ABSTRACT

According to college curricular under department of transport engineering and technology to

conduct industrial practical training for the aim of increasing knowledge and earning experience
concerning with mechanical engineering students are supposed to participate in training effective ly
for their benefits. The training began on 14th September,2020 and ended on 25th October,2020 at
YOUNG ENGINEERS LTD workshop located at SIDO-Tanga, the company is concerning with
manufacturing and maintenance of different machines/vehicles components. Most of the
production processes performed are filtering and fabrications processes and I exposed in all
activities performed in the workshop including lathe machine operations, milling machines
operations, welding activities, shearing and sheet bending activities. The activity that performed
almost the whole period of training was production of sisal trailers which pulled by tractor at sisal
estate in Tanga region, the company received an order from sisal company to produce more than
three trailers and in all activities concerning with production of these trailers I participated as one
of the technicians.

i
 DECLARATION
I hereby declare that the report has been prepared by myself to fulfil the curricular requirement of
Mechanical engineering offered by department of Transport Engineering and Technology.

Signature…………….

Date……………

ii
 ACKNOWLEDGEMENT
With due respects and honors I take this chance to thank God for granting me good and strong
health during the training as well as protect me from unexpected accidents occurred during work.
I acknowledge all those whose guidance and encouragement have made my efforts successful in
this training. I wish to express my deep sense of gratitude to my industrial supervisor Mr. Abasi
H. Pangala from YOUNG ENGINEERS LTD and other technicians for their encouragement and
contributions, which went a long way in the successful completion of my training. I acknowledge
my college administration to arrange this program for students to participate in industrial practic al
training and increasing our knowledge also special thanks to my college supervisor Ms. Nyangi
Masanja who came at site for assessments and advise during my training. Without leaving my
parents behind I acknowledge them very much for their full support in the whole period of my
training.

iii
 LIST OF ABBREVIATION/NOMENCLATURE
i. SIDO-Small Industries Development Organization.

ii. Z-number of teeth

iii. d-reference diameter

iv. da-tip dimeter

v. df- root diameter

vi. s- tooth thickness

vii. ha-addendum

viii. hf-dedendum

iv
 TABLE OF CONTENTS
ABSTRACT .......................................................................................................................................i
DECLARATION................................................................................................................................ ii
ACKNOWLEDGEMENT.................................................................................................................. iii
LIST OF ABBREVIATION/NOMENCLATURE ............................................................................... iv
LIST OF FIGURES ........................................................................................................................... vi
CHAPTER ONE...............................................................................................................................1
1.0 INTRODUCTION. ....................................................................................................................1
1.1 HISTORICAL BACKGROUND ................................................................................................1
1.2 ORGANISATION FUNCTION .................................................................................................1
1.3 ORGANISATION CHART .......................................................................................................1
1.4 ORGANISATION MISSION, VISION AND OBJECTIVES .......................................................2
1.4.1 VISION ..........................................................................................................................2
1.4.2 MISSION .......................................................................................................................2
1.4.3 OBJECTIVE OF ORGANISATION.................................................................................2
CHAPTER TWO ..............................................................................................................................3
2.0 MILLING OPERATIONS .........................................................................................................3
2.0.1 Gang milling ..................................................................................................................3
2.0.2 End milling .....................................................................................................................4
2.0.3 Form milling ...................................................................................................................4
2.0.4 Straddle milling...............................................................................................................5
2.1 GEAR MACHINING ................................................................................................................5
2.1.1 GEAR MACHINING PROCEDURES .............................................................................6
2.2 OBJECTIVES OF THE PROJECT.............................................................................................6
2.3 PROBLEM IDENTIFICATION .................................................................................................6
2.4 ANALYSIS ..............................................................................................................................7
2.5 DESIGN ...................................................................................................................................7
CHAPTER THREE........................................................................................................................ 10
3.0 CONCLUSION AND RECOMMENDATION .......................................................................... 10
3.1 CONCLUSION....................................................................................................................... 10
3.2 RECOMMENDATION ........................................................................................................... 10
References ....................................................................................................................................... 11
Appendix sketches/pictures ............................................................................................................... 12

