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Design & Force Analysis Of Portable Hand Tiller 1
CHAPTER 1
INTRODUCTION
Agriculture in India has a significant history. As Per the 2010 world agriculture
statistics, India is the world's largest producer of many fresh fruits and vegetables, milk,
major spices, select fresh meats, select fibrous crops also.
A report from 2008 claimed India's population is growing faster than its ability to
produce rice and wheat [1]. Other recent studies claim India can easily feed its growing
population, plus produce wheat and rice for global exports, if it can reduce food staple
spoilage, raise its farm productivity.
So in order to raise its productivity more machines must be implemented, to help
small scale farmers hand tillers are introduced. It is a power tool used to prepare the land
for agricultural purpose.
Rotary tiller or rotavator (derived from rotary cultivator) is a tillage
machine designed for preparing land by breaking the soil with the help of rotating blades
suitable for sowing seeds (without overturning of the soil).
Nowadays, utilization of rotary tiller has been increased in agriculture
applications because of simple structure and high efficient for this type of tillage
implement.
A rotary tiller is a specialized mechanical tool used to plough the land by a
series of blades which are used to swirl up the earth. Rotary tillers have become world
famous for preparation of seedbed in filed.
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 2
CHAPTER 2
LITERATURE REVIEW
A hand tiller is a specialized mechanical tool used to Plough the land by a
series of blades which are used to swirl up the earth. Rotary tillers are either self propelled
or drawn as an attachment behind either a two-wheel tractor or four-wheel tractor. Small,
self-propelled rotary tillers are used in domestic gardens. When attached to two-wheel or
four-wheel tractors, rototillers are used on farms. In addition, rotary tillers have been used
to clean the exterior of oilfield pipes and to prepare the ground for road construction.
Rotary tillers have become world famous for preparation of seedbed in
fields. Nowadays, utilization of rotary tillers has been increased in agricultural
applications because of simple structure and high efficiency for this type of tillage
implements.
By taking advantage of rotary tillers, the primary and secondary tillage
applications could be conjugated in one stage. Despite of their high energy consumption,
since rotary tillers have the ability of making several types of tillage applications in one
stage, the total power needed for these equipments is low. Because rotary tillers power is
directly transmitted to the tillage blades, the power transmission efficiency in rotary tillers
is high and so it will be very effective for the farmers
While coming on to the working of the rototiller or hand tiller, it is
typically propelled forward (via 1-5 horsepower petrol engine or .8 - 3.5 kilowatts) by the
rotating tines and do not have powered wheels, though they may have small transport/level
control wheel(s). To keep the machine from moving forward too fast, an adjustable tine is
usually fixed just behind the blades so that through friction with deeper un-tilled soil, it
acts as a brake, slowing the machine and allowing it to pulverize the soils.
The slower a rototiller moves forward, the more soil tilts can be obtained.
The operator can control the amount of friction/braking action by raising and lowering the
handlebars of the tillers [2].
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 3
2.1 STUDIES ON AVAILABLE TILLERS
Before going in to the design of a new tiller we had a thorough study on presently
available hand tillers and then also learn about the its advantages and disadvantages. Some
of the tillers that we gone through are
1. HONDA F 400 [3]
2. HONDA FG 110 [4]
3. EARTHQUAKE MC 43 MINI CULTIVATOR [5]
We had gone through different hand tillers as mentioned above. Specification and
diagram of HondaF400 is discussed below.
2.1.1 Honda F400
The product figure with parts mentioned is given below [3]
1. Throttle Lever 2. Handlebar Column3. Fuel Tank Cap4. Muffler5. Engine Oil Filler Cap6. Engine Oil Drain Plug7. Handlebar8. Ignition Switch9. Clutch Lever And Lock10. Handlebar Clamp Lever11. Shift Lever.12. V-Belt Cover13. Tine Assy
Fig 2.1 (Component Identification)
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 4
2.1.2 Cutting operation and installation of blade in Honda F400 is dhjhj
fshjd discussed in their official manual is explained in fig 2.2 [3]
1. Install the tine assembly on each axle with the cutting edges facing in the direction
of rotation
2. Align the tine assembly so that the tine on each side contact the soil
simultaneously; otherwise the tiller may yaw.
3. Insert the wheel pins through holes in the axles, and install snap pins to secure tine
assemblies.
