Design and Fabrication of Engine Powered Two Rows Rice Transplanting Machine

DESIGN AND FABRICATION OF ENGINE POWERED TWO ROWS RICE TRANSPLANTING MACHINE

Group Members: ABDULLAH AHMED

(100663)

SOHAIB IMRAN

(100696)

BE MECHANICAL (2010-2014) Project Supervisor Dr. Tahir Rasul Foreign Professor

DEPARTMENT OF MECHANICAL AND AEROSPACE ENGINEERING

INSTITUTE OF AVIONICS AND AERONAUTICS

1

AIR UNIVERSITY, ISLAMABAD

DESIGN AND FABRICATIN OF ENGINE POWERED TWO ROWS RICE TRANSPLANTING MACHINE FINAL YEAR PROJECT REPORT (2010-2014)

DEPARTMENT

OF

MECHANICAL

ENGINEERING

2

AND

AEROSPACE

DESIGN AND FABRICATIN OF ENGINE POWERED TWO ROWS RICE TRANSPLANTING MACHINE

Submitted By: ABDULLAH AHMED

(100663)

SOHAIB IMRAN

(100696)

Project Supervisor

____________________________ ____________________ ________ Dr. Tahir Rasul Foreign faculty, IAA

Head of Department

____________________________ ____________________________ Dr. Basharat Ullah Malik

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Acknowledgments We express our humblest and profound gratitude to Allah Almighty Who has given us the strength and direction to accomplish our purpose and guided us through every think and thin. This project would not have been possible without the guidance and the help of several individuals who have in one way or the other contributed and extended their valuable assistance in the preparation and completion of this project. We would like to acknowledge the assistance of our supervisor Dr. Tahir Rasul for guiding us throughout the designing process, for the support for our study and research, for his patience, motivation and immense knowledge. We thank him for his support and help and guidance with so much interest because of which we are able to complete our final year project in time. He assisted in performing a comprehensive literature review and the practical know how of things in the fabrication phase. He helped us in converting our computer aided design into a physical form. Moreover he is regularly checking our progress on the project. We are also thankful to the Head of the Department of Mechanical and Aerospace Engineering, Dr. Basharat Ullah Malik for his motivation, guidance and suggestions. Last but not the least; we would like to thank our parents and families for their financial, motivational and never ending support in our study and in its success.

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Abstract This report provides a thorough description of the modeling and designing of an Engine Powered Rice Transplanting Machine. It begins with research into the problems of transplantation of rice in Pakistan and there solution, a brief study of already existing machines and there working. Specified operating requirements and working conditions stipulate the design, material and working principles constraints. As part of the project, a schedule is laid out following industry techniques. Brainstorming and decision matrices are utilized as well, conveying our design process. A basic structure is designed using strength of materials, precision in working and applied/allowable stress analysis, and material deflection. Additional features are developed based on a more specific investigation of customer requirements. This report not only covers the design, but also docu ments its software analysis and simulation of the structure. Cost analysis and material choices are relayed along with a complete set of engineering drawings for the manufacture of the machine. We are thankful to our advisor and parents as without their support and prayers it wouldn’t have been possible.

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List of Figures Figure 1: Map showing the rice growth in Pakistan ......................................................... 12 Figure 2: Random method for Rice planting ................................................................... 13 Figure 3: Straight row method for rice planting ........................... .................................... 13 Figure 4: Broadcasting method for rice planting .............................................................. 14 Figure 5:Drilling method for rice transplanting ................................................................ 14 Figure 6: Dibbling method for rice transplanting ............................................................. 15 Figure 7: Initial design of frame ....................................................................................... 28 Figure 8: Final design of frame ......................................................................................... 29 Figure 9: Highlighted slots for holding planting arm ....................................................... 30 Figure 10: Initial design of seedling displacement assembly ............. .............................. 30 Figure 11: Initial design of planting arm asembly ........................... ................................. 31 Figure 12: Initial design of seedlings tray ......................................................................... 31 Figure 13: Initial design of seedlings support ................................................................... 32 Figure 14: Final design of Planting assembly ................................................................... 33 Figure 15: CAD of planting arm ....................................................................................... 33 Figure 16: CAD of ground support ................................................................................... 34 Figure 17: back and front perspective view of Seedling box assembly ............................ 34 Figure 18: Seedling box .................................................................................................... 35 Figure 19: Finalized CAD of seedling box support .......................................................... 35 Figure 20: CAD of engine carrier ..................................................................................... 36 Figure 21: Initial design of wheel assembly ..................................................................... 37 Figure 22: Finalized design of wheel assembly ................................................................ 37 Figure 23: CAD of Floater ................................................................................................ 39 Figure 24: Planting arm assembly (arrow pointing to shaft) ............................. ............... 40 Figure 25: Velocity graph for Planting arm shaf ................................ .............................. 41 Figure 26: Stress analyses of frame .................................................................................. 42 Figure 27: Displacement analyses of frame ...................................................................... 43 Figure 28: Stress analyses of floater ................................................................................. 44 Figure 29: Displacement analyses on Floater ................................................................... 45 Figure 30: Stress analyses on wheel assembly ................................................................. 47 Figure 31: Displacement analyses on Wheel Assembly ................................ ................... 48 Figure 32: Stress analyses on rpm conversion shaft ......................................................... 49 Figure 33: Displacement analyses on rpm conversion shaft ............................................. 50 Figure 34: Stress analyses on planting assembly ground support .................................... 51 Figure 35: Displacement analyses on planting assembly ground support ....................... 52 Figure 36: Stress analyses on seedling box support .......................................................... 53 Figure 37: Displacement analyses on seedling box support ........................... .................. 54 Figure 38: Metal sheets for frame fabricaition.................................................................. 55 Figure 39: Gas cutting for frame ....................................................................................... 56 Figure 40: Drilling for frame ............................................................................................ 56 Figure 41: Eclectic spark welding for frame manufacturing ................................ ............ 57 Figure 42: Fabricated wooden floater ............................................................................... 57 Figure 43; Frame handle ................................................................................................... 58 6

