Report Main Section

2010

WISDOM PATRICK ENANG

UNIVERSITY OF BATH

5/19/2010

POWER TRAIN TECHNICAL REPORT 1 (YEAR 3, DESIGN PROJECT GROUP 8)

POWER TRAIN TECHNICAL DESIGN – RICE TRANSPLANTER

P O W E R T R A I N T E C H N I C A L D E S I G N – ( R I C E T R A N S - P L A N T E R )

POWER TRAIN TECHNICAL DESIGN FOR

THE DESIGN OF A RICE TRANS-PLANTING MACHINE FOR RURAL AREAS OF

DEVELOPING COUNTRIES

A PROJECT PRESENTED TO

THE DEPARTMENT OF MECHANICAL ENGINEERING

BATH UNIVERSITY, BATH

IN PARTIAL FULFILMENT

OF THE REQUIREMENTS FOR AN MEng DEGREE IN MECHANICAL

ENGINEERING

WISDOM PATRICK ENANG

MAY, 2010



SUMMARY

It is in response to the growing need for the cultivation of more rice to feed the growing population

of rice eaters in Indonesia, that this project has been under taken. Considering the fact that the

manufacture of this machine is meant to be carried out in rural areas of Indonesia, some key

constraints like availability of materials, costs and availability of manufacturing techniques have

deeply been taken in to consideration at every phase of this project.

In furtherance of the power train feasibility studies, this detailed technical design has been carried

out. This technical design aims to make a final engine selection needed to power the rice

transplanting machine. In addition an engine carrier design was also under taken so as to address

the problems associated with direct engine mountings, such as need for height adjustability of

engines, and the need for easy adaptation of different engines in to the rice trans-planter. While

undertaking this design, all the engine power train interfaces were identified and well defined, also

all the necessary interface requirements were also identified and addressed accordingly.

In the end of the of this detailed design, the chosen engine is a Briggs and Stratton 3.5HP Model

series (91252-1049) engine with a 6:1 inbuilt gear box. This decision was arrived at, after vetting

that this engine was capable of meeting both the end user machine requirement specifications, and

their engine requirements specifications. The engine carrier design in the end was vetted to have

exceeded end user requirements. Possible power train risks were identified and possible preventive

and curative measures were equally provided. During the power train risk analysis it was noted that

no serious risk existed between in the engine carrier design. The only possible risk was over heat,

which is more to do with the engine. Engine carrier alternative design was also provided.



ACKNOLEDGEMENTS

Wisdom Enang, May 2010. (Power train technical design) – Rice trans-planter design project. The

author expresses his in depth appreciation to God, His parents, the members of the group 8,

Business Design Project 2010, and their supervisors, Supervisor (Graham Outram and Rod Veazey),

for their moral and technical support in the execution of this work.



Table of Contents SUMMARY ....................................................................................................................................... 3

ACKNOLEDGEMENTS .............................................................................................................................. 4

LIST OF FIGURES ...................................................................................................................................... 8

LIST OF TABLES ........................................................................................................................................ 9

INTRODUCTION ..................................................................................................................................... 10

ENGINE BACK GROUND INFORMATION - INDONESIA .......................................................................... 11

IDENTIFICATION OF END USER ENGINE REQUIREMENTS ..................................................................... 12

ENGINE SELECTION ............................................................................................................................... 13

ENGINE BRAND AVAILABILITY ............................................................................................................... 14

ENGINE MODEL SELECTION .................................................................................................................. 14

PERFORMANCE OF ENGINE WHEN THE MACHINE IS USED AS A RICE TRANSPLANTER ....................... 18

POWER TRAIN MODULARITY CONCERN ............................................................................................... 19

PERFORMANCE OF ENGINE WHEN THE MACHINE IS USED AS A ROAD VEHICLE................................. 21

BENEFITS OF THE CHOSEN ENGINE TO THE END USER ......................................................................... 22

ENGINE CARRIER DESIGN ...................................................................................................................... 23

INTRODUCTION ..................................................................................................................................... 24

DEFINITION OF ENGINE CARRIER DESIGN REQUIREMENTS .................................................................. 24

DEFINITION OF ENGINE CARRIER DESIGN CONSTRAINTS ..................................................................... 25

ENGINE CARRIER PERFORMANCE SPECIFICATION ................................................................................ 27

DETAILED DESIGN ANALYSIS OF ENGINE CARRIER................................................................................ 28

ENGINE CARRIER FAILURE ANALYSIS RESULTS...................................................................................... 29

ENGINE CARRIER ASSEMBLY BOLT ANALYSIS ....................................................................................... 30

POWER TRAIN SOLUTION SPECIFICATION ............................................................................................ 31

ENGINE CARRIER MANUFACURING GUIDE ........................................................................................... 32

ENGINE CARRIER DESIGN COST AND WEIGHT ESTIMATION ................................................................ 34

ENGINE CARRIER ASSEMBLY GUIDE ...................................................................................................... 35



EVALUATION OF ENGINE CARRIER DESIGN TO ENSURE COMFORMITY TO PERFORMANCE

REQUIREMENT SPECIFICATION ............................................................................................................. 36

EVALUATION OF ENGINE CARRIER DESIGN TO ENSURE COMFORMITY TO END USER REQUIREMENTS

.............................................................................................................................................................. 37

POWER TRAIN INTERFACES ................................................................................................................... 39

FULL POWER TRAIN SUB ASSEMBLY ..................................................................................................... 44

DESIGN SOLUTION SPECIFICATIONS ..................................................................................................... 44

ENGINE CARRIER PRODUCT BENEFITS TO END USER ........................................................................... 44

ENGINE CARRIER DESIGN ALTERNATIVE ............................................................................................... 47

DESIGN RISK, FAILURE AND RELIABILITY ANALYSIS .............................................................................. 48

CONCLUSIONS ....................................................................................................................................... 49

REFERENCES .......................................................................................................................................... 50

Appendix 1 – Requirement Specification .............................................................................................. 51

Appendix 2 – Product Specification ...................................................................................................... 53

Appendix 3- Internal Specification ........................................................................................................ 54

Appendix 4: Power/ Torque Estimations assuming the machine is used as a rice Trans-planter ........ 55

Appendix 5: Power/ Torque Estimations assuming the machine is used as a Road Vehicle ................ 56

Appendix 6 – Rotational Speed estimations ......................................................................................... 57

Appendix 7 –Engine Requirement Specification ................................................................................... 58

Appendix 8 - Qualitative Comparison of performance, of the different 4 stroke gasoline engine

classifications, to stipulated Engine Requirements .............................................................................. 60

Appendix 9: - Detailed Evaluation of the Performance characteristics of 4 Briggs and Stratton Engines

Analysed for suitability in this design ................................................................................................... 63

Appendix 10 – Detailed Speed Reduction configurations .................................................................... 68

Appendix 11: - Detail On Chosen Engine .............................................................................................. 73

Appendix 12 – Adaptation of chosen engine for alternative purposes ................................................ 83

Appendix 13: - Detailed Manufacturing Material selection ................................................................. 84

Appendix 14 - Detailed Engine Carrier Deflection Calculations ............................................................ 86

Appendix 15 - Engine Carrier Assembly Calculations ........................................................................... 90



Appendix 16 – Assembly Bolt Calculations ........................................................................................... 94

Appendix 17 - Bolt Torque Limit Calculation Reference: (NORD LOCK bolt security system) .............. 95

Appendix 18 – Forming process selection ............................................................................................ 96

Appendix 19 – Sprocket Selection Catalogue ....................................................................................... 99

Appendix 20 – Grub Screw calculations .............................................................................................. 100

Appendix 21 - Risk and Reliability analysis of the engine and the engine carrier assembly .............. 102

APPENDIX 22 – LIST OF ENGINEERING DRAWINGS ............................................................................ 108



LIST OF FIGURES

Figure 1- Engine population by type 2008 ............................................................................................ 12

Figure 2 - Chosen speed reduction configuration - rice trans-planter ................................................. 17

Figure 3 - Performance characteristics of engine while the machine is operating as a rice trans-

planter ................................................................................................................................................... 18

Figure 4 - Chosen speed reduction configuration - road vehicle .......................................................... 20

Figure 5 - Performance characteristics of engine while the machine is operating as a road vehicle... 21

Figure 6 - Power train sub-assembly ..................................................................................................... 39

Figure 7 - Alternative assembly configuration for the engine carrier ................................................... 45



LIST OF TABLES

Table 1 - Comparison of engine performance to required technical engine requirement specifications

.............................................................................................................................................................. 67

Table 2 - Speed reduction configuration comparison........................................................................... 72

Table 3 - Bending technique selection for engine carrier design ......................................................... 98



INTRODUCTION

Due to the rising need for improved rice yields, and reduction in rice farming labour time, this

project has been undertaken to provide a rice transplanting machine in rural areas of developing

countries, like Indonesia. In order to promote rural enterprise in Indonesia, the entire manufacturing

processes of the machine have been fashioned such that they could be performed in rural areas of

Indonesia. This thus puts constraints on the manufacturing processes, and materials prescribed for

the entire product manufacture.

As part of the overall project, a power train technical design has been carried out. This technical

design was carried out in order to investigate viable engine options that could power the rice trans-

planting machine. In order to facilitate this choice, investigations were carried out in to the quantity

of available 4 stroke engines and 2 stroke engines, as well the manufacturing brands responsible for

this availability. End user engine requirements and the machine power requirements were also laid

out, upon which all considered engines, were analysed.

In the end of this investigation, the most available engine brands were vetted for technical suitability

in this design. The final engine selection was made based on which engine best met the overall

product, and end user requirements of the design, at the least possible cost. Alternative uses of the

chosen engine, was also given.

In order to address the problems associated with direct mounting of engines to the main machine

frame, and to create room for easy adjustability of engine position (modularity), an engine carrier

design was also undertaken. The engine carrier manufacturing and materials selection constraints

were also identified and well dealt with.

The different interfaces between the power train and other sub systems of the machine design were

identified and particular emphasis was laid on their interface requirements. Design analysis was

carried out which showed that the designed engine carrier exceeds the product requirement

specifications, as well as the end user requirements.

Manufacturing guide and an overall cost and weight estimations was also carried out to ensure that

the engine carrier was able to meet the design cost and weight constraints, stated in the end user

requirement specifications. Risk analysis was also carried out on the entire power train, which

proved that engine carrier was very reliable. Design alternatives were equally specified along side

with their manufacturing implications in Indonesia.



ENGINE BACK GROUND INFORMATION - INDONESIA

The extraordinary increase in mobile power requirement in machines, cars and scooters has greatly

contributed to the development and spread of different brands of engines in Indonesia. Currently

there are 9 main engine manufacturers that are based there. These manufacturers include, Kubota,

Yamaha, Kohler, Kymco, Kanzen, APP-KTM, Honda, Kawasaki, and Suzuki. Besides these

manufacturers, other non Indonesia based companies like Briggs and Stratton, Techumeh, have

gained a very great reputation for being one of the highest suppliers of Engines to Indonesia for the

past 30 years.

