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MANUFACTURING TECHNOLOGY LAB

(U18LCAU4L2)

B.TECH AUTOMOBILE ENGINEERING

LAB MANUAL

DEPARTMENT OF AUTOMOBILE ENGINEERING

Bharath Institute of Higher Education and Research (BIHER)

173, Agaram Main Rd, Selaiyur, Chennai, Tamil Nadu, India-600073.

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U18LCAU4L2

MANUFACTURING TECHNOLOGY LAB L T P C

Total Contact Hours - 45 0 0 2 1

Prerequisite – Workshop Technology

Course Designed by- Department of Automobile Engineering

OBJECTIVE

To make the student understand various process, capabilities of lathe, drilling machine, milling machine and shaper machine

LIST OF EXPERIMENTS 1. Cylindrical surface process 2. Lathe – Taper turning and external thread cutting

3. Drilling machine – Drilling, Tapping & Reaming

4. Milling process – Surface milling

5. Gear manufacturing process – spur gear, gear hobbing

6. Shaping process – keyway cutting

7. Surface finishing process – surface grinding, cylindrical grinding

Course Outcomes

Ability to use different machines depending on job profile requirement

Ability to use different machine tools depending on job surface requirement

Ability to manufacture single point cutting tool using cutter grinder

Ability to manufacture gear through generation process

Ability to use different grinding machine process

Mapping of Course Outcomes with Program outcomes (POs)

(H/M/L indicates strength of correlation) H-High, M-Medium, L-Low

1 COs/POs a b c d e f g h i j k l PSO1 PSO2 PSO3

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CO1 H M L M M M H H

CO2 H M L M H H

CO3 H H M M M M L H H

CO4 M H M L M L H H

CO5 M M H L L M M

CO6 M H H H

3 Category Professional Core (PC)

4 Approval 47th Meeting of Academic Council held in Aug, 2018

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LIST OF EXPERIMENTS

1. Cylindrical surface process

2. Lathe – Taper turning and external thread cutting

3. Drilling machine – Drilling, Tapping & Reaming

4. Milling process – Surface milling

5. Gear manufacturing process – spur gear, gear hobbing

6. Shaping process – keyway cutting

7. Surface finishing process – surface grinding, cylindrical grinding

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TABLE OF CONTENTS Ex

p.

No.

Name of Experiments Page

No.

1 Introduction to lathe machine 6

2 Cylindrical surface process 10

3 Lathe- Taper turning 13

4 Lathe- External Thread cutting 17

5 Drilling Machine-Drilling, Tapping

and Reaming

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6 Milling Process-Surface Milling 25

7 Gear manufacturing process – spur

gear

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8 Gear manufacturing process- gear

hobbing

31

9 Shaping process – keyway cutting 33

10 Surface finishing process – surface

grinding

37

11 Surface finishing process –cylindrical

grinding

39

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GENERAL INSTRUCTIONS

1. All the students are instructed to dress appropriately. Remove

any necklaces or other dangling jewelry, wristwatch or rings.

Secure any loose-fitting clothing and roll up long sleeves. Wear

an apron or a properly fitted shop coat. Safety glasses are a

must.

2. Do not attempt to operate a machine until you know the proper

procedures and have been checked out on its safe operation by

your instructor.

3. Keep the machine clear of tools and always stop the machine

before making measurements and adjustments.

4. Don't operate any machine without getting concerned staff

member's prior permission.

5. All the students are advised to come with completed record and

corrected observation book of previous experiment.

6. Extreme care must be taken to avoid any possible injury while

on laboratory work.

7. In case, anything occurs immediately report to the staff

members.

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Experiment No-01

Introduction to Lathe Machine

LATHE (Turning Machine)

INTRODUCTION

A lathe is the father of all machine tools. It is a basic machine tool, probably the most important one

of all lathe was actually the first machine tool.

Lathe is a particular type of machine tool in which the work is held and rotated against a suitable

cutting tool for the purpose producing surface of revolution in any material.