Depending on the width of the crop rows and soil condition, the number of the tine blades
can be changed one or two on each side. Always have the same number of blades on each
side.
Fig 2.2(Tine Installation)
2.1.3 Handling Tips
Adjust the handlebar height to a comfortable
Position
Should the machine jerk forward while tilling,
press down on the handlebar
If the machine willnot move forward move the
handlebar from side to saide.
Turn: the proper method of negotiating a turn
during a tilling operation is to lower the handlebar
to bring the weight towards the rear and then make
the tue
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 5
Fig 2.3 (Handling Tips)
2.1.4 SPECIFICATIONS
Displacement 144cc
Maximum output 3.5HP/4000rpm
Maximum torque 66.0Kg-cm
Clutches Manual V-belt
Dimensions 54.7 X 23.2 X 35.4 in
Transmission Belt
Tab 2.1 (Specifications)
Drawbacks of available tillers
1. Difficult to carry forward the tiller if the transport wheel is located behind the
blade(while tilling)
2. If both wheels and blades are mounted on same shaft, its not possible to control the
till depth manually
3. The engine is mounted near to the operator more weight is distributed to the
operators hand
4. Also operator is exposed to more noise and pollution
5. The power is distributed to control wheel too more fuel consumption and energy
wastage occurs
2.2. Tiller blades
Tiller blades or rotavator are mostly available in the size of 1.20 – 1.80 m working
width and which is suitable for tractors having 45 hp and above. Further, rotavator may
have ‘L’ shape, ‘C’ shape, ‘J’ shape, hook tines and straight knife Blades to suit various
operating conditions (Fig. 1). Generally, L-shaped blades are used in Indian rotavator. The
work quality by using a rotavator not only depends on design parameters but rotor blade
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 6
layout, speed of rotors, forward speed etc. which are significantly affects the machine
performance [5].
Depending on the soil conditions, blade geometry and velocity ratio, the
interference of the backside of the blade and the uncut soil may result in severe soil
compaction and high power consumption. This is the main reason to cause vibrations,
which are a result of the reaction of soil upon the tiller blades.
The proper design of the rotary tiller blades is essential to efficient operation. The
matrix equations for describing the motion of the blade of rotary tiller were described
which demonstrated that energy consumption in rotary tillage can be decreased through
improved blade design. In maize and spring barley production systems in combination
with a chisel plow, rotary tillers have been found to have high energy requirements, but
rotary tilling is more effective in saving labor compared to conventional tillage systems.
The continuous fluctuating impact of soil crust / clods / stone develops high stress
areas on blade tip or blade critical edges. A rotavator has a useful life of 2400 h (8 year)
with annual use hour as 300.The local blades need replacement after 80-200 h of their use;
however, imported blades need replacement after 300-350 h in normal soil. It is estimated
that around 5 lakh blades are required annually towards replacement and for new
machines. 533 Proceedings of the 1st International and 16th National Conference on
Machines and Mechanisms (iNaCoMM2013), IIT Roorkee, India, Dec 18-20 2013.
Therefore, proper design of these blades is necessary in order to increase their working life
time and reduce the farming costs.
In India, because of variety of soil conditions in different regions, different blades
are used, but most of the blades faces similar problem like high rate of wear which
ultimately reducing the service life/working life. Working life time of the blades can be
increased by a suitable design according to the soil type and soil condition [5]. Standard
tiller blades are available in the market, all variety blades with longer life are readily
available [6]
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 7
CHAPTER 3
DESIGN
3.1 DESIGN BASICS
Machine design is creation of plans for machine to perform the desired
functions. The machine may be entirely new in concept of performing new type of work or
it may perform more economically work that can be done by existing machine. It may be
an improvement or enlargement of an existing machine for better economy and capability.
Machine design is defined as the use of scientific principles, technical information and
imagination in the description of a machine or a mechanical system to perform specific
function with maximum economy and efficiency. This definition of machine design
contains following important features [7]:
1. A design uses principles of basic and engineering sciences such as physics,
mathematics, statics and dynamics, thermodynamics and heat transfer, vibration
and fluid mechanics. Some of the examples of these principles are,
(1) Newton’s law of motion,
(2) D’Alembert’s principle,
(3) Boyle’s and Charles Law of gases,
(4) Carnot cycle and ,
(5) Bernoulli’s principle.