Over the last 2 decades there have been an entirely new complex posed to both the major engine

manufacturers based in Indonesia and around the world. This problem was associated with the

demand for a small internal combustion engine, of low weight, smaller space requirement, and

specific high output during continuous operations. A comprehensive survey in to these

manufacturers led to the discovery that every one of them reacted to this problem, by introducing

the 4 stroke gasoline engine, which was aimed at replacing the 2 stroke gasoline engine with a more

pleasant user interface and higher fuel efficiency.

Ever since the introduction of the 4 stroke gasoline engine, there have been massive controversies

as to which engine was a better value for money in various automobile applications. In order to

address this controversy a technical investigation, detailed in the ‘’power train’’ technical feasibility

report was carried out. This study however led to the discovery that in terms of technical properties,

the 2 stroke engine, offered a higher torque value at low speeds, when compared to a 4 stroke

engine of the same size.

In order to fully confirm the viability of the 2 stroke gasoline engine in this design, it is important to

examine its availability in the environment that we are concerned with (Indonesia) so as to decide,

whether or not it could be adopted in to the rice trans-planter design. Figure 1 has been drawn, so

as to facilitate this analysis. With reference to this figure, in 2008, there was about 4,000,000 2

stroke gasoline engines and about 9,000,000 4 stroke engines in circulation in Indonesia. Although

these figures were obtained 2 years back, but there wouldn’t be a massive difference between then

and now. An inference from Figure 1, leads to the understanding that even up till now, 4 strokes

engines are quickly replacing the 2 stroke gasoline engines in Indonesia. Furthermore, most of the

engine producing companies supplying to Indonesia, have all stopped the production of 2 stroke

http://en.wikipedia.org/wiki/Kymco

http://en.wikipedia.org/w/index.php?title=Kanzen&action=edit&redlink=1

http://en.wikipedia.org/w/index.php?title=APP-KTM&action=edit&redlink=1

http://en.wikipedia.org/wiki/Honda

http://en.wikipedia.org/wiki/Kawasaki

http://en.wikipedia.org/wiki/Suzuki



engines, due to its high level of noise and high carbon emission. This discontinuation simply implies

that in the next 20 year all 2 strokes gasoline engines will completely be faced out. Based on these

facts the 4 stroke engines will further considered for a final engine selection for this design.

Figure 1- Engine population by type 2008

IDENTIFICATION OF END USER ENGINE REQUIREMENTS

Having certified the availability 4 stroke engines in Indonesia, a selection is needed to be made in

terms of engine type and brand for our design. In order for this selection to be made, the end user,

statutory and technical requirements of the engine detailed in Appendix 7 was composed. These

requirements were composed based on the End user requirement specification detailed in Appendix

1 and the Power and Torque values derived from the estimations detailed in Appendix 4 and 5.

Having identified all the requirements expected of the engine as detailed in Appendix 7, these

requirements will then be incorporated in to the final engine type selection, and the engine type

that closely meets all the stipulated requirements will be selected.



ENGINE SELECTION

Background Literature

Variegated motorisation demands in Indonesia and other parts of the world, has led to various

developments of different types of 4 stroke engines all round Indonesia and the world. Although

undertaken differently by different engine producing companies, the new developments were aimed

to fill in the gap, since existing engines at that point in time, wasn’t able to meet motorization

requirements any more.

As a result of these developments the following classifications of engines have been achieved under

the 4 stroke cc classification:

1. Utility - All purpose engines, e.g. Lawn mowers.

2. High Output engines – This includes motorcycle engines and single – purpose (Industrial

engines).

3. Maximum output engines (Not Applicable for use in this design and as such cannot be

evaluated for consideration) which includes Sports engines, road racing engines and light

plane engines.

Considering the Torque (5.2Nm) and the Power Requirement (3.2HP) of the engine required, a 150cc

stroke 4stroke engine needs to be sort after for this design.

Although this will offer a lot of speed than what is required, but a gearing mechanism will be needed

to bring down the output speed to 32rpm, which is what is required for the machine to function as a

rice trans-planter as well as 160rpm, which is what is needed for the machine to function as a road

vehicle.

Preliminary Engine Selection by Classification

In order to make a choice of what classification of a 4 stroke engine to make use of in this design,

Appendix 8 has been put together so as to make a comparison, of the performance characteristics of

the various classifications, against the stipulated engine requirements in Appendix 7

Due to the torque (5.2Nm) and power requirement (3.2HP) of the engine needed, a 150cc 4 stroke

engine has been considered, and the comparison in Appendix 8 is made based on this choice. In

order to averagely specify the technical properties of the different types of 4 stroke engines



considered in Appendix 8, mean values of their engine properties have been assumed. This also

compensates for the fact that different 150 cc 4 stroke engine manufacturers design their engines

differently.

At the end of the performance characteristics analysis detailed in Appendix 8, it was found that the

general purpose engine (lawn mower engine), will more closely meet all the engine requirements

stipulated, as compared to the scooter engines. Having decided that an all purpose 150 cc engines

will well suit our design, there is a need for the selection to be narrowed to a particular model and

then model.

ENGINE BRAND AVAILABILITY

Briggs and Stratton currently command an unrivalled reputation world wide as the World Largest

producers of air-cooled gasoline engines for outdoor equipments. Besides this, they also earn their

reputation as the world most reputable air – cooled engine suppliers. Currently most of their engines

are being patronize in items like, stand by generators, pressure washers, snow throwers, lawn and

garden equipments, blowers and vacuums worldwide. In Indonesia alone, Briggs and Stratton

supplies about 65% of the air cooled gasoline engines used on outboard equipments. Many

Indonesian based outdoor machine manufacturers like CV. ASA, karangtina , JOHELD PRIMATECH, PT

LARIS JAYA, and many more do outsource their engines from Briggs and Stratton. For example, In

2008 Briggs and Stratton were responsible about 6 million 4 stroke engines supplies to Indonesia,

which more than doubled the total value of 9 million 4 stroke engines that were in circulation at that

point in time. Based on the grounds of availability and reliability a 150 cc Briggs and Stratton Engine

will be considered an appropriate choice for this design.

ENGINE MODEL SELECTION

Having chosen Briggs and Stratton as a reliable and available 4 stroke engine brand In Indonesia, a

final model choice is needed to be made amongst their range of 4 stroke engines. This choice is

going to be made based on the following factors:

(1) Cost

(2) Torque - Speed characteristics

(3) Power - Speed characteristics

http://www.alibaba.com/company/10696658.html







(4) Easy ability of speed reduction from engine output speed to required speed for the machine

to function both as a rice trans-planter and a road vehicle.

There are more than 100 different Briggs and Stratton 4 stroke engine model currently in circulation.

However in order to specify a suitable model for this design a comparison will be made between 3

models, that closely match the Technical requirements of the machine.

Machine Technical Requirements

Speed 32 -160 rpm

Torque 2.8Nm - 5.2Nm

Power 2.HP - 3.53HP

Weight 40Kg

Power to Weight ratio 0.25 Kg/Hp

The Technical Requirements stated above specifies that the highest Torque needed from the

machine is 5.2 HP and the highest power needed from the engine is 3.2 HP. The Briggs and Stratton

engine choice must be able to provide these technical requirements at the least possible cost. In

addition to these major criteria, weight, size, service life, durability and performance will be

considered.

Engine Models Analysed

(1) Briggs and Stratton 3.5 HP Model Series 91200 – 1016

(2) Briggs and Stratton 3.5 HP Model Series 91252 – 1049 (with gear box)

(3) Briggs and Stratton 6 HP VANGUARD ™ Model Series 118400

(4) Briggs and Stratton 6 HP VANGUARD ™ Model Series 86400



Analysis of Results

Appendix 9 provides a detailed summary of the Torque – Speed and the Power – Speed

characteristic of each of the 4 brands of Briggs and Stratton engine considered. From the analysis

detailed in Appendix 9 – Table 1 it could be inferred that technically all the 4 considered engines

could be adapted in to the machine design. However the final choice factor will now be based on

price and ease ability of speed reduction to required transplanting or road vehicle speed. On the

basics of affordability the two cheaper engine options for further considerations are (Briggs and

Stratton – 91252 – 1049 with 6:1 gear box) and (Briggs and Stratton- 91252 – 1049). Amongst these

two engines, a final selection will be made at the end of the speed reduction technique analysis.

Speed Reduction and Final Selection of Engine

The two nominated engines (Briggs and Stratton – 91252 – 1049 with 6:1 gear box) and (Briggs and

Stratton- 91252 – 1049), although satisfactory for the design in terms of Torque and Power

requirements, has got a higher speed value than what is needed for the machine to function both as

a rice transplanted and a road vehicle. Hence the engine speed value needs to be reduced by some

sort of gearing to give the required speed at the wheel drive shaft. In the course of analysing the

different speed reduction techniques a final engine model will be decided on for this design. This

choice will be based on simplicity, reliability, size and weight of each of the speed reduction

technique(s), required for both engines.

Machine Technical Speed Requirements

As detailed in Appendix 6, the machine requires about 32 RPM to operate as a rice trans-planter and

about 162 PRM to operate as a road vehicle. However because this design is primarily aimed at

providing a rice transplanting machine for farmers in Indonesia, the target speed reduction will be to

32 RPM, which is the ideal speed required for the machine to function as a rice trans-planter.

In order to carry out the speed reduction analysis detailed in Appendix 10, an output engine speed

valued of 333.33 RPM was assumed for the 3.5 HP 91252-1049 Briggs and Stratton series and 2000

RPM for the 3.5HP 91200-1005 Briggs and Stratton engine.

Table 2 in Appendix 10 has been drawn out to make a comparison of all the 4 speed reduction

configurations considered as detailed in Appendix 10. In these configurations 2 different engines of

the same model series are used to draw a comparative literature on their overall suitability in this

design. Table 2 aims to facilitate this comparison and ultimately the choice of a final engine model.



Final Engine choice, and best speed reduction configuration

Having analysed all 4 speed reduction configurations, configuration 2 was decided as the most

suitable choice for this design. This configuration as detailed in Appendix 10 comprises of a Briggs

and Stratton 3.5HP Model series (91252-1049) with a 6:1 inbuilt gear box, which ultimately is the

final engine choice for our design. An extract of the Briggs and Stratton product manual for the

chosen engine, is detailed in Appendix 11. This extract is aimed at giving an overview of the different

features of the engine as well as provides maintenance and operational advices about the engine. A

pictorial overview of the chosen speed reduction configuration is shown below in Figure 2.

Figure 2 - Chosen speed reduction configuration - rice trans-planter



PERFORMANCE OF ENGINE WHEN THE MACHINE IS USED AS A RICE TRANSPLANTER

Figure 3 below shows the performance characteristics of the chosen engine, when the machine is

operating as a rice trans-planter. The shaded portion shows the operating Torque and Power range

of the engine under the machine use as a rice trans-planter. Using the configuration in Figure 2, the

speed of the rice trans-planter is reduced to a range of (1.98MPH – 3.39MPH).

Figure 3 - Performance characteristics of engine while the machine is operating as a rice trans-planter



POWER TRAIN MODULARITY CONCERN

In accordance with the machine’s specification requirement, the machine is required to function

both primarily as a rice trans-planter travelling at 2MPH, and in addition as a road vehicle travelling

at a speed of 10 MHP (capable of going up the hill of 10% gradient). However, the chosen speed

reduction configuration detailed in Figure 2 does only provide the speed range of 2 MPH to 3.4 MPH.

