PART PROGRAMMING:
Computer automated part programming extends the notion of automating certain
portions of the NC part programming procedure to its logical conclusion. It automates the
complete part programming task using software that is capable of making logical even
quasi intelligent decisions about how the part should be machined.
For writing CNC programming the required data are
 Dimension of the work pieces
 Finished dimension with tolerance of the final component
 Sequence of the operations to be performed
 Types of tools to be used
 Optimum cutting speed & feed at each stage
 Method of clamping / chucking of job
 Mounting of tools

The process of putting all these data into the proper order and translating them into a
language that the machine control system can understand is called part programming.
Therefore a part program is the set of (alpha- numeric) coded form of step by step
instructions in a pre determined sequence that are entered into the control system of CNC.
General Format of a Block
End of Block
N0018 G00 X12 Z21 S500 M03;
Words
Block No.

NC Words
The list of addresses used in the words are
CHARACTER FUNCTION
A Rotating about X axis
B Rotating about Y axis
C Rotating about Z axis
D & E Rotating about additional axis
F Feed
G
Preparatory function, identifying the action
to be executed
H Unassigned
I
Interpolation parameter / Thread pitch
parallel to X axis
J Thread pitch parallel to Y axis
K Thread pitch parallel to Z axis
L Unassigned
M Auxiliary function
N Block number
O Prefix add the program no
P,Q,R
Thread movement parallel to X,Y & Z axes
respectively. P&Q are also used as
parameters in cycles
S Spindle speed
T Tool No
U,V,W
Second Movement parallel to X,Y,Z
respectively
X Movement in X axis
Y Movement in Y axis
Z Movement in Z axis

PREPARATORY FUNCTION (G-FUNCTION) FOR CNC MACHINES
The preparatory function (also called as G-code) is those, which decides the
mode of tool movement operation. The purpose of G-code is to initiate motion
command, canned cycles, various machine functions, and other control
capabilities. More than one G-code may be specified per block .If conflicting G-
code are specified on a block, an error message will appear.
G – Codes (Preparatory Function )
GODE FUNCTIONS
CNC MILLING CNC LATHE
G00 Rapid traverse Rapid traverse
G01 Linear cutting Linear cutting
G02 Circular cutting clock wise Circular cutting clock wise
G03 Circular cutting anti clock wise Circular cutting anti clock wise
G04 Dwell time Dwell time
G20 Inch command input Inch command input
G21 Metric input Metric input
G28 Automatic zero return Automatic zero return
G40 Cutter radius offset cancel Cutter radius offset cancel
G41 Cutter radius offset LEFT Cutter radius offset RIGHT
G42 Cutter radius offset RIGHT Cutter radius offset LEFT
G70 -- Multiple turning finishing cycle
G71 -- Multiple turning roughing cycle
G73 Peck drilling Pattern repeating cycle
G74 Reverse tapping cycle End face peck drilling
G75 -- Grooving cycle
G76 Fine boring cycle Multiple threading cycle
G80 Canned cycle cancel Canned cycle cancel

G81 Spot drilling cycle Drilling cycle
G82 Counter boring cycle Counter boring cycle
G83 Peck drilling cycle Peck drilling cycle
G84 Tapping cycle Tapping cycle
G87 Back boring cycle Back boring cycle
G90 Absolute command Turning cycle
G91 Incremental command Incremental command
G94 Feed in mm/min Facing cycle
G95 Feed in rev/min Feed in rev/min
G98 Initial point level return Feed in mm/min
G99 Point ‘R’ level return Point ‘R’ level return
M – Codes (Miscellaneous Codes)
GODE
FUNCTIONS
CNC MILLING CNC LATHE
M00 Program stop Program stop
M01 Optional stop Optional stop
M02 Program end Program end
M03 Spindle rotation Clock wise Spindle rotation Clock wise
M04
Spindle rotation anti clock
wise
Spindle rotation anti clock
wise
M05 Spindle rotation stop Spindle rotation stop
M06 Automatic Tool changing Automatic Tool changing
M08 Coolant ON Coolant ON
M09 Coolant OFF Coolant OFF
M30 Program End and Rewind Program End and Rewind

M70 X axis mirror image ON --
M71 Y axis mirror image ON --
M80 X axis mirror image OFF --
M81 Y axis mirror image OFF --
M98 Sup program call Sup program call
M99 Sup program call Sup program call
SPECIFICATIONS
CNC LATHE:
GENERAL:
Length :600 mm
Width :425 mm
Height :430 mm
CAPACITY:
Distance between centers :250 mm
Swing over cross slide : 38 mm
Swing bed : 38 mm
Spindle taper : no :1MT
Spindle bore :10 mm
X axis ball screw dia :8 mm x 2.5 mm pitch
Z axis travel :10 mm x 4 mm pitch

CNC MILLING MACHINE
GENERAL
Length :550 mm
Width :540 mm
Overall height :880 mm
CAPACITY
Max cross travel :90 mm
Max longitudinal travel :170 mm
Max head travel :115 mm
Spindle nose to table top :190 mm
Spindle to column :110 mm
Spindle topper :R8
Working table surface :360 x 130 mm
3-axis scale :10 x 50 mm center
Z axis ball screw :16 mm dia 5mm pitch
Yaxis ball screw :16 mm dia 5mm pitch
X axis ball screw :16 mm dia 5mm pitch
Machine resolution :0.01 mm
RESULT:
An overview about CNC machine is studied in detail.