Figure 44: Rings for fabricating wheels ............................................................................ 59 Figure 45: Bending of rings in to circle ............................................................................ 59 Figure 46: Welding of rings .............................................................................................. 60 Figure 47: Welding of rings together (top), Welding of bars with wheel rings for support and strengthening (bottom) ............................................................................................... 61 Figure 48: Finished wheel set ........................................................................................... 61 Figure 49: Fabricated Planting assembly support frame ................................................... 62 Figure 50: Fabricated planting arm ................................................................................... 62 Figure 51: Fabricated Crank pair for planting arm assembly ............................ ............... 63 Figure 52: Fabrictated link for Planting arm assembly ..................................................... 63 Figure 53: Whole planting arm assembly ......................................................................... 64 Figure 54: Final assembly of wheel .................................................................................. 65

List of Tables Table 1: FYP time line…………………………………………………………..20

Table 2: Wheel assembly parts design details and specifications……………….40 Table 3: Floater engineering properties………………………………………….46 Table 4: Wheel assembly engineering properties………………………………..48 Table 5: Speed control shaft engineering properties……………………………..51 Table 6: Planting arm assembly support engineering properties…………………53 Table 7: Seedling box support engineering properties……………………………55 Table 8:Cost table for materials…………………………………………………..67

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List of Symbols Following are the representing terms which are used by us in the calculations: RTP = Rice transplanter v = velocity w = angular velocity r = radius T = number of teeth of sprocket N = angular velocity d = diameter p = pitch of sprocket Ʈ = torque

P = power J = polar moment of inertia c = radius τ = shear stress θ = angle

t = time

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Table of Contents

2

1.1

Acknowledgments ...................................Error! Bookmark not defined.

1.2

Abstract ...................................................Error! Bookmark not defined.

1.3

List of figures & Tables ..........................Error! Bookmark not defined.

1.4

List of Symbols ........................................................................................ 8

Chapter 1............................................................................................ ............ 12 Literature Review ...................................................... ........................................ 12 1.1.

Rice Crop .................................................... ........................................ 12

1.2.

Rice Zones .......................................................................................... 12

1.3.

Methods of Rice Planting[1] .................................................... ............ 13

1.3.1. a.

Random .................................................................................................. 13

b.

Straight Row ........................................................................................... 13

1.3.2.

3

Transplanting .................................................................................. 13

Direct seeding ................................................................................. 14

a.

Broadcasting ........................................................................................... 14

b.

Drilling ................................................................................................... 14

c.

Dibbling .................................................................................................. 15

Chapter 2............................................................................................ ............ 16 Understanding of project .................................................... ............................... 16

4

2.1.

Advantages ..................................................... ........................................ 16

2.2.

Parts and functions ................................................................................. 17

Chapter 3............................................................................................ ............ 18 3.1.

Timeline ................................................................................................. 18

3.2.

Scope: ..................................................... ................................................ 18

3.3.

Parts that will be bought and fabricated ................................................. 19 9

5

Chapter 5............................................................................................ ............ 21 Mathematical Modeling .................................................................................... 21 5.1.

Power transmission mechanism design .............................................. 21

5.1.1.

Engine ..................................................... ........................................ 21

5.1.2.

Velocity of machine ........................................................................ 21

5.1.3.

Gear Box ......................................................................................... 21

5.1.4.

Calculating diameter of shafts ........................................................ 23

5.2. 6

Position analysis of planting mechanism............................................ 24

Chapter 6............................................................................................ ............ 27 Computer Modeling .......................................................................................... 27 6.1.

Design of frame: ................................................................................. 27

6.1.1. 6.2.

CAD Model of Frame: ........................................................ ............ 27 Design of planting mechanism: ...........Error! Bookmark not defined.

6.2.1.

Initial Design:...................................Error! Bookmark not defined.

6.2.2.

Finalized Design: .............................Error! Bookmark not defined.

6.3.

Engine carrier: ..................................................... ............................... 36

6.4.

Wheel Assembly:................................................................................ 36

6.4.1.

Initial Design:................................................... ............................... 36

6.4.2.

Final Design: .................................................... ............................... 37

6.5.

Bevel Gears addition: ......................................................................... 38

6.6.

Floater: ................................................................................................ 39

Chapter 7 ...................................................... .................................................... ..... 40 Analysis .................................................... .................................................... ..... 40 7.1.