This speed range however satisfies the speed needed for the machine to operate as a rice trans-

planter, but not the 10MPH needed for the machine to operate as a road vehicle (going up the hill of

10% gradient). This thus implies that with this particular configuration the machine cannot be driven

up the hill, otherwise it will stall.

Recommendations to changes needed in order to transform the machine from a rice trans-planter

to a road vehicle

Rice transplanting is done 17 days a week, which implies that the machine will only be required to

function as a rice trans-planter for these 17 days, in which case the configuration in Figure 2 is used.

However, for the rest of the 348 days, the machine could be used as a transport vehicle. In order for

the machine to function as a vehicle, some changes are needed to be done on to the speed

reduction configuration used for rice transplanting. Since, the chosen rice transplanting

configuration (Detailed in Figure 2) does not have any adjustable gears, the only way of changing the

machine from a rice trans-planter operating at 2MPH at least to a vehicle operating at 9.41 MPH, at

least, is for the lay shaft to be flipped around. When this is done the ratio of the lay shaft output

sprocket to axle input sprocket becomes 1 (48:48) as shown in Figure 4. In order words the speed

step down occurs only between the engine output shaft sprocket and the lay shat input sprocket

(10:22). This then saves the cost of buying different sprockets. (PLEASE REFER TO THE DRIVE TRAIN

TECHNICAL REPORT) FOR SPECIFICATION OF SPLIT CHAIN USED TO LINK THE ENGINE SPROCKET TO

THE LAY SHAFT SPROCKET)



Figure 4 - Chosen speed reduction configuration - road vehicle

With this configuration the speed range expected of the machine as a road vehicle is (9.41 MPH – 16

MPH). With this sort of speed range the machine could easily go up a 10% gradient hill without

stalling or sleeping downhill.



PERFORMANCE OF ENGINE WHEN THE MACHINE IS USED AS A ROAD VEHICLE

Figure 5 below represents the Torque and Power range of the engine, while the machine is

operating as a road vehicle. As detailed in Figure 4, the best way of changing the machine speed

range of (1.98MPH – 3.39MPH), which is used for rice transplanting, to the speed range of

(9.41MPH – 16MPH) which is needed for the machine to operate as a road vehicle, is by flipping the

lay shaft around. By doing this a 1:1 speed ratio is created between the lay shaft sprocket and the

drive wheel sprocket. That way through a slight adjustment in lay shaft orientation, 1 engine can be

used for both powering the machine as a rice trans-planter and as a road vehicle.

Figure 5 - Performance characteristics of engine while the machine is operating as a road vehicle



BENEFITS OF THE CHOSEN ENGINE TO THE END USER

(1) Big air box capacity, which improves filter access and ensure rapid cooling of engine.

(2) Integral fuel tank, which makes the engine compact.

(3) Integral gear box which makes further speed reduction easier to achieve without any further

expenses.

(4) Great power to speed ratio.

(5) Ability to be converted easily to a generator to supply electricity to rural homes, and ability

to be used directly to power a Lawn mower without any changes(Please Refer to Appendix

12) for directives on how to adapt the engine to become a generator

(6) Economical in terms of fuel consumption

(7) Clean engine emissions



ENGINE CARRIER DESIGN

VIABLE ENGINE CARRIER CONCEPT



INTRODUCTION

The orientation of the engine on the rice trans-planter is very important if optimum power and

torque must be transferred from the engine to the drive train. Although an engine have been

specified for this design, it is important to note that there are a variety of engines that meet the

technical requirement specifications of the rice trans-planting machine and can equally be used as

engine alternatives. However the main concern is that engines of similar technical specifications may

differ in orientations of its output shaft. In order to make sure that the centre line of the engine’s

output shaft always aligns with that of the lay shaft, there is need for some form of engine mount

adjustability. In the wake of this concern, an adjustable engine carrier will be designed and

incorporated between the engine and main carrier interface.

DEFINITION OF ENGINE CARRIER DESIGN REQUIREMENTS

All machine elements usually operate within an overall structure such as casings, carriage or frames.

This is usually to hold these elements in place, so it could perform its task. One of the most

considered factors for the design of any carrier is usually the cost and aesthetic considerations.

However the functional and end user requirements expected of the carrier included:

(1) Rigidity – Resistance to torsion and bending on the engine carrier when the engine is

operating.

(2) Service Access – Access for users to easily detach engine

(3) Safe and Secure

(4) Weight – Not more than 10 kg in total

(5) Corrosion resistant and environmentally safe

(6) Size – Large enough to accommodate all engine sub systems

(7) Assembly considerations – Able to permit interface between engine and drive train as well

as interface between the carrier and the main machine frame

(8) Life – Long cycle life

(9) Strength – Strong enough to with stand all possible loadings under the operation with failing

(10) Ergonomics – Low centre of gravity and light



DEFINITION OF ENGINE CARRIER DESIGN CONSTRAINTS

Considering the fact that this design is aimed to take place in Indonesia, there are some constraints

as to what manufacturing materials and processes could be carried out. Other constraints include

cost ergonomics, environmental impact and maintenance.

Materials Availability and Suitability:

The construction of the rice trans-planter is aimed at the developing countries including Indonesia,

and as such it is important for a choice of manufacturing material for the carrier to be made based

on what materials are available in these areas. Investigations reveal that steel is the most available

metal in Indonesia. Steel universally also command a good reputation for its anti corrosiveness, and

high strength to weight ratio as proved in the material selection analysis detailed in Appendix 13.

Based on these facts, the steel type specified in the table below has been considered the most

suitable material for further calculations and further design considerations.

STEEL (AISI 1020 ANNEALED)

ULTIMATE TENSILE STREGTH

448 MPa

YIELD STRENGTH 346 Mpa

ELONGATION % 36 %

REDUCTION OF AREA 59 %

HARDNESS (HB) 143 HB

Manufacturing Capability:

The fact that the manufacture of the engine carrier, is to be done in rural areas of Indonesia, puts

great constraints, on what processes are available for this manufacture and at what cost. A detailed

breakdown of the relevant manufacturing processes and related costs in Indonesia are shown

below.

Forming Processes Tooling costs Equipment costs Labour Intensity Steel

Cutting Low Medium Medium Yes

Drilling Low Medium High Yes

Filling of rough edges Low Low Low Yes



Costs

As part of a non profit project, the cost of the engine carrier manufacture must be kept to a

minimum, in order to enable its price fit very well in to the target sale price of the machine aimed at

$250 USD (Appendix 2). This sale price in no way reflects the overall production costs. In order to

facilitate the production of this machine, Charity grants and government subsidies, will play a major

role, as rice serves as the main food for more than 70% of the rural population in Indonesia.

Environmental and sustainability Considerations

Indonesia has no real defined rules and regulations with regards, recycling and safe disposal of waste

materials, and as such the steel material considered for this engine carrier design will be derived

from scrap metals, and all manufacturing techniques used will be environmentally friendly.

Modularity

The engine carrier design must be able to allow for easy height and length adjustments in order to

suit different shaft configurations. The engine carrier should also be able to accommodate other

sorts of engines. With the height adjustments available, the required height, the height of any

replacement engine used could be set.

Weight and Ergonomics

Having decided on steel as the most commonly available and most suitable material for the

manufacture of the engine carrier, weight reduction will now be characterised as a function of size

and shape, of the carrier. Considering the fact that most of the field workers in Indonesia are women

of height 5ft.3 and weight 55kg, a target weight of not more than 10kg has been stipulated for the

engine carrier design. This will enable easy lifting and handling at any time.

Maintenance

Considering the fact that steel metal will be used for this design, regular painting of the engine

carrier with oil paint will be important, so as to serve as a protective covering to shield the carrier

from rusting, considering that the rice trans-planter will be used in humid conditions.

Bending Processes Tooling costs Equipment costs Labour Intensity Steel

Air Bending Low Low low Yes

Bottoming Low Low low yes

Wiping Die Bending Low High low yes

V Bending Low Low Low Yes



ENGINE CARRIER PERFORMANCE SPECIFICATION

To further advance the Engine carrier design, technical constraints such as deflection allowance,

Allowable stress and weight of the required carrier must be well defined, so as to ensure that the

engine carrier does conform to the end user requirement, as well as the overall product design

specification.

Deflection

One typical requirement for an engine carrier is for it to be able to limit deflection due to bending

when the engine is operating. That way, the centre line of the engine output shaft is always aligned

with the centre line of the lay shaft. As a design guide, the engine carrier will allow no deflections

under loading up to 150kg. 150kg has been estimated to be more than enough weight to make up

for additional fuel tanks, or any other attachments, that may be mounted on the carrier.

Allowable Stress

In order to enable the engine carrier have a great distribution of compressive and tensile stress due to

different loading conditions, a material selection of steel have been decided upon, which will make sure

the allowable stress of the engine carrier is 10 times or more than the maximum stress the engine carrier

is expected to operate in on daily basis.

Weight

In order to enable the engine carrier to be carried by a small Asian woman of 55kg, the carrier weight

must not exceed 10kg.

Summary of Engine carrier require specifications

Weight ˂ 10klg

Deflection = 0

Allowable engine carrier stress ≥ 10 X Normal Working stress.



DETAILED DESIGN ANALYSIS OF ENGINE CARRIER

e = 42.0 mm Bolt Head Clearance

b = 15.0 mm Edge Distance

H = 300.0 mm Horizontal Fastener Spacing

v = 150.0 mm Vertical Fastener Spacing

D = 10.0 mm Fastener Nominal Diameter

n = 2 Number of Tension Fasteners Per Side

tc = 3.0 mm Thickness of Base of Angle Clip

tf = 3.0 mm Thickness of the Radius Filler

R = 5.0 mm Bend Radius

W = 400.0 mm Clip Width (Parallel to Bend Line)



Properties of Manufacturing Materials:

(E) Young’s Modulus = 200 MPA

A deflection calculation detailed in Appendix 14, was carried out on the base plate of the engine

carrier model shown above. In the end of the calculation it was found that up to an applied load of

150kg, the engine carrier will not deflect. This result was further confirmed using an FEA of the

engine carrier base plate. From the FEA it was inferred that under the exaggerated load value of

150kg, the base of the engine carrier doesn’t deflect, and the max stress the engine carrier

experiences under this load is 8.7Mpa, which is way lower than the yield stress of the manufacturing

material of the Engine carrier which is 346Mpa.

Having ascertained the suitability of the carrier in terms of deflection, the engine carrier assembly

test calculations detailed in Appendix 15 was carried out. These calculations were aimed at

providing information about the safe load and failure load about the engine carrier, as well as vet its

overall suitability and reliability in this design. In the end of these calculations, the following key

values about the Engine carrier were found. These values will be ultimately be incorporated in to the

final solution specification.

