University College of Engineering

Science and Technology

Workshop ManualDepartment of Mechanical Engineering

TABLE OF CONTENTS

Sr.

No.

Date Name of Experiment Page

No.

Remark

s

Signature

1 Study of Different Parts of

Lathe Machine

2 Facing, Plain Turning and

Step Turning

3 Taper Turning using

Compound Rest

4 Right Hand Metric Thread

Cutting on Lathe Machine

5 Knurling Operation on Lathe

Machine

6 Study of Different Parts of

Shaper Machine

7 Machining a Block on

Shaper Machine

8Producing V-Shape on

Rectangular Block on

Shaper Machine

9 Study of Different Parts of

Milling Machine

10 To perform Milling Operation

According to Drawing

GENERAL INSTRUCTION

1. Every student should obtain a set of instruction sheets entitled

manufacturing processes Laboratory.

2. For reasons of safety, every student must come to the laboratory in

shoes (covering the whole feet). It is unsafe for the students to come to

the laboratory wearing garments with parts that hang about loosely and

as such the lab users are requested to avoid wearing garments with

loose hanging parts. Students should preferably use half-sleeve shirts

wherever possible. The Students should also ensure that floor around

the machine is clear and dry (not oily) to avoid slipping. Please report

immediately to the lab staff on seeing any coolant / oil spillage.

3. An apron will be issued on a returnable basis (returnable after each lab

turn) to each student. Students not wearing an apron will not be

permitted to the work in the laboratory.

4. Instruments and tools will be issued from the tool room. Every student

must produce his identity card for the purpose. Tools, etc. must be

returned to the tool room on the same day after work hours.

5. The student should take the permission and guidance of the Lab Staff /

Tutors before operating any machine. Unauthorized usage of any

machine without prior guidance may lead to fatal accidents and injury.

6. The student will not lean on the machine or take any kind of support of

the machine at any point of time. If found leaning on a machine without

proper reasons serious action would be taken

7. Power to the machines will be put off 10 minutes before the end of

laboratory session to allow the students to return the tools.

8. Students are required to clear off the chips from the machine and

lubricate the guides etc. at the end of each laboratory session.

9. Laboratory reports should be submitted on A4 size sheets. The students

must fill these reports and hand it over to their CR after the laboratory

session. These have associated some grades.

10. Reports will not be returned to the students. Students may see the

graded reports while in the laboratory.

SAFETY PRECAUTIONS

1. Do not wear watch, ring etc in your hand while machining

2. Wear shoe and lab coat

3. Attention to be paid for clamping the job, tool, tool holders or supporting

items.

4. Care should be taken for avoiding accidental contact with revolving cutters.

5. Do not handle chips with bare hands, use brush or hand gloves.

6. Pay attention while selecting tools or blades for the proposed use to avoid

accidents.

7. Do not remove chip while machine is running.

8. Care should be taken while selecting rapid feed.

9. Follow safety precautions while approach with cutter to avoid tool damage.

10. Use coolants for heat dissipation.

11. Avoid sharp edge tools.

12. Select proper speed or feed or depth of cut.

OBJECTIVES

The student will able to

Know basic workshop processes.

Read and interpret job drawing.

Identify, select and use various marking, measuring, holding,

striking and cutting tools & equipment.

Operate, control different machines and equipment.

Inspect the job for specified dimensions.

Produce jobs as per specified dimensions.

Adopt safety practices while working on various machines

Experiment No.1 Study of Different Parts of lathe Machine

IntroductionLathe is called the father of machine tools. The main function of lathe is to

remove metals from work piece to give a required shape and size. In the lathe

the work piece is held in a chuck. The tool is moved at an angle 90o to the

axis. Various operations such as straight turning, taper turning, and

chamfering, facing, knurling, grooving, thread cutting, taper turning are

Parts of Lathe Machine

carried out. When the operations above set are done automatically, then

the lathe is called automatic lathe.