Motion analysis: ...................................................... ............................... 40

7.1.1.

Bevel shaft: ......................................Error! Bookmark not defined.

7.1.2.

Planting arm dynamic: ........................................................ ............ 40

7.1.3.

Seedling box: ...................................Error! Bookmark not defined.

7.2.

Stress analyses:........................................Error! Bookmark not defined.

7.2.1.

Stress Analyses on Frame: ...............Error! Bookmark not defined.

Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined. 10

7.2.2.

Stress Analyses on Engine Carrier:..Error! Bookmark not defined.

Von Moses stress analyses: ............................Error! Bookmark not defined. Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined. 7.2.3.

Stress Analyses for Floater: .............Error! Bookmark not defined.

6.1.1

Von Moses Stress Analyses: ............Error! Bookmark not defined.

Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined. 7.2.4.

Stress Analyses on Wheel Shaft: .....Error! Bookmark not defined.

Von Moses Stress analyses: ............................Error! Bookmark not defined. Figure 26.a ......................................................Error! Bookmark not defined. Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined. 7.2.5.

Stress analyses on bevel gear shaft: .Error! Bookmark not defined.

Von Moses stress analyses: ............................Error! Bookmark not defined. Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined. 7.2.6. Stress analyses on planting assembly support: .....Error! Bookmark not defined. Von Moses stress analyses: ............................Error! Bookmark not defined. Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined. 7.2.7. Stress analyses on Seedling box assembly support: ................ Error! Bookmark not defined. Table 10 ..........................................................Error! Bookmark not defined. Von Moses stress analyses: ............................Error! Bookmark not defined. Study results: ..................................................Error! Bookmark not defined. Conclusion: .....................................................Error! Bookmark not defined.

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CHAPTER 1 Literature Review 1.1. Rice Crop Rice, an important food and cash crop, is the second staple food grain crop of Pakistan after wheat and major source of foreign exchange earnings after cotton. It is planted on an area of over 2.57 million ha (10% of the total cropped area) and accounts for 17% of the total cereals produced annually. The annual production of milled rice is about 6.5 million tons sharing 4.9% in agriculture sector and 1.1% in GDP. Pakistan is famous for growing and exporting long grain aromatic Basmati rice. The rice export increased manifold during the recent years and a record ex port of 4.5 million tons of worth about US$ 1735.2 million was made during 2011-12 Pakistan ranks 13th in terms of rice production and 4th in rice export in the world.

1.2. Rice Zones In Pakistan, rice is grown under diverse climatic and edaphic conditions. Basmati predominates in traditional rice tracts of Punjab. In Swat at high altitude mountain valleys, cold tolerant rice are grown. In the south of NWFP, Sindh and Baluch istan IRRI type medium long grain heat tolerant tropical rice are grown (Figure 1).

Figure 1: Map showing the rice growth in Pakistan

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1.3.Methods of Rice Planting [1]

There are two methods of planting rice: 1.3.1. Transplanting

In this method prepared seedlings are transplanted in the field. Transplanting is done with following two methods: a. Random

In the random method, seedlings are transplanted without a definite distance or space between plants as you can see in this frame.

Figure 2: Random method for Rice planting

a. Straight Row

The straight-row method follows a uniform spacing between plants. The seedlings are transplanted in straight rows.

Figure 3: Straight row method for rice planting

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1.3.2. Direct seeding

In this method, direct seeding of rice with dry land preparation is done. Direct seeding is done with three methods: a. Broadcasting

You can broadcast seeds uniformly on the field or in furrows in a field. After broadcasting, cover the seeds using a spike-tooth harrow.

Figure 4: Broadcasting method for rice planting

a. Drilling

Another technique is drilling seeds by hand on prepared furrows, or by seed drillers.

Figure 5:Drilling method for rice transplanting

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b. Dibbling

The third technique is dibbling, or hill planting. This is usually practiced along mountain slopes or where plowing and harrowing are difficult. Use a long wood or bamboo pole with a metal scoop attached at the end for digging holes. Then drop the seeds into the holes and cover them with soil.

Figure 6: Dibbling method for rice transplanting

The techniques discussed above are commonly used in Pakistan for the production of rice. After the study of above techniques the need of a more efficient rice production technique is felt which should be efficient in cost and time, which can be fulfilled by the implementation of a mechanical rice transplanter.

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CHAPTER 2 Understanding of project Mechanical Transplanting of Rice is the process of transplanting specifically raised seedling of rice using an engine powered mechanical rice transplanter at pre-determined and desired spacing. A common rice transplanter comprises of: 





A seedling tray like a shed roof on which rice seedlings are set. Seedlings pickup forks that pick up a seedling from the seedling tray and put the seedling into the earth. Floaters and power transmission.

Machine transplanting using rice transplanters requires considerably less time and labor than manual transplanting. It increases the approximate area that 2 people can plant from 1acre/10hr to 1acre/3.7hr. However, rice transplanters are considerably expensive for almost all Asian small-hold farmers. Rice transplanters are popular in industrialized countries where labor cost is high, for example in South Korea. These were first developed in Japan in 1960s, whereas the earliest attempt to mechanize rice transplanting dates back to late 19th century. In Japan, development and spread of rice transplanters progressed rapidly during 1970s and 1980s.

