DIRECTORATE OF TECHNICAL EDUCATION

CHENNAI-600025

DIPLOMA IN MECHANICAL ENGINEERING

PROJECT REPORT

2015-2016

FABRICATION OF ABRASIVE BELT GRINDER

DONE BY

NAME REG.NO.

MOHANAVATHANAN R 14255963

RAJESH A 14259982

SARAVANAN C 14255990

SATHISHKUMAR A 14255992

VIJAYAKUMAR B 14256016

GUIDE BY

Mr.S.SARAVANAN,B.E.,

Lecturer in Mechanical Engg.

Dr.M.G.R.POLYTECHNIC COLLEGE,

ACS NAGAR,ARNI-632317.

T.V.MALAI DIST.

BONAFIDE CERTIFICATE

Certified that is the confide record of the project work done

By_____________________________________ of the final year diploma

in MECHANICAL ENGINEERING, during the academic year 2015-

2016.

REGISTER NO :

GUIDE H.O.D

Submitted for the practical examination held on ______________

INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWEDGEMENT

We thank our gratitude to our Correspondent Thiru

A.C.SHANMUGAM,B.A.B.L., for his words which inspired us a lot in completing

this project work successfully.

We Thank sourprincipal Mr.D.ARUMUGAMUDALI,

B.E.,B.TECH.ED,M.I.S.T.E.,M.I.E.,C.ENGG for his valuable suggestion and timely

advises during various stages of our work.

We Thanks our regards to Mr.A.KARTHIKEYAN,M.E., Head of the

Mechanical Engineering Department, Dr.MGR Polytechnic College, ARNI for

providing necessary facilities to carry the project.

Our hearty thanks to our Guide Mr.S.SARAVANAN,B.E Lecturer of

Dr.MGR Polytechnic,ARNI. who has been the lifeblood of our project. Amidst him

busy schedule, he had spent her valuable time in explaining certain crucial concepts.

She constantly motivated us and animated our spirits to implement our project in an

efficacious manner. His enriched ideas and his vision beyond horizon have accelerated

us throughout our research.

I also thank all our faculty members and my friends for their kind support and

providing necessary facilities to carry out the work.

Last but not least we are heavily indebted to our beloved PARENTS for their

continuous source of encouragement.

CONTENTS

ACKNOWLEDGEMENT

INTRODUCTION

WORKING PRINCIPLE

PART DRAWING

ASSEMBLY DRAWING

INDUCTION MOTORS

ADVANTAGES AND LIMITATION

APPLICATION

SPECIFICATIONS

LIST OF MATERIALS

PROJECT SHEDULE

COST ESTIMATION

CONCLUSION

PHOTOGRAPHY

BIBLIOGRAPHY

ABSTRACT

ABSTRACT

The Machine we designed and fabricated is used for grinding any shape of object

like Circular, Rectangular, and Polygon. In our project the work abrasive belt is used

to grinding the material. The abrasive belt is rotated by the single phase induction

motor. Hence our project namely abrasive belt grinder is a Special type of Machine.

According to the type of material to be grind, the grinding tool can be changed.

This project gives details of grinding various shapes and sizes of components.

This machine can be widely applied in almost all type of industries. By varying the

pulley sizes I can get a high end speed of over 10,000 rpm if needed. The only change

I would make is to have a totally enclosed motor to keep out the grit.

INTRODUCTION

INTRODUCTION

Our project is design and fabrication of Multi Use abrasive belt

Grinder. It is used to grind the machining surfaces to super Finish and accuracy.

It can be used as an external Grinder by fixing the belt grinder attachment on the

conveyor roller. The principle parts of this attachment are main body, motor with

pulley, bearings, rope pulley and conveyor abrasive belt etc.

WORKING

PRINCIPLE

WORKING PRINCIPLE

The abrasive belt is used to grind the material. This abrasive belt is rotated by

the single phase induction motor. In our project consist of end bearings with bearing

cap, roller wheel, shaft, single phase induction motor and abrasive belt. This whole

arrangement is fixed on the frame structure where the component rests.