The main function of a lathe is to remove metal in the form of chips from a workpiece to give it the

required shape and size. Generally, single point cutting tool is used as the cutting tool. The tool

material should be harder and stronger than the workpiece material.

PARTS OF CENTRE LATHE:

1. Bed 2. Head stock 3. Tail stock.

4. Carriage (a) Saddle (b) Cross-slide (c) Compound rest (d) Tool post (e) Apron

SPECIFICATIONS:

Capacity

(i) Distance between centers (ii) Swing diameter over the bed (iii) Swing over Carriage

Other Factors

(a) Horse power of the motor (b) Cutting speed range (c) Feed range

(d) Screw cutting capacity (e) Accuracy achievable (f) Spindle nose diameter and hole size.

TYPES OF LATHE

1. Centre lathe

(a) Belt drive (b) Individual motor drive (c) Gear head lathe

2. Speed lathe.

(a) Wood working lathe (b) Centering (c) Polishing lathe (d) Metal spinning

3. Bench lathe

This is a small lathe, usually mounted on a bench. This is used for small and precision work.

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4. Tool room lathe

A tool room lathe is a very accurate lathe. This lathe mainly used for precision work on tools,

dies, gauges and in machining work where accuracy is needed.

5. Capstan and Turret lathe (Semi-automatic lathe)

These lathes are development of engine lathe and used for mass production. Instead of tail

stock it has hexagonal turret fixed in the carriage carrying six tools. The advantage is that

several different types of operations can be done on work piece a without re-setting of work

or tools.

6. Automatic lathe

In this, all the operations and all the tool movements are automatic, and changing of tools,

speeds are also done automatically. No participation of the operator is necessary during the

operation.

7. Special purpose lathe (a)

Wheel lathe (b) Gap bed lathe (c) T/- lathe (d) Duplicating lathe (e) Missible lathe

FEED MECHANISM

1. End of bed gearing 2. Feed gear box 3. Feed rod and lead screw 4 Apron mechanism,

THREAD CUTTING MECHANISM

1. Right hand thread 2. Left hand thread 3. Single start thread 4. Multi start thread

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Study of Lathe Introduction:

The most important machine used in workshop is Lathe. The main function of a lathe is to remove

metal from a piece of work to give the required shape and size. A lathe removes metal by rotating the

work piece against a single point cutting tool. Generally, lathe is used to machine cylindrical shapes.

The parts to be machined can be held between two rigid supports called live and dead centers. The

tool is moved perpendicular to the work piece axis to produce a cylindrical surface.

Principle parts of Lathe:

Principle parts of the Lathe are as follow:

1. Bed; 2. Headstock; 3. Tails stock; 4. Carriage; 5. Saddle ; 6. Compound rest;

7. Tool post; 8. Apron

Bed:

It is the base of the lathe. The head stock is mounted on the left end, the carriage in the middle and the

tailstock at the right end of the bed. The bed has flat and inverted ‘V’ guide ways which is ground

smooth finish to slide the carriage and tailstock smoothly along the guide ways over the bed.

Head Stock:

It consists of hallow spindle which rotates with the help of prime mover (motor) through belt drive. A

live center be fitted into the hallow spindle to hold the work piece along with dog ( Screw

clamp with elbow). A chain of gear drive is attached with the head stock to change the speed and

direction of the rotation of the lathe.

Tail Stock:

It is mounted on the bed at its right end and can slide along the bed and clamped rigidly as required

the length of work piece. It is used for supporting the right end of the work piece to hold by means of

a dead center.

Carriage:

It is fitted on the middle portion of lathe bed over the guide ways and can move in a direction parallel

to the lathe axis. It carries Saddle, Cross-slide, Compound rest, Tool post and Apron.

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(i) Saddle:

It carries the cross slide. compound rest and ‘tool post. It is a ‘H’ shaped casting fitted over the

bed and move along the guide ways.

(ii) Cross-slide:

It carries the compound rest and tool post. It is mounted on the top of the saddle. It can be moved

by hand or may be given power feed through apron mechanism.

