1

A

Minor Project Report on

Fabrication of Lawn Mower

Submitted to

RAJIV GANDHI PROUDYOGIKI VISHWAVIDHYALAYA

BHOPAL (M.P.)

In Partial fulfillment for the award of degree of

BACHELOR OF ENGINEERING

IN

MECHANICAL ENGINEERING

By

Ashwani Dixit, 0714CS111017

Karan Singh Rathore, 0714ME111053

Under the Guidance of

Mr. Ankur Dave

Assistant Professor

MAHAKAL INSTITUTE OF TECHNOLOGY & MANAGEMENT,

UJJAIN

2

FABRICATION OF LAWN MOWER

Ashwani Dixit

Karan Singh Rathore

MAHAKAL INSTITUTE OF TECHNOLOGY & MANAGEMENT, UJJAIN

3

ABSTRACT

The design objective is to come up with a mower that is portable, durable, easy to operate and maintain. It also aims to design a self- powered mower of electrical source; a cordless electric lawn mower. The heart of the machine is a battery-powered DC electric motor. It comprises of a system of speed multiplication pulleys which drive the cutting blades and the charging unit comprising of a 12V alternator and a lift mechanism meant to alter the height of cut. This is achieved by means of a system of pulleys with minimal slip effect; collapsible blades to reduce the common problem of wear. The use of collapsible blades and incorporation of an alternator for recharging the battery make the design unique such that no engine is involved. Performance test gave a cutting efficiency of 89.55% with 0.24kN human effort. Thus, the machine is considered highly efficient and is readily adaptable to different cutting conditions.

KEYWORDS

Lawn

Mower

Electric Motor

Battery

4

Declaration

We hereby declare that the project entitled FABRICATION OF LAWN MOWER

is the actual work carried out by us in the department of MECHANICAL

ENGINEERING under the guidance of Mr. ANKUR DAVE, Asst. Professor.

Name Enrollment Number Signature

Ashwani Dixit 0714CS111017

Karan Singh Rathore 0714ME111053

5

CERTIFICATE

This is to certify that the project entitled FABRICATION OF LAWN MOWER

has been carried out by Ashwani Dixit with 0714CS111017 & Karan Singh

Rathore with 0714ME111053 under my guidance in partial fulfillment for the

award of BACHELOR OF ENGINEERING in MECHANICAL by the Rajiv

Gandhi Technical University, Bhopal (M.P.), during the academic year 2014-

15.

Prof. Bharat Chede Mr. Ankur Dave

Head Project Guide

Department of Mechanical Engineering Asst. Professor

6

ACKNOWLEDGEMENT

First and foremost, I would like to express my highest appreciation to my

supportive academic professor, Mr. Ankur Dave. His supervision and support

that gave me truly helps during the period of conducting my project. His never-

ending supply of valuable advice and guidance has enlightens me and deeply

engraved in my mind. Next, I would like to dedicate my thankfulness to him, for

his enthusiastic support and supervision of the thesis revision. I’m also happy

to present my gratefully acknowledge to Machinery laboratory technicians, who

has been so warmth and kind to provide sincere assistance and good

cooperation during this period. Their co-operation is much indeed appreciated.

In addition, I would like to convey thanks to lecturers, for their assistance, which

really spends their time to teach me a lots of knowledge regarding to the design

development. Last but not least, I would like to state my appreciation to the

staff – Faculty of Mechanical Engineering, my friend and colleagues for

supporting me and administration department for their help in the project .

Thank you!!!