The roller wheel is mounted on the two end bearings with bearing cap by suitable

arrangement. There are two roller wheel is used in our project to rotate the abrasive

belt. One side of the roller wheel shaft, one v-pulley is coupled by the suitable

arrangement. The single phase induction motor with V-pulley arrangement is used to

rotate the abrasive belt through the belt drive mechanism.

Belt grinding is an abrasive machining process used on metals and other

materials. It is typically used as a finishing process in industry. A belt, coated in

abrasive material, is run over the surface to be processed in order to remove material

or produce the desired finish.

APPLICATIONS

Belt grinding is a versatile process suitable for all kinds of different

applications. There are three different applications of the belt grinding technology:

1. Finishing: surface roughness, removal of micro burrs, cosmetic finishes,

polishing

2. Deburring: radiusing, burr removal, edge breaking

3. Stock removal: high stock removal, cleaning (e.g. of corrosion), eliminating mill

or tool marks, dimensioning

GRINDING METHODS

Wide belt grinding is a familiar process in industry as well as home applications.

There are several basic methods for belt grinding:

Stroke belt

Platen belt

Wide belt

Backstand (pressure)

Centreless

Portable (manual)

WIDE BELT GRINDING

One of the most common methods is wide belt grinding.

The belt grinding process is variable by adjusting certain parameters such as belt

speed, grinding pressure, feed speed, durometer of the contact drum, size of the contact

drum and the abrasive belt that is used. The machines can be made for wet or dry

operation. Furthermore, a wide belt grinding machine can be constructed with single

or multiple heads. The first head is used for coarse grinding and the next heads

gradually make a finer finish. Wide belt grinding is also used as a high stock removal

method for special

CHANGING VARIABLES

There are several objectives possible for grinding with coated abrasives. Among

them are the right application (e.g. finish or stock removal), time saving and efficiency

of the abrasive tool.

To achieve the above objectives, it is essential to look in more detail to the

variables which affect them. These include the work material properties, the grit and

abrasive type of the grinding belt, belt speed, belt sequences, contact wheel hardness

and diameter, serration, type of lubricant (or dry) and grinding pressure

ABRASIVE

An abrasive is a material, often a mineral, that is used to shape or finish a

workpiece through rubbing which leads to part of the workpiece being worn away.

While finishing a material often means polishing it to gain a smooth, reflective surface

which can also involve roughening as in satin, matte or beaded finishes.

Abrasives are extremely commonplace and are used very extensively in a wide

variety of industrial, domestic, and technological applications. This gives rise to a large

variation in the physical and chemical composition of abrasives as well as the shape of

the abrasive.

MECHANICS OF ABRASION

Abrasives generally rely upon a difference in hardness between the abrasive and

the material being worked upon, the abrasive being the harder of the two substances.

Typically, materials used as abrasives are either hard minerals (rated at 7 or

above on Mohs scale of mineral hardness) or are synthetic stones, some of which may

be chemically and physically identical to naturally occurring minerals but which cannot

be called minerals as they did not arise naturally.

Abrasive minerals

Abrasives may be classified as either natural or synthetic. When discussing

sharpening stones, natural stones have long been considered superior but advances in

material technology are seeing this distinction become less distinct. Many synthetic

abrasives are effectively identical to a natural mineral, differing only in that the

synthetic mineral has been manufactured rather than been mined. Impurities in the

natural mineral may make it less effective.