2.1.    





Advantages

Efficient use of resources by saving on labor. Cost saving (Rs 980 per acre). Timely transplanting of seedlings of optimal age. Ensures uniform spacing and optimum plant density (30 -35 hills/m2 with 4-6 seedlings/hills). Less transplanting shock, uniform maturity of crop that facilitate timely harvest and reduce harvest losses. Reduces stress, drudgery and health risks of farm labors.

16



Generates employment and alternate sources of income for rural youth through custom services on nursery raising and mechanical transplanting.

2.2. 







Parts and functions

The rice transplanter has two parts i.e. front and rear portions. The front portion has diesel engine ranging from 3-4 HP depending on the make and toothed iron wheel, the rear portion has floating board, nursery platform, transplanting fingers with screws for adjusting plants/hill, depth setting lever, chains for height adjustment of float board and pedal for float-lifting. The floating board of the transplanter serves as a base and also helps in movement of the machine over excess water in the field. In general, rice transplanters transplant 2 rows in single pass with spacing arrangements i.e. 30 cm x 12 cm that maintains 30 hills/ m², respectively. Similarly, number of plants per hill can be varied (2-4 seedlings/ hill). The labor requirement for transplanting using transplanter is 2 man-days per acre and 1 transplanter can cover 2.2 acres a day.

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CHAPTER 3 3.1.

Timeline

Table 1

3.2.

Scope:

Our project requires to build a low cost rice transplanter which is suitable to be used in the rice fields of Pakistan. In light of this, we will be covering following areas in this project: 3.2.1. Initial Data and information gathering:

Initial information for rice transplanting machine will be collected from online literature, Farmers who work in the rice fields will also be contacted. Information obtained from the farmers will be of prime importance as they will be asked what kind of machine they want and what type of machine will be suitable for their fields. 3.2.2. Selecting Testing parameters:

After the essential information of machine is gathered from literature review and surveying the farmers, testing parameters will be selected that are essential for the machine to be successful and usable in the practical environment.

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3.2.3. Solid modeling:

Solid modeling of our machine will be carried out on computer software package. Following are the main parts of the machine that will be modeled. Frame Planting mechanism Seed feeding tray Padded wheels Drive train Floaters 3.2.4. Fabrication: 











After the solid modeling has been finalized, the machine will be fabricated with some parts manufactured according to specifications and some bought from the market.

3.3.

Parts that will be bought or fabricated Following are the parts that will be fabricated: 

Frame:

Frame will be modeled and designed on PTC CREO 2.0 software package. 

Planting assembly

This assembly comprises of various parts that include shafts, bars, linkages, chains and sprockets. All parts will be modeled and designed on CREO and only following parts will be fabricated, remaining parts will be bought from the market: a. Shafts b. Linkage bars



Seed feeding box: It is the box on which seedlings will be placed and fed to the planting mechanism. These box are not

19





readily available in the market according to our requirements so they will be manufactured. Padded wheels: These will be designed and fabricated by us as they are not readily available in the market according to our requirement. Floaters: Floaters will be fabricated by us according to our requirement.



Single speed Gear assembly:

Gear assembly was made to order from the market. Following are the parts that will be bought readily from the market: 

Engine:

5 Hp engine will be purchased from the market.

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CHAPTER 4 Mathematical Modeling 4.1. Power transmission mechanism design 4.1.1. Engine The output power of engine is 3.6KW with the net torque at 2500rpm is 10.3Nm 4.1.2. Velocity of machine The normal human walking speed is 1m/s and in mud its speed reduces that is taken as 0.75m/s, this speed is the speed on which machine will run during its operation in the field.

The engine output rpm are 2500 when the max torque is delivered by it, and the required velocity of machine is 0.75 m/s, so the relation is derived between the engine output and machine speed, that is: As

v= r * w

v = 0.75 m/s r is taken as: so

r = 0.15317 m

0.75 = 0.15317 * w w = 0.75 / 0.15317 w = 48.5 rev/min

So w of wheel is 48.5 rpm 4.1.3. Gear Box As rpm of wheels are known so a speed reduction mechanism is designed which is chosen a “gear box”.

To design the compound gear train we have formula of the relation between teeth numbers and revolution per minute of a gear.  



 

21

In this formula N is the number of rpm gears and T is the number of teeth of gear. Two conversion shafts are used for the purpose of speed reduction so the formula becomes: ∗∗ ∗∗



 

T1 is for engine output shaft and gear box input sahft. T2 and T3 are on first conversion shaft. T4 and T5 are on second conversion shaft. T6 and T7 are on third conversion shaft. T8 is on wheel shaft

T1, T3 and T5 and T7 are assumed as 12 teeth because to reduce the speed input gear should have low number of teeth then output gear. We know the value: N1 = 2500rpm N8 = 48.5 rpm Putting values in the formula

 1 ∗  3 ∗  5 ∗  7 8   2 ∗  4 ∗  6 ∗  8 1 The output teeth are assumed as equal in numbers i.e T2 = T4 = T6 = T