2. The designer has technical information of the basic elements of a machine. These
elements include fastening devices, chain, belt and gear drives, bearings, oil seals
and gaskets, springs, shaft, keys, couplings and so on. A machine is a combination
of these basic elements. The designer knows the relative advantages and
disadvantages of these basic elements and their suitability in a particular
application.
3. The designer uses his skill and imagination to produce a configuration which is a
combination of these basic elements. However, these combinations are unique and
different in different situations. This intellectual part of selection of proper
configuration is creative in nature.
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 8
4. The final outcome of design process consists of description of the machine. The
description is in the form of drawing of assembling and individual components
5. A design is created to satisfy a recognized need of the customer. The need may be
perform a specific function with maximum economy and efficiency.
Machine design establishes and designs solutions and pertinent structures for problems
not solved before and provided new solution to problems that have previously been solved
in different way. Design should not be confused with the word `Discovery`. Discovery
means getting the first sight of, or the first knowledge of something [7].
Tab 3.1 (Design procedure)
Dept. of Mechanical Engg, AWH. Engg College
Market Survey
Define Specifications of Products
Study Alternative Mechanisms for Productsand
Select Proper Mechanism
Design Individual Componentsand
Select Joining Methodsbetween
Individual Components of Products
Prepare Assembly and Detail Drawingsand
Modify Drawings after Testing Proto type Modals
Design & Force Analysis of Portable Hand Tiller 9
3.2 MECHANISM
3.2.1 Power transmission
Mainly two types of mechanism are used for transmitting power and they are
chain driven and belt driven mechanism and in our project we selected belt driven
mechanism.
Advantages of belt driven mechanism over chain
• It can absorb a good amount of shock and vibration.
• It can take care of some degree of misalignment between the driven and the
driver pulleys
• Long distance power transmission
• Extra lubrication is not necessary
• Better exposure to dust moisture than chain
Elements in the power transmission mechanism
Fig 3.1(Elements in the Mechanism)
3.2.2 Cutting mechanism in hand tiller
The cutting mechanism for a tiller includes rotating cutting knives, usually two
in number or more, which rotate at very high speeds in a Substantially horizontal plane,
the inclination of which may, however, be slightly varied as desired. Preferably, the cutters
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 10
are disposed on substantially vertical axes which are slightly offset with respect to each
other in the forward direction of travel and which are otherwise disposed so that the path
of movement of the ends of the blades overlap in the bight there between. Such a cutting
mechanism, with its rotating velocity cutters, includes a supporting frame arrangement
preferably adapted for attachment to the front end of the tractor or other propelling vehicle
so as to lead the same in the cutting operation, although the cutting mechanism may be
mounted underneath the tractor in certain instances as will be hereinafter pointed out [8].
Fig 3.2 (cutting mechanism)
L-type blades showing methods of mounting and cutting action
3.3 Designing of individual components
By using the AutoCAD software we had done the designing of major
components. Explanations and details on each component are as follows.
3.3.1 Driven Shaft
This is the shaft to which the driven pulley is connected and all the blades are
mounted so with the help of the driven pulley this shaft is rotated and thus tilling happens.
The geometrical view of the shaft is shown in fig 3.1.
Material: Alloy Steel
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Design & Force Analysis of Portable Hand Tiller 11
The material for making the Driven Shaft is selected as Alloy Steel. Alloy
steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and
50% by weight to improve its mechanical properties [9].
The following is a range of improved properties in Alloy steels
• Strength
• Hardness
• Toughness
• Wear resistance
• Corrosion resistance
• Hardenability
• Hot hardness.
To achieve some of these improved properties the metal may require heat treating.
Determining the geometry is complicated part in designing.