ENGINE CARRIER FAILURE ANALYSIS RESULTS

ESTIMATED PRODUCT LIFE

Max allowable Stress of Assembly

Tension to cause permanent

deformation

Stress to cause Ultimate failure

Tension to cause Ultimate Failure

8 YEARS 49.4 Mpa 19771 N 237.3 Mpa 94903 N

The above derived values shows that under a 1500N speculated maximum load, the carrier structure

will not deflect, and provided the applied load, is not up to 19771N, the structure will not deform

permanently. The failure load value gives more than a 300% safety margin, when compared to the

estimated maximum load of 1500N speculated for the engine carrier. Using FEA, it was estimated

the maximum stress, the structure will expect to have under the 1500N loading will be 8.7Mpa.

However the assembly calculations has led to the inference that the Maximum allowable stress of



the engine carrier is 49.4Mpa, which in fact gives more than a 300% safety margin on the carrier

design. This thus confirms that this engine carrier has been able to exceed the end user

requirements.

ENGINE CARRIER ASSEMBLY BOLT ANALYSIS

As detailed in Appendix 16, a calculation was done in order to ascertain the type of bolts to be used

for the engine carrier assembly, considering the target load of 1500N. In the end of this analysis the

bolts specified in the table below will be used for the engine carrier assembly. 16 of these bolts,

costing a total of $4.8 in Indonesia will be required for the overall engine carrier assembly. As

detailed in Appendix 17, the bolts will be torque to a value of 31.0Nm.

Size Diameter (mm) Pitch Steel grade Bolt Yield Strength

(MPA)

M10x12 10 1.50 5.80 400.00



POWER TRAIN SOLUTION SPECIFICATION

Detailed Power train solution Specification

Final product Specification

Performance

Engine 3.5 Hp 4 stroke Engine

Price $125

Starting Method: Chord pull

Speed 300 rpm - 600 rpm

Key Features Integral fuel, and oil tan, Intergral gear box

Engine Carrier Dimensions

Weight: 6.40 kg

Width: 400 mm (When Assembled)

Height: 150 mm

Length: 600 mm (When Assembled)

Technical

Maximum Allowable stress 49.4Mpa

Tension to cause permanent deformation

19771N

Stress to cause ultimate failure 237.3Mpa

Tension to cause ultimate failure 94903N

Maintance Interval Repaint Once a year

Features

Engine Carrier Height adjustability: up to 300 mm

Product life 8 years

Additional Features:

Possibility of Alternative configurations, for easy machine weight distribution and manoeuvre ability

Operational conditions

Temperature Range: (-10 )degrees to 40 degrees

Humidity: 20-100% relative humidity

Social, Economic and Political Requirements

Price: $10.03

Keys

Engine specification

Engine carrier specification



ENGINE CARRIER MANUFACURING GUIDE

From manufacturing processes investigation carried out in Appendix 18, V Bending, has been

selected as a viable bending process for the engine carrier manufacture.

The manufacturing plant of the engine carrier arm is detailed below



The manufacturing plant of the engine carrier base is detailed below



ENGINE CARRIER DESIGN COST AND WEIGHT ESTIMATION

In order to keep the overall machine cost to the barest minimum, very basic materials and

manufacturing techniques have been selected for the engine carrier design. Materials prices are

evaluated per kilogram in Indonesia. The material used for both engine carrier parts is steel which is

estimated at $1.03/kg. As shown in the table below, the entire manufacturing and material cost of

the engine carrier has estimated at just about $10.03, which is considerably cheap.

Manufacturing and Material Cost for engine carrier design

The total engine carrier sub assembly cost is $139.83

and the overall weight of the power train

subassembly including the engine without fuel is

42.40kg.

TOTAL SUB ENGINE CARRIER ASSEMBLY COSTING

ENGINE CARRIER MANUFACTURING COST

$10.03

ENGINE COST $125.00

COST OF 16 (M10X12) BOLTS

$4.80

GRAND TOTAL COST $139.83



ENGINE CARRIER ASSEMBLY GUIDE



EVALUATION OF ENGINE CARRIER DESIGN TO ENSURE COMFORMITY TO PERFORMANCE

REQUIREMENT SPECIFICATION

Deflection At the end of the engine carrier design, it was simulated using solid edge to check it

manner of deflection under safe load of up to 1.5KN. As detailed in Appendix 14, the engine carrier

plate has demonstrated a good anti deflection characteristic under the value of 1.5KN, which thus

means that the ‘’Deflection requirement specification’’, has fully been met.

Strength Using Solid edge, the design was also simulated to check the maximum possible stress that

could be experienced in the model, under the 1.5kN speculated load. In the end of this simulation as

detailed in Appendix 14 it was found that the maximum possible stress that may exist in the engine

carrier under the prescribe safe load of 1.5KN will be 8.7 Mpa, which is 24 times less than the

calculated failure stress of the Assembly (237.3 Mpa) (please refer to Appendix 15 for details of this

calculations)

Weight and Ergonomics According to performance specification of the engine carrier, the total

weight of the carrier is not allowed to exceed 10kg, so as to make it easy for a small Asian lady of

55kg to carry. Having taken this in to great consideration, the total engine chassis weight is 7.3kg.



EVALUATION OF ENGINE CARRIER DESIGN TO ENSURE COMFORMITY TO END USER

REQUIREMENTS

In order to fully create a good appreciation of the engine carrier in the minds of our end users, the

design must be evaluated against the end user requirements, so as to make sure that most or all of

the end user requirements are met by the design.

Safety: The use of an engine carrier, as supposed to direct engine mounting, makes it possible for

the engine to taken off even when it is hot, without the fear of wounds and burns.

Comfort ability: The attachment of the engine carrier, also makes it possible for engine height

adjustments, in order to achieve an even weight distribution on the machine, thus preventing the

machine for feeling top heavy or tipping over while in use. This will help prevent injury to the users.

Able to withstand a lot of operational conditions, without failure: In order to make sure the engine

carrier is able to withstand a load of 1.5KN without deflecting, or failing a steel material with yield

strength of 346 Mpa have been chosen for the carrier manufacture. Having incorporated this

material in to the final design, An FEA analysis was done, which proved that the maximum stress

possible in the carrier under the speculated load of 1.5KN is 8.7Mpa. This stress is however far less

than the yield stress of the manufacturing material. Considering the fact that the rice trans-planter

will be used in different weather conditions, a protective paint will applied to the engine carrier

frame during its manufacture, so as to prevent it from rusting, due to high humidity and contact with

water from rain, or the paddy fields.

Maintenance: The entire assembly of the engine carrier is done using bolts, which makes it possible

for any faulty part of the assembly to be removed for repair or replacement should the need arise.

Especially if the engine carrier rust, it could be taken off the main machine frame and repainted

separately which will be cheaper than repainting the entire frame.

Socio Economic and Political requirements: The entire carrier will be made using recyclable

materials (Steel), which means that at the end of the working life of the engine carrier, it could

safely be disposed off under the already set Indonesian government recycling plan. The use of basic

manufacturing materials and techniques, keeps the price of the engine carrier low, and thus the

overall cost of the rice transplanting machine. The length and height adjustability of the engine

carrier makes it possible for it to suit a variety of engines, without the need for a purchase of

another engine carrier.



Materials and Manufacture: In order to make sure the engine carrier could easily be produced by

the end user, steel has been chosen as the manufacturing material. Steel is widely available in

Indonesia, and at a cheap cost of 1.03 per kg. In terms of manufacturing processes, the engine

carrier could be manufacturing through cutting, filling, V bending and drilling, which are all cheap,

available and harmless technological processes already in use presently in rural areas of Indonesia.



POWER TRAIN INTERFACES

Having produced a fully working design for the engine carrier detailed in (Figure 6), and also chosen

an engine to power the rice transplanting machine, the interfaces between the power train

subassembly and the other parts of the machine must be defined. There are 3 interfaces between

the engine power train and the machine. Interface 1, is between the engine and the drive train,

Interface 2 is between the engine on its carrier and the main machine frame and interface 3 is

between the engine throttle control and the machine user controls.

Figure 6 - Power train sub-assembly

NOTE – SOME MODIFICATIONS HAVE BEEN MADE TO THE ORIGINALLY DESIGNED ENGINE CARRIER

DURING THE OVERALL MACHINE ASSEMBLY



Power train – Drive train Interface

Interface Requirement

The main requirement for this interface is a sprocket and a chain on the engine shaft. A combination

of both creates a simple and effective power and torque transfer to the lay shaft, and then to the

wheels, planting and feeding mechanism. (PLEASE REFER TO DRIVE TRAIN TECHNICAL DESIGN

PROJECT FOR MORE DETAILS ON POWER TRANSFER TO FEEDING AND PLANTING MECHANISM).

Sprocket Selection

With reference to the chosen speed reduction technique detailed in Figure 2, a 48 tooth sprocket

has been specified as needed for the input sprocket of the lay shaft and the axle sprocket. A 22

tooth sprocket is also needed for the output sprocket of the lay shaft. The engine will make use of a

10 tooth sprocket.



With reference to the RBL sprocket catalogue extract contained in Appendix 19, the values detailed

below were obtained for the engine shaft sprocket. (PLEASE REFER TO DRIVE TRAIN TECHNICAL

PROJECT FOR SPECIFICATION OF OTHER SPROCKETS, AND DRIVE TRAIN)

No. of teeth

Outer Diameter

– OD (Inches)

Outer Diameter

- OD (mm)

Pitch (Inches)

Pitch (mm)

Length (Inches)

Length (mm)

10 1.38 35.052 0.375 9.525 0.75 19.05

Engine - Drive train reliability concern

One overriding concern in the drive train interface is the risk of a jam or a chain slack, which may

result in damage to the engine shaft and or the drive train, which will be very expensive to replace.

However in order to address this problem, a grub screw of size (M5X8), made of steel has been

incorporated in to the interface between the engine shaft and the engine sprocket. That way should

there be a jam or a chain slag the grub screw will get more stressed than the shaft. Detailed analysis

of this have been carried out and confirmed in Appendix 20.

Should the jam or chain slag get more serious the grub screw then reaches it failure stress and fails

by shearing, that way the engine shaft is protected from damaging.



Power train – Machine Interface

The second interface is between the power train assembly and the main machine frame. This

interface is very vital, when considering the comfort ability of the end user. Engines in general give

off a lot of vibrations and as such the mountings between the engine carrier and the main frame

must, be done using an anti vibration mounting rubber in between the mounting bolts. That way,

the vibrating effect of the engine is reduce from affecting the user. The engine carrier is then bolted

to the main machine frame, using the bolt specified below with a nut, and bolted to a torque value

of 31Nm.


(MPA)

M10x12 10 1.50 5.80 400.00



Engine User Control Interface

The chosen Engine for this design which is a Briggs and Stratton 3.5 HP Model Engine Series 91252 –

1049 (with a 6:1 gear box), has its speed control throttle on its main engine body. However for easy

throttle manoeuvre ability of the engine by the User, a hand throttle bar has been connected from

the engine to the main machine handle bar as shown in the picture below. This makes it possible for

the machine user to accelerate or decelerate the engine, easily without having to always reach back

to the engine which is quite far from the handle. While positioning this throttle control bar on the

machine, ergonomics have been taken in to considerations; such the throttle bar is wide enough to

accommodate the ergonomic needs of a variety of engine users.