7

Contents

Chapter 1:- Introduction………………………………………………………………………………………. 1

Chapter 2:- Literature Review ……………………………………………………………………………4 - 12

2.1 History ……………………………………………………………………………………..…4

2.2 Further Improvements ………………………………………………………………..…...7

2.3 Types of Lawn Mower ……………………………………………………………..……11

2.3.1 Cylinder or Reel Mower …………………………………………………..…….11

2.3.2 Rotary Mowers …………………………………………………………….……..11

2.3.3 Gasoline (Petrol) …………………………………………………………..…….11

2.3.4 Electricity ………………………………………………………………………….12

Chapter 3:- Material and Methods …………………………………………………………………….13 - 21

3.1 Materials ……………………………………………………………………………………13

3.1.1 Blade ……………………………………………………………………………..…13

3.1.2 Body Frame ………………………………………………………………………..13

3.1.3 Wheel ……………………………………………………………………………….14

3.1.4 Push Handle …………………………………………………………………….…14

3.1.5 Motor ………………………………………………………………………………..15

3.1.6 Bag ………………………………………………………………………………….15

3.1.7 Battery ……………………………………………………………………………...15

3.2 Specifications ……………………………………………………………………………...16

3.3 Methodology Adopted for Assembling of Lawn Mower………………………….…17

3.4 Technical Specifications …………………………………………………………….…..18

3.5 Method of Use ……………………………………………………………………….…….18

3.5.1 Starting ………………………………………………………………………..…….18

3.5.2 Moving ……………………………………………………………………………....19

3.5.3 Area of cut (Battery Duration) ………………………….............…………..….19

3.5.4 Setting the cutter depth ……………………………………………………..…...19

3.5.5 Charging the battery ………………………………………………………...……19

3.5.6 Maintenance ………………………………………………………………………..20

3.5.7 Replacing the Cutting Blade …………………………………………………….20

3.5.8 Replacing Fuses …………………………………………………………………..20

3.5.9 Cleaning Blades ……………………………………………………………….…..21

3.5.10 Dispose of Batteries ……………………………………………………...………21

3.5.11 Dispose – Recycling …………………………………………………...…………21

Chapter 4 :- Results and Discussions……………………………………………………………………….22

References ……………………………………………………………………………………………………….23

8

Chapter 1

INTRODUCTION

A lawn mower is a machine that uses one or more revolving blades to cut

a lawn to an even height. The blades may be powered either by hand pushing

the mower forward to operate the mechanical blade(s), or may have an electric

motor or an internal combustion engine to spin their blades. Some mowers also

include other abilities, like mulching or collecting their clippings.

An electrical Lawn Mower is more suitable & easy to use than the lawn mower

with an engine, so we are making an electrical lawn mower with an electric

motor, which is providing the high speed rotation to the blades. Cordless electric

mowers are powered by a variable number (typically 1-2) of 12-volt

rechargeable batteries. Typically, more batteries mean more run time and/or

power. Batteries can be in the interior of the lawn mower or on the outside. If

on the outside, the depleted batteries can be quickly swapped with recharged

batteries. Cordless mowers have the maneuverability of a gasoline powered

mower and the environmental friendliness of a corded electric mower.

(Fig. 1): A typical Modern Battery Powered Lawn Mower

9

The design of an electrical lawn mower contents a blades, bed knife, body

frame, wheels, push handle, bag, & motor. The power system there are many

Options, but we are using rechargeable battery powered motor, which is

attached to the cutting blades. Sizing the battery will depend on what we are

powering, specifically the motors. Like batteries, there is a range of motors to

choose from. We went with 24 volt motor with integrated gear heads.

(Fig. 2)

Electrical Circuite Diagrame of the Lawn Mower

Lawn mower are very common in an open area. Even when left unattended for

a few days grass, weeds and wild shrubs cover the ground. A lot of grass cutter

machines are available in market for cutting grass but these machines are not

able to cut thick shrubs. Therefore these shrubs have to be cut manually or by

using some special machines like brush cutters. In this work to revamp an

existing setup. Various shortcomings of the machine were carefully examined

and machine was customized to meet the requirements of a shrub cutter

machine.[1]

The electrical circuit of a lawn mower, which are shown in the fig. 2. In this

Circuit diagram the battery connected to the motor by an alternator.

Cutter deck housing — This houses the blade and the drive system of the

mower. It is shaped to effectively eject the grass clippings from the mower.

10

Blade mounting and drive system — The blade of a rotary mower is usually

mounted directly to the motor shaft.