Geometry will directly effect on the performance and reliability of the product.
some of the reasons for choosing this geometry are as follows
Length of the minimum dia of the shaft is 240mm, this space is provided to
accommodate the blade assembly and the Plummer block, and thus we get a till width of
max 10inch (the 10 inch dimension is choose because from the market survey we could
conclude that the mostly preferred tilling width by the farmer is 8-10inch and most of the
machine comes with the same too) and
The length of the bigger dia of the shaft is 140mm; this is provided for
accommodating driven pulley plus working clearance. The diameter of the shaft is chosen
from the force analysis and its further details are explained in chapter 4.1
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Design & Force Analysis of Portable Hand Tiller 12
CALCULATION
P = 2Πnt [14]
60*100
P = power in watts
N = speed in rpm
T = torque Nmm
N = 588rpm
P =1.5 HP=1119W
T = 1119*60*1000 = 18182Nmm
2π588
1/3
D =
Ss = stress of shaft N/mm2 D = diameter of shaft mm Fos =2
Ss =55N/mm2 [14]
=
Dept. of Mechanical Engg, AWH. Engg College
16*TπSs
16*18182 π*55/2
Design & Force Analysis of Portable Hand Tiller 13
= 18.2 mm
Std: diameter = 20mm [14]
Fig 3.3 (Driven Shaft)
Material Properties
Name Alloy Steel
Model type Linear Elastic Isotropic
Yield strength 6.20422e+008N/m^2
Tensile strength 7.23826e+008N/m^2
Elastic modulus 2.1e+011N/m^2
Poisson’s ratio 0.28
Mass density 7700kg/m^3
Shear modulus 7.9e+010N/m^2
Thermal expansion coeff 1.3e-005/ Kelvin
Tab 3.2(material properties driven shaft)
3.3.2 Wheel Shaft
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Design & Force Analysis of Portable Hand Tiller 14
This is the shaft on which the transport wheel is mounted this shaft should
withstand the total weight of the tiller because while moving the tiller from one place to
other the complete load will be concentrating on to the shaft. So the confirmation of the
maximum load that the shaft can with stand is found out by using force analysis and its
details are listed below. The detailed drawing is shown in fig 3.2.
Material: Plain Carbon Steel
Material selected for making wheel shaft is plain carbon steel, carbon steel are
most widely used steel. The properties of carbon steel depend Primarily on carbon it
contains. Plain carbon steel is a type of steel having a maximum carbon content of 1.5%
along with a small percentage of silicon, magnesium, sulpher and phosphorus.
Generally with an increase in the carbon 0.01 to 1.5% in the alloy its strength
and hardness increase but still such an increase beyond 1.5% cause appreciable reduction I
malleability and ductility of steel [10].
General effects of alloying elements are
• Improves tensile strength
• Improves harden ability
• I mproves toughness
• Improves wear resistance
• Improves abrasion resistance
The geometry of the fixed shaft is chosen with respect to the inner diameter of
the wheel to be mounted on, the length is selected in such a way that it can hold on the
frame rigidly and also it can accommodate the wheel and its working clearance. The force
analysis on the same is done and its further details are explained in chapter 4.2
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Design & Force Analysis of Portable Hand Tiller 15
Fig 3.4 (Wheel Shaft)
Material Properties
Name Plain Carbon Steel
Model type Linear Elastic Isotropic
Yield strength 2.2059e+008N/m^2
Tensile strength 3.99826e+008N/m^2
Elastic modulus 2.1e+011N/m^2
Poisson’s ratio 0.28
Mass density 7800kg/m^3
Shear modulus 7.9e+010N/m^2
Thermal expansion coeff 1.3e-005/ Kelvin
Tab 3.3(material properties of wheel shaft)
3.3.3 Blade
Tiller blades are available in different shapes and size depending up on the soil
and tilling requirements, in our design we selected the ‘L’ type(generally, L-shape are
used because of the soil physics ) and its geometrical drawing is available below. In case
of damage the blades can replace easily by removing the nut and bolts. The detailed
drawing is shown in fig 3.3.
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 16
Material: Boron Steel
The material for making the Driven Shaft is selected as Boron Steels . it’s the
commonly used material for the manufacturing of blade [11].
Characteristics of Boron steels
• Potential savings on raw material costs. Particularly significant where a medium
carbon alloy steel is being replaced
• Lower as-delivered hardness giving improved blanking tool life
• Inclusion control for good cold formability
• Reproducible harden ability ensuring consistency of the end product
• Good harden ability encouraging minimal distortion after heat treatment
• Water quenching can be used for certain grades and applications
• Good case hardening response with consistent, reproducible properties
• Lower tempering temperatures used, giving savings on energy costs
• Tempering treatments may be incorporated into paint curing processes for
some applications
• Increased toughness for equivalent hardness compared to traditional carbon
steels
• Improved weld ability through low carbon equivalent.