Working principle of latheIn a lathe, the workpiece is held in chuck and rotates about its axis by means

of power. A single point cutting tool is mounted in tool post. When the chuck

rotated the work piece also rotated. The tool moves parallel to the axis of

rotation of work piece to produce a cylindrical surface, where as the tool

moves perpendicular to the work piece to produce a flat surface. The tool

moves at an angle to the axis of work piece to produce a turn surface. The

material is removed in the form of chip from the work piece by giving proper

feed and depth of cut. So, the required size and shape of the work is

obtained.

Main parts of latheThe lathe consists of various parts. Their parts and function are discussed

below.

Bed

Bed is the base of the lathe. The headstock is mounted on the left end; the

carriage is in the middle and the tailstock at the right end of bed. The bed is

made up of cast iron, alloyed with nickel, chromium. The bed is made up of

cast iron to observe shock and vibration created during machining. The guide

ways of the bed may be flatter inverted ‘V’ shape.

Headstock

It is mounted on the left end of the bed. It carries a hollow spindle. The live

center can be attached in the spindle. The spindle nose is threaded. In chuck

faceplates can be attached to the spindle. The headstock may be back

threaded type. The headstock has two types of driving mechanism

• Back geared mechanism

• Belt driven mechanism

TailstockIt is located on the bed at the right end. It is used for supports right end of work

and also for holding drills, reamer tools for drilling, reaming and such other

operations. The tailstock can be moved along the bed and clamped at any

position, to support the different length work.

CarriageCarriage is used for giving various feed to the tool by hand or by power. The

carriage is attached with the saddle.

SaddleIt is a H shaped casting fitted on the bed and moves along the guide ways. It

carries the cross slide, compound rest and a tool post.

Cross slideIt is attached to the upper side of saddle and carries compound slide and tool

post. The cross slide can be moved cross wise by hand or power. The

micrometer dial is mounted on the cross slide hand wheel, with an accuracy of

0.05mm.

Compound RestIt is attached over the cross slide. It is used during the taper turning opening

operations to set the tool for angular cuts. Here the micrometer dial is

mounted to show the depth of cut.

Tool post

The tool is clamped over the tool post. It is fixed over the compound rest.

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

Apron

Apron is attached to the saddle and hangs in front of the bed. It has gears,

levers, clutches for moving the carriage automatically. A split nut is attached

for engaging and disengaging the carriage from the lead screw. It is used in

thread cutting work.

Lead ScrewIt is a longer screw with standard ACME square threads and used for

transmitting power for automatic feed for thread cutting operation.

Feed rodThe feed rod is the long shaft used for the movement of carriage along the

axis of bed. It is used for operations like facing, turning and boring.

Experiment No.2 Performing Facing, Plain Turning and Step Turning

Drawing of Stock

Drawing of Finished Job

Material usedMild steel rod.

Tools required

• Lathe

• Three-jaw chuck

• Chuck key

• Vernier caliper

• Single-point cutting tool

Procedure

1. First loosen the jaw in the chuck key to position the work piece, and then

tighten the jaws.

2. Fix the cutting tool in the toolpost.

3. Switch on the lathe and move the carriage near to the workpiece. Give it a

small cross feed, and then move carriage longitudinally to the required length

slowly.

4. Bring the carriage to the original position, give a small cross feed and

move carriage longitudinally. Repeat this step until required diameter is

obtained.

5. To get smooth surface give a very small feed when the diameter is

nearing the required value.

6. To face the end surface of the workpiece, move the carriage to make

the tool touch the end surface of the work piece.

7. Give a small feed in longitudinal direction, and then move the tool towards

the axis of the workpiece using the cross slide to complete the workpiece.

8. The turning operation is done with cutting tool to reduce the

diameter upto the required dimension for the two steps of various

diameters.

9. The workpiece is removed from the chuck and the dimensions of

workpiece are checked for the requirement

Experiment No.3 Performing Taper Turning using Compound Rest

Drawing of Stock

Drawing of Finished Job

Material used

Mild steel rod.

Tools required

• Single point cutting tool

• Lathe

• Vernier caliper

• Try square

• Chuck key

Procedure

1. First loosen the jaw in the chuck key to position the work piece, and then

tighten the jaws.

2. Fix the cutting tool in the toolpost.

3. Switch on the lathe and move the carriage near to the workpiece. Give it a

small cross feed, and then move carriage longitudinally to the required length

slowly.