FULL POWER TRAIN SUB ASSEMBLY

DESIGN SOLUTION SPECIFICATIONS

Max allowable Stress of Assembly

Tension to cause

permanent deformation

Stress to cause

Ultimate failure

Tension to cause

Ultimate Failure

Product Life

Recommended Repainting intervals

49.4 Mpa 19771 N 237.3 Mpa 94903 N 8 Years Once a year

ENGINE CARRIER PRODUCT BENEFITS TO END USER

(1) Modularity: Whilst still maintaining the same engine mounting interface, the engine carrier can

be adjusted in terms of height so as accommodate different types of engines, with different

orientation of output shaft. This could be achieved using the spare bolt sluts on the side arms of

the engine carrier. Through height adjustment, the output shaft of the alternative engines can



easily be arranged in the required position, with no need for adjustment of drive train

components, which could be very complex. This engine carrier also gives room for engine

horizontal adjustment, along the carrier base plate. This is to ensure that the sprocket on the

engine is always aligned with the input sprocket on the lay shaft. The engine carrier also

provides an addition space where extra fuel tanks and engine attachments could be mounted,

should such the need arise.

Although for easy manoeuvre ability, a low centre of gravity is required between the engine and

carrier assembly, but in some occasions there may be a need for the engine carrier to be

remounted as shown in Figure 7 below, such that entire centre of gravity of the whole engine-

carrier assembly is raised up.

Figure 7 - Alternative assembly configuration for the engine carrier



(2) Portability: The engine carrier consists of 3 main parts, which could be taken apart when the

carrier is not in use. The fact that the engine carrier could be broken down in to 3 parts, makes it

easier to carry around.

(3) Weight Distribution: The engine carrier allows for a variety of engine orientations and height

adjustments. This makes it possible for the engine height to be adjusted such that a good weight

distribution is achieved on the machine. Having a good weight distribution creates stability of

the machine while in the use and also makes the manoeuvrability of machine very easy.

However when adjusting the engine height care must be taken so the engine doesn’t get soaked

up in the paddy fields which could be as deep as 0.5 meters.

(4) Easy Maintenance: Over a long period of steel exposure to the atmosphere, rusting is bound to

set in. Having a separate engine carrier makes it possible and easy for the engine carrier to

either be painted separately to prevent rusting, or replaced, following the onset of a potential

defect.

(5) Resistance to Vibrations and Damping: Considering the fact that the engine is capable of

generating a lot of vibrations, there is need for an interface between the engine and the main

machine chassis. The engine carrier however acts as this interface, which takes up most of the

Initial engine vibrations, thus reducing the vibration taken by the rice transplanting machine and

its user. That way, the machine is more comfortable for the operator to use, and the possibility

of premature failure of welded joints in the main machine chassis is avoided.



ENGINE CARRIER DESIGN ALTERNATIVE

Shown in figure 8 below, is an engine carrier design alternative. This design alternative works very

similar to the viable design option. However the drilled holes in the main designed carrier side bar

have in this case been replaced with 2 slots on the carrier side arm. Considering the fact that slut

cutting and milling are highly technical and expensive manufacturing process, making this engine

carrier in rural areas of developing countries may not be easy, never the less it is still possible.

Figure 8 - Engine carrier Design Alternative



DESIGN RISK, FAILURE AND RELIABILITY ANALYSIS

Detailed in Appendix 21, is a long table containing risks, reliability and failure analysis of the engine,

the engine carrier, and the entire power train. This table was composed in order to throw more light

on the high risk areas of the entire power train sub assembly and its interfaces with other sections of

the machine. Potential preventive and curative solutions are also given in Appendix 21 to counter

these risks in order to maintain a safe and reliable power train sub assembly. At the end of this

analysis it was found that the greatest source of risk with regards the engine is over heat. It was also

found that the greatest risk associated with the engine power train sub assembly is non alignment of

the engine sprocket with the drive train, which may be due to manufacturing fault. On the overall

the risk priority numbers indicates that the engine carrier design is very reliable.



CONCLUSIONS

In the summary of this technical design, a Briggs and Stratton 3.5HP Model series (91252-1049)

engine with a 6:1 inbuilt gear box was chosen as a viable engine for this design. This engine was

vetted to have met all end user engine requirements. Besides this engine’s suitability for use in the

rice trans-planter, it could also easily be used on lawn mowers and can also be easily converted to

become a generator to provide electricity to the rural homes in Indonesia.

In order to address most of the problems associated with direct engine mounting, a detachable

engine carrier was designed to create an interface between the trans-planting machine, and the

engine. Advantages of this include, reduction of vibration effect on machine and end user, as well as

height and length adjust abilities of different engines. This design have been tested and proved to

exceed both the product specifications, and the requirement specifications of the end user. An

alternative engine carrier design which will equally exceed the product specifications and

requirement specifications of the end user, have also been provided.



REFERENCES

Abbott Aerospace ‘’ Online ‘’ http://www.abbottaerospace.com/(17/04/2010)

Thee Kian Wie (February, 2006). ‘’Technology and Indonesia’s Industrial Competiveness’’

RBL catalogue ‘’ http://www.ringball.com/pdf_files/RCS2006.pdf’’, (19/04/2010)

R.S Khurmi, J.K.Gupta, ‘’ A text book of Machine Design’’ (2005). Eurasia Publishing House (PVT.) LTD.

Timothy J. Cyders. ‘’Design of a Human – Powered Utility Vehicle for Developing Communities’’

(2008,Novermber).

Performance of manually operated paddy trans-planter, (18 May 1998). University of Putra Malaysia

Press ISSN-0128-7680

Simon badocock ‘’Chassis design and integration technical feasibility study’’ (2010), University of

Bath.

http://www.abbottaerospace.com/(17/04/2010)

http://www.ringball.com/pdf_files/RCS2006.pdf



Appendix 1 – Requirement Specification

Requirements

Specification

Date: 03/03/2010

Issue: 3

Demand Wish Requirement Modified

Weighting H/M/L

Performance

H Plant a minimum of 2 rows simultaneously in order to maximise productivity 03/03/2010

H Modular design to allow for further banks of planters to be added 03/03/2010

H Planting row spacing of 300mm to optimise yield

M Variable planting pitch to accommodate users preferred planting methodology 03/03/2010

H Maximum planting pitch of 300mm to enable SRI planting methodology 03/03/2010

M Ability to plant up to 6 seedlings of 4mm diameter per planting action 03/03/2010

H Maximum planting depth of 50mm to accommodate all rice varieties

M Depth adjustable to allow operation in paddies with uneven paddy floors

Desired planting rate of between 0.05 – 0.0625 hectares per hour

H Minimum transplanting speed of 1.7kph 12/03/2010

Features

M Storage space onboard the device in order to store spares and valuables

M Method to lock, secure or disable the device to prevent theft

H Core device must be portable to allow for transportation using private vehicles 03/03/2010

M Core device must be compact to allow for storage within users home 03/03/2010

H Ability to accept a variety of rice types and seedling sizes

H Suitable for safe operation by an average sized woman of Asian origin

H Ergonomically suitable or adjustable for a broad range of users

H Operated and transported by one person

Safety

M Guards employed to protect users from hot surfaces and exposed mechanisms

H Weight of core device limited to 30kg to enable lifting by two small women


H Temperature range of operation of 0-45 degrees centigrade

H Humidity Range of operation of 20-100% relative humidity

M Ability to operate in mud and water up to 0.5m deep

M Robust enough to operate after a 360 degree roll

Maintenance and Reliability

H Service Interval of 52.5 hours (1 week)

M MTTR of 105 hours and MTTF of 1050 hours

L Prototype must be extensively field tested for a minimum of 7 full days

H Key parts are not secured using permanent fixings to allow for servicing/repair

Materials and Manufacture

L Where available and suitable materials which do not corrode to be used

H Production of distinct processes to facilitate flat packed factory ideology 03/03/2010



H Designed for manufacture using processes available in developing countries 03/03/2010

H Jigging used to ease the manufacture of the main components 03/03/2010

M Manufacturing processes suitable for factories without specialised machinery 03/03/2010

L Manufacture and assembly can be completed without skilled workers 03/03/2010


M Designed for disassembly to allow parts to be re-used

M Use of recycled and recyclable materials where possible

H Product designed to encourage purchase using microfinance 03/03/2010

H Target cost to customer of US$ 250 to appeal to selected market

H Must not infringe on existing patents registered in market countries



Appendix 2 – Product Specification

Product

Specification

Date: 16/03/2010

Issue: 1

Initial Product Specification Modified

Performance

Engine: 3.5Hp 4 Stroke Engine

Starting Method: Pull Chord

Speed:

3.3kph (during off-road planting operation)

16kph (maximum speed on-road)

NOTE: requires additional seat and trailer unit for on-road duty conversion

Performance: 0.05 – 0.0625 hectares per hour planting rate (single planting module)

Weight:

Dimensions

90kg inc. all liquids (during off-road planting operation)

100kg inc. all liquids (during on-road configuration)

Load carrying Capacity: 100kg (during on-road configuration)

Total Kerb Weight: 200kg not inc. operator (road configuration at maximum load capacity)

Width: 800mm

Height: 1500mm

Length:

2500mm (main tractor unit including 1500mm handlebar length)

3000mm (off-road planting configuration)

3500mm (on-road configuration)

Features

User Control Height: Adjustable (1000mm – 1500mm)

Planting Depth: Adjustable (20mm – 50mm)

Planting Width: 300mm

Planting Pitch: Adjustable (150mm – 300mm)

Additional Features: Ability to accept a variety of rice types and seedling sizes


Temperature Range: 0-45 degrees centigrade

Humidity: 20-100% relative humidity

Fording Depth: 500mm

Gradient: +/- 10% Maximum

Price:


250 US$ (off-road transplanting configuration)

On-road configuration price TBC



Appendix 3- Internal Specification

Internal

Specification

Date: 12/03/2010

Issue: 3

Demand Wish Requirement Modified

Weighting H/M/L

Internal Design Brief

Create a multi-purpose vehicle that achieves the required transplanting rate and

productivity, whilst also functioning as a small, road going transport vehicle.

Modula design is key to achieving this with different modules being designed to

for different operational conditions.

The transplanting assembly should be detachable and a storage container

designed for the same mounting point.

