BHARAT HEAVY ELECTRICALS LIMITED JHANSI

2015

BHARAT HEAVY ELECTRICALS LIMITED JHANSI

A ROTATION REPORT AND PROJECT REPORT ON

CNC FLAME CUTTING MACHINE

SUBMITTED TO: SUBMITTED BY:

SHRI HARISH BANSAL NAMAN JAIN

ENGINEER (FBM) B.tech (MECHANICAL) 3rdYEAR

B.H.E.L. JHANSI (U.P.) HCST MATHURA(U.P)

Acknowledgement

We are highly thankful to B.H.E.L. (Jhansi) engineers and technical staff for providing us vital information and valuable information about different faces and industrial management system.

We express our attitude to HRD department for giving us a chance to feel industrial environment and its working BHEL.

We are thankful to MR. HARISH BANSAL (ENGINEER (FBM)) for various

theoretical and practical aspects of our project. We would also like to thank all other

members of fabrication section for providing enough support and co-operation.

Last but not the least, I would like to thank my parents & all my fellow

trainees who have been a constant source of encouragement & inspiration during

my studies & have always provided me support in every walk of life.

NAMAN JAIN

B.tech (Mechanical) 3rd YEAR

HCST Mathura (UP)

PREFACE

At very outset of the prologue it becomes imperative to insist that vocational training is an integral part of engineering curriculum. Training allows us to gain an insight into the particle aspects of the various topics we wish. We came across while pursuing our B.tech. (Mechanical) that is vocational training gives us particle implementation of various topics. We have already learner and will learn in near future. Vocational training always emphasizes on logic common sense instead of theoretical aspect of subject. On my part I persuaded four weeks of training at B.H.E.L. (Jhansi). The training involved a study of various department of organization as per the time logically scheduled and well planned given to us. The rotation in various departments was necessary in order to get an overall idea of the working of the organization.

NAMAN JAIN

B.tech (Mechanical) 3rd YEAR

HCST MATHURA (U.P)

A - BRIEF INTRODUCTION

OF

BHARAT HEAVY ELECTRICAL LIMITED

OVERVIEW OF BHEL

Bharat Heavy Electricals Limited (BHEL) is an Indian state-owned integrated

power plant equipment manufacturer and operates as engineering and

manufacturing company based in New Delhi, India. BHEL was established in 1964,

ushering in the indigenous Heavy Electrical Equipment industry in India. The

company has been earning profits continuously since 1971-72[6] and paying

dividends since 1976-77. It is one of the only 7 mega Public Sector Undertakings (PSUs) of India clubbed under the esteemed 'Maharatna' status. On 1 February 2013, the Government of India granted Maharatna status to Bharat Heavy Electricals Limited.

BHEL is the largest engineering and manufacturing enterprise in India in the

energy related infrastructure sector today. BHEL was established more than 40

years ago when its first plant was setup in Bhopal ushering in the indigenous

Heavy Electrical Equipment Industry in India a dream which has been more than

realized with a well-recognized track record of performance it has been earning

profits continuously since 1971-72.

BHEL caters to core sectors of the Indian Economy viz., Power Generation's &

Transmission, Industry, Transportation, Telecommunication, Renewable Energy,

Defence, etc. The wide network of BHEL's 14 manufacturing division, four power

Sector regional centres, over 150 project sites, eight service centres and 18

regional offices, enables the Company to promptly serve its customers and

provide them with suitable products, systems and services – efficiently and at

competitive prices. BHEL has already attained ISO 9000 certification for quality

management, and ISO 14001 certification for environment management

POWER GENERATION

Power generation sector comprises thermal, gas, hydro, and nuclear power plant

business.

TELECOMMUNICATION

BHEL also caters to Telecommunication Sector by way of small, medium and large

switching systems.

TRANSMISSION AND DISTRIBUTION (T&D)

BHEL offers wide-ranging products and systems for T&D applications. Products

manufactured include: power transformers, instrument transformers, dry type

transformers, series &shunt reactors, capacitor banks, vacuum &SF6 circuit breakers,

gas-insulated switchgears and insulators.