(iii) Compound rest

It is mounted on the cross slide. It carries a circular base called swivel plate which graduated in

degrees. It is used during taper turning to set the tool for angular cuts. The upper part known as

compound slide can be moved by means of a hand wheel.

(iv) Tool post:

The tool post is fitted over the compound rest. The tool is clamped in the tool post. There are four

types of tool post.

(a) Single screw tool post

(b) Open side tool post

(c) Four bolt tool post

(d) Four way tool post

(v) Apron:

The hanging part in front to the carriage is termed as the apron. It is attached the saddle and hangs

in front of the bed. It contains gears, clutches and levers for moving the carriage by a hand wheel

or power feed.

Operations performed on Lathe:

Some of the typical operations performed on the lathe are listed and briefly explained below.

Facing: It is the machining of the end of the work piece to produce the flat surface. This

operation may be performed by using facing tool or ordinary turning tool.

Turing: It is the process of removing excess material from a work piece to produce a cylindrical

surface. For ’Rough Turning’ the rate of feed of tool is fast and the depth of cut is heavy. For

‘Finish Turning feed and depth of cut will be small and it is to bring the work piece to the required

size and to produce a good surface finish.

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Taper turning: Producing a conical or taper surface is called taper turning. This taper turning is

achieved by any one of the following methods

Forming tool method

Compound rest method

Tail stock set over method

Taper turning attachment method.

Drilling: In lathe the work rotates and the drill is fixed in tail stock and fed. The job is

held in a chuck or face plate. An impression is first made at the center of the job then drilling is

proceed by hand feed by rotating the tail stock wheel, where the drill penetrates horizontally to

the work piece.

Thread cutting: The principle of thread cutting is to produce helical groove on a cylindrical or

conical surface by feeding the tool longitudinally, The job is held between centers or by a chuck.

The tool used is called threading tool.

Knurling: It is the process of producing straight or diamond shaped impression on the

surface of the work piece. A knurling tool is used to produce knurled surface.

Grooving: It is the machining of reducing the diameter of work piece on a particular

position by a grooving tool as forming method. Recessing, Undercutting, Necking are all the

same type of operation done different kind of tools.

Chamfering: It is the operation of turning as taper at the end of work. It removes the sharp

edge. It is done by chamfering tool or side edge cutting face of ordinary turning tool.

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Experiment No-02

Cylindrical Surface Process

OBJECTIVE: Finishing of a surface on surface –grinding machine.

APPARATUS: Steel rule Try square, Vernier caliper

THEORY: Surface grinding machines are useful to produce and finish flat and plane surface.

Types of grinding machines: Transverse grinding, Plunger grinding

PROCEDURE: (take square section)

1. The given work piece is taken and checked for its dimensions.

2. The job is placed on the grinding magnet at opened position.

3. Then each face is grinded to the required accuracy by constant speed.

4. The job is removed from the required accuracy. It is checked by using

vernier caliper and squareness is checked by using try square.

Result: Thus the square section is grinded to the required accuracy in grinding machine.

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Experiment No-02

Lathe – Taper Turning and External Thread Cutting

1. Step Turning and Taper Turning On Lathe

AIM:

To perform Step turning and Taper turning operations on the given work piece.

MATERIAL REQUIRED:

Mild steel rod of 25 mm diameter and 100 mm long.

TOOLS REQUIRED:

Vernier calipers, steel rule, spanner, chuck spanner, and H.S.S. single point

cutting tool.

SPECIFICATION OF LATHE:

Length of bed 1390 mm

Width of bed 200 mm

Height of centers 165 mm

Admit between centers 700 mm

Lead screw pitch 4TPI

Power of the motor 1 hp.

THEORY:

Lathe removes undesired material from a rotating work piece in the form of chips with the help

of a tool which is traversed across the work and can be fed deep in work. The tool material

should be harder than the work piece and the later help securely and rigidly on the machine. The

tool may be given linear motion in any direction. A lathe is used principally to produce

cylindrical surfaces and plane surfaces, at right angles to the axis of rotation. It can also produce

tapers and bellows etc.