4. Bring the carriage to the original position, give a small cross feed and

move carriage longitudinally. Repeat this step until required diameter is

obtained.

5. To get smooth surface give a very small feed when the diameter is

nearing the required value.

6. To face the end surface of the workpiece, move the carriage to make the

tool touch the end surface of the work piece.

7. Then the taper turning operation is done on the workpiece according to

the taper angle calculated. The compound rest base is swirled and set a

calculated taper angle, for this the tool is moved by 45o to the lathe axis.

8. The workpiece is removed from the chuck and the dimensions of

workpiece are checked for the requirements.

Experiment No.4 Right Hand Metric Thread Cutting on Lathe Machine

Drawing of Stock

Drawing of Finished Job

Material used

Mild steel rod of 25 mm diameter.

Tools required

• Single point thread cutting tool

• Lathe

• Vernier caliper

• Try square

• Chuck key

Procedure

1. Arrange for as much distance from the chuck to the end of the proposed

screw thread as possible, and if possible, cut a 'run-off' into the workpiece

which is of a smaller diameter than the root diameter of the proposed screw

thread. Also, long threads may require the use of one or more 'steadies'.

2. Install the appropriate gears for the thread required, and correctly mount

the cutting tool. Set the required depth of cut, and position the tool ready to

begin cutting. Note that the depth of cut is vitally important and may be

calculated or obtained from an appropriate reference manual.

3. Take all necessary precautions previously stated, and start the machine

with the automatic feed lever in the UP or disengaged position and set the

speed of the lathe as appropriate.

4. Set the depth of cut for an initial test pass. Engage the auto-feed lever

sharply whilst your left hand is on the FORWARD/OFF/REVERSE (F/O/R)

switch. As the tool approaches the end of the desired thread, turn the switch to

'OFF'. Do not disengage the auto-feed lever. Use a thread pitch gauge to

check that the pitch is as required.

5. Retract the tool, using the cross-slide feed handle, noting the exact

position on the scale and the exact number of turns. Turn the F/O/R switch to

'REVERSE', whereupon the saddle will wind back to the beginning and turn

the switch to 'OFF'. Reset the tool by winding in the cross-slide the exact

number of turns previously wound out, plus the desired depth of cut.

6. Turn the F/O/R switch to FORWARD. As the tool approaches the end of the

desired thread, turn the switch to 'OFF'. Do not disengage the auto-feed lever.

7. Repeat steps 5 & 6 until the thread is completed.

Preparation for Threading

Check thread pitch after initial threading pass

Completing the threading process

Thread Dial Indicator Tables

Experiment No.5 Knurling Operation on Lathe Machine

Introduction

Knurling is a process of impressing a diamond shaped or straight line pattern

into the surface of a workpiece by using specially shaped hardened metal

wheels to improve its appearance and to provide a better gripping surface.

Straight knurling is often used to increase the workpiece diameter when a

press fit is required between two parts.

Knurling ToolsThe knurling tool can be designed differently, but all accomplish the same

operation. Two common types of knurling tools are the knuckle joint and

revolving head type of knurling tools. The knuckle joint type is equipped with a

single pair of rollers that revolve with the work as it is being knurled. The

revolving head type of tool is fitted with three pairs of rollers so that the pitch

can be changed to a different knurl without having to change the setup. There

are two knurl patterns, diamond and straight.

Shaper Machine and its Parts

Experiment No.6 Study of Different Parts of Shaper Machine

Introduction

The shaper is a machine tool used primarily for:

1. Producing a flat or plane surface which may be in a horizontal, a vertical or

an angular plane.

2. Making slots, grooves and keyways

3. Producing contour of concave/convex or a combination of these

Working Principle

 The job is rigidly fixed on the machine table. The single point cutting tool held

properly in the tool post is mounted on a reciprocating ram. The reciprocating

motion of the ram is obtained by a quick return motion mechanism. As the ram

reciprocates, the tool cuts the material during its forward stroke. During return,

there is no cutting action and this stroke is called the idle stroke. The forward

and return strokes constitute one operating cycle of the shaper.