v
 LIST OF FIGURES

Figure 1: The organization structure

Figure 2: The gang milling operation
Figure 3: The end milling operation

Figure 4: The form milling operation

Figure 5: The straddle milling operation

Figure 6: The index head, plate and foot stock

Figure 7: demonstration of gear terminologies

Figure 8: Index plate and sector

vi
 CHAPTER ONE
1.0 INTRODUCTION.
The industrial training had been taking place at YOUNG ENGINEERS COMPANY workshop to
perform different industrial activities concerning with engineering production based on
mechanical engineering. Most of the workshop activities were fitter and turner as well as
fabrications of different engineering staffs.

1.1 HISTORICAL BACKGROUND

Young Engineers Ltd established on 1994 when government (SIDO) suspended to provide service
according to different reasons and endorse their workshop as well as equipment to private person.
On that year Mr. Jabe Mwapachu took over and establish young engineers company which is
running until today.

1.2 ORGANISATION FUNCTION

The company deals with repair, fabrications and production of different machines components
such as gears, shafts and so on.

1.3 ORGANISATION CHART

General Director

Accountancy Foreman/Manager

Workshop technicians

Figure 1: The organization structure.

1
1.4 ORGANISATION MISSION, VISION AND OBJECTIVES
1.4.1 VISION
i. To increase number of tools and equipment of high capacity and modern condition in
operations.
ii. To increase number of technicians so to widen the company and increase accuracy in
service provision.
iii. To increase enough capital to rise the company as their visions to accomplish.

1.4.2 MISSION
i. To became a large company with branches in different regions in our country.
ii. To became a company with high technology in terms of tools and equipment.

1.4.3 OBJECTIVE OF ORGANISATION

i. To continue providing services that could be provided by SIDO.
ii. To rise the knowledge and encouraging young engineers to perform their duties as
engineers.
iii. To support government, aim in rising industrial economy since the late Mwalimu J.K.
Nyerere established the concept.

2
 CHAPTER TWO
2.0 MILLING OPERATIONS
Milling machine removes metal with revolving cutting tool called a milling cutter. With various
attachments, milling machines can be used for boring, slotting, circular milling dividing, and
drilling. This machine can also be used for cutting keyways, racks and gears and for fluting taps
and reamers. The milling operations can be classified into four categories according way cutter
revolves about its axis

i. Face milling. Machining flat surfaces which are perpendicular to the axis of the cutter,
ii. Plain or slab milling. Machining flat surfaces which are parallel to the axis of the cutter.
iii. Angular milling. Machining flat surfaces which are at an inclination to the axis of the cutter.
iv. Form milling. Machining surfaces having an irregular outline.

Consider the following brief explanations over milling operations.

2.0.1 Gang milling

Gang milling is a horizontal milling operation that utilizes three or more milling cutters grouped
together for the milling of a complex surface in one pass. Consider the figure below, different type
and size of cutters should be selected for achieving the desire profile on the work piece.

Figure 2: The gang milling operation.

3
 2.0.2 End milling
The process of milling a flat surface with the axis of the cutter perpendicular to the machining
surface. This operation can be used to make a features like keyways and slot, the cutter used in
this operation is known as end milling cutter. Consider the following figure.

Figure 3: The end milling operation.

2.0.3 Form milling

Form milling is the process of machining special contours composed of curves and straight lines,
or entirely of curves, at a single cut. This is done with formed milling cutters, shaped to the contour
to be cut. The more common form milling operations involve milling half-round recesses and
beads and quarter-round radii on workplaces. This operation is accomplished by using convex,
concave, and corner rounding milling cutters ground to the desired circle diameter. Check the
figure below showing form milling operation.

Figure 4: The form milling operations.

4
 2.0.4 Straddle milling
When 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 work piece are machined simultaneo us ly
and final width dimensions are exactly controlled.