A lathe (shown in fig.) basically consists of a bed to provide support, a head stock, a cross side to

traverse the tool, a tool post mounted on the cross slide. The spindle is driven by a motor through

a gear box to obtain a range of speeds. The carriage moves over the bed guide ways parallel to

the work piece and the cross slide provides the transverse motion. A feed shaft and lead screw

are also provided to power the carriage and for cutting the threads respectively.

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SEQUENCE OF OPERATIONS:

Centering

Facing

Plain turning

Chamfering

Step turning

Grooving

Taper turning

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PROCEDURE:

The work piece is fixed in a 3-jaw chuck with sufficient overhang.

Adjust the machine to run the job to a required cutting speed.

Fix the cutting tool in the tool post and centering operation is performed so that the axis

of the job coincides with the lathe axis.

Give the feed and depth of cut to the cutting tool

Facing operation is performed from the center of the job towards outwards or from the

circumference towards the center.

Plain turning operation is performed until the diameter of the work piece reduces to 23

mm.

Check the dimensions by using vernier calipers.

Then chamfering is done on the 23mm diameter surface.

Reverse the work piece in the chuck and facing operation is performed to reduce the

length of work piece to the required dimensions.

Again Plain turning operation is performed until the diameter of the work piece reduced

to 18mm.

Using V-cutting tool grooving operation is performed according to the given dimensions

and finish the groove using parting tool.

Swivel the compound slide to the required angle and taper turning operation by rotating

the compound slide wheel.

The angle can be measured by using the formula.

Finally check the dimensions by using vernier calipers.

PRECAUTIONS:

The work piece should be held rigidly in the chuck before operating the machine.

Tool should be properly ground, fixed at correct height and properly secured, and work

also be firmly secured.

Before operating the machine see whether the job and tool is firmly secured in devices or

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not.

Optimum machining conditions should be maintained.

Chips should not be allowed to wound around a revolving job and cleared as often as

possible

Apply cutting fluids to the tool and work piece properly.

RESULT: The job is completed successfully and safely.

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Experiment No-03 Lathe – Taper Turning and External Thread Cutting

2. Thread Cutting and Knurling on Lathe

AIM:

To perform Thread cutting and Knurling operation on the given work piece.

MATERIAL REQUIRED:

Mild Steel rod of 25 mm diameter and 100 mm long

TOOLS REQUIRED:

Vernier calipers, steel rule, spanner, chuck spanner, and H.S.S. single point

cutting tool, parting tool and V- cutting tool.

SPECIFICATION OF LATHE:

Length of bed 1390 mm

Width of bed 200 mm

Height of centers 165 mm

Admit between centers 700 mm

Lead screw pitch 4TPI

Power of the motor 1 H.P.

THEORY:

Lathe removes undesired material from a rotating work piece in the form of chips with the help

of a tool which is traversed across the work and can be fed deep in work. The tool material

should be harder than the work piece and the later help securely and rigidly on the machine. The

tool may be given linear motion in any direction. A lathe is used principally to produce

cylindrical surfaces and plane surfaces, at right angles to the axis of rotation. It can also produce

tapers and bellows etc.

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A lathe basically consists of a bed to provide support, a head stock, a cross side to traverse the

tool, a tool post mounted on the cross slide. The spindle is driven by a motor through a gear box

to obtain a range of speeds. The carriage moves over the bed guide ways parallel to the work

piece and the cross slide provides the transverse motion. A feed shaft and lead screw are also

provided to power the carriage and for cutting the threads respectively.

SEQUENCE OF OPERATIONS:

Centering

Facing

Plain turning

Chamfering

Step turning

Grooving

Thread cutting

Knurling

PROCEDURE:

The work piece is fixed in a 3 – jaw chuck with sufficient overhang.

Adjust the machine to run the job to required cutting speed.

Fix the cutting tool in the tool post and centering operation is performed so that the axis of

the job coincides with the lathe axis.

Facing is performed by giving longitudinal depth of cut and cross feed.

Perform plain turning operation until the diameter of the work piece reduced to 20mm.

Chamfering operation is done according to the given dimensions.