Some naturally occurring abrasives are:

Calcite (calcium carbonate)

Emery (impure corundum)

Diamond dust (synthetic diamonds are used extensively)

Novaculite

Pumice

Rouge

Sand

Corundum

Garnet

Sandstone

Tripoli

Powdered Feldspar

Staurolite

Some abrasive minerals (such as zirconia alumina) occur naturally but are

sufficiently rare or sufficiently more difficult/costly to obtain such that a synthetic

stone is used industrially. These and other artificial abrasives include:

Borazon (cubic boron nitride or CBN)

Ceramic

Ceramic aluminium oxide

Ceramic iron oxide

Corundum (alumina or aluminium oxide)

Dry ice

Glass powder

Steel abrasive

Silicon carbide (carborundum)

Zirconia alumina

Boron carbide

MANUFACTURED ABRASIVES

Abrasives are shaped for various purposes. Natural abrasives are often sold as

dressed stones, usually in the form of a rectangular block. Both natural and synthetic

abrasives are commonly available in a wide variety of shapes, often coming as bonded

or coated abrasives, including blocks, belts, discs, wheels, sheets, rods and loose grains.

BONDED ABRASIVES

Assorted grinding wheels as examples of bonded abrasives.

A grinding wheel with a reservoir to hold water as a lubricant and coolant.

A bonded abrasive is composed of an abrasive material contained within a

matrix, although very fine aluminium oxide abrasive may comprise sintered material.

This matrix is called a binder and is often a clay, a resin, a glass or a rubber.

COATED ABRASIVES

A German sandpaper showing its backing and FEPA grit size.

A coated abrasive comprises an abrasive fixed to a backing material such as

paper, cloth, rubber, resin, polyester or even metal, many of which are flexible.

Sandpaper is a very common coated abrasive. Coated abrasives are commonly the same

minerals as are used for bonded abrasives.

OTHER ABRASIVES AND THEIR USES

Here the abrasiveness of toothpaste is detailed by its Relative Dentin Abrasivity (RDA)

Sand, glass beads, metal pellets copper slag and dry ice may all be used for a

process called sandblasting (or similar, such as the use of glass beads which is "bead

blasting"). Dry ice will sublimate leaving behind no residual abrasive.

INDUCTION MOTOR

I. OBJECTIVES

A.

To experimentally evaluate the circuit model elements for a 3-phase induction

motor.

B.

1. To start and test the performance of an induction motor under full load when it

is powered from the three-phase line by a FVNR (full voltage, non-reversing)

combination starter.

2. To compare the actual performance of a three-phase induction motor with that

predicted by the circuit model.

3. To start an induction motor, examine variable speed operation, and perform a

full-load test when it is powered by the AC Test Drive.

4. To obtain the data for the torque vs. speed and current vs. speed characteristics

of the induction motor using a lab computer program.

II. THEORY AND BACKGROUND

A. CONSTRUCTION

The induction machine has two parts - stator and rotor. The stator carries a

distributed 3-phase winding. The stator winding is the input/output winding and is the

armature of the machine. The lab machine has a squirrel cage rotor. A squirrel cage

rotor has solid bars in the slots and they are shorted together at the ends.

B. OPERATION

When a balanced 3-phase voltage is supplied to the armature, a rotating magnetic

field is produced (just as in a synchronous machine). The speed of rotation is the

synchronous speed given by

s 4f1

p rad / s

or

ns 120 f1

p rpm,

where p is the number of poles of the armature winding and f1 is the line frequency.

However, the rotor rotates at a speed less than the synchronous speed. We will

designate the angular speed of the rotor in rad/s by w and the speed in rev/min (rpm)

by n. The slip speed is speed of the rotor relative to the field, i.e.,

Slip speed = ws – w (rad/s)

= ns – n rpm

C. EQUIVALENT CIRCUIT

The equivalent circuit given in Figure 1 serves as an approximate circuit model

for one phase of the induction motor.

Figure 1. Per phase Equivalent Circuit of Induction Motor

The symbols used in Figure 1 are defined below:

V1 = line-to-neutral terminal voltage. The phase windings are considered to be

in a Y configuration.

r1 = stator resistance per phase

x1 = stator leakage reactance per phase

r2 = rotor resistance referred to the stator, per phase

x2 = rotor leakage reactance referred to the stator, per phase

xm = a shunt reactance supplied to provide a path for the magnetizing

component of the current flowing in the stator. It is this current which

produces the revolving field in the motor.