INDUSTRIES

BHEL is a major contributor of equipment and systems to industries, cement, sugar,

fertilizer, refineries, petrochemicals, paper, oil and gas, metallurgical and other

process industries. The range of systems & equipment supplied includes: captive

power plants, co-generation plants, DG power plants, industrial steam turbines,

industrial boilers and auxiliaries, waste heat recovery boilers, gas turbines, heat

exchangers and pressure vessels, centrifugal compressors, electrical machines,

pumps, valves, seamless steel tubes, electrostatic precipitators, fabric filters, reactors,

fluidized bed combustion boilers, chemical recovery boilers and process controls.

TRANSPORTATION

BHEL is involved in the development, design, engineering, marketing, production,

installation, and maintenance and after-sales service of rolling stock and traction

propulsions systems. BHEL manufactures electric locomotives up to 5000 HP,

diesel electric locomotives from 350 HP to 3100 HP, both for mainline and

shunting duty applications. It also produces rolling stock for special applications viz.

overhead equipment cars, special well wagons, and Rail-cum road vehicle.

RENEWABLE ENERGY

Technologies that can be offered by BHEL for exploiting non-conventional and

renewable sources of energy include: wind electric generators, solar photovoltaic

systems, solar heating systems, solar lanterns and battery-powered road vehicles.

OIL AND GAS

BHEL’s products range includes Deep Drilling Oil Rigs, Mobile Rigs, Work Over

Rigs, Well Heads and X-Mas Trees, Choke and Kill Manifolds, Full Bore Gate

Valves, Mudline Suspension System, Casing Support system Sub-Sea Well Heads,

Block valves, Seamless pipes, Motors, Compressor, Heat Exchangers etc.

INTERNATIONAL OPERATIONS

BHEL is one of the largest exporters of engineering products & services from

India, ranking among the major power plant equipment suppliers in the world. .

Apart from over 1110MW of boiler capacity contributed in Malaysia, and

execution of four prestigious power projects in Oman, Some of the other major

successes achieved by the Company have been in Australia, Saudi Arabia, Libya,

Greece, Cyprus, Malta, Egypt, Bangladesh, Azerbaijan, Sri Lanka, Iraq etc.

VISION, MISSION AND VALUES OF BHEL

VISION

A global engineering enterprise providing solutions for a better tomorrow.

MISSION

Providing sustainable business solutions in the fields of Energy, Industry &

Infrastructure.

VALUES

GOVERNANCE: We are stewards of our shareholders investments and we take

that responsibility very seriously. We are accountable and responsible for delivering

superior results that make a difference in the lives of the people we touch.

RESPECT: We value the unique contribution of each individual. We believe in

respect for human dignity and we respect the need to preserve the environment

around us.

EXCELLENCE: We are committed to deliver and demonstrate excellence in

whatever we do.

LOYALTY: We are loyal to our customers, to our company and to each other.

ENTEGRITY: We work with highest ethical standards and demonstrate a behavior

that is honest, decent and fair. We are dedicated to the highest levels of personal

and institutional integrity.

COMMITMENT: We set high performance standards for ourselves as individuals

and our teams. We honour our commitments in a timely manner.

INNOVATION: We constantly support development of newer technologies,

products, improved processes, better services and management practices.

TEAM WORK: We work together as a team to provide best solutions & services to

our customers. Through quality relationships with all stakeholders we deliver value

to our customers.

VARIOUS BHEL UNITS

FIRST GENERATION UNITS

Bhopal : Heavy Electrical Plant.

Haridwar : Heavy Electrical Equipment Plant.

Hyderabad: Heavy Electrical Power Equipment Plant.

SECOND GENERATION UNITS

Tiruchy : High Pressure Boiler Plant.

Jhansi : Transformer and Locomotive Plant.