EX.NO: DATE:
MANUAL PART PROGRAMMING FOR STEP TURNING
AIM:
To write a manual part program for Step turning and to machine the given work piece.
MATERIALS REQUIRED:
Aluminium round rod -  25 x 100 mm
TOOLS REQUIRED:
1. CNC Turning machine
2. Micrometer
3. Vernier caliper
Fig – 15.1 Given Workpiece
Fig – 15.2 Finished Workpiece

PROGRAM:
O101;
BILLET X25 Z100;
G21 G98;
G28 U0 W0;
M06 T08;
M03 S800;
G00 X26 Z1;
G71 U0.3 R1;
G71 P11 Q12 U0.2 W0.2 F60;
N12 G01 X21;
G01 X21 Z-25;
G01 X23 Z-25;
G01 X23 Z-50;
G01 X23 Z-50;
N13 G01 X25 Z-50;
G70 P11 Q12 F70;
G28 U0 W0;
M05;
M30;
PROCEDURE:
1. The given geometry is studied and a part program is written using G - Codes
and M – Codes.
2. The CNC machine control unit is switched on.
3. Then the computer is switched on in DOS mode.
4. Enter into the NOVATURN directory.
5. Type the command FLSTEP.
6. Now it enters into the simulation mode.
7. The part program which have been written already is entered into the
system.

8. For verifying the simulation F9 key is pressed and the machining process is
verified.
9. The appropriate tool is selected from the tool magazine.
10. The tool offset is obtained by moving the tool.
11. Using AUTO and CYCLE START buttons the program is executed and
actual machining is done on the given work piece.
RESULT:
The manual part programming is written and the given workpiece is machined in CNC
machine to obtain the completed workpiece.

EX.NO: DATE:
COMPONENT DRAWING, MANUAL PART PROGRAMMING AND
EXECUTION ON CNC MILLING MACHINE
AIM:
To write a given manual part program for the given component drawing and
to machine the given work piece.
MATERIALS REQUIRED:
Aluminium plate - 100 x 100 x 10 mm
TOOLS REQUIRED:
1. CNC Milling machine
2. Micrometer
3. Vernier caliper
Fig – 16.1 Given Workpiece

Fig – 16.2 Finished Workpiece
PROGRAM:
O106;
BILLET X100 Y100 Z10;
EDGEMOVE X0 Y0;
TOOLDEF TO1 D06;
G21 G94;
G91 G28 X0 Y0 Z0;
M06 T01;
M03 S800;
G90 G00 X0 Y0 Z5;
G00 X22 Y20;
G01 Z-0.3 F60;

G91 G01 X68 Y0;
G01 X0 Y60;
G01 X-25 Y0;
G03 X-32 Y0 R16;
G01 X-25 Y0;
G01 X0 Y-48;
G01 X12 Y-12;
G00 Z10;
G90 G00 X21 Y25.5;
G172 P1 Q0.3 R0 X 21 Y25.5 Z-1 I18 J27 K0;
G173 I0.1 P60 S1500 R35 F45 B2000 J50 Z2;
G00 G90 Z5;
G00 X50 Y80;
G170 P1 Q0.3 R0 X50 Y80 Z-1 I0.1 J0.1 K12.5;
G171 P60 S1500 R35 F45 B2000 J50;
G90 G00 Z10;
G00 X61 Y45;
G83 X61 Y45 Z-5 Q2 F40;
X73 Y24;
X73 Y58;
G91 G28 X0 Y0 Z0;
M05;
M30;

PROCEDURE:
1. The given geometry is studied and a part program is written using G - Codes and M
– Codes.
2. The CNC machine control unit is switched on.
3. Then the computer is switched on in DOS mode.
4. Enter into the XLMILL directory.
5. Type the command FANUCMD.
6. Now it enters into the simulation mode.
7. The part program which have been written already is entered into the system.
8. For verifying the simulation F9 key is pressed and the machining process is verified.
9. The appropriate tool is selected from the tool magazine.
10.The tool offset is obtained by moving the tool.
11.Using AUTO and CYCLE START buttons the program is
executed and actual machining is done on the given work piece.
RESULT:
The manual part programming is written and the given workpiece is machined in CNC
machine to obtain the finished workpiece.

Mt 2 me8462- lab manual

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