1 2 ∗ 1 2 ∗ 1 2 ∗ 1 2 48.5   2500 T = 32 teeth

Calculating diameter of gears

After evaluating the teeth of sprockets radius is also evaluated to use it in designing phase and calculating force phase. 22

The formula for the diameter calculation of sprocket is

=  

ℎ

The teeth t1 = T1 = T2 = T3 = 12 and t2 = T2 = T4 = T6 = 32 Using the formula described above to fine out the diameter of all gears. Pitch of teeth is 0.005meters

0.005= 

For t1:



d1 = 0.0191 meters for

t2:

0.005=  

d2 = 0.05 m

Transmission of Torque

The engine that is selected have maximum torque of 10.3 Nm at the 2500rpm and this torque is transmitted to wheels and planting mechanism. The formula of torque transmission between two gears is: Ʈ 



Ʈ 

Calculating torque transmitted from engine to wheel shaft: Ʈ8 = 521.06 Nm

4.1.4. Calculating diameter of shafts The radius of shafts are calculated by using bending moment diagrams of each shaft.

The formula used for this purpose is:

23

 



Ʈ 

J = ԉ/  c is radius of shaft τall is the max allowable shear stress of mild steel = 115 MP a Ʈmax is calculated by using the force and bending moment diagrams on wheel shaft. ԉ   





Ʈ 

ԉ  Ʈ   2  Calculating diameter of wheel shaft:

ԉ  1394.76   2 115∗10 C = 0.0197 m Diameter = 3.94 cm̌ 4cm 4.2. Position analysis of planting mechanism As the planting mechanism is four bar so first of all linkage system is is designed for the required motion of planting mechanism.

The linkages lengths are taken from the literature review which are then changed to the required dimentions for our machine using grashof conditions to analyze the proper motion of four bar mechanism. Which is as follow.

The lengths and known angles are: a = 7cm

ɵ = 0 degrees

b = 19.3cm

ɵ = to be calculate 24

c = 12 cm

ɵ

d = 17.9cm

ɵ = 9 degrees

= to be calculate

Applying the Grashoff conditions The formula is: S + L ≤ Q + P S = length of shortest link L = length of longest link Q and P are lengths of remaining links Putting lengths in above formula 7 + 19.3 ≤ 17.4 + 12 26.3 ≤ 29.4 The above equality is true thus the condition is satisfied which shows that the shortest link will take full rotation and no toggle will occur. Now to formulate the equation of relations between the input ɵ and the output ɵ and ɵ . Equating the vector sum of all linkages in x -axis

 +  =   ̅ = R  ɵ = R cosɵsinɵ Replacing the scalar and vector value of all four links using the above formula.

√ 

 = 2tan− − ±   A= cos    sin   cos  B = -2sin + 2

  

C = cos   sin   cos 

  

Now 25

 

. 

 

. 

  

 −   −  −



√ 

 = 2tan− − ±   A=cos   sin   cos  B = 2sin - 2 C = cos   sin   cos 

  

  

Now

 

. 

 

. 

  

 +   −  + 



The above formulation shows that with any input of  the values of    can be evaluated.

26

CHAPTER 5 Computer Modeling 5.1.

Design of frame: Frame of the machine is the part which will hold all the components of RTP machine. These components include:

1. 2. 3. 4. 5. 6. 7. 8.

Seedlings picking assembly Seedlings planting assembly Tray Assembly Wheel Assembly Engine and engine carrier Floater Handle Conversion shafts with sprockets

5.1.1. CAD Model of Frame: Initial Design:   

Material of frame: Mild Steel Length of frame: 160 cm Width of frame: 50 cm

27

2

7 1

8

3 4 5 6

1. 2. 3. 4. 5. 6. 7. 8.

Figure 7: Initial design of frame

Frame Handle 2x holes for padded wheel shaft, 1 on each side 2x holes for conversion shaft_2, 1 on each side 2x holes for conversion shaft_1, 1 on each side 8x holes for engine carrier, 4 on each sides 4x holes for holding floater, 2 on each sides 2x holes for holding seedling tray support, 1 on each side

28

Finalized Design:

Figure 8: Final design of frame

Following were the changes that were made later on and was finalized to be fabricated: 1. Change in length of the frame:

Length of the frame was reduced from 160 cm to 140 cm, due to following reasons. 1. Removal of conversion shafts due to addition of gear box. 2. To reduce the mass of the machine. 2. Change in Width of the frame: Width of the machine was changed from 50 cm to 65 cm due to following reasons: 1. Requirement of bigger engine carrier due to installment of gear box and clutch assembly to the machine 3. Slots for holding planting arm: Two slots for holding planting arm were created in the rear end of the frame that will hold the planting mechanism of the machine, as shown in figure 8.

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Figure 9: Highlighted slots for holding planting arm

6.1.Design of planting mechanism: 6.1.1. Initial Design: The initial design that we picked for the planting mechanism of the machine comprised of three steps process, which included; Picking of Seedlings from seedling tray, passing the seedlings o the planting arms via picking assembly and planting the seedlings in the rice field. 

Seedlings picking assembly:

Seedling picking assembly comprises primarily of a simple cam and follower mechanism. In which a trajectory upon which gripper will move is used as a cam, while the gripper will function as a follower. A set of forks will be used with the gripper to hold the seedlings in place. Function of seedling picking assembly is to pick the seedlings from the tray and pass them on to the planting arms of the seedling planting assembly.