Haridwar : Central Foundry and Forge Plant.

Tiruchy : Seamless Steel Tube Plant.

UNITS THROUGH ACQUISTION & MERGER

Bangalore : Electronics Division

Electro Porcelain Division.

NEW MANUFACTURING UNITS

Ranipet : Boiler Auxiliaries Plant.

Jagdishpur: Insulator Plant.

Govindwal : Industrial Valve Plant.

Rudrapur : Component and Fabrication Plant.

Bangalore : Energy Systems Division

BHEL is growing concern to meet the changing needs of the nation has taken it

beyond power into the total gamut of energy, industry and transportation BHEL is

able to offer a service in each of this fields. It;s manufacturing capability is supported

by a corporate R&D division at Hyderabad works closely with the research and

development cells at various units and Welding Research Institute at Tiruchinapalli.

ACTIVITY PROFILE OF BHEL

POWER SECTOR PROJECTS

Thermal sets and Auxiliaries.

Steam generators and Auxiliaries.

Industrial fans.

Electrostatic precipitators.

Air pre heaters.

Nuclear power equipments.

Hydro sets and Auxiliaries.

Motors.

Transformers.

Rectifiers.

Pumps.

Heat Exchangers.

Capacitors.

Porcelain/Ceramics insulators.

Seamless steel tubes.

Casting and forging.

SYSTEMS/SERVICES

Turnkey power station.

Data acquisition Systems.

Power systems.

HVDC Commissioning systems.

Modernization and Rehabilitation.

TRASPORTATION SECTOR

Diesel Electric generators.

AC/DC locomotives.

DC locomotives and loco shunters.

Traction system for railways.

Electric trolley buses.

INDUSTRY SECTOR

Boilers.

Valves.

T.G. sets.

Power devices.

Solar Cells.

Photo Voltaic cells.

Gas Turbines.

BHARAT HEAVY ELECTRICALS LIMITED JHANSI (UNIT)

A BRIEF INTRODUCTION

By the end of 5th five-year plan, it was envisaged by the planning commission that the

demand for power transformer would rise in the coming years. Anticipating the

country’s requirement BHEL decided to set up a new plant, which would

manufacture power and other types of transformers in addition to the capacity

available in BHEL Bhopal. The Bhopal plant was engaged in manufacturing

transformers of large ratings and Jhansi unit would concentrate on power

transformer upto 50 MVA, 132 KV class and other transformers like Instrument

Transformer s, Traction transformers for railway etc.

This unit of Jhansi was established around 14 km from the city on the N.H. No 26

on Jhansi Lalitpur road. It is called second-generation plant of BHEL set up in 1974

at an estimated cost of Rs 16.22 crores inclusive of Rs 2.1 crores for township. Its

foundation was laid by late Mrs. Indira Gandhi the prime minister on 9th Jan. 1974.

The commercial production of the unit began in 1976-77 with an output of Rs 53

lacs since then there has been no looking back for BHEL Jhansi.

The raw material that are produced for manufacture are used only after thorough

material testing in the testing lab and with strict quality checks at various stages of

productions. This unit of BHEL is basically engaged in the production and

manufacturing of various types of transformers and capacities with the growing

competition in the transformer section, in 1985-86 it under took the re-powering of

DESL, but it took the complete year for the manufacturing to begin. In 1987-88,

BHEL has progressed a step further in under taking the production of AC

locomotives, and subsequently it manufacturing AC/DC locomotives also.