III. THE LABORATORY MACHINE

The induction machine of the laboratory has the following name plate data:

H.P. 5; Phase 3; Hz 60; Design B;

RPM 1750; Amps (for 230V) 12.5; Amps (for 460V) 6.25

The stator has two 3-phase windings. The corresponding phases may be

connected in series or in parallel. For a series connection, the rating of 460 V, 6.25 A

applies and for a parallel connection 230 V, 12.5 A. The latter applies for our case.

Thus before starting lab work, you must remember to connect the two 3-phase windings

in parallel

+

–

I1 I2 x2 x1

xm

r1

r2

r2 1 s

s

r2

s V1

IV. INSTRUCTOR LABORATORY PREPARATION

The blocked rotor test in Day 1 will need a special supply, namely, 3-phase AC

of 15 Hz. This section assists the instructors to generate this supply. A separate work

station with a synchronous machine is to be used and the supply will reach other

stations through the station tie line.

Figure 2. Circuit for Generating the Special Supply

Turn the dyno and AC Test Drive circuit breakers ON and put the contactor

panel in the HAND mode. 2M may be OFF as it is not used. To protect the field

exciter, make sure that the field connection is made and the exciter is off. Now make

the following settings on the dyno:

SPEED mode; FULL field; Current Limit = 50%.

Field Exciter

Synchronous Machine

3-phase Meter

Package

F

F

1

2

Tie Line

1M

V. LABORATORY PROCEDURE - DAY 1

In the first day's work, experiments will be performed for determining

impedances of the equivalent circuit. The MONITOR computer program will act as

your "multimeter" for these experiments.

A. DC RESISTANCE TEST

The schematic for this test is given in Figure 3. Connect the two leads from the

DC circuit to any two stator terminals of the induction motor. Make sure all of the

load box switches are in the off (center) position. Using proper procedures, connect

the input to the 125 V DC laboratory supply. Have your wiring checked by your

instructor

If the 250 V DC supply is used instead of 125 V, a slightly different

configuration is to be adopted for the load box. If the resistors (which are 39 ohms

each) are connected in parallel then the current through each would be about 6.4 amps,

which would be well over the rated current of the element. Thus, groups of two

resistors (in series) should be connected in parallel in this case.

Figure 3. Schematic for DC Stator Resistance Test

B. NO-LOAD TEST

The schematic for this test is given in Figure 4. Be sure that the motor is

uncoupled from the dynamometer. Connect the motor terminals to the output of the

transducer package which encompasses power measurement by the 2-wattmeter

method. Then make connections to the Combination Starter output, using proper safety

procedures. Your wiring should be checked by your instructor before proceeding.

Close the circuit breaker and press START on the Combination Starter panel. The no-

load speed should be about 1799 rpm. Read and record the line currents, line voltage,

and wattmeter readings (you may prefer to just print the monitor and highlight the

channels of interest, as usual).

Figure 4. Schematic for No-Load and Full-Load Motor Tests.

VI. LABORATORY PROCEDURE - DAY 2

For this period, the objectives are full load operation of the induction motor with

line supply and AC Test Drive supply, and obtaining data for induction motor

characteristics by a computerized test.

A. FULL LOAD TEST WITH LINE OPERATION

The motor must be coupled to the dyno with the chain guard in place. Unpin

and zero the torque table with the computer. The circuit for this test is the same as that

used for the no-load test (Figure 4). After your instructor has checked your wiring,

START the induction motor. If the direction of rotation is not positive (as per our

I

Induction Motor

I

I

A

C

B

P

P

P

A

C

B

V

V

Combination Starter

230 V

360 Hz

convention), STOP the motor, interchange two terminals at the motor connection, re-

zero the torque table, and again START.

B. AC TEST DRIVE SUPPLY

A detailed description of AC Test Drive is in the Synchronous Machine

Experiment 6 (Section III: Laboratory Equipment). Here, the induction machine is

operated with this kind of supply.

The circuit diagram is the same as in Figure 4, except for two differences:

(a) The AC input is from the 3-phase output terminals of the AC Test Drive

(rather than the combination starter).

and (b) Connect one of the line voltages to an isolation package.