Then reverse the work piece in the chuck and plain turning operation is performed

according to the given dimensions.

Using V-cutting tool and parting off tool perform grooving operation to the required

dimensions.

Reduce speed of the spindle by engaging back gear and use Tumbler

feed reversing mechanism to transmit power through the lead screw.

And calculate the change gears for the required pitch to be made on the work piece.

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Using half nut mechanism perform thread cutting operation(right hand threading)

according to the given dimensions and continues it until required depth of cut is obtained.

At the same speed knurling operation is performed using knurling tool.

For every operation check the dimensions using vernier calipers.

PRECAUTIONS:

Before starting the spindle by power, lathe spindle should be revolved by one revolution

by hand to make it sure that no fouling is there.

Tool should be properly ground, fixed at correct height and properly secured, and work

also be firmly secured.

Chips should not be allowed to wind around a revolving job and cleared as often as

possible.

Before operating threading operation, V-tool should be properly ground to the required

helix angle.

Apply cutting fluids to the tool and work piece property.

No attempt should be made to clean the revolving job with cotton waste.

On hearing unusual noise, machine should be stopped.

RESULT: The job is completed successfully and safely.

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Experiment No-04

Drilling, Reaming and Tapping

1. AIM:

To perform Drilling, reaming and tapping operations on a mild steel flat work piece

2. MATERIAL REQUIRED:

Mild steel flat of 70x50x14mm.

3. TOOLS REQUIRED :

i) Drill bits of 3 mm, 8.5mm, 9.8 mm,

ii) Floating reamer of 10 mm,

iii) M10 hand tap set,

iv) Vernier height gauge, surface plate,

v) Center punch and ball peen hammer.

4. MEASURING INSTRUMENTS REQUIRED:

Vernier caliper, outside caliper,steel rule

5. EQUIPMENT REQUIRED:

Radial Drilling Machine

6. SEQUENCE OF OPERATIONS CHART:

Si No. Operation Tool s used

1. Marking Surface plate , vernier height gauge

2 Punching Center punch ,ball peen hammer

3. Pilot hole drilling Drill bit of 3 mm.

4. Drilling Drill bit of 8.5 mm, 9.8 mm.

5. Reaming Floating reamer of 10 mm

6. Tapping( 1st stage) M10 taper tap.

7. Tapping(2nd stage) M10 intermediate tap.

8. Tapping(3rd stage) M10 bottoming tap.

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6.1. Marking:

Before drilling any hole on the given work piece, the center of the hole is located

by drawing two lines at right angles to each other by means of Vernier height gauge placed on the surface plate.

6.2. Punching:

After locating a center, an indentation is made at the point where the hole is to be

drilled.

Punching is done by means of center punch and ball peen hammer.

6.3. Pilot hole drilling:

Before drilling a hole of larger diameter, a pilot hole of approximately > 3 mm

which is slightly greater than the width of the chisel edge must be drilled. The reason is that,

the action of the chisel edge during drilling is more pr less an extrusion process, so 80 to 85% of total thrust i.e., vertically upward force will come on chisel edge which increases the

power requirement and decreases the tool-life. Therefore, to eliminate the thrust acting on the chisel edge, a pilot hole has to be drilled.

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6.4. Drilling:

Drilling is the operation of producing a cylindrical hole by removing metal by

the rotating edge of a cutting tool called the drill. The drilling is one of the simplest methods

of producing a hole. Drilling does not produce an accurate hole in a work piece and the hole

location is not perfect. The internal surface of the hole so generated by drilling becomes rough and the hole is always slightly oversize than the drill used due to the vibration of the

spindle and the drill is as shown in figure no.4.1.

6.5. Reaming:

Reaming is an accurate way of sizing and finishing a hole which has been

already drilled. In order to finish a hole and to bring it to the accurate size, the hole is drilled

slightly under size. The speed of the Reamer is made half that of drilling and automatic feed may be employed. The tool used for reaming is known as the reamer which has multiple

cutting edges. Reamer cannot originate a hole. It simply follows the path which has been previously drilled and removes a very small amount of metal. The Material removed by this

process is around 0.375 mm and for accurate work this should not exceed 0.125mm drill is as shown in figure no.4.2.