BHEL JHANSI PERFORMANCE FINANCIAL (In Rs. /Crore)

PRODUCT 2011 – 12

(Actual)

2012 – 13

(Provisional)

Growth %

Power Transformer 564 457 –19

Non Power Transformer 304 376 24

Loco 430 532 24

Total 1300 1365 5

THE PRODUCT PROFILE OF BHEL JHANSI UNIT

PRODUCTS RATINGS

1. Power transformer up to 400 KV class 250

2. Special transformer up to 180 KV.

3. ESP transformer. 95 KVp, 1400 mA.

4. Freight Loco transformer 3900 to 5400 KVA &

7350 KVA for 3 phase

5. ACEMU transformer up to 1000 KVA (1-phase)

1385 KVA (3 phase)

6. Dry type transformer up to 6300 KVA 33 KV class

7. Instrument transformer VT & CT up to 220 KV class

8. Diesel electric locomotives up to 2600 HP.

9. AC/DC locomotives 5000 HP

10. Over Head Equipment cum Test

Car

11.

12.

13.

Well wagon

Rail cum road vehicle

Dynamic track stabilizer

200 tone

FABRICATION:

Fabrication is nothing but production. It comprises of 3 bays i.e., Bay0, Bay1

&Bay 2.

BAY 0

It is the preparation shop while the other two bays form the

assembly shop.

This section has the following machines:

1. Planner machine – To reduce thickness

2. Shearing machine

3. CNC Flame Cutting machine – To cut complicated shaft items using

using oxy acetylene flame

4. Bending machine

5. Rolling machine

6. Flattening machine

7. Drilling machine

8. Nibbling machine

9. Pantograph flame cutting machine

BAY-1

It is also a sub part of Fabrication. It is an assembly shop where different parts of

tank come from bay 0.Here welding processes are used for assembly, after which

a rough surface is obtained Grinder operating at 1200 rpm is used to eliminate the

roughness.

BAY-2

It is also a sub part of Fabrication It is an assembly shop dealing with making

different objects mentioned below.

1-Tank assembly 5-cross feed assembly

2-Tank cover assembly 6-core clamp assembly

3-End Frame assembly 7-pin and pad assembly

4-foot assembly

Before assembly, short blasting (firing of small materials i.e., acid pickling) is

done on different parts of jobs to clean the surface before painting.

BAY-3

Here are basically three sections in the bay:

Machine section

Copper section

Tooling section

BAY 4

It is the winding section.

There are four types of coil fixed in a transformer, they are :

1. Low voltage coil (LV)

2. High voltage coil (HV)

3. Tertiary coil

4. Tap coil

The moulds are of following types

1. Belly types

2. Link types

3. Cone type

BAY-5

It is core and punch section. The lamination used in power, dry, ESP transformer

etc for making core is cut in this section.

CRGO (cold rolled grain oriented) silicon steel is used for lamination, which is

imported in India from Japan, U.K. Germany. It is available in 0.27 and 0.28 mm

thick sheets, 1mt wide and measured in Kg.The sheet s are coated with very thin

layer of insulating material called “carlites”.

For the purpose of cutting and punching the core three machines are installed in

shop

BAY-6

Single-phase traction transformer for AC locomotives is assembled in this

section. This Freight locomotive transformers are used where there is frequent

change in speed. In this bay core winding and all the assembly and testing of

traction transformer is done.

Three-phase transformers for ACEMU are also manufactured in this section. The

supply lines for this transformer are of 25 KV and power of the transformer is

6500 KVA. The tap changer of rectifier transformer is also assembled in this bay.

These transformer used in big furnance like Thermal Power Plant(TPP).

BAY-7

1. This is the insulation shop. Various types of insulations are

2. AWWW - All Wood Water Washed press paper.

3. The paper is 0.2-0.5mm thick cellulose paper and is wound on the

conductors for insulation.

4. PRE COMPRESSED BOARD: This is widely used for general insulation

& separation of conductors in the forms of blocks.

5. PRESS BOARD: This is used for separation of coils e.g. L.V. from H.V. It

is up to 38 mm thick.

6. UDEL(Un Demnified Electrical Laminated) wood or Permawood

7. This is special type of plywood made for insulation purposes.

8. FIBRE GLASS: This is a resin material and is used in fire pron areas.

9. BAKELLITE

10. GASKET- It is used for protection against leakage.

11. SILICON RUBBER SHEET- It is used for dry type transformer.

BAY 8

It is the instrument transformer and ESP transformer manufacturing section.