Mower blade — A rotary mower generally has two blades that rotates

horizontally. The blade features edges that slightly curved up to generate a

continuous air flow as the blade rotates, thus creating a sucking and tearing

action. [1]

11

Chapter 2

LITERATURE REVIEW

A lawn mower, alternatively spelled lawn mower, is a device which by mean of

one or more revolving blades is used to cut grass or other plants to an even

length. Lawn mower employing a blade that’s rotate about a vertical axis are

known as rotary mowers, while those employing a blade assembly that’ rotate

about a horizontal axis are known as cylinder or reel mowers. Many difference

design have been made each suited to a particular purpose. The smallest

types, pushed by a human, are suitable for small residential lawns. And

gardens, while larger, self- contained, ride on mowers are suited for large

lawns, and the largest multi speed mowers pulled behind a tractor are design

for large expanses of grass such as golf courses and municipal parks. [2]

2.1 History

The first Lawn mower was invented by English engineer Edwin Beard Budding

in 1827. Budding’s mower was designed primarily to cut the lawn on sports

grounds & expensive gardens as a superior alternative to the scythe. His patent

of 25 October 1830 described “a new combination and application of machinery

for the purpose of cropping or shearing the vegetable surfaces of lawns, grass

plates and pleasure ground. The patent went to state. “Country gentlemen may

find in using my machines themselves an amusing, useful and healthy

exercise”. It took ten more years and further innovations to create a machine

1that could be worked by donkey or horse power & 60 years before a steam

powered lawn mower was build. In an agreement between John Ferrabee and

Edwin Budding dated May 18, 1830, Ferrabee paid the cost of development,

12

obtained latters of patent and acquired right to manufacture, sell and licensed

to other manufacturers in the production of lawn mowers.

Manufacture of lawn mowers began in the 1850s. By 1862, Farage’s company

was making eight models in various roller sizes up to 900 mm (36inches). He

manufactured over 5000 machines until production ceased in 1863. Thomas

green produced the first chain driven mower in 1859, named the Silence Mess

ore. On May 9, 1899, an improved cylinder mower was patented in U.S. patent

624, 749, with the wheel placement altered for better performance.

Mariah M. Hills went on to found the Archimedean Lawn Mowers Co. 1871.

Around 1900, one of the best known English was the ransoms Automation,

available in chain or driven models. About this time, an operator could ride

behind animals that pulled the large machines. This were the first riding

mowers. Invention.

(Fig. 3)

An early cylinder (reel) mower, showing a fixed cutting blade in front of

the rear roller and wheel-driven rotary blades.

13

The first lawn mower was invented by Edwin Budding in 1827 in Thrupp, just

outside Stroud, in Gloucestershire. Budding's mower was designed primarily to

cut the grass on sports grounds and extensive gardens, as a superior

alternative to the scythe, and was granted a British patent on August 31,

1830.[2]

Budding's first machine was 19 inches (480 mm) wide with a frame made

of wrought iron. The mower was pushed from behind. Cast iron gear wheels

transmitted power from the rear roller to the cutting cylinder, allowing the rear

roller to drive the knives on the cutting cylinder; the ratio was 16:1. Another

roller placed between the cutting cylinder and the main or land roller could be

raised or lowered to alter the height of cut. (Fig. 3) The grass clippings were

hurled forward into a tray-like box. It was soon realized, however, that an extra

handle was needed in front to help pull the machine along. Overall, these

machines were remarkably similar to modern mowers. [3]

Two of the earliest Budding machines sold went to Regent's Park Zoological

Gardens in London and the Oxford Colleges.[4] In an agreement between John

Ferrabee and Edwin Budding dated May 18, 1830, Ferrate paid the costs of

enlarging the small blades, obtained letters of patent and acquired rights to

manufacture, sell and license other manufacturers in the production of lawn

mowers. Without patent, Budding and Ferrabee were shrewd enough to allow

other companies to build copies of their mower under license, the most

successful of these being Ransomes of Ipswich, which began making mowers

as early as 1832. [3]

His machine was the catalyst for the preparation of modern-style sporting

ovals, playing fields (pitches), grass courts, etc. This led to the codification of

modern rules for many sports, including for football, lawn bowls, lawn tennis and

others.