Base

The base is a heavy and robust in construction which is made of cast iron by

casting process. It is the only part to support all other parts because all parts

are mounted on the top of this base. So, it should be made to absorb

vibrations due to load and cutting forces while machining.

Column

The column has a box type structure which is made of cast iron. The inside

surface is made as hollow to reduce the total weight of the shaper. It is

mounted on the base. The ram driving (Quick return) mechanism is housed.

The two guide ways are supplied on the top. The ram reciprocates on the

supplied guide ways. Similarly, there are two guide ways at the front vertical

face of the column to move the cross rail along these guide ways.

TableIt is also a box type rectangular hollow cast iron block. This table slides along

the horizontal guide ways of the cross rail. The work is held in the table. The

table has machined surfaces on the top and sides of T-slots for clamping

work. It can be moved vertically by the elevating screw. An adjustable table

supports the front face of the table.

RamRam of cast iron has cross ribs for rigidity. Generally, it is a reciprocating type

which slides over the guide ways on the top of the column. It is linked to

driving mechanism of any one and also it carries the tool head at the front end.

Tool HeadIt holds the tool rigidly having swivel base with degree graduation. So, the tool

head can be swiveled to any angle as required. The tool head has a vertical

slide and apron to provide vertical and angular feed to the tool. A feed screw

with graduated dial moves the vertical slide vertically to set the accurate

movement.

Apron is clamped upon the vertical slide which can be titled to right or left and

also clamped at a correct position. The clapper box hinges a tool block

previously fixed with apron. The tool block holds a tool post to hold the tool.

The tool block fits inside the clapper box rigidly. In the return stroke, the tool

block lifts out of clapper box to minimizing rubbing of the tool on the job.

Cross rail It is also a heavy cast iron construction. It glides on the front vertical ways of

the column with two mechanisms. One is aimed at elevating the table and the

other one is for cross travel of the table. A saddle slides over two guide ways

already provided in the front face of the cross slide. The crosswise movement

of the table is obtained by cross feed screw and the vertical movement of the

cross rail is obtained by an elevating screw.

Shaper Cutting Speeds and Feeds

Vise

A vise, fastened to the shaper table, is used to hold most of the work in place

for machining on the shaper. It has a movable jaw, a fixed jaw, and a base

that is graduated in degrees. The vise can be rotated on its base to any

desired angle. A workpiece in the vise is held either parallel to or at right

angles to the ram.

Saddle

Saddle is gibbed to the cross rail and supports the table. If the table is

removed, the work can be bolted or clamped to the T-slots in front of the

saddle. Crosswise movement of the saddle causes the work table to move

sideways.

Calculate shaper speeds

Shaper cutting speeds and feeds are dependent upon a number of factors,

including:

the type of cutting tool

the type of material to be machined

the depth of cut required

the amount of feed

Following Table presents standard shaper cutting speeds and feeds when

using HSS and carbide cutting tools to cut machine steel, tool steel, cast iron

and brass.

x 0.06N =

x 0.06 = 88 stroke/minuteN =

With the information in Table 1 and two standard formulas (one for imperial

measurements and one for metric measurements) you can calculate the

number of strokes per minute that the shaper ram should deliver (i.e., shaper

speed).

To Find Strokes/minute

If you are using a HSS cutting tool to cut a piece of brass 300 mm long, to

determine how many strokes per minute the ram should deliver, you can use

the metric speed calculation formula:

C S

T

Where N = number of strokes per minute

CS = standard cutting speed in metres per minute of a

particular kind of cutting tool for a particular material

(see Table above)

L = length of work in metres, plus 25 mm to provide too

clearance

48

0.375

So

To cut a 300 mm piece of brass with a HSS cutting tool requires the ram

to deliver 88 strokes/minute:

Setting Shaper Stroke Length and Position

1. Correctly mount the workpiece in the vise.

2. Measure the length of the workpiece and add 25 mm (or 1") to determine

the length of stroke.

3. Use the start-stop button or the stroke regulator shaft crank and move the

ram to the back end of its stroke.

4. Loosen the stroke regulator locknut.

5. Turn the stroke regulator shaft until the stroke indicator shows the

desired stroke length.