6.6. Tapping:

Tapping is the operation of cutting internal threads by means of a cutting

tool called a tap. Tapping may be performed by hand or machine drill is as shown in figure

no.4.3.

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Tap:

A tap may be considered as a bolt with accurate threads cut on it and 3 or 4 flutes cut across the thread. The edges of the thread formed by the flutes are the cutting edges which are

hardened and ground. The lower part of the tap is somewhat tapered, so that it can dig in to the walls of the drilled hole. The upper part of the tap consists of a shank ending in a square

for holding the tap in the machine spindle or by a wrench. Taps are made from carbon steel or

H.S.S and are hardened and tempered. Taps are classified as

a) Hand tap and

b) Machine tap Hand taps are usually made hi three sets as shown in Fig (9.4).

i) Taper tap (rougher), ii) Second tap (intermediate), iii) Bottoming tap (finisher).

Taper tap (rougher):

The end of the rougher has about 6 threads tapered .This is used to start the thread so that the threads are formed gradually as the tap is turned in to the hole.

Second tap (intermediate):

The intermediate is tapered back from the edge about 3 or 4

Threads .This is used after the rougher tap has been used to cut the thread as far as possible.

Bottoming tap (finisher):

This tap has full threads for the whole of its length. This is used to finish the work

prepared by the other two taps.

Tap drill size:

The size of the tap being the outside diameter of its threads, it is necessary that the drilled

hole must be smaller than the tap. The drill size which is sufficiently accurate for most cases

= Out side diameter X 0.8.

7. PROCEDURE:

i) Before drilling holes, centers of the holes are located on the work Piece by

drawing two lines at right angles to each other using vernier height gauge and surface

plate,

ii) The indentations are made at the points where the holes are to be drilled using

center punch and ball peen hammer.

ii) The Work piece is firmly fixed in the vice on a drilling machine and drill bit of

3 mm is held firmly by the self centering chuck rotated along with the spindle,

iv) Two pilot holes of 3 mm are drilled at the chosen locations by starting

theDrilling machine.

v) 3 mm drill bit is replaced by 8.5 mm drill bit and the drilling is performed in

one of the previously drilled pilot hole.

vi) 8.5 mm drill bit is replaced by 9.8 mm drill bit and the drilling is performed

in the second pilot hole.

vii) 9.8 mm drill bit is replaced by the reamer of 10 mm and the subsequent sizing and finishing of the hole is done by performing reaming operation in the second hole by giving hand feed.

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viii) Finally tapping operation is performed manually in three stages using taper tap, Intermediate tap and bottoming tap one after the other holding by a wrench.

8. PRECAUTIONS:

1. Ensure that edges of the flat are perfectly square. 2. Slightly lower speeds of the order of 25% less than drilling should be used in

reaming operation,

3. Drilling should be performed only after pilot hole is made.

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Experiment No-05

Milling Process-Surface Milling

Spur Gear Cutting in Milling Machine

Aim: To produce a spur gear out of the given work piece using milling machine

Apparatus Required:

� Horizontal Milling machine

� M10 – End Mill Cutter ( HSS )

� Gear tooth Vernier

Materials Required:

� Cast Iron Work piece – 55mm diameter, 20mm thickness

Milling Machine

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Procedure:

� The gear blank is held between the dividing head and tailstock using a mandrel.

� The cutter is mounted on the arbor and the cutter is centred accurately with the

gear blank

� Set the speed and feed for machining. For giving depth of cut, the table is raised

till the

periphery of the gear blank just touches the cutter

� The Micrometre dial of vertical feed screw is set to zero at this position. Then

the table is raised further to give the required depth of cut

� The machine is started and feed is given to the table to cut the first groove of

the blank.

� After the cut, the table is brought back to the starting position. Then the gear

blank is indexed for the next tooth space.This is continued till all the teeth are cut

� Dimensions of the gear teeth profile are checked using the gear tooth Vernier.