Figure 10: Initial design of seedling displacement assembly

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

Planting arm Assembly:

Planting arm assembly is the part of the machine that will plant seedlings in to the rice field after picking it from the seedlings picking assembly. This assembly comprises of closed loop four bar mechanism. As our machine is two row planting machine so there are two planting arms that will plant the seedlings into the field.

Figure 11: Initial design of planting arm assembly 

Seedling tray:

Seedlings tray is the part of the machine that will hold the stack of seedlings. Picking arm will then pick the seedlings from the tray and then will carry it to the planting arm to plant them to the ground.

Figure 12: Initial design of seedlings tray

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

Seedling tray support:

It is the support that holds the seedling trays and seedling picking mechanism.

Figure 13: Initial design of seedlings support

6.1.2. Finalized Design: Planting assembly design was entirely changed from three step planting method that included picking the seedlings from try, transferring them to the planting arm via picking arm and planting into the soil via planting arm.

New design is a two-step process that includes picking the seedlings from seedling box and planting them into the soil via planting arms. It removes the need of having a picking arm in the whole mechanism. The reasons for this design change are: 



To avoid breakage of seedlings roots which in a three-step planting method breaks away due to transferring the seedlings from picking to planting arm. Reduction of weight and complexity of the machine while maintaining the workability.

The above mentioned design changes necessitated the changes in following parts:

32



Planting arm assembly:

Figure 14: Final design of planting assembly

1.

Change in Planting arm:

Change in the planting arms design and thus it was carried out accordingly. The new planting arm design details are as under.

1x Set of planting arms  





Material: Mild Steel Max vertical length of arms: 21 cm Distance between arms: 22.2 cm Crank hole dia: 1.5 cm

Connecting link hole dia: 1.5 cm

Figure 15: CAD of planting arm

33

2.

Change in Planting mechanism’s frame:

Design changes in planting mechanism’s frame ar e as under: 1x Planting arm frame  



Material: Mild steel Frame thickness: 0.5 cm Frame width: 18 cm

Max length: 30.6 cm

Figure 16: CAD of ground support

3.

Changes in Seedling carrying assembly:

The seedlings carrying assembly was entirely changed from seedlings carrying tray to seedlings boxes that are triangular at the bottom to allow the passage of desired number of seedlings from the box openings.

Figure 17: back and front perspective view of Seedling box assembly

Following are the design specifications for this assembly. 2x Seedling box 

 

Length: 35 cm 34

Width: 16 cm Depth: 14.5 cm

 



Inclined angle: 65º 2x holes for nuts of 5mm diameter Material: iron

Figure 18: Seedling box

1x seedling box assembly support: 

4x holes, 2 seedling box for 5 mm dia nuts

Figure 19: Finalized CAD of seedling box support

35

5.2. Engine carrier: Engine carrier is the part of the machine that will hold the engine in place.

Figure 20: CAD of engine carrier    

Material: wood Max length: 660 cm Width: 37 cm Height: 50 cm

5.3. Wheel Assembly: 5.3.1. Initial Design: Initially the wheel assembly was designed to work only n the rice field with protruding paddles on the periphery of wheel that will help the machine to move in the muddy rice field. Two wheels are connected together with the help of shaft, which have a sprocket on it, that takes power from engine via chain mechanism to rotate the shaft.

36

Figure 21: Initial design of wheel assembly

5.3.2. Final Design:

Figure 22: Finalized design of wheel assembly

In the final design of the wheel assembly, following changes were made in the wheel and shaft; 



An outer rim was added at the ends of the paddles of the wheel to allow the machine to move on a smooth surface. Two sprockets were added instead of one for the purpose of transferring engine motion to the conversion shaft ahead 37

Details of the design are as follows: Part name and details

Computer model

2x Padded wheels  





Material: Mild Steel Inner rim diameter: 30 cm, Thickness: 2 cm Outer rim diameter: 42 cm, Thickness: 1 cm Number of paddles on each wheel: 13

2x sprockets: 



Small sprocket: o Material: Alloy Steel No. of teeth: 57 o Pitch diameter: o 272.3 Pitch: 0.015 m o Large Sprocket Material: Alloy o Steel o No. of teeth: Pitch diameter: o 272.3 Pitch: 0.015 m o

1x Shaft   

Material: Mild Steel Shaft dia: 3 cm Shaft length: 80 cm

Table 2

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5.4. Floater: Floater is the part of the machine which will help the machine to float smoothly over the rice filed, as the rice field consists largely of muddy water. It will help the machine to remain above the water level at all times.

1

Figure 23: CAD of Floater

1. 4x connecting column with frame Material : Wood Maximum Length: 144.6 cm Width: 65 cm Thickness: 2.4 cm    

39

CHAPTER 6 Analysis 6.1.Motion analysis:

The above motion analyses of the bevel gear shaft shows that the shaft rotates with the constant velocity of 602.5 deg/sec as desired. 6.1.1. Planting arm dynamic:

Figure 24: Planting arm assembly (arrow pointing to shaft)

40

Figure 25: Velocity graph for Planting arm shaft

With the above motion analyses of the planting arm shaft it is confirmed that the shaft rotates with the desired velocity of 1240.6 deg/sec The above motion analyses graph shows the to and fro motion of the seedling boxes with the help of slider joints as the box moves from mean position to the two extreme positions.