The geometry of the plate on which the blades are mounted is determined by
considering the pitch and margin dimensions and also one plate can accommodate four
blades. The inner hole diameter is same to that of the shaft minimum diameter (different
type of blades can be used, here used blade is L type and is readily available in the market)
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Design & Force Analysis of Portable Hand Tiller 17
Fig 3.5 (Blade)
3.3.4 Driver & Driven Pulley
The driving pulley is called the Driver, and the driven pulley the Driven. The
fig 3.6.a is the drive pulley here the power from the driver is transmitted to the driven
pulley using belt drive. The fig 3.6.b shows the driver pulley. The power transmission is
by belt derive because it is very cheap, reliable and low maintenance too
Material: Cast Iron
Cast iron is iron or a ferrous alloy which has been heated until it liquefies, and is
then poured into a mould to solidify. It is usually made from iron. The alloy
Constituents affect its color when fractured. whitecast iron has carbide impurities which
allow cracks to pass straight through. Grey cast iron has graphite flakes which deflect a
passing crack and initiate countless new cracks as the material breaks [12].
General properties of cast iron are as follows
• Compressive strength
• Shock resistance
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 18
• Tensile strength
• Brittle
• Castability
• Resistance to distortion
• Good strength and density
Driver pulley
Fig 3.6.a (Driver Pulley)
Driven Pulley
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 19
Fig 3.6.b (Driven Pulley)
3.3.5 Structure
Structure is the biggest component among the design and it is on to which all the
elements are mounted and fastened. The handle of the structure can be adjusted depending
on the worker needs.
Material: Galvanized Iron Pipe
The material for making the structure is selected as GI pipe because it is
• More Strong
• Good Welding Property
• Corrosion Resistant
• Light In Weight
• Good Surface Finish
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 20
The width of the structure is the length of the shaft plus clearance i.e. 700mm and
the height from the ground to the handle is adjustable from a minimum of 520 and to a
maximum of 900mm , depending up on the worker i.e. they can manually adjust the height
to their needs. Fig 3.5 shows the Structure.
Figure 3.7 (Structure)
3.4 SLECTION OF JOINIGN METHODES
A proper brain storming must be done before selecting the joining methods
because the machine will not be able to with stand the force acting upon it. Also correct
tightness of fit must be provided in correct areas otherwise it may lead to scoring and
jamming of different elements of the machine. Here in this tiller the frame is made pipe
bending and welding and the other parts of the tiller are mounted using the Plummer block
nut, bots, etc, on looking in to the final cad assembled view the methods of joining can be
easily understood. The two pulleys ie the driven pulley and the driven pulleys are
connected each other using the belt drive mechanism [7].
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 21
Chapter 4
ANALYSIS
4.1 Software used
Solid Works is solid modeling CAD (computer-aided design) software that
runs on Microsoft Windows and is produced by Dassault Systèmes SolidWorks Corp, a
subsidiary of Dassault Systèms. SolidWorks is currently used by over 2 million
engineers and designers at more than 165,000 companies worldwide. SolidWorks is
a Parasolid-based solid modeler, and utilizes a parametric feature-based approach to create
models and assemblies.
Parameters refer to constraints whose values determine the shape or geometry of
the model or assembly. Parameters can be either numeric parameters, such as line lengths
or circle diameters, or geometric parameters, such as tangent, parallel, concentric,
horizontal or vertical, etc. Solidworks integrates easy to use analysis tools with design to
verify operations and performance during product development. Solidworks design
analysis increases product innovation by reducing risk in design, significantly reduces the
number of physical prototype needed, and helps lower material and other costs.
SOLIDWORKS simulation technology ensures the quality and performance of the
design before we commit to production. Comprehensive analysis tools let us test models
digitally for valuable insight early in the design process. With the information you
develop, we can easily determine methods to reduce weight and material costs, improve
durability and manufacturability, optimize margins, and compare design alternatives to
best meet specific customer requirements [13].
Some of the advantages of solid work stimulations are
• Easy to Learn, Easy to Master
• Provides Powerful Insight
• Eliminates Prototypes, Sparks Innovation
• Enables Clear Communication
• Optimized for Speed and Accuracy
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Design & Force Analysis of Portable Hand Tiller 22
4.2 Analysis of components
Here we had done the force analysis of the components with the help of a
software (solidworks).