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2.2 Further improvements

It took ten more years and further innovations to create a machine that could

be drawn by animals, and sixty years before a steam-powered lawn mower was

built. In the 1850s, Thomas Green & Son of Leeds introduced a mower called

the Silens Messor (meaning silent cutter), which used a chain to transmit power

from the rear roller to the cutting cylinder. These machines were lighter and

quieter than the gear driven machines that preceded them, although they were

slightly more expensive. [3] The rise in popularity of lawn sports helped prompt

the spread of the invention. Lawn mowers became a more efficient alternative

to the scythe and domesticated grazing animals.

Manufacture of lawn mowers took off in the 1860s. By 1862, Ferrabee's

company was making eight models in various roller sizes. He manufactured

over 5000 machines until production ceased in 1863. The first grass boxes were

flat trays but took their present shape in the 1860s. James Sumner

of Lancashire patented the first steam-powered lawn mower in 1893. His

machine burned petrol and/or paraffin (kerosene) as fuel. These were heavy

machines that took several hours to warm up to operating pressure. After

numerous advances, these machines were sold by the Stott Fertilizer and

Insecticide Company of Manchester and Sumner. The company they both

controlled was called the Leyland Steam Motor Company.

Around 1900, one of the best known English machines was the Ransoms'

Automaton, available in chain- or gear-driven models. Numerous

manufacturers entered the field with petrol (gasoline)-driven mowers after the

start of the 20th century. The first was produced by Ransomes in 1902. JP

Engineering of Leicester, founded after World War I, produced a range of very

popular chain driven mowers. About this time, an operator could ride behind

animals that pulled the large machines. These were the first riding mowers.

The first United States patent for a reel lawn mower was granted to Amariah

Hills on January 12, 1868.[5] In 1870, Elwood McGuire of Richmond, Indiana

designed a human-pushed lawn mower, which was very lightweight and a

commercial success. John Burr patented an improved rotary-blade lawn mower

15

in 1899, with the wheel placement altered for better performance. Amariah Hills

went on to found the Archimedean Lawn Mower Co. in 1871.

(Fig. 4)

Commercial lawn mower is used in April 1930 in Berlin.

For centuries, grass was cut by workers who walked through pastures or fields

wielding small, sharp scythes. In addition to being tiring and slow, manual

cutting was ineffective—the scythes worked well only when the grass was wet.

The first mechanical grass-cutting device appeared in 1830, when an

English textile worker named Edwin developed a mower allegedly based on

a textile machine used to shear the nap off of cloth. Budding's cylindrical mower

was attached to a rear roller that propelled it with a chain drive, and it shaved

grass with a curved cutting edge attached to the cylinder. He created two sizes,

large and small. The large mower had to be drawn by horses, whose hooves

were temporarily shod with rubber boots to prevent them from damaging the

turf; the head gardener at the London Zoo was among the first to purchase this

model. Budding marketed the smaller mower to country gentlemen, who would,

he claimed, "find in [his] machine an amusing, useful and healthful exercise."

16

Mechanized grass cutting was evidently slow to catch on, perhaps because

Budding's mower was quite heavy in addition to being inefficiently geared. Only

two lawn mower manufacturers exhibited their machines at England's Great

Exhibition in 1851.(fig. 4) However, several decades later the new machines

experienced a surge in popularity due to the interest in lawn tennis that arose

in England during the late Victorian period. Before the turn of the century,

Budding's initial designs were improved. Weighing considerably less than their

predecessors and based on the side wheel design still used in today's most

popular mowers, these refined machines were soon visible in yards throughout

England.

The earliest gas-driven lawn mowers were designed in 1897 by the Benz

Company of Germany and the Coldwell Lawn Mower Company of New York.

Two years later an English company developed its own model; however, none

of these companies mass produced their designs. In 1902 the first commercially

produced power mower, designed by James Edward Ransome, was

manufactured and sold. Although Ransom’s mower featured a passenger seat,

most early mowers did not, and even today the most popular models are

pushed from behind.