41

6.2.

Stress analyses: The yield strength of low carbon steel is 28.2e+006 N/m² 6.2.1. Stress Analyses on Frame:

Figure 26: Stress analyses of frame

Study results: Minimum Stress: 2.53435 N/m 2

Maximum Stress: 6.3178e+006 N/m2

Conclusion: From the CAD results, it is concluded that this part will not fail under the given stresses as the maximum stress are much lower than the yield strength of the part.

42

6.2.2. Displacement Analysis on frame:

Figure 27: Displacement analyses of frame

Study results: Minimum Displacement: 0 mm

Maximum Displacement: 0.0917051 mm

Conclusion: From the CAD results, it is concluded that this part will not carry out any significant deformations according to loading conditions applied.

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6.2.3. Stress Analyses for Floater: Model Reference

Properties Name:

1060 Alloy

Model type:

Linear Elastic Isotropic

Default criterion:

failure

Max von Mises Stress

Yield strength:

2.75742e+007 N/m^2

Tensile strength:

6.89356e+007 N/m^2

Elastic modulus:

6.9e+010 N/m^2

Poisson's ratio:

0.33

Mass density:

2700 kg/m^3

Shear modulus:

2.7e+010 N/m^2

Thermal coefficient:

2.4e-005 /Kelvin

expansion

Table 3

Figure 28: Stress analyses of floater

Study results: Minimum Stress: 6.54482e-008 N/m 2

Maximum Stress: 100265 N/m2

44


6.2.4. Displacement analyses on Floater:

Figure 29: Displacement analyses on Floater




45

6.2.5. Stress Analyses on Wheel Shaft: Model Reference

Properties Name:

1023 Carbon Steel Sheet (SS)

Model type:

Linear Elastic Isotropic

Default failure criterion:


Yield strength:

2.82685e+008 N/m^2

Tensile strength:

4.25e+008 N/m^2

Elastic modulus:

2.05e+011 N/m^2

Poisson's ratio:

0.29

Mass density:

7858 kg/m^3

Shear modulus:

8e+010 N/m^2

Thermal expansion coefficient:

1.2e-005 /Kelvin

Table 4

46

Stress analyses:

Figure 30: Stress analyses on wheel assembly

Study results: Minimum Stress: 1.47848e-008 N/m^2

Maximum Stress: 6.76768e+007 N/m^2


47

6.2.6. Displacement analyses on Wheel Assembly:

Figure 31: Displacement analyses on Wheel Assembly




6.2.7. Stress analyses on rpm conversion shaft: Model Reference

Properties

48

Name:


Model type:

Linear Isotropic



Yield strength:

2.82685e+008 N/m^2

Elastic

Tensile strength:

4.25e+008 N/m^2

Elastic modulus:

2.05e+011 N/m^2

Poisson’s ratio:

0.29

Mass density:

7858 kg/m^3

Shear modulus:

8e+010 N/m^2

Thermal coefficient:

expansion

1.2e-005 /Kelvin

Table 5

Stress analyses:

Figure 32: Stress analyses on rpm conversion shaft

Study results: Minimum Stress: 6260.85 N/m^2



49

6.2.8. Displacement analyses on rpm conversion shaft:

Figure 33: Displacement analyses on rpm conversion shaft

Study results: Minimum Displacement: 3.51493e-007 mm



6.2.9. Stress analyses on planting mechanism ground support: Model Reference

Properties Name:

1023 Carbon Sheet (SS)

Model type:

Linear Isotropic

Default criterion:

50

failure

Steel

Elastic


Yield strength:

2.82685e+008 N/m^2

Tensile strength:

4.25e+008 N/m^2

Elastic modulus:

2.05e+011 N/m^2

Poisson’s ratio:

0.29

Mass density:

7858 kg/m^3

Shear modulus:

8e+010 N/m^2


1.2e-005 /Kelvin

Table 6

Stress analyses:

Figure 34: Stress analyses on planting assembly ground support




51

6.2.10. Displacement analyses on planting mechanism ground support:

Figure 35: Displacement analyses on planting assembly ground support




6.2.11. Stress analyses on Seedling box assembly support: Model Reference

Properties

52

Name:


Model type:

Linear Isotropic


Max von Stress

Yield strength:

2.82685e+008 N/m^2

Tensile strength:

4.25e+008 N/m^2

Elastic modulus:

2.05e+011 N/m^2

Elastic

Mises

Poisson's ratio:

0.29

Mass density:

7858 kg/m^3

Shear modulus:

8e+010 N/m^2


1.2e-005 /Kelvin

Table 7

Stress analyses:

Figure 36: Stress analyses on seedling box support




53

6.2.12. Displacement analyses on seedling box support:

Figure 37: Displacement analyses on seedling box support




54

CHAPTER 7 Manufacturing 7.1.Frame Frame is made by low carbon steel sheet of 2.7mm. Desired shape of frame is obtained by using press and cutting machine. Sheets are then drilled using bench drilling machine. Then parts of frame are weld to give a proper structure to it. 