Figure 5: The straddle milling operation.

2.1 GEAR MACHINING

A gear is a rotating machine part having cut teeth, which mesh with another toothed part to transmit
torque. Geared devices can change the speed, torque, and direction of a power source. Gears almost
always produce a change in torque, creating a mechanical advantage, through their ratio. The teeth
on the two meshing gears all have the same shape. Two or more meshing gears, working in a
sequence, are called a gear train or a transmission. Spur gear machining is a process which
performed on milling machine to cut the gear teeth

Dividing head (index head)

This is additional component/attachment which is used to divide circumference of work piece into
equally spaced divisions when milling gear teeth, squares, hexagons, and octagons. It can be right
or left handed depending on which end you have it assembled, but also used to rotate work piece
at predetermined ratio to table feed rate

Foot stock

Foot stock is working similar to tail stock on lathe machine that is supporting the work piece such
as long shaft. The foot stock is also working altogether with center rest to support long work pieces

5
 Figure 6: The index head with index plate and foot stock.

2.1.1 GEAR MACHINING PROCEDURES

i. Fix the form cutter to the arbor.
ii. Fix the indexing head to the table.
iii. Adjust the speed of the spindle by adjusting the gears.
iv. Now switch on the machine and engage the automatic feed rod setting the require feed rate.
v. After one tooth is cut change the position of the indexing crank with the help of crank pin.
vi. Again another tooth is cut by applying feed and change the crank pin position up nth teeth.

2.2 OBJECTIVES OF THE PROJECT

i. To learn and increase knowledge about milling machine and its operations.
ii. To learn and understand the process and procedures of gear machining.
iii. To learn different alternative operations of gear machining.

2.3 PROBLEM IDENTIFICATION

The problem that led to machining a new gear was to replace the old one from which the teeth
were broken due to bearing problem, the gear was from lathe machine.

6
2.4 ANALYSIS

There are different alternative procedures or process of maintenance of the old broken gear; the
following are some of them, which should be adhered to repair the gear.

i. To fill the broken gear teeth with welding, then to machine the new teeth from the old gear.
ii. To machining the new gear using a form cutter from the milling machine, the process
known as form milling.
iii. To perform hobbing process using a hob and a generating process for creating a tooth
profile.
iv. To perform shaping using a shaper cutter and a generating process for creating a tooth
profile.
v. The last alternative is to purchase a new gear from the manufacturer of the old one with
the same specification, this is supported by interchangeability of manufactured machine
components

2.5 DESIGN

Consider the following gear terminologies from gear profile diagram

Figure 7: demonstrating gear terminologies important for gear designing.

7
Type of gear produced: Spur gear with involute teeth

Type of cutter: Form cutter (gear type)

Number of teeth Z= 21 teeth

Module (m)= 2

Pitch= Pi x Module= πm= 3.1416 x 2=6.2832mm

Depth= (Addendum + Dedendum) =2.25m=4.5mm

Addendum (ha)=1.00m=2mm

Dedendum (hf)= 1.25m=2.5mm

Reference diameter (d)= Zm=21x 2=42mm

Tip diameter (da)= d + 2m= 46mm

Root diameter (df) = d- 2.5m= 39.5mm

Tooth thickness (s)= πm/2=3.14mm

Indexing or turn of the crank= 40/Z

Indexing

Indexing is the process of evenly dividing the circumference of a circular work piece into equally
spaced divisions, such as in cutting gear teeth, cutting splines, milling grooves in reamers and taps,
and spacing holes on a circle. The index head of the indexing fixture is used for this purpose.

Calculating the indexing or number of turns of crank for most, simply divide 40 by number of
divisions or flats to be cut. Milling a spur gear with 21 teeth, Using the rule previously given,
divide 40 by 21 which equals 1 19/21 turns, or one full turn plus 19/21 of a turn or any circle whose
number is divisible by 21. Take the denominator which is 21 into which of the available hole
circles it can be evenly divided. In this case, 21 can be divided into the available 42-hole circle
exactly 2 times. Use this result 2 as a multiplier to generate the proportional fraction required.