C. COMPUTERIZED TEST FOR CHARACTERISTICS

In this part of the experiment, the dyno will force the induction motor through

speeds zero (blocked rotor) through 1800 rpm (synchronous speed). The computer will

run the test in accordance with your specifications and record the data.

(a) the actual maximum magnitude of the current

and (b) avoidance of saturation (for the sake of accuracy).

Figure 5. Circuit Diagram for Computerized Characteristics Test

For the numerical values (test parameters) requested by the program, enter

the following:

Initial Speed (RPM): 1860

Final Speed (RPM): 0

Ramp Time (seconds) 10 (sec.)

Dyno Current Limit : 100 %

Figure 6. Wiring Diagram for Figure 5.

Once you press a key to start the test, the dyno will be turned on first and then

the 1M contactor will be turned on. Note that the dyno is set to SPEED mode by the

program. The speed setting will be ramped according to the test parameters entered

and the data stored. When the program exits, save the data file.

FURNAS

125 V DC 250 V DC

DYNAM- DRIVE

DC TEST DRIVE

230 V ACAC TEST

DRIVE

ICL

STARTERAC COMB

IAL

IBR

ID

ICR

IBL

IAR

230 V AC AC STARTER

TIE LINE

AC TEST DC TEST

125 V DC 250 V DC

A F

Furnas Motor Control Center

CIRCUIT BREAKERS

CONTROL POWER 110 V AC

THERMOCOUPLE

2-STEP STARTER

TACH

BLOWER

2A

IE

2B

Induction Motor

CT

sec

pri

VII. CALCULATIONS AND GRAPHS

1. Determine the impedances (resistances and inductances) of the equivalent circuit

model using the DC test, Blocked Rotor test, and No-Load test data.

2. Use this model to predict motor performance at the same voltage and speed as

in the full load line operation.

3. Calculate the average line current, power, power factor, horsepower, and

efficiency from:

(a) full load line operation data,

and (b) full load AC Test Drive Supply data.

4. From the computer controlled experiment data, plot Torque vs. Speed and

(Average) Current vs. Speed from 0 to 1800 rpm. Discard points (if any) above

1800 rpm.

VIII. ANALYSIS

1. Prepare a table comparing predicted and measured performance of the induction

motor operated from the 230 V line. Mention some sources of the discrepancies.

2. Compare efficiencies from line and inverter (AC Test Drive) operation and

comment on the difference.

3. In terms of the equivalent circuit, explain the relationship of increasing current

and decreasing power factor as the motor is slowed below synchronous speed.

4. Examine the graphs in the neighborhood of ns. In terms of the equivalent circuit,

what are the speed, torque, power, and stator current at ns?

Dynamic modelling of the induction motor

Vector control purpose

Mechanical motion.

Linear motion

For linear motion, the forces acting on a body may usually be simplified to a driving

force, Fe, acting on the mass, and an opposing force (or load), Fl, as shown on Figure

1.

Figure 1: A body acted on by two forces.

For translational motion the following may be written:

e LF Fdv

dt M

In any speed and position control of linear motion, force is the fundamental variable

which needs to be controlled.

Rotary motion

If the motion is rotary about an axis instead of translational, a situation as shown in

Figure 2 arises.

Figure 2: A body acted on by two torques.

For rotary motion the following may be written:

Ldw T T

dt J

In any speed and position control of rotary motion, torque is the fundamental variable

which needs to be controlled.

Torque in an electric drive

Electromagnetic torque produced by a motor is opposed by load torque. The difference,

em LT T , will accelerate the system.

Figure 3: A load acted on by a motor

Transformation of currents, voltages, flux-linkage, etc.

What remains is to define a method for performing the phase transformations to

the rotating frame of reference. The transformation is done by defining a

transformation-matrix for the systems as

dq abc dq abcf T f

where f denote currents, voltages, flux-linkage, etc. For current case, this is shown in

Figure 4.