Performance

Maximum transplanting speed of 3.3kph 12/03/2010

Maximum road speed of 16kph 12/03/2010

Maximum Weight limit of 90kg (transplanting walk-behind configuration) 12/03/2010

Maximum carrying load of 100kg (road going configuration) 12/03/2010

Maximum kerb weight including user and cargo of 250kg 12/03/2010



Appendix 4: Power/ Torque Estimations assuming the machine is used as a rice Trans-

planter

RICE TRANS - PLANTER

Power / Torque Calculator

CdA Coefficient of friction

Drive Efficiency

Wheel x 3 Driver Vehicle Planting and

Feeder Mechanism

Total (Mass)

(Cd x m²) (no unit) (%) (kg each) (kg) (kg) (kg) (kg)

0.5625 0.0250 80 5 0 200 10 210

Wind Temp ± Pressure Slope ± Acceleration Velocity

Power Needed to

run the vehicle

Human power Limit

(km/h) (Cº) (mm Hg) (%) (km/h/h) (MPH) (watts)

10 23 762 10.0 2 2 1859.1

Safety Factor Engine

Output shaft radius

Linear velocity

Angular Velocity

Torque

No unit (m) m/s rads/s Nm

2.0 0.015 20 1333.3 2.8



Appendix 5: Power/ Torque Estimations assuming the machine is used as a Road Vehicle

Vehicle

Power / Torque Calculator

CdA Coefficient of friction

Drive Efficiency

Wheel x 3 Driver Vehicle Planting and

Feeder Mechanism

Total (Mass)

(Cd x m²) (no unit) (%) (kg each) (kg) (kg) (kg) (kg)

0.5625 0.0250 80 5 80 200 0 280

Wind Temp ± Pressure Slope ± Acceleration Velocity

Power Needed to

run the vehicle

(km/h) (Cº) (mm Hg) (%) (km/h/h) (MPH) (watts)

10 23 762 10.0 2 20 2350

Safety Factor Engine

Output shaft radius

Linear velocity

Angular Velocity

Torque

No unit (m) m/s rads/s Nm

2.0 0.015 20 1333.3 5.2



Appendix 6 – Rotational Speed estimations

(A) PLANTING MACHINE

Technical Assumption

2 MPH speed required for the machine to run as a planting machine

Calculations:

2MPH is 0.894m/s

Radius of driving wheel is 0.265

Circumference of wheel is 1.665m

Rotating Speed for the Machine to operate as a rice trans-planter = 0.89/1.665 = 0.53 RPS

Or 32 RPM

(B) ROAD VEHICLE

Technical Assumption

15 MPH speed required for the machine to run as a planting machine

Calculations:

10MPH is 4.4704m/s

Radius of driving wheel is 0.265

Circumference of wheel is 1.665m

Rotating Speed for the Machine to operate as a rice trans-planter = 2.685rps or 161.15 RPM

Thus a rotational speed of 32 rpm at the wheel for the machine to operate a rice transplanting

machine running at 2 MPH, and 161.15 RPM in order to operate as a road vehicle running at

161.15 MP



Appendix 7 –Engine Requirement Specification

(1) End user Engine requirements

Economic Factors

Cheap purchase Cost

Availability of Engine locally to save transport cost

Use of existing technical know-how in repair engine work, with little or no

retraining needed

Servicing Interval of at least once in 2 months

Resistance to and compatibility with dust, humidity, types of lubricants.

Simple to repair

Cheap cost of repair and availability of repair tools

Low fuel consumption

Strategic Factors

Modularity in used and ability to be used for various applications

Possibility of spare part purchase locally, in the event of a break down

Easy to start in cold conditions

Start Mechanism easy to operate by an average Indonesian lady of weight 55kg

Variation of speeds to suit different road profiles e.g. up hills, flat lands, down

hills, muddy areas etc.

Operation temperatures should range between -100 C to 50Oc (Extreme

temperatures in Indonesia)

Service life 3000 hrs



Ability to start at very low speed values

Safe e.g. Explosion proof in case of fuel leakage

Variation of assemblies

Easy adaptability to extreme altitudes and climates.

(2) Statutory requirements

Sound level about 90 db

4% CO2 content at idle

(3) Technical requirements

Torque Characteristics

2.8Nm Required for the machine to function as a rice trans-planter

5.2Nm Required for the machine to function as a road vehicle

Power Requirements

1.9KW or 2.5HP for the machine to function as a rice trans-planter

2.35KW or 3.2HP for the machine to function as a road vehicle

Power to weight ratio 3kg/hp

Speed Requirements

32 (Appendix 6) rpm output speed needed for the machine to function as a rice

trans-planter

160 (Appendix 6) rpm output speed needed for the machine to function as a road

vehicle



Appendix 8 - Qualitative Comparison of performance, of the different 4 stroke gasoline

engine classifications, to stipulated Engine Requirements

TECHNICAL REQUIREMENTS

Criteria Specifications All purpose

Engines - (Lawn Mower Engines)

Comments Scooter Engines Comments

Speed 32 -160 rpm (2500 - 8000) rpm ˅ (1800 -3600)

rpm ˅

Torque 2.8Nm - 5.2Nm 7.5Nm ˅ 7Nm ˅

Power 2.HP - 3.2HP 10Hp ˅ 8Hp ˅

Weight 40Kg 42kg x 37kg ˅

Power to Weight ratio

0.25 Kg/Hp 0.667kg/Hp ˅ 0.667kg/Hp ˅

STATUTORY REQUIREMENTS



Comments Scooter Engines

Comments

Noise level 90db 75db ˅ 70db ˅

CO content at Idle

6% 3% ˅ 3% ˅



END USER REQUIREMENTS

Economic Factors



Comments Scooter Engines

Comments

Cost $250 $180 - $400 ˅ $200 - $ 600 ˅

Quantity in Indonesia

As much as Possible

6.5 million as at 2008 ˅

5.5 million as at 2008 ˅

Servicing interval Once in 4 months

Once in 6 months ˅ Once in 3 months

x

Resistant to dust and humidity

Very Resistant Very Resistant ˅ Very Resistant ˅

Adaptability to different types of

Lubricants Easy Easy ˅ Easy ˅

Complexity of Repair

Simple Simple ˅ Simple ˅

Fuel consumption

30 miles/ Gallon 20 - 40

miles/gallon ˅

20 - 40 miles/gallon

˅



Strategic Factors



Comments Scooter Engines Comme

nts

Modularity in Use and

Applications Very Very ˅

Not very, due to a kick start

mechanism, meant for scooters

x

Availability of Spare part in the event of a break

down

High

Highly available due the high

volume in circulation

˅ Not so much

available x

Complexity of starting

Mechanism Very Simple

Very simple (pull start)

˅

Not very simple (Crank Start) or Key

start & Battery is required.

x

Complexity of mode of

operation Very simple Very simple ˅ Very simple ˅

Temperature of operation

-10 to 50 degrees Celsius'

-20 to 50 degrees Celsius' ˅

-20 to 50 degrees Celsius' ˅

Service life 3000hrs More than

3000hrs ˅ More than 3000hrs ˅

Ability to start at low speed values

Very Very able to ˅ Very able to ˅

Ability to vary output Speeds to

suit different road profiles

Very

Not able to, due to no inbuilt gear

box, or a non adjustable gear

x Able to due to in built adjustable

gears ˅

Safety Very Very safe due to

custom made enclosures

˅

Not very safe unless mounted

inside the component

x

Adaptability to extreme

altitudes and climates

Very Very able to ˅ Very able to v

Keys

V - Means suitable

X - Means not

suitable



Appendix 9: - Detailed Evaluation of the Performance characteristics of 4 Briggs and

Stratton Engines Analysed for suitability in this design

Briggs and Stratton 3.5 HP Model Series 91200 – 1016

TOP FEATURES

Dura-Bore cast iron cylinder sleeve for

extended life

Dependable aluminium alloy Pulsa-Jet

carburettor

Maintenance-free Magnetron electronic

ignition for quick, dependable starts

Dual-Clean air cleaner pleated paper filter with

a foam pre-cleaner ensures maximum protection for

extended engine life

Cost of second hand In Indonesia: $ 120



Briggs and Stratton 3.5 HP Model Series 91252 – 1049 (with gear box)

TOP FEATURES


extended life

Dependable aluminium allay Pulsa-Jet

carburettor



Dual-Clean air cleaner pleated paper filter

with a foam pre-cleaner ensures maximum protection

for extended engine life


Briggs and Stratton 6 HP VANGUARD ™ Model Series 118400



TOP FEATURES


extended life

Float carburettor for consistent easy

starting



Dual-Clean ™ air cleaner pleated paper

filter with a foam pre-cleaner ensures maximum

protection for extended engine life

Oil Guard ® low oil engine shutdown

device

Overhead valve design (OHV) for cooler

operation and longer valve life


Briggs and Stratton 6 HP VANGUARD ™ Model Series 86400



TOP FAETURES

Dura-Bore ™ cast iron cylinder sleeve for

extended life

Float carburettor for consistent easy

starting

Maintenance-free Magnetron ® electronic


Dual-Clean air cleaner pleated paper filter

with a foam pre-cleaner ensures maximum

protection for extended engine life

Oil Guard ® low oil engine shutdown device

Overhead valve design (OHV) for cooler

operation and longer valve life

Buyer protection package provides two-

year commercial engine warranty




Table 1 below shows a detailed comparison of all the technical characteristics of the 4 Briggs and

Stratton engine models, analysed for suitability in this design.

Table 1 - Comparison of engine performance to required technical engine requirement specifications

Series 91252 - 1049 with 6:1

inbuilt gear box

Series 91200 - 1016 without any gear box Series 86400 Series 118400

Power Range

required 2HP - 3.5HP

1.7 - 3.5Hp Suitable

1.7HP -

3.5HP Suitable 1.9HP -

4HP Suitable 3.2HP - 4.6HP Suitable

Torque range

required

2.8Nm - 5.2 Nm

5.7Nm -

6.7Nm Suitable

5.7Nm -

6.7Nm Suitable 7.80Nm - 8.7Nm Suitable

8.0Nm - 11.5Nm Suitable

Speed range

required

32 - 160 rpm

300 - 600 rpm

Not too high

1800 - 3600 rpm

Too High

1800- 3600 rpm

Too High

1800 - 3600 rpm

Required cost $240 $125 Suitable $120 Suitable $320

Too high $350

Too High

Selected Engines



Appendix 10 – Detailed Speed Reduction configurations

Detailed pictures of the different speed step down configurations are contained in figures 2-5, Please

note that on these figure (U.L) stands for lower limit and (U.P) – stands for upper limit.

Configuration 1

Configuration 1 – Speed Reduction using Briggs and Stratton 91200-1005 series with 2 lay shafts



Configuration 2

Configuration 2 – Speed Reduction using Briggs and Stratton 91252-1049 series with 1 lay shaft



Configuration 3

Configuration 3 - Speed Reduction using Briggs and Stratton 91200-1005 series with 1 lay shaft and

an External gear box



Configuration 4

Configuration 4 - Speed Reduction using Briggs and Stratton 91200-1005 series with 1 lay shaft



Table 2 - Speed reduction configuration comparison



Appendix 11: - Detail On Chosen Engine

Declaration: All the contents of this Appendix have been extracted from the Briggs and Stratton

Engine manual for (91252-1049) 4 Stroke Engine. This extract is aimed at providing operational, and

maintenance advises on the engine.

Engine Name: Briggs and Stratton 3.5HP Model series (91252-1049) WITH 6:1 speed reduction gear

box.