6. Tighten the stroke regulator locknut.

7. With the ram still at the back end of its stroke, loosen the ram positioning

lock.

8. Pull the toolhead and the ram (or turn the ram adjusting screw) until the

toolbit is within 12 mm (1/2") of the workpiece.

9. Tighten the ram positioning lock.

10. With the cutting tool clear of the workpiece, start the machine and check

that the toolbit clears each end of the workpiece by 12 mm (1/2"); if so, the

shaper stroke length and position are now correctly set.

Experiment No.7 Machining a Block on Shaper Machine

Drawing of Block

Material used

Mild steel block having sides greater than 75 mm each side.

Tools required

• Single point thread cutting tool

• Shaper Machine

• Vernier caliper

• Try square

• Vise

Procedure1. The job was checked to the given dimensions.

2. The square 75 mm sides was marked one side of block and Punching was

done.

3. The job was attached in the vise of a shaper

4. Strokes / mm was calculated for Mild Steel and Shaper was set

accordingly.

5. Stroke Length was adjusted according to length of workpiece.

6. Single point cutting tool was fixed in the tool holder.

7. After finishing one side, the job surface is inverted and again fixed in the

vise.

8. The job was checked for perpendicular parallelism.

9. The job was checked for dimensions.

8. Then the square of 75 mm from stock was obtained in the shaper

9. The work piece was removed and burns are removed with accuracy was

checked.

Experiment No.8

Producing V-Shape on Rectangular Block on Shaper Machine

Drawing

of V-Groove

on Job

Length of

Block =

75 mm

Material used

Mild steel block having sides 75x30x75 mm sides.

Tools required

• Single point thread cutting tool

• Shaper Machine

• Vernier caliper

• Try square

• Vise

Procedure

1. Work piece of required dimension to be cut on power hack saw.

2. The job is fixed in vice of shaper machine.

3. Top surface is machined first.

4. The Job surface is inverted and clamped tightly in the vice.

5. All the remaining surfaces are machined in sequence.

6. Then marking is done as per the drawing for making groove.

7. The groove is machined using round nose cutting tool.

8. For making the groove feed to the table and tool is given simultaneously.

9. The groove is shaped in different cuts to achieve the desired depth.

PARTS OF MILLING MACHINE

HORIZONTAL MILLING MACHINE

INTRODUCTION:

Milling is the cutting operation that removes metal by feeding the work

against a rotating, cutter having single or multiple cutting edges. Flat or

curved surfaces of many shapes can be machined by milling with good

finish and accuracy. A milling machine may also be used for drilling,

slotting, making a circular profile and gear cutting by having suitable

attachments.

WORKING PRINCIPLE: The workpiece is holding on the worktable of

the machine. The table movement controls the feed of workpiece

against the rotating cutter. The cutter is mounted on a spindle or arbor

and revolves at high speed. Except for rotation the cutter has no other

motion. As the workpiece advances, the cutter teeth remove the metal

from the surface of workpiece and the desired shape is produced.

HORIZONTAL MILLING MACHINE CONSTRUCTION: The main part of machine is base, Column, Knee, Saddle, Table, Overarm,

Arbor Support and Elevating Screw.

Base: It gives support and rigidity to the machine and also acts as a reservoir for the

cutting fluids.

Column:

The column is the main supporting frame mounted vertically on the base. The

column is box shaped, heavily ribbed inside and houses all the driving

mechanisms for the spindle and table feed.

Knee:

The knee is a rigid casting mounted on the front face of the column. The knee

moves vertically along the guide ways and this movement enables to adjust

the distance between the cutter and the job mounted on the table. The

adjustment is obtained manually or automatically by operating the elevating

screw provided below the knee.

Saddle: The saddle rests on the knee and constitutes the intermediate part between

the knee and the table. The saddle moves transversely, i.e., crosswise (in or

out) on guide ways provided on the knee.

Table:

The table rests on guide ways in the saddle and provides support to the work.

The table is made of cast iron, its top surface is accurately machined and

carriers T- slots which accommodate the clamping bolt for fixing the work. The

worktable and hence the job fitted on it is given motions in three directions:

a). Vertical (up and down) movement provided by raising or lowering the knee.

b). Cross (in or out) or transverse motion provided by moving the saddle in

relation to knee.

c). Longitudinal (back and forth) motion provided by hand wheel fitted on the

side of feed screw.