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Calculation:

After Machining

� Pitch circle Diameter DP = Diameter of the Blank(D) – ( 2 X Module(m)) =

65-(2X2.5)=60

� Number of teeth Z = Pitch circle Diameter / module = 60 / 2.5 = 24

� Circular Pitch PC = πDP / Z

� The relationship between normal pitch and transverse pitch is given by

PN = PC X cosα

Helical Gear considerations:

� Helix Angle α is related to Pitch circle diameter (DP) and the lead of the helix

(L) by the following relation

Tan α = πDP / L

�With any of the two known values, the third value can be found

Indexing Calculation: Indexing = 40 / Z

Result: Thus a spur gear is made from the given work piece using milling

machine.

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Experiment No-06

Gear Manufacturing Process

1. Spur gear

OBJECTIVE: Gear cutting on milling machine (Spur Gear).

APPARATUS: Steel rule, Milling cutter, Spanner, Mandrel, Dog carrier

THEORY: Milling is the machining process of using rotary cutters to remove material from a

work piece advancing (or feeding) in a direction at an angle with the axis of the tool. It covers a

wide variety of different operations and machines, on scales from small individual parts to large,

heavy-duty gang milling operations. It is one of the most commonly used processes in industry

and machine shops today for machining parts to precise sizes and shapes.

Main Components of milling machine:

Base, column, knee, saddle, table

Type of milling machine:

Plain milling machine, vertical milling machine, universal milling machine, simplex milling

machine, triplex milling machine

Type of Milling Cutter:

Plain milling cutter, slide milling cutter, arbor cutters, shank cutters, face cutters.

PROCEDURE:

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1. The raw blank is selected with reference to the number of teeth to be cut.

2. Indexing number is calculated to the position of the blank.

3. Gear blank is mounted on mandrel in milling machine.

4. Centering of the blank is done by upward and cross feed.

5. The depth of the cut is calculated for the given module.

Result: Thus the gear cutting is performed in a milling machine.

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Gear Manufacturing Process

2. Hobbing Machine

GEAR HOBBING PROCESS

In gear generating process the gear are formed by machining by means

of form cutter the cutting teeth of the gear have the shape and size of

the teeth of gear to be cut.

In generating process the gear teeth are machined as a result of

some relative motion between gear blank and cutter. A cutter of

pitch of capable of generating gear hobbing different number of

teeth.

The common generaating process used for cutting teeth are as follows.

GEAR HOBBING

Hobbing is a gear generating process by means of a rotating cutter

hob. The hob resemble a worm with straight and helical thread

parallel to the axis.

This will form reach shaped cutting teeth with proper rake and

clearance angle of the holes are either single threaded or

multithreaded.

A single threaded hob will complete one revolution for the

generation of each teeth when as threaded the gear cutting with a

hob involves the basic motions.

1) Rotation of hob and gear blank

2) Radial movement of gear blank

3) Down ward feed of job.

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RESULT

Thus the study of gear hobbing process is studied.

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Experiment No: 7

Key Way By Using Slotting Machine Date

AIM :

To make a key way in the given hollow cylindrical

work piece. MATERIAL REQURED

Cylindrical work piece.

TOOLS REQUIRED

1. Single point cutting tool

2. Allen Key

3. Chuck key

4. Work piece

5. Outside caliber

6. Vernier Caliber

PROCEDURE

1. Hold the work piece on the table by using boltand nut.

2. Set the tool in the tool post.

3. Arrange for slotting movement.

4. Give 0.1 mm depth of cut.

5. Finish to dimensions

6.Switch of the machine

Check the work piece for dimensions.

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RESULT

Thus the Key way is machined in the given hollow cylindrical work piece by

using slotting machine.