Power mowers are presently available in four basic designs: the rotary mower,

the power reel mower, the riding mower, and the tractor. Because the rotary

mower is by far the most common, it is the focus of this entry. Pushed from

behind, rotary mowers feature a single rotating blade enclosed in a case and

supported by wheels. As the engine turns, it spins the blade. The blade whirls

at 3,000 revolutions per minute, virtually 19,000 feet (5,800 meters) per minute

at the tip of the blade where the cutting actually occurs. The best rotaries feature

a horn of plenty (cornucopia) or wind tunnel shape curving around the front of

the housing and ending at the discharge chute through which the mown grass

flies out. Self-propelled models are driven by a chain or belt connected to the

engine's drive shaft.[5] A gearbox usually turns a horizontal axle which in turn

rotates the wheels. Some models have a big chain- or belt-driven movable unit

that rises up off and settles down on the wheels.

17

The power reel mower features several blades attached at both ends to drums

that are attached to wheels. The coupled engine drive shaft that spins the reel

can also be rigged to propel the mower, if desired. Overlapping the grass, this

machine's five to seven blades pull it against a cutting bar at the bottom of the

mower. Then one or more rollers smooth and compact the clippings as the

mower goes over them. Reel mowers are more efficient than rotary mowers

because the latter actually use only the end of the blade to do most of the

cutting, whereas the fixed blades in a reel mower cut with the entire length of

both edges. However, rotary mowers are easier to manufacture because the

basic design is simpler, and they are also favored over reel mowers on most

types of turf. By industry estimates, most of the 40 million mowers in use on

any given summer Saturday are rotary mowers.

Rotary mowers were not developed until engines were small enough and

powerful enough to run the blades at a high speed. Many people experimented

with rotary blades in the late 1920s and early 1930s, and Power Specialties Ltd.

introduced a gasoline-powered rotary mower. The story of one experiment in

the design of rotary mowing equipment is that of C C Stacy, a farmer in the

Midwest region of the United States. His concept was the use of a toothed

circular saw blade mounted horizontally on a vertical shaft, which would be

suspended at a height of approximately 2 inches (50 mm) and moved across a

lawn to cut grass and other lawn vegetation at a uniform height. The power for

his experimental mower was an electric motor. The success of Stacy's design

was limited by two factors: the relatively small diameter of the saw blades he

used for his experiments, which were about 8 inches (200 mm); and the fact

that toothed circular saw blades are not an ideal tool for cutting free-standing

grass and other plants. Stacy did not come up with any idea for a cutter similar

to modern rotary mower straight blades, and soon dropped his experiments

with rotary mowing.

18

2.3 Types of Lawn Mower

2.3.1 Cylinder or reel mowers:-

A cylinder mower or reel mower carries a fixed, horizontal cutting blade at the

desired height of cut. Over this is a fast-spinning reel of blades which force the

grass past the cutting bar. Each blade in the blade cylinder forms a helix around

the reel axis, and the set of spinning blades describes a cylinder. [6]

The basic push mower mechanism is also used in gangs towed behind

a tractor. The individual mowers are arranged in a "v" behind the tractor with

each mower's track slightly overlapping that of the mower in front of it. Gang

mowers are used over large areas of turf such as sports fields or parks. [6]

2.3.2 Rotary mowers:-

A rotary mower rotates about a vertical axis with the blade spinning at high

speed relying on impact to cut the grass. This tends to result in a rougher cut

and bruises and shreds the grass leaf resulting in discoloration of the leaf ends

as the shredded portion dies. This is particularly prevalent if the blades become

clogged or blunt. Most rotary mowers need to be set a little higher than cylinder

equivalents to avoid scalping and gouging of slightly uneven lawns, although

some modern rotaries are fitted with a rear roller to provide a more formal

striped cut. These machines will also tend to cut lower (13 mm) than a standard

four-wheeled rotary.