Specifications

ENGINE SPECIFICATIONS

Displacement 9.02 cl (148cc)

Bore 65.08 mm

Speed range 300 – 600 RPM

Torque 6.6NM

Power 3.5HP

Stroke 44.45 mm

Oil Capacity (0.54 - 0.59L)

Gear Reduction oil 80W - 90W

TUNE UP SPECIFICATIONS

Spark Plug Gap 0.76 mm

Spark Plug Torque 20Nm

Armature Air gap (0.15 - 0.25 mm)

Intake valve clearance (0.13 - 0.18 mm)

Exhaust valve clearance (0.18 - 0.23 mm)

FACTORS THAT AFFECT ENGINE PERFORMANCE

Altitude 3.5% decrease in engine power for every 300 meters height above sea level

Temperature 1% decrease in engine power for every 25 degrees change in temperature

Gradient Engine performance will be satisfactory up to 15 degrees gradient

Engine Part List



(1) Engine Model 91252-1049

(2) Rope Handle

(3) Fuel Tank

(4) Stop Switch

(5) Fuel Fill

(6) Air cleaner

(7) Muffler

(8) Spark Plug

(9) Blower Housing

(10) Finger guard

(11) Carburettor

(12) Spark arrester if equipped

(13) Oil filter plug

(14) Drain Plug

(15) Oil Level



Pre-Use Requirements

Checking and Addition of Oil

Guide lines:

(1) Check oil level before starting the engine

(2) Recheck oil level every 8 hours of use

(3) Do not over fill oil level at any point in time

How to add or Change Oil

Oil Recommendations



High quality detergent oil ‘’SAE 30’’, without adding any special additives and choose

viscosities using the SAE viscosity chart detailed below.

CAUTION ABOUT OIL SELECTION

SAE 30 oil if used below 4 degree Celsius will result in hard starting and possible engine bore

damage as a result of inadequate lubrication.

Fuelling and Checking of fuel level

Addition of Fuel:

(1) Fill fuel tank outdoors or in well ventilated area away from sparks, and open flames

(2) In the event fuel spills wait until it evaporates before starting

(3) When refuelling, turn the engine off and let the engine cool at least 2 minutes before

removing the gas cap.

(4) Remove the cap and then fill the tank to approximately ½ inch below the lowest portion

of the fill opening to allow for fuel expansion.

(5) Replace the cap before staring the engine.



Fuel Recommendations

Clean fresh, regular gasoline with a minimum of 77 Octane. Fuel quantity should be used up within

30 days of purchase. Avoid using fuels with methanol as well as fuels formed from gasoline mixed

with oil.

Engine Starting

The following procedures detailed below should be taken to start the engine

Procedures to stop the Engine



Engine maintenance Chart

Note:

(*) Change oil after first 5 to 8 hours of first used, then every 50 hours or every season.

Change oil every 25 hours when operating in high conditions.

(**) Clean more often under dusty conditions and replace air cleaner parts if very dirty.



How to change Oil in the engine

How to Remove and Install air cleaners



Guide Lines:

(1) Loosen screws and remove covers

(2) Remove pre-cleaner and cartridge carefully so as to prevent debris from entering the

carburettor

(3) Re-install clean air cleaner assembly in base

(4) Replace cover and tighten screws.

Cleaning of Combustion Deposits



After every 100 hours of engine use, it is recommended that the air cooling system be cleaned.

Cleaning of Debris

It is important for the engine to be kept clean, so as to reduce the risk overheating, and ignition of

accumulated debris. Parts that needs daily cleaning includes Finger guard, Linkage, springs, Controls,

Muffler and Spark Arrester.

Engine Speed Adjustments



Sometimes there may be need for adjustment of the engine idle speed so as to enable it to be

adapted for different uses, or make the engine run smoothly. The factory idle speed has been set to

292 rpm. However if any speed reduction is required, the following steps could be followed in order

to achieve this.

(1) To adjust the idle speed, start the engine and warm up for about 5 minutes

(2) Then with the engine running, place equipment throttle control in slow position

(3) Rotate the carburettor lever against the throttle stop and hold it while adjusting the idle

speed screw to the desired value.

Engine Storage

When the engine is not in use and needs to be stored over 30 days, then the fuel needs to be

drained so as to prevent gum from forming in the fuel system or any essential carburettor parts. It is

also important to clean engine parts before storage and when storing, it must be in a dry area that is

spark free.



Appendix 12 – Adaptation of chosen engine for alternative purposes

(A) As already explained, one great advantage of this engine is its ability for it to be utilized for

other purposes. One of this uses is converting it in to a generator, so as to supply electricity

to rural homes, when the transplanting machine is not in use. In order to achieve this, the

following steps are could be taken.

(1) Remove the engine and its carrier from the machine by losing the M10 bolts

attaching the engine – carrier assembly to the machine.

(2) Mount an alternator on to the engine carrier and connect it to the engine

(3) Attach a motor pulley to the engine

(4) Place the attachment belt between the fan blade and the pulley attached

(5) Wire the motor to the alternator and then to an external battery to get it working

(6) Test the alternator, and make necessary adjustments to stop any rattling.

(B) Besides converting it to a generator, it could be used directly on a lawn mower without any

further change.



Appendix 13: - Detailed Manufacturing Material selection

End User Profile: Indonesia (Developing Country)

End User Material Requirement:

(1) Light Weight

(2) High Strength

(3) Low price

(4) High Availability

Materials Selection Technique for Engine Carrier design

In order to suit the above stated material requirements of the end user, the engine carrier must be

manufactured using a material that is cheap, strong and light.

In order to achieve this, a merit index was inputted in to the CES EDU pack software. The merit

index was created in the form M = E1/3/ρ which could be written as Log E = 3 Log ρ + Log M. The

defined merit index, used in the CES EDU pack as shown below, makes sure all selected materials

have very high Strength to weight ratio. In order to finally narrow the material results down, a price

constraint of £1.5/kg, was also put in to the CES EDU pack constraints section. The final material was

then selected amongst the remaining list on the basics of availability.



In the end of the Analysis the chosen manufacturing material was:

STEEL (AISI 1020 ANNEALED)

ULTIMATE TENSILE STREGTH

448 MPa

YIELD STRENGTH 346 Mpa

ELONGATION % 36 %

REDUCTION OF AREA 59 %

HARDNESS (HB) 143 HB

Durability of STEEL (AISI 1020 ANNEALED)



Appendix 14 - Detailed Engine Carrier Deflection Calculations

The deflection characteristic of the I Beam above is:

𝝏 = (𝑭 × 𝑳 × 𝑳 × 𝑳)/ E × I

Considering the fact that the manufacturing materials have already been specified as steel, the

carrier deflection is now a function of size and shape.

Engine carrier base plate deflection calculations:

Free Body Diagram of Base Engine carrier base plate



In order to undertake the bending analysis and make the carrier safe for loads up to 150kg without

deflecting, the following assumptions have been made:

(1) Plate thickness is 0.003m

(2) Plate breadth is 0.2m (Wide Enough to carry the chosen engine)

(3) Plate length is 0.6m (Long enough to accommodate alternative engine mounting patterns

and mounting of other engine attachments).

(4) Engine base plate is considered approximately as a uniform I beam.

Properties of Manufacturing Materials:

(E) Young’s Modulus = 200 MPA

Properties of plate:

Length = 0.6m, breadth = 0.2, thickness = 0.003m



Deflection Calculations

The figure below represents a set of graphs computed, considering a point centre load of 1500N. The

total engine weight without fuel is 36kg (360N), but the 1500N load, has just been exaggerated to

accommodate all approximations, and assumptions made, as well as make up for any future change

in engine to a heavier option or addition of a bigger fuel tank on to the engine carrier.

Max Bending Moment = 0.8KN

Location = 0.3 m

Max Bending Moment = 0.1KN.m

Location = 0.0 m

Max Bending Moment = 0.000

Location = 0.3 m



Analysis of Deflection calculation results

Inferring from the figure above, the exaggerated load value of (1500N) gives a 0 deflection,

which is exactly what the engine carrier needs in order to make sure that the output shaft of the

engine always aligns with the lay shaft. In confirmation of this Bending analysis, an FEA analysis

has been done as shown below. These analyses have equally been done, considering a total safe

load of 1.5KN, which makes up for the weight of any additional component or a heavier engine

that may be used in future. From the FEA it could be inferred that under the speculated load of

(1.5KN) the plates will experience no deflections, and very little stresses. This thus agree very

much to the calculations carried out in the Bending analysis, which implies that in terms of

sustainability and durability, the designed engine carrier has met the required engine carrier

design specifications, as well as the ultimate end user requirements.

FEA Showing Engine carrier Stress distribution under 150kg load

FEA Showing Engine carrier plate deflection under 150kg load



Appendix 15 - Engine Carrier Assembly Calculations

Having ascertained in the bending analysis that the specified top plate of the assembly

configuration, is fully capable of carrying a more than 5 times the 36kg estimate as weight of the

engine, there is need to ascertain the strength of the entire assembly from which the maximum

weight to cause deformation and failure can be specified and incorporated in to the design safety

warnings.

In order to make this analysis the calculations, detailed below were made.

Detailed Engine Carrier Assembly Calculations

LIMITATIONS TO ANALYSIS

1. Material applicability - the methods and factors are considered to be valid for clips and fittings

made from homogenous alloys for which FTY > 0.65 FTU and material maximum elongation >= 4%.

2. A normal washed is used under the nut.

3. These limits to geometric ratios apply: 0 ≤ tf/tc ≤ 5.0 and 2.0 ≤ e/(tc + tf) ≤ 15.0.

4. The clip bend radius should not be less than 1.5tc (thickness of base of angle clip)



EQUATIONS INVOLVED

For maximum elastic load, or load for zero permanent deformation in the angle:

[N/mm] Eq'n 1

For load for 0.25 tc permanent deformation:

[N/mm] Eq'n 2

For ultimate failure load:

[N/mm] Eq'n 3

For tension failure of fasteners (applicable to thick angles):

[N/mm] Eq'n 4

Where:

PFU = Minimum Axial Ultimate Tensile Strength of Fastener

Note: Eq'n 4 is based on tests conducted on assemblies having one or two fasteners per side where

there is no doubt as to how much of the load was resisted by each.

e3

ttFtP

fctyc

)MEL(A

e

ttFtP

fctyc

)SPD(A

e

ttFt6.1P

fctyc

)ULT(A

1ben

W

PP FU

)FAS(A



Design Assembly Calculations

CALCULATIONS

e = 42.0 mm Bolt Head Clearance

b = 15.0 mm Edge Distance

H = 300.0 mm Horizontal Fastener Spacing

v = 150.0 mm Vertical Fastener Spacing

D = 10.0 mm Fastener Nominal Diameter

n = 2 Number of Tension Fasteners Per Side

tc = 3.0 mm Thickness of Base of Angle Clip

tf = 3.0 mm Thickness of the Radius Filler

R = 5.0 mm Bend Radius

W = 400.0 mm Clip Width (Parallel to Bend Line)

Material = STEEL AISI 1020

Ftu = 346 MPa Tensile Yield Strength of Angle Material

Fty = 346 MPa Tensile Yield Strength of Angle Material

PT = 150 N Applied Load (Ultimate)

f = 2 mm Fitting Factor



PA(MEL) = 49.4 N/mm Maximum Elastic Loading (Eq'n 1)

PA = 19771 N Tension to Cause Zero Permanent

Deformation, PA = PA(MEL) W

PA(SPD) = 148.3 N/mm Max. Loading to Cause 0.25tc Deformation (Eq'n 2)

PA = 59314 N Tension to Cause 0.25tc Perm. Def., PA = PA(SPD) W

PA(ULT) = 237.3 N/mm Max. Loading to Cause Ultimate Failure (Eq'n 3)

PA = 94903 N Tension to Cause Ultimate Failure, PA = PA(ULT) W

PFU = 133891 N Minimum Axial Ultimate Tensile Strength of Fastener

PA(FAS) = 176 N/mm Maximum Loading to Cause Fastener Failure (Eq'n 4)

PA = 70469 N Tension to Cause Fastener Failure, PA = PA(FAS) W

For no permanent deformation the margin is:

MS = 2PA / f PT - 1 = 13081%

Margin for the tension failure of fasteners is:

MS = 2PA / f PT - 1 = 46879%



Appendix 16 – Assembly Bolt Calculations

Assembly Bolt Characteristics

16 (M10X12) bolts are needed for the overall assembly and at an individual cost of $0.3; the total

cost of all the needed M10 bolts will be $4.8.