Figure 4. Transformation of phase quantities into dq winding quantities (current

case).

The electromagnetic torque

Properly the most important task for the induction motor is to produce a torque

on the shaft. The developed torque may be written on the flowing form,

2

em rq rd rd rq

pT i i

d-q equivalent circuit

The result from the above is a set of equations describing the electromagnetic

system in the rotating frame of reference. The equations describing the system may be

interpreted as equivalent circuits, which may help in understanding the dynamics of

the system.

a) d-axis

b) q-axis

Figure 5. dq-winding equivalent circuits.

Computer simulation

In order to carry out computer simulations, it is necessary to calculate intial

values of the state variables, that is, of the flux linkages of the dq windings. These can

be calculated in terms of the initial values of the dq windings currents. These currents

allow us to compute the electromagnetic torque in steady state, thus the initial loading

of the induction machine. Initial conditions are computed in Example 3-1 and in the

matlab file EXE_1.m (or EXE_2.m).

Finally, the Simulink model is shown in Figure 6.

Eq. 3-48

Figure 3-13 Simulation of Example 3-3; File Name EX3_3_1.mdl

Entrada

trifasica

ELECRODINAMICS

DQ-WINDING REPRESENTATION

-K-

rad/s --> RPM

1

s

Va

Vb

Vc

Wmech

i_dq

abc --> dq

Vc

Vb

Va

f(u)

Torque Eq. 3-47

Info

Load Torque

1/Jeq

Inertia

Start

Double Click to

load parameters and initial conditions

Plot

After Simulation, Double Click to

plot results using MATLAB

Wmech

Tem

Tem RPMi_dq

ADVANTAGES AND DISADVANTAGES

ADVANTAGES:

The machine is compact and rigid in size.

Maintenance is less.

It can be used on any place of small grinding application

By varying the pulley diameter the speed of the abrasive belt to be

changed.

DISADVANTAGES :

The abrasive belt should be changeable one for different material. This

process takes more time.

APPLICATIONS

Grinding outside the job in any size of body can be done.

As the feed is given automatic, 0.8 micron finish may be achieved.

By changing the grades of abrasive belt grinding it can be used to

grind the carbon steel, Alloy steel and stainless steel etc.

SCHEDULE FOR PROJECT

SL.NO PROGRESS OF

WORK OCT NOV DEC JAN FEB MAR

1. Received the approval for

project title

2. Collecting the information

from various text book

and selecting materials

3. Construct the body of the

project.

4. Purchasing

5.

Collecting the Additional

information to complete

the project and painting

work

6. Report and extra work

was completed. Attending

the final evaluation

COST ESTIMATION

S.NO. NAME OF THE PARTS QUANTITY TOTAL

COST

1 MOTOR 1 2800

2 PULLEY BEARING 2 500

3 V-BELT 1 100

4 PULLEY 1 200

5 PAINTING 1 Lit 110

6 ABRASIVE BELT 1 45

7 TRANSPORT …. 1200

8 REPORT …. 1150

TOTAL 6105

TOTAL COST : 6,105.00

CONCLUSION

Grinding has traditionally been associated with small rates of

material removal and finishing operations. However, grinding can also be used

for large-scale metal removal operations similar to milling, shaping, and planing.

In creep-feed grinding, the depth of cut d is as much as 6mm, and the workpiece

speed is low. The wheels are mostly softer grade resin bonded with open structure

to keep temperatures low. Creep-feed grinding can be economical for specific

applications, such as grinding cavities, grooves, etc.

PHOTOGRAPHY

BIBLIOGRAPHY

REFERENCES

Stephenson, David A.; Agapiou, John S. (2006). Metal Cutting

Theory And Practice. CRC Press. p. 52. ISBN 0824758889.

Cubberly, W.H. (1989). Tool and Manufacturing Engineers

Handbook. Society of Manufacturing Engineers. Ch. 26. ISBN

0872633519. Retrieved 2013-01-31.

O.p kanna.Tool and Manufacturing Engineers hand book Society

of Manufacturing Engineers