2.3.3 Gasoline (petrol):-

Most rotary push mowers are powered by internal combustion engines. Such

engines are usually four-stroke engines, used for their greater torque. (Although

a number of older models used two-stroke engines), running

on gasoline (petrol) or other liquid fuels. Internal combustion engines used with

lawn mowers normally have only one cylinder. Power generally ranges from

two to seven horsepower (1.5 to 6.75 kW). The engines usually have

19

a carburetor and require a manual pull crank to start them, although a starters

offered on some models. Some mowers have a throttle control on the handlebar

with which the operator can adjust the engine speed.

(Fig.5)

The first gasoline-powered lawn mower, 1902.

Other mowers have a fixed, pre-set engine speed. Gasoline mowers have the

advantages over electric mowers of greater power and distance range. They

do create pollution due to the combustion in the engine,(Fig. 5) and their

engines require periodic maintenance such as cleaning or replacement of

the spark plug and air filter, and changing the engine oil.[7][8]

2.3.4 Electricity:-

Electric mowers are further subdivided into corded and cordless electric

models. Both are relatively quiet, typically producing less than 75 decibels,

while a gasoline lawn mower can be as loud as 95 decibels or more. [9]

20

Chapter 3

MATERIALS AND METHODS

3.1 Materials

The main parts of a cylinder or reel mower are:-

3.1.1 Blade - Consist of blades that are attached to a vertically rotating shaft,

to the downward direction. The blades rotate, creating a cutting

motion.(fig. 6)

(Fig. 6)

A High-Carbon Steel Cutting Blade

It’s important to cut lawn, with a sharp blade as blunt blades can rip or

tear grass from the roots, damaging our greenery and causing our lawn

to become patchy over time.

Size: - 13 inches, Metal: - The blade is made of Steel.

3.1.2 Body frame - The main structural frame of the mower onto which the

other parts of the mower are mounted.

21

The frame is that provides a base unit that all of the

components/subsystems are mounted on. The hollow Iron piped frame

will be designed to provide adequate sectioning for the separate

subsystems. The rear wheel motors are mounted to the rear exterior

section of the frame. The Batteries will have a separate compartment

for mounting and secured safely.

The Frame is to be composed of 1.5”x2.5”. Hollow Iron pipe was chosen

due to its strength and availability.

3.1.3 Wheels - These help propel the mower in action. Generally, our lawn

mowers have four wheels. The diameter of the wheel is 8 inches.(Fig. 7)

(Fig. 7)

A Base Frame with Four Wheels of the Lawn Mower

The wheels having rubber gripped, for better moving on grass. We are

using wooden wheels for reducing the cost of lawn mower.

3.1.4 Push handle - The "power source" of a manually operated mower.

(Fig.8) .This is a sturdy U-shaped handle that is connected to the frame,

wheels and blade chamber. The length of push handle is 36 inches.

(Fig 8) A push Handle of the Lawn Mower

The hollow Iron piped push handle will be designed to provide adequate

sectioning for the separate subsystems.

22

3.1.5 Motor - The power source of a lawn mower that is powered by electric.

The electric motors for lawnmowers are typically 24V DC motor. (Fig. 9)

The benefits of the electric motors are that they run very quietly and they

do not take up too much space on the mower chassis.

(Fig. 9)

Merathon Electric Motor

3.1.6 Bag – The bag is carried catted grass clippings.

3.1.7 Battery –For this project, a Lithium battery or batteries will be needed to

provide 24V to the electric motors and another 250 Watts of power to the

mower in order to run these system.(Fig. 10)

Features: - Voltage – 24V,

Weight – 1.05 Kg.,

Height – 7.1875 inches

(Fig. 10)

A Typical view of Battery

23

3.2 Specifications:-

Voltage (volts)

24 Assembled Depth(inches)

61

Assembled Height(inches)

41.5 Assembled Width(inches)

21.5

Blade Length 13 inches.