In addition to the above motions, the table of a universal milling machine

can be swiveled 45° to either side of the centre line and thus fed at an angle

to the spindle.

Overarm: The Overarm is mounted at the top of the column and is guided

in perfect alignment by the machined surfaces. The Overarm is the support

for the arbor.

Arbor support: The arbor support is fitted to the Overarm and can be clamped at any

location on the Overarm. Its function is to align and support various arbors.

The arbor is a machined shaft that holds and drives the cutters.

Elevating screw: The upward and downward movement to the knee and the table is given by

the elevating screw that is operated by hand or an automatic feed.

MILLING OPERATIONS

1. Plain or slab milling

2. Face Milling

3. Angular Milling

4. Straddle Milling

5. Form Milling

6. Gang Milling

Plain or slab milling: Machining of a flat surface which is parallel to the axis of the rotating cutter.

Face milling:

Machining of a flat surface which is at right angles to the axis of the

rotating cutter.

Angular milling: Machining of a flat surface at an angle, other than a right angle, to the

axis of revolving cutter.

Straddle milling:

Simultaneous machining of two parallel vertical faces of the work-pieces by

a pair of side milling cutters.

Form milling: Machining of surfaces which are of irregular shape. The teeth of the form

milling cutter have a shape which corresponds to the profile of the surface

To be produced

.

Gang milling: Simultaneous machining of a number of flat horizontal and vertical surfaces

of a workpiece by using a combination of more than two cutters mounted on

a common arbor.

8. STRADDLE MILLING OPERATION

1. AIM: To perform straddle milling operation on the given specimen (mild

steel) & get to its correct dimensions.

2. MATERIALS REQUIRED: mild steel specimen.

3. MACHINE REQUIRED: horizontal milling machine

4. MEASURING INSTRUMENTS: Vernier calipers

5. CUTTING TOOLS: side and milling cutter

6. MARKING TOOLS: steel rule, scriber

7. Work holding fixtures: work piece supporting fixtures

8. Miscellaneous tools: Hammer, brush, Allen keys

Straddle MillingWhen two or more parallel vertical surfaces are machined at a single cut, the

operation is called straddle milling. Straddle milling is accomplished by mounting

two side milling cutters on the same arbor, set apart at an exact spacing. Two

sides of the workpiece are machined simultaneously and final width dimensions

are exactly controlled.

PROCEDURE FOR SETTING UP STRADDLE MILLING

1. Select and mount a work-holding device that will hold the workpiece

with the faces to be milled exposed.

2. Securely mo unt the workpiece in the work-holding device, use

solid fixed abutments where possible.

3. Select a matched pair of side and face milling cutters and a range of

spacing collars.

4. Mount both side and face milling cutters on the machine’s arbor,

separated by collars.

5. The width of the collars should be equal to the required distance

between the component’s faces.

6. Carefully measure the distance between the milling cutter’s cutting

edges. The distance can be adjusted by changing collars for once with

different widths or adding shims. Adjustable milling collars may also be

used if available.

7. Set the machine spindle speed and feed rate.

8. Position the machine’s table so that the cutters cut the workpiece as

required.

9. Take a cut across part of workpiece.

10. Stop the machine and measure the workpiece accurately, and if

necessary adjust the collar distance between the cutters on the arbor by

either inserting, changing or removing milling collar shims.

11. Re-cut the workpiece if necessary.

PRECAUTIONS1. The milling machine must be stopped before setting up or removing a

work piece, cutter or other accessory.

2. Never stop the feeding of job when the cutting operation is going on,

otherwise the tool will cut deeper at the point where feed is stopped.

3. All the chips should be removed from the cutter. A wiping cloth

should be placed on the cutter to protect the hands. The cutter should

be rotated in the clockwise direction only for right handed tools.

4. The work piece and cutter should be kept as cool as possible (i.e.

coolant should be used where necessary to minimize heat absorption).

5. The table surface should be protected with a wiping cloth.

RESULTThe workpiece has been produced as per drawing