4.2.1 Driven shaft
The maximum working safe load acting up on the shaft is 100 N and the
analysis of this load acting on the driven shaft is done using solid works (Software) and its
effects are shown below (here in working condition the maximum load that will act on the
shaft will be 50-80 , but considering the Factor of Safety we took 100N load)
Fig 4.1(driven shaft-analysis)
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Design & Force Analysis of Portable Hand Tiller 23
Material Properties
Name Alloy Steel
Model type Linear Elastic Isotropic
Yield strength 6.20422e+008N/m^2
Tensile strength 7.23826e+008N/m^2
Elastic modulus 2.1e+011N/m^2
Poisson’s ratio 0.28
Mass density 7700kg/m^3
Shear modulus 7.9e+010N/m^2
Thermal expansion coeff 1.3e-005/ Kelvin
Tab 4.1(driven shaft material properties)
Mesh Information
Mesh type Solid Mesh
Mesher Used: Curvature based mesh
Jacobian points 4 Points
Maximum element size 6.88933 mm
Minimum element size 6.88933 mm
Mesh Quality High
Total Nodes 13169
Total Elements 8073
Tab 4.2 (driven shaft mesh information)
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Design & Force Analysis of Portable Hand Tiller 24
Fig 4.2 (driven shaft mesh drawing)
Study Result
Name : Stress
Type of load : Static
Min : 4.24883e-006N/m^2 Node: 8933
Max : 1.25076e+006N/m^2 Node: 4325
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Design & Force Analysis of Portable Hand Tiller 25
Fig 4.3(driven shaft: stress-analysis result)
Name : Displacement
Type of load : Static
Min : 1.94732e-012mm, Node: 46
Max : 0.00017209mm, Node: 4467
Fig 4.4 (driven shaft: displacement- analysis result)
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 26
Name : Strain
Type : Equivalent Strain
Min : 1.5365e-017, Element: 5105
Max : 3.26318e-006, Element: 1982
Fig 4.5(driven shaft: strain-analysis result)
Force Analysis Comments:
The Fixed shaft doesn’t fail on the given Conditions
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 27
4.2.2 Wheel shaft
Fig 4.6 (fixed shaft-analysis)
Material Properties
Name Plain Carbon Steel
Model type Linear Elastic Isotropic
Yield strength 2.2059e+008N/m^2
Tensile strength 3.99826e+008N/m^2
Elastic modulus 2.1e+011N/m^2
Poisson’s ratio 0.28
Mass density 7800kg/m^3
Shear modulus 7.9e+010N/m^2
Thermal expansion coeff 1.3e-005/ Kelvin
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 28
Table 4.3 (fixed shaft-material properties)
Mesh Information
Mesh type Solid Mesh
Mesher Used: Curvature based mesh
Jacobian points 4 Points
Maximum element size 3.35422 mm
Minimum element size 3.35422 mm
Mesh Quality High
Total Nodes 13053
Total Elements 8502
Table 4.4(fixed shaft-mesh information)
Figure 4.7(fixed shaft-mesh drawing)
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 29
Study Result
Name: Stress
Type of load: Static
Min: 4191.35N/m^2 Node: 1977
Max: 3.97116e+007N/m^2 Node: 2413
Fig 4.8(fixed shaft: stress-analysis)
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Design & Force Analysis of Portable Hand Tiller 30
Name: Displacement
Type of load: Static
Min: 0mm, Node: 38
Max: 0.00446072mm, Node: 3212
Figure 4.9 (fixed shaft: displacement-analysis)
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 31
Name : Strain
Type : Equivalent Strain
Min : 3.66609e-008, Element: 1849
Max : 0.00013675, Element: 2313
Fig 14.10(fixed shaft: strain-analysis)
Force Analysis Comments:
The Fixed shaft doesn’t fail on the given Conditions
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 32
CHAPTER 5
ASSEMBLY
5.1 MAIN ASSEMBLY
The drawing is done using the auto cad software. Fig 5.1.a shows the
cad drawing with the safety guards and Fig 5.1.b shows the cad drawing
without safety guard.