Cutting and bending

Figure 38: Metal sheets for frame fabrication

55



Gas cutting

Figure 39: Gas cutting for frame



Drilling

Figure 40: Drilling for frame

56



Electric Spark welding

Figure 41: Eclectic spark welding for frame manufacturing

7.2.Floater and engine carrier Floater is made of poplar wood. Saw cutting is done to get desired shape and white glue and nails are used to join all parts of structure.

Figure 42: Fabricated wooden floater

7.3.Seedling box

Seedling boxes are made of iron. Hand tool is used to cut the sheet which is the weld by electric welding. 57

7.4.Seedling box support Seedling box support is made of square pipe of steel. the thickness of sheet is 2.7mm. angle grinder is used to cut the pipe of desired dimensions and electric welding is used to weld the parts. 7.5.Machine handle Machine handle is made of iron circular pipe. Angle grinder is used to cut the parts and then electric welding is done to weld the parts together.

Figure 43; Frame handle

58

7.6.Wheels: Bending, cutting and welding is used in fabricating the wheels.

Figure 44: Rings for fabricating fabricating wheels



Bending:

Figure 45: Bending of rings in to circle 59



Welding:

Figure 46: Welding of rings rings

60

Figure 47: Welding of rings together (top), Welding of bars with wheel rings for support and strengthening (bottom)



Finished Wheel set:

Figure 48: Finished wheel set

61

7.7.Planting Arm Assembly Method of sheet metal cutting, welding and drilling is used in fabricating the whole planting arm assembly.

Figure 49: Fabricated Planting assembly support frame

Figure 50: Fabricated planting arm

62

Figure 51: Fabricated Crank pair for planting arm assembly

Figure 52: Fabrictated link for Planting arm assembly

63

Figure 53: Whole planting arm assembly

7.8.Final Assembly of machine:

64

Figure 54: Final assembly of machine

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CHAPTER 8 Cost Sr. No.

Product

Cost (Rs)

1

Engine

10000

2

Clutch

5500

3

Gear box

7000

4

Frame

1600

5

Seedling box

1000

6

Floater

2300

7

Handle

700

8

Wheels

4000

9

Planting mechanism

1000

10

Engine carrier

600

11

Sprockets

5000

12

Chain

1300

13

Machine Assembly

32000

TOTAL

783000 Table 8

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CHAPTER 9 Visits 9.1.Daska In Daska we first searched for already existing machines for rice transplanting then studied there mechanisms and problems.

Then we searched all the market of sheet metal and sprockets and shafts, we inquired different prices of process like cutting, welding of sheet and manufacturing of sprockets. 9.2.Lahore We went to Lahore to buy engine and clutch for machine, first we surveyed Bilal Ganj market which is the biggest market for car parts. But we didn’t find our required parts their after doing a lot of survey. Then we went to Branth road where we found a huge market of new, imported and locally made engines. We found a shop name SHINGHAI HARDWARES from where we brought an engine of 5 h.p and a clutch assembly which is actually used in engine powered lawn mower machines. 9.3.Rawalpindi In Rawalpindi we first visited National Agricultural Research Center to know about the current work being done on research and planting methods on Rice Transplanting. We met Senior Research Engineer at NARC who gave us valuable information on the subject. He also showed us a Japanese made rice transplanting machine which was modified by NARC to be suitable to work on Pakistani soil. We gathered all the valuable stats and info from this visit.

We needed sheet metals for the planting assembly and material for fabricating wheels of the machine. For this purpose we visited City Saddar Road, checked various sheet metal cutting shops and finally ordered the required material from Shabbir Steels which specializes in “cut to size” job. They made us the required material at very economical rates.

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CHAPTER 10 Conclusion A rice transplanter is a machine that transplants the seedlings of rice in the paddy field from seedling box through planting arm using power of engine. This machine has vast application is Pakistan and Asia. The basic motivation of selecting this project was to solve the problem of farmers in transplanting rice seedlings by providing a facility of fast and economical transplantation. A basic structure was designed using dynamic study, strength of materials, sprocket chain mechanisms, applied and allowable stress analysis. We have used Creo pro and Solidworks software applications for modeling, simulation and stress analysis. Through farms and farm machinery institute visits we were able to understand the problem and work done so far on this machine more deeply and also the methods and techniques used to manufacture agriculture machinery. Fabrication of parts was done using different tools e.g. press machine, grinder, welding plant, lathe, shaper and gas cutter. Choice of material relayed upon the strength required and material available. Cost analysis is done on the basis of CAD model and material selection. Testing will be done in the season of rice plantation.

Recommendation 







Laser leveling of rice field is always recommended before the use of rice transplanting machine. There should be two persons all the times with the machine while it is working in the field, one to operate the machine and other to place seedlings in machine boxes. The machine can be further improved by incorporating automated feedback control systems and actuators to its planting assembly. By incorporating a seat for worker on top of machine and in turn incorporating steering to the machine.

Further recommendations will be given after testing of machine.

68

Design and Fabrication of Engine Powered Two Rows Rice Transplanting Machine

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