Design and construction of a small scale engine powered millet harvester/ Maganda, Aziz

CONTENTS
ABSTRACT..................................................................................................................................... i
DECLARATION ............................................................................................................................ ii
ACKNOWLEDGEMENT.............................................................................................................iii
DEDICATION............................................................................................................................... iv
APPROVAL ................................................................................................................................... v
LIST OF FIGURES ....................................................................................................................... ix
LIST OF TABLES......................................................................................................................... ix
1.0 INTRODUCTION ............................................................................................................... 1
1.1 Background ...................................................................................................................... 1
1.2 Problem statement............................................................................................................ 2
1.3 Purpose of the study ......................................................................................................... 2
1.4 Objectives of the Project .................................................................................................. 2
1.4.1 Main objective .......................................................................................................... 2
1.4.2 Specific objectives.................................................................................................... 2
1.5 Scope of the Project.......................................................................................................... 3
1.6 Justification ...................................................................................................................... 3
2.0 LITERATURE REVIEW .................................................................................................... 4
2.1 Introduction ...................................................................................................................... 4
2.2 The millet crop ................................................................................................................. 4
2.2.1 Categories of finger millet ........................................................................................ 5
2.2.2 Economic importance of millet in Uganda ............................................................... 5
2.2.3 Nutritional benefits ................................................................................................... 6
2.2.4 Millet production ...................................................................................................... 7
2.2.5 Cultivation practices of finger millet ........................................................................ 7
2.2.6 Physical properties/features of the millet crop.......................................................... 8
2.3 Harvesting of millet.......................................................................................................... 8
2.3.1 Analysis of the available methods of harvesting millet............................................ 9
2.3.2 Mechanized harvesting; .......................................................................................... 11
2.4 Main components of a millet harvesting equipment ...................................................... 15
2.5 Fabrication methods commonly used in engineering..................................................... 16
2.6 Performance of harvesters.............................................................................................. 19
2.7 Economic evaluation of harvesters ................................................................................ 22
2.7.1 Payback period method........................................................................................... 22
2.7.2 The average return rate method (ARR) .................................................................. 22
2.7.3 The net present value (NPV)................................................................................... 23
3.0 METHODOLOGY ............................................................................................................ 24
3.1 Design considerations for the harvester ......................................................................... 24
3.2 Physical properties of the millet at maturity .................................................................. 24
3.3 Design of the different components of harvester ........................................................... 24
3.3.1 Description of the machine ..................................................................................... 24
3.3.2 Design of the cutter bar........................................................................................... 25
3.3.3 The cutting force required for direct cutting of millet ............................................ 25
3.3.4 The power requirement for cutting ......................................................................... 26
3.3.5 The slider-crank mechanism................................................................................... 26
3.3.6 Design of the frame................................................................................................. 27
3.3.7 Design of the wheels............................................................................................... 28
3.3.8 Design of the drive wheels shaft............................................................................. 30
3.3.9 The pulley and the transmission system ................................................................. 32
3.3.10 Bevel gear selection for the gear box...................................................................... 35
3.3.11 Selection of the bearings......................................................................................... 35
3.3.12 Design of the reel.................................................................................................... 36
3.3.13 Design of the container........................................................................................... 36
3.4 Fabrication of the harvester............................................................................................ 37
3.4.1 Fabrication of the frame.......................................................................................... 37
3.4.2 Fabrication of the cutter bars .................................................................................. 38
3.4.3 Fabrication of the reel ............................................................................................. 38
3.4.4 The crank ................................................................................................................ 39
3.4.5 The collecting container.......................................................................................... 40
3.4.6 Fabrication of the wheels........................................................................................ 40
3.5 Assembly of the various components............................................................................. 41
3.6 Performance evaluation of the harvester........................................................................ 41
4.0 RESULTS AND DISCUSIONS........................................................................................ 42
4.1 Cutting efficiency........................................................................................................... 42
4.2 Theoretical field capacity............................................................................................... 42
4.3 Field efficiency............................................................................................................... 43
4.4 Actual field capacity....................................................................................................... 43
4.5 Economic analysis and evaluation ................................................................................. 43
4.5.1 Harvesting by hands................................................................................................ 43
4.5.2 Harvesting by the machine...................................................................................... 44
4.5.3 The payback method............................................................................................... 45
5.0 CONCLUSION, CHALLENGES AND RECOMMENDATIONS .................................. 46
5.1 Conclusion...................................................................................................................... 46
5.2 Challenges...................................................................................................................... 46
5.3 Recommendations.......................................................................................................... 47
APPENICES ................................................................................................................................. 48
Appendix A ............................................................................................................................... 48
Appendix B ............................................................................................................................... 49
Appendix C ............................................................................................................................... 50
Appendix D ............................................................................................................................... 51
Appendix E................................................................................................................................ 52
Appendix F................................................................................................................................ 52
REFERENCES ............................................................................................................................. 55

Includes bibliographies