INSTRUMENT TRANSFORMER

These are used for measurement. Actual measurement is done by measuring

instruments but these transformers serve the purpose of stepping down the

voltage to protect the measuring instrument. They find application in protection

of power system and for the operation of over voltage, over current, earth fault

and various other types of relays.

ESP TRANSFORMER

The Electrostatic Precipitator transformer is used for environmental application. It

is used to filter in a suspended charge particle in the waste gases of an industry.

They are of particular use in thermal power stations and cement industry.

The ESP is a single-phase transformer. It has a primary and secondary. The core is

laminated and is made up of CRGOS. It is a step up transformer. The output of the

transformer must be DC the is obtained by rectifying AC using a bridge rectifier

(bridge rectifier is a combination of several hundred diodes).

One side of the transformer output is taken and other side has an ‘marshalling box’

which is the control box of the transformer.

BAY-9

In this bay power transformer are assembled. After taking different input from

different bays 0-9 assembly is done Power transformer is used to step and step

down voltages at generating and sub-stations. There are various ratings –11KV,

22KV, manufactured, they are

1. Generator transformer.

2. System

3. Autotransformer.

The stepS involved in assembly are:

1. Core building

2. Core Lifting.

3. Unlacing.

4. Delacing and end-frame mounting.

5. High voltage terminal gear and low volt terminal gear mounting

6. Vapour phasing and oil soaking

7. Final servicing and tanking.

8. Case fitting.

STORE

There are three sections in store:

1. Control Receiving Section

2. Custody Section

3. Scrap Disposal Section

LOCOMOTIVE PRODUCTION (LMP)

There are following products are manufactured at Loco shops

Alternating Current Locomotive (ac Loco)

WAG-5H

AC./D.C. Loco

WCAM-2P

WCAM-3

Diesel Electric Locomotive Shunting (DESL)

350 HP

700 HP

450 HP

1400 HP

1150 HP

1350 HP

2600 HP

1150 HP and 1350 HP DESL s are non-standard locomotives and are

modified versions of 1400 HP DESL based on requirement of customer.

Under mention are the new non-conventional products designed and

developed for Indian Railways based on their requirement.

OHE (Overhead electric) recording and testing cars

UTV(Utility vehicle )

RRV(Rail cum road vehicle)

DETV( Diesel electric tower car)

BPRV(Battery power road vehicle)

BCM(Blast cleaning machine)

200 T Well wagon for BHEL Haridwar

Metro Rake-Kolkata Metro Railways

LOCOMOTIVE MANUFACTURING (LMM)

This section deals with manufacturing of locomotives. The main parts of the

locomotive are

Under frame: The frame on which a locomotive is built

Super structure: The body of locomotive is called superstructure

or Shell and is made of sheet of Mild steel

DC motor

Alternator

Compressor

Flower

Static Rectifier-MSR

Static Converter-SC

Exchanger

Bogie-The wheel arrangement of a loco is called a bogie. A bogie

essentially contains

1-wheel axle arrangement

2-Suspension

3-Brake rigging

Traction transformer:

It is fixed on under frame and gets supply from an overhead line by

equipment called pantograph. The type of pantograph depends on supply.

This transformer steps down voltage and is fitted with a tap changer.

Different taps are taken from it for operating different equipment. One tap

is taken and is rectified into DC using MSR and is fed to the DC motor.

Railways has two types of power supplies – 25 KV , 1 Phase ,50hz AC

-1500 V DC

An AC/DC loco is able to work on both of these supplies.

For e.g. WCAM-3.

ENVIRONMENTAL POLICY

Compliance with applicable Environmental Legislation/Regulation;

Continual Improvement in Environment Management Systems to protect

our natural environment and control pollution;

Promotion of activities for conservation of resources by Environmental

Management.

Enhancement of Environmental awareness amongst employees, customers

and suppliers.