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Experiment No-9

Surface Finishing Process

INTRODUCTION:

It consists of the main driving motor situated over the housings. This motor drives the

countershaft through an open V- belt. The countershaft, at its extreme carries two

driving pulleys; one for open belt and the other for cross belt. The main driving shaft is

provided below the bed. One end of it passes through the housing and carries a pinion,

which meshes with the rack provided under the table of the machine as shown. The

other end of this shaft carries two pairs of pulleys – each pair consisting of a fast pulley

and loose pulley. One of these pairs is connected to one of the driving pulleys by means

of a open belt and the other to the second driving pulley by means of a cross belt. A

speed reduction gear box is mounted on the main driving shaft and the same is

incorporated between the pinion and the pairs of driven pulleys. One set of the above

pulleys is used for the forward motion of the table and the other set for backward or

return motion. the cross belt will be used for forward motion and the open belt for return

motion. Note that the driving pulley on the counter shaft for cross belt is smaller than

the pair of fast and loose pulleys for the same. Against this the driving pulley on the

countershaft for open belt is bigger than the pair of fast and loose pulleys for the same.

Consequently therefore for the same speed or number of revolutions of the countershaft

the main driving shaft will run faster when connected by open belt than when the cross

belt is used. It is obvious therefore that the return stroke will be faster than the forward

stroke. It should also be noted here that the pulleys are so arranged that when the cross

belt is on the fast pulley, i.e. in forward stroke the open belt will be on the loose pulley

and its reverse will take place during the return stroke. In order that this relative shifting

of belt may take place automatically at the end of each stroke, without stopping the

machine, a belt shifter and its operating lever are provided on the machine. Trip dogs

are mounted one each at both ends, on the table. At the end of each stroke these dogs

strike against the operating lever alternately and the belt shifted accordingly. Thus the

table movement is reversed automatically.

OPERATION DONE ON A PLANER:

The common operations performed on a planer include the following:

Machining horizontal flat surfaces.

Machining vertical flat surfaces.

Machining angular surfaces, including dovetails.

Machining different types of slots and grooves.

Machining curved surfaces.

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Machining along pre-marked contours.

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Experiment No: 10

Surface Finishing Process

1. Plain Surface Grinding

Aim: To perform plain surface grinding on the given work piece to the

required dimensions.

Apparatus required:

� Grinding machine

� Grinding Wheel

� Vernier Caliper

Material Required:

� MS / CI plate 12mm X 50mm X 75mm

Procedure:

� First the work piece is placed on the magnetic chuck

� The positioning of the work piece is aligned at right angles to the

grinding wheel and exactly parallel to the sides of the magnetic chuck by

using slip gauges if necessary

� The magnetic chuck is switched on and the powerful electromagnet

holds the job firmly in position

� Now the spindle is turned on and the grinding wheel is just touched the

work piece surface to mark its zero / reference position

� Now the required feed, either totally or in steps, is given to the grinding

wheel and the wheel is traversed all over the work piece

� Same procedure is repeated until the required dimensions are achieved

� Care should be taken for maintaining the surface finish

� Finally the dimensions are checked using either a Vernier calliper or a

screw gauge.

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Result: Thus plain surface grinding is performed on the given work piece up to the required Dimensions.

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Surface Finishing Process

3. Cylindrical Grinding

Aim: To grind the cylindrical surface of the given work piece by cylindrical

grinding.

Apparatus Required:

� Grinding machine

� Cylindrical grinding wheel setup

� Steel Rule

� Vernier Calliper

Materials Required:

� Cast iron work piece

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Procedure:

� First the given work piece is preliminarily finished to the pre-required

dimensions on a lathe before beginning the grinding process

� Now the work piece is fitted in the chuck of the cylindrical grinding

machine

� The grinding wheel is just touched with the work piece and is taken as

the zero reference

� Coolant circulation is switched on and the grinding wheel is engaged

with the work piece.

� Both the work piece and the grinding wheel roll on contact with each

other like two gears in mesh

� Now slowly the wheel is moved over the entire length of the work piece

to get the grinded finish

� After one feed is over, the grinding wheel is moved further towards the

axis of the work piece and the process is repeated until the required

dimensions are achieved

� Finally the dimensions are checked using a Vernier caliper.

Result: Thus cylindrical grinding is performed on the given work piece to

the given dimensions.