Therefore: -
19 2 38
× =
21 2 42

Therefore, 1 full turn of the crank plus spaces on a 42-hole circle is the correct indexing
for 2 divisions.

8
 Figure 8: Index plate and sector

Setup

The success of any milling operation depends, before setting up a job, be sure that the to a great
extent, upon judgment in setting up the job, work piece, the table, the taper in the spindle, selecting
the proper milling cutter, and holding the cutter by the best means under the circumstances Some
fundamental practices have been proved by experience to be necessary for and the arbor or cutter
shank are all clean and good results on all jobs. Some of these practices are mentioned below.

i. Before setting up a job, be sure that the work piece, table, the taper in the spindle, and the
arbor or cutter shank are free from chips, nicks, or burrs.
ii. Do not select a milling cutter of larger diameter than is necessary.
iii. Check the machine to see if it is in good running order and properly lubricated, and that it
moves freely, but not too freely in all directions.
iv. Consider direction of rotation. Many cutters can be reversed on the arbor, so be sure you
know whether the spindle is to rotate clockwise or counterclockwise.
v. Feed the work piece in a direction opposite the rotation of the milling cutter (conventio na l
milling).
vi. Do not change feeds or speeds while the milling machine is in operation.
vii. When using clamps to secure a work piece, be sure that they are tight and that the piece is
held so it will not spring or vibrate under cut.
viii. Use a recommended cutting oil liberally.
ix. Use good judgment and common sense in planning every job, and profit from previous
mistakes.

9
 CHAPTER THREE

3.0 CONCLUSION AND RECOMMENDATION

From the beginning of the industrial training until the end including preparation of this report, the
following are conclusion and recommendation of this report, which should be provided, to the
mechanical department.

3.1 CONCLUSION

From the beginning of the training till the completion of this project, there many lesson earned
including using different production machines concerning with mechanical engineering and
operations or processes, this machines were milling machine, lathe machine, shearing machine,
bending machine, surface grinding machine, hand grinding machine, manual pressing machine and
welding process, but also from the project a new spur gear produced with the same specificatio ns
of the old gear.

3.2 RECOMMENDATION

The recommendation about industrial training and report are as follows:

i. Mechanical department should improve the log book by increase the size and provide
enough pages for demonstration of technical drawings.
ii. Also should make sure their students are being supervised enough when they are in their
training by introducing communication between industrial supervisor and college
supervisor so as to ask for the progress of their students.
iii. Government should support our institute enough in terms of workshop quality includ ing
modern machines and equipment so as to produce highly trained and qualified engineers.
iv. Department should arrange the periods of practical as much as it possible for students to
understand and being capable of running workshop machines and industrial as well.

10
References
Army, Us. (1988). Milling Machine Operations. Chicago: US Army.
DeGarmo,E. Paul. (2000). Materials and Processes in Manufacturing. McMillan Publishing.
Groover, M. (1996). Fundamentals of Modern Manufacturing. Prentice Hall.
Groover, P. M. (2002). Fundamentals of Modern Manufacturing. WILEY Inc.
Schey, John A. ( 1987). Introduction to Manufacturing Processes. McGraw Hill.
Tlusty, G. ( 2000). Manufacturing Process and Equipment. Prentice Hall Inc.

11
Appendix sketches/pictures

Moving tail stock on lathe machine during drilling operation.

After drilling operation from the milling machine

12
 Square faces making from the milling machine

After surfacing of the crankshaft from milling machine

13
The crank shaft with gear and bearing after making key way from milling machine.

The step turning operation on lathe machine

14
Data input on bending machine before sheet bending

Sheet metal bending operation on bending machine

15
 Spline cutting on milling machine

Digital operated sheet metal bending machine

16
Gear cutting from the milling machine.

17
NIT/BME/2019/977

18
19