OCCUPATIONAL HEALTH AND SAFETY POLICY

Compliance with applicable Legislation and Regulations.

Setting objectives and targets to eliminate/control/minimize risks due to

Occupational and Safety Hazards.

Appropriate structured training of employees on Occupational Health and

Safety (OH&S) aspects.

Formulation and maintenance of OH&S Management programmes for

continual improvement;

Periodic review of OH&S Management System to ensure its continuing

suitability, adequacy and effectiveness;

Communication of OH&S Policy to all employees and interested parties

CNC Machine

CNC stands for “Computer Numerated Control. ” A CNC machine directs a cutting

tool, based on directions that the operator has entered into a computer that controls

the movement of the head holding the tool.

This lead to results that are far faster and more accurate than cutting by hand or on

manually controlled power tools.

There are few main types of CNC machines used in metal shop as well as

production shops around the world today.

These machine uses computer controls to make intricate movements to cut and

shape metal, wood and plastics..

To manufacture complex curved geometries in 2D or 3D was extremely expensive

by mechanical means (which usually would require complex jigs to control the

cutter motions)

Machining components with repeatable accuracy

Unmanned machining operations

HISTORY:

CNC allows a computer to dictate the moves a machine makes to perform cutting

function. Originally, all machines are operated manually with distinct possibility of

mistakes.

The CNC machine performs these actions with more precision as well as more

speed. The first CNC was manufactured in 1970s to speeds up production t large

manufacturing plants and were very expensive and difficult to use.

Types of CNC machines

Based on Motion Type:

Point-to-Point or Continuous path

Based on Control Loops:

Open loop or Closed loop

Based on Power Supply:

Electric or Hydraulic or Pneumatic

Based on Positioning System

Incremental or Absolute

Open Loop vs. Closed Loop controls

HOW TO USE A TYPICAL CNC MACHINE

Develop or obtain the 3D geometric model of the part, using CAD..

Run CAM software to generate the CNC part program.

Verify and edit program.

Download the part program to the appropriate machine.

Verify the program on the actual machine and edit if necessary.

Run the program and produce the part.

OR

The design is loaded into the computer which is attached to the CNC machine The

computer change the design into a special code [numerical] that controls the way

the CNC cuts and shapes the material.

Process working

In oxy-fuel cutting, metal is heated to its kindling temperatue. A stream of oxygen is then trained on the metal, burning it into a metal oxide that flows out of the kerf as slag.

The metal is first heated by the flame until it is cherry red. Once this temperature is attained, oxygen is supplied to the heated parts by pressing the "oxygen-blast trigger". This oxygen reacts with the metal, forming iron oxide and producing heat. It is this heat that continues the cutting process. The cutting torch only heats the metal to start the process; further heat is provided by the burning metal.

The melting point of the iron oxide is around half that of the metal; as the metal burns, it immediately turns to liquid iron oxide and flows away from the cutting zone.

Acetylene when combined with oxygen burns at 3200 °C to 3500 °C (5800 °F to 6300 °F), highest among commonly used gaseous fuels. As a fuel acetylene's primary disadvantage, in comparison to other fuels, is high cost.

Cutting is initiated by heating the edge or leading face (as in cutting shapes such as round rod) of the steel to the ignition temperature (approximately bright cherry red heat) using the pre-heat jets only, then using the separate cutting oxygen valve to release the oxygen from the central jet. The oxygen chemically combines with the iron in the ferrous material to oxidize the iron quickly into molten iron oxide, producing the cut. Initiating a cut in the middle of a workpiece is known as piercing.

For preheating purpose usually neutral flame is used.

Types Of Various Flames

Neutral Flame with Oxygen Cutting Stream

CNC Flame Cutting

It provides a very efficient and accurate method for preparing component shapes

prior to fabricating part. Individual component drawings in DXF format are first

imported into a nesting software to generate an optimum layout on the available

raw material. Once the cutting plan is finalized, the layout is transferred to CNC

flame cutting machine which rapidly cut all the individual parts from the loaded

plate using a completely automated Oxy/Fuel flame cutting head.