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 33
Fig 5.1.a (with safety guard)
Fig 5.1.b (without safety guard)
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Design & Force Analysis of Portable Hand Tiller 34
5.2 Driven Shaft Assembly
The fig 5.1 shows the Driven shaft Assembly where the Tilling blade,
Plummer block, Main Pulley and Driven shaft are assembled together. This is
the major assembled part of this Tiller.
Fig 5.2 (Driven Shaft Assembly)
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Design & Force Analysis of Portable Hand Tiller 35
5.3 Main Assembly
The fig 5.2 shows the main assembly where we can see all the
assembled parts from the top side view
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Design & Force Analysis of Portable Hand Tiller 36
Fig 5.3 (Main Assembly-top view)
CHAPTER 6
ADVANTAGES
1. Easy to carry forward the tiller as the transport wheel is located in front of the
blade(while tilling)
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 37
2. As wheels and blades are mounted on different shaft, it is possible to control the
till depth manually
3. The engine is mounted away from the operator so less weight is distributed to the
operators hand
4. Also operator is not exposed to more noise and pollution
5. As power is not distributed to control wheel too more fuel consumption and
energy wastage occurrence is avoided
6. As only one wheel available it is very easy to carry through narrow space
7. This design is more efficient and low cost
8. In case of any wear and tear of blade it can be easily replaced
CHAPTER 7
APPLICATIONS
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 38
Some of the major applications of the hand tiller are as follows
Weeding
Tilling
Furrowing
Soil preparation for Vegetable cultivation and orchards & Sugarcane
fields
Spade work in coconut groves
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 39
CHAPTER 8
MAINTENANCE AND SAFETY
A rotary tiller needs to be operated and maintained with proper care. It is important to
avoid contact with the rotating tines, as they can cause serious injury. By standers,
especially children, should be kept at a safe distance. Tree stumps, large roots, and rocks
should be cleared out before using the tiller, as the tines could catch on such objects and
cause the tiller to "jump" out of control.
Given that a rotary tiller digs up the soil, its engine oil and filter need to be
changed regularly. The recommended interval for oil changes is at least once a year or
after 50 hours of use, or more often if the oil appears dirty. In addition, the air filter needs
to be cleaned or replaced often, and the tines and housing should be washed after each use
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 40
CHAPTER 9
CONCLUSION & FUTURE SCOPE
CONCLUSION
We were able to successfully complete the design of the hand tiller. While
designing the hand tiller we came across various tiller blades and various tiller designs its
drawbacks, advantages etc. we also learned about the importance of preparing the land
before tilling.
FUTURE SCOPE
• Fabrication of a tiller made of light metal will give better results.
• By electrifying the power source more results can be brought.
• If we could utilize solar energy as source with minimum cost and maintenance,
then we could reduce the pollution and cost of farming
Dept. of Mechanical Engg, AWH. Engg College
Design & Force Analysis of Portable Hand Tiller 41
Chapter 9
REFERENCES
1. Staff, India Brand Equity Foundation Agriculture and Food in India Accessed 7
May 2013
2. www.parentpacth.com/gardening-tools-about-the-hand-tiller
3. Honda-F400 user manual from http://www.allotment-
garden.org/rotovator/manuals/Honda-F400-tiller-manual.pdf
4. A study about Honda tiller fg110 from
http://powerequipment.honda.com/tillers/models/fg110
5. Study about mini cultivator from
http://www.getearthquake.com/foundations/store/shopdetail.asp?
params=MC43E*89**Mini_Cultivator_-_Gas-
Powered_Weeding_Tool_with_Electric_Start
6. http://dir.indiamart.com/impcat/power-tiller.html
7. A Textbook of Machine Design by R.S.KHURMI AND J.K.GUPTA, S. Chand
Publications ,since 1980
8. Tractor mounted rotary disc cutting assembly by Lilliston Implement Company,
Dec 17, 1957
9. Foundation of material science and engineering(4th edition) by smith William and
hashemi javad
10. C lassification of Carbon and Low-Alloy Steels
11. www.tatstssleurope.com
12. John Gloag and Derek Bridgwater, A History of Cast Iron in Architecture, Allen
and Unwin, London (1948)13. Review about solidworks from http://www.solidworks.com/
14. Design data handbook by S Md. Jalaludheen , Anuradha Publications
Dept. of Mechanical Engg, AWH. Engg College
Recommended