(MPA)

M10x12 10 1.50 5.80 400.00



Appendix 17 - Bolt Torque Limit Calculation Reference: (NORD LOCK bolt security

system)



Appendix 18 – Forming process selection

Bending definition and Introduction:

Bending is a manufacturing process by which metal can be formed by plastically deforming the

material thus changing its shape. By so doing the material is stress beyond its yield strength but well

below its Ultimate tensile strength. In this process little or no change is notice on the material

surface, as it usually involves deformation about one axis only.

In bending the variety of shapes are formed using a set of standard die or bench brakes. The press

brakes used usually range from 20 to 200 tons so as to accommodate metal stocks form 1m to 4.5m

Air Bending:

This is a type of bending process in which the punch touches the work piece and the work piece does

not touch the lower cavity. In this sort of bending as the punch is released the work piece springs

back giving the material a slight bend. The amount of spring back, is however dependent on the

material, and its thickness. The inner radius of the bend is usually exactly the same radius on the

punch. Although in this sort of bending the forces required is quite slow, but accurate control of the

punch stroke is however necessary to obtain the desired bend angle.

Air Bending



Bottoming:

Bottoming is a bending process where the punch and the work piece touches on the die. This thus

creates a controlled angle of 90 degrees bend with very little spring back effect. In the Bottoming

bending process a heavier punch than that of the air bending is required in order to form the

material.

Bottoming

V Bending:

In V bending, the clearance between the punch and the dies is usually constant (equal to the

thickness of the sheet formed. It is widely used with little or no specialist knowledge needed.

V Bending



Wiping Die Bending:

Wiping die bending is otherwise known as flanging, where one edge of the metal sheet is bent to 90

degrees while the other end is restrained by the material itself and by a force from the blank holder

and pad. The bend radius in this sort of process is determined by the radius of the edge of the die.

Wiping Die Bending

Comparison of Bending Methods and Choice of Viable bending method

Table 3 below shows a comparison of all the available bending methods available in Indonesia that

are applicable to this design. Having considered the factors shown on the table below, V bending

was chosen as the most viable method that should be incorporated in to the engine carrier

manufacturing processes.

Table 3 - Bending technique selection for engine carrier design

Method Max

Score

Weight of

Punch needed

Score Punch force

required Score

Spring back effect

experienced Score

Level of angle

control Score Availability Score

Total Score

Air Bending

5 Low 4 Low 4 Very high 2 Low 2 Medium 2 19

Bottoming 5 High 2 High 2 Low 4 High 4 Medium 2 19

V Bending 5 Low 4 Low 4 Low 4 High 4 High 4 25

Wiping Bending

5 High 2 High 2 High 2 High 4 Medium 2 17

Keys

High values

required

Low values Required

Best

Bending Method



Appendix 19 – Sprocket Selection Catalogue



Appendix 20 – Grub Screw calculations

Calculation of Torsional Stress in Shaft:

Diameter of shaft = 15mm, Transmitted Torque of Engine (T) is 5.2 Nm

ɽ max = (TxR)/J

J = πD4/32

J = 5 x10-9 m4

ɽ max = (5.2x0.0075)/5x10-9

ɽ max = 7.8 Mpa (Engine Shaft)

Calculation of Bending Stress in Shaft:

The grub screw experiences a Shearing force:

Calculation of bending stress in Grub screw:



Diameter of grub screw = 5mm, Transmitted Torque of Engine (M) is 5.2Nm

ɽ max = (MxR)/I

I= πD4/64

J = 3.067 x10-11 m4

ɽ max = (5.2x0.0025)/3.067x10-11

ɽ max = 425 Mpa (Grub Screw)

CONCLUSIONS

Under the normal working conditions of the engine at a 6.8Nm torque, the grub screw takes up

more shear stresses (425Mpa), than the engine shaft experiences Torsional stress (7.8 Mpa), this

means that should there be a jam in the drive train, the grub screw is going to fail first due to shear

stress, thus preserving the engine shaft from failure due to Torsional stress.



Appendix 21 - Risk and Reliability analysis of the engine and the engine carrier assembly

Detailed below is the risk, reliability and failure analysis for the entire engine and the entire engine

carrier assembly. From this analysis, engine over heat is the biggest concern.

Risk and reliability table keys



# Part and Function

Potential Risk Mode

Potential Effect(s) of

Risk

SE

V

Potential Cause(s)/Mechanism(s)

of Failure

OC

C

Prevention Plan

DE

T

RP

N

1

Engine, Power and Torque

transmission to drive train

Fire Severe burns or

death

10 Fuel Leakage 10

Check for fuel leakage when filling the fuel

tank, as well as cracks on the

tank. Replace fuel tank where necessary

1 100

2 10 Tipping of engine at angle

more than 15 degrees 10

Engine should not be inclined above

or below 15 degrees angle

about the horizontal

1 100

3 10 Sparks from starting engine 10

Ensure that the plugs used are

approved ones for the engine and that the engine spark arrester is

correctly installed

1 100

4 10 Engine fuel flood leading to Fire out break on exposure

to heat 10

Set choke to open/run position and then place a throttle in Fast

and crank engine until its starts

2 200

5 10 Machine contact with furnaces, stoves and

heaters 10

When contained with fuel, keep machine out of flame inducing

substances

2 200



6

# Part and Function

Potential Risk Mode


Risk

SE

V


of Failure

OC

C

Prevention Plan

DE

T

RP

N

7



Explosion Severe burns or

death

10 Spilled fuel during fuel

expansion 10

Do not over fill the fuel tank. Fill to

approximately 1/2 inch below the

lowest portion of the opening. In the event of a spill, wait for gasoline to

evaporate before switching on the

engine

4 400

8 10 Over heated engine 7

Check out for increasing engine

temperature, when in use to

avoid explosion. Also turn off

engine and let it cool before

removing the gas cap

6 420

9 10 Choking Carburettor to stop

Engine 8

When stopping the engine, move throttle control to slow, and the to stop, then push

the stop switch to off

1 80

10 10 Using Pressurized Fuels 9 Fuelling should be done outdoors in ventilated area

1 90

11

12



Release of Poisonous gas

(Carbon Monoxide)

Nausea, Fainting or Death

10 Starting engine in enclosed area, leading to incomplete

combustion of the fuel 8

Start and Run engines,

Outdoors only 2 160

13



# Part and Function

Potential Risk Mode


Risk

SE

V


of Failure

OC

C

Prevention Plan

DE

T

RP

N

14



Injury Traumatic

amputation or severe laceration

10

Rotating Engine parts coming in contact with any

parts of the body

8 (1) Operate

equipment with guards in place

2 160

15 10 8 (2) Keep hands and feet away

from rotating parts 2 160

16 10 8

(3) Long hair should be ties up

and all Jewelleries removed

2 160

17 10 8

(4) Do not wear loose-fitting

clothing close to the engine

2 160

18

19



Kick Back

Broken bones, fractures, bruises or sprains could

result

10 Rapid retraction of engine

starter cord 6

When starting the engine, pull chord

slowly until resistance is felt, then pull rapidly

1 60

20

21



Health Complications

birth defects, and cancer

10 Exhaust gases and engine

chemicals 10

Wash hands after every use of the

engine 1 100

22



# Part and Function

Potential Risk Mode


Risk

SE

V


of Failure

OC

C

Prevention Plan

DE

T

RP

N

23



Hard start Engine damage

5 (1) Using wrong fuel 7 Use Specified

fuels 1 35

24 5 (2) refilling or adding oil at

wrong temperature 8

Use specified oil and refill oil at recommended temperatures

1 40

25

26



Water in Oil Engine damage

8 (1) Damaged oil seals 8 Check oil seals

from time to time 4 256

27 8 (2) Careless exposure of

engine to very wet condition with open oil tank

7

Make sure in rainy conditions

the engine is properly shielded

to avoid water from getting in

4 224

28 Engine, Power

and Torque transmission to

drive train

Engine out of fuel Engine damage

6 (1) Fuel tank Leakage 7

When fuelling engine, look out for cracks on the

tank and any leakage

1 42

29 6 (2) Fuel tank very small 7 Use bigger engine tank if necessary

1 42



# Part and Function

Potential Risk Mode


Risk

SE

V


of Failure

OC

C

Prevention Plan

DE

T

RP

N

30



Over heating Engine damage

6 (1) Deposit of dirt on the

moving engine parts 6

Clean regularly to avoid dirt on

rotating engine parts

3 108

31 6 (2) Operating of engine

indoors 7

Allow engines to cool if too hot and use engines out door at all times

1 42

32

33

Engine assembly with sprocket and

Engine carrier

Engine shaft not aligning with Lay

shaft

Lots of losses in chain

transmission or break down of

chain transmission

5 Machine assembly fault 5

Adjust engine height, using the adjustable engine

chassis design

7 175

34

Engine sprocket free wheels

around the engine output shaft

Stops transmission of engine power to drive mechanism

5 Broken grub screw 5 Replace broken

grub screw 1 25

35 Engine falling off its chassis in to the paddy fields

Water gets in to the engine and

causes and engine knock

8 Loosen nuts from the base

of the engine 4

In order to prevent this make

sure the bolt attaching the engine to its

chassis is well torque to an

appropriate value before the

machine is used

2 64

36

37

Engine and Engine carrier

assembly, Creates an interface

between the engine and the main machine

frame

Rusting

Crack initiation, which may lead to stress due to cyclic loading

7 None painting of Engine

carrier, before exposing it to damp weather conditions

4

Paint Engine carrier upon

manufacture, and repaint, when the

previous pain begins to wear to

prevent direct exposure of the engine carrier

material to direct atmospheric conditions

1 28

38

Engine Falling off frame, or unable to transmit torque

and power efficiently to drive

train

Uncontrolled engine vibrations,

and inefficient torque and power

transmission

3 Loosen nuts` 4

Make sure engine nut and bolts are

tightened to specified Torque limit before the

machine is used, and chain worn out bolts should

need be

6 72

39 Ultimate Failure

of Engine chassis Engine damage 6

Over loading of Engine carrier beyond the Ultimate

failure load 2

Avoid loading Engine carrier up to the estimated failure load of

95KN

4 48

40



APPENDIX 22 – LIST OF ENGINEERING DRAWINGS

(Please see attached engineering drawings for details)

1. Power train assembly drawings

2. Power train exploded view, with part list

3. Engine carrier assembly

4. Manufacturing drawings for engine carrier base plate

5. Manufacturing drawings for engine carrier arm

Report Main Section

Documents

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