Cutting and machining allowances as well as single bevels if any may be specified

ahead of time. Dimensional accuracy as well as cut surface finish are far superior

to manual methods and this directly translates to fast fabrication and machine

Metal Number cutting oxygen fuel gas speed KERF

Thickness orifice(kg/cm2) bar(kg/cm2) mm/min width(mm)

6 0 68 0.2-0.3 430-610 1.3

16 0 60 0.2-0.4 410-560 1.5

25 1 56 0.2-0.4 360-460 2

51 2 53 0.3-0.6 300-450 2.3

76 3 51 0.3-0.6 250-360 2.5

102 4 45 0.3-0.7 200-300 3

178 5 39 0.6-0.8 130-200 3.8

254 6 31 0.6-1.0 80-130 5.3

305 7 25 0.6-1.0 50-80 6.1

356 8 20 0.6-1.0 50-80 6.6

GAS CUTTING NOZZLE OPERATION PERFORMANCE TABLE

Basic Concept of Part Programming

Part programming contains geometric data about the part and motion

information to move the cutting tool with respect to the work piece.

Basically, the machine receives instructions as a sequence of blocks

containing commands to set machine parameters; speed, feed and other

relevant information.

A block is equivalent to a line of codes in a part program.

N135 G01 X1.0 Y1.0 Z0.125 T01 F5.0

Preparatory command (G code)

The G codes prepare the MCU for a given operation, typically involving a cutter

motion.

G00 rapid motion, point-to-point positioning

G01 linear interpolation (generating a sloped or straight cut)

G06 parabolic interpolation (produces a segment of a parabola)

G17 XY plane selection

G20 circular interpolation

G28 automatic return to reference point

G33 thread cutting

Miscellaneous commands (M code)

M00 program stop

M03 start spindle rotation (cw)

M06 tool change

M07 turn coolant on

Feed commands (F code)

Used to specify the cutter feed rates in inch per minute

Speed commands (S code)

Used to specify the spindle speed in rpm.

Tool commands (T code)

Specifies which tool to be used, machines with automatic tool changer.

Example of a part program

N001 G91 (incremental)

N002 G71 (metric)

Loading tool

N003 G00 X0.0 Y0.0 Z40.0 T01 M06

Positioning tool at P1

N004 G01 X75.0 Y0.0 Z-40.0 F350 M03 M08 Start coolant

Linear interpolation

Rapid motion

Example of a part program

Moving tool from P1 to P3 through P2

N005 G01 X110

N006 G01 Y70.0

Moving tool from P3 to P4 along a straight line and from P4 to P5

clockwise along circular arc.

N007 G01 X-40.86

N008 G02 X-28.28 Y0.0 I-14.14 J-5.0

ADVANTAGES

- Easier to program.

- Easy storage of existing programs.

- Easy to change a program.

- Avoids human errors.

- NC machines are safer to operate.

- Complex geometry is produced as cheaply as simple ones.

- Usually generates closer tolerances than manual machines.

DISADVANTAGES

1. CNC machines are more expensive than manually operated machines, although

costs are slowly coming down.

2. The CNC machine operator only needs basic training and skills, enough to

supervise several machines. In years gone by, engineers needed years of training

to operate centre lathes, milling machines and other manually operated

machines. This means many of the old skills are been lost.

3. Less workers are required to operate CNC machines compared to manually

operated machines. Investment in CNC machines can lead to unemployment.

CONCLUSIONS

Working on this live project and being a part of summer training in BHEL, Jhansi has been a wonderful experience. Development of the project provided immense learning opportunities to me. I have been fortunate to be able to work with the widely used technologies. It was a great exposure to real time development and implementation issues and working in a team has been a priceless experience.

REFRENCES

Following are some of the sources I reached out to while working on

this project,

Google

Wikipedia

www.bheljhs.co.in

www.wabco.com