Features

Bagger , push handle , Four wheels, height

adjustment , Tool-free adjustments

Charge time (hours)

12 Cordless

Yes

Cutting Options

Bag, Mulch Cutting Width

13 inches

Fuel Type

Rechargeable Battery

Included

Bag Kit, Batteries

Lawn Mower Type

Walk Behind

Manual Push Mower (Type of power)

Electric

Maximum cutting height (inches)

3.5 Mower Deck Width

14 inches

Mulching Capability

Yes Number of adjustable handlebar positions

2

Run Time (min.) 45 min./fully charged battery

Size of yard ¼ - ½ Acre

Product weight(lb.)

90(apex.) Front Wheel size Dia.

8 inches

Start type Electric Rear Wheel Size Dia.

8 inches

Total no. of wheels

4 Speed of the electric motor

3000 r.p.m.

(Table No. 1)

Specifications of battery powered Lawn Mower

24

3.3 Methodology adopted for assembling of Lawn Mower:-

1) First we are cut the iron pipe whose outer diameter is 1”, and then welded

together at an angle of 90˚ between each other. (1.5 × 2.5 feet’s, Base of

the main frame).

2) Then the push Handle (3 feet’s) are welded at the rear wheels frame.

3) Now, four wheels are attached to the frame. The diameter of the wheels is

8” each.

4) Assemble the wheels:-

(a) Put the wheels, and the screws on the Mower.

(b) Pull the screws using the supplied Screwdriver to tighten.

5) A wooden ply are placed and fitted on the base frame of size 1.5 × 2.5

feet’s.

6) Now, the 24v Electric DC motored are placed and fitted by the supporters,

at the center of the wooden ply.

7) Assemble the Blade: - Now, Blade are fitted at the bottom side of the lawn

mower, to the shaft of the motor. (Fig. 11) These blade is fitted by the bolts.

(Fig. 11)

Assembling the Blade with the Electric Motor’s Shaft

25

8) Assemble the battery: - The 24v Lithium ion battery is assembled at the

rear wheels of the wooden ply.

9) Now, the battery and the motor is attached for giving electric power to the

motor.

10) The switch is attached to the battery for ON/OFF the power supply.

11) Now, testing the Lawn Mower on the ground.

3.4 Technical Specification

Motor Power 250W

Motor Model 24V D.C.

Battery Specification 24V/7Ah

Battery charge time 10 to 12 hours

Cutting height 3.5”

Wheel Diameter 8 inches

Wheel width 2 inches

(Table no.2)

Some Other Specifications

3.5 Methods of Use

3.5.1 Starting:-

Press the main Switch, to give the power supply from the battery to the electric

motor, for start the rotation of the cutting blade.

26

3.5.2 Moving:-

Place the lawnmower on the edge of the lawn, switch on the lawnmower and

walk through the lawn. When mowing do not allow the motor to labor particularly

in heavy conditions. When the motor labors the speed of the motor drops and

you will hear a change in the motor sound, when this occurs stop mowing,

release the switch lever and raise the height of cut. Failure to do so will reduce

area of cut and could damage the product or battery.

Protect the battery from heat, for example, also the continuous exposure to sun

radiation and fire. Product will not function if temperature is below 0 ℃ or above

45℃. Do not leave the battery in the mower in direct sunlight.

3.5.3 Area of cut (battery duration):-

1) The area of cut (battery duration) depends on lawn conditions, grass

density, moisture content, grass length and height of cut.

2) Switching the product on and off frequently during cutting will also

reduce the area of cut (battery duration).

3) To improve the area of cut (battery duration) it is recommended to cut

more frequently, raise the cutting height and walk at a normal pace.

3.5.4 Setting the cutting depth:-

Switch off the motor and remove the contact key. Push the adjust lever out to

the direction of wheel. The Maximum cutting height is 3.5 inches.

3.5.5 Charging the battery:-

Caution! The charger must only be operated in dry rooms.

General charging instructions

To prolong the service life of the battery, read the following instructions:

27

1) To charge the battery, first switch from the mower.

2) Then open the battery compartment cover and remove the battery.

3) Connect the battery with the included charging cable. On charger will

light a red LED. Once the download is complete, it turns to green. Insert

the battery into the mower. You can take the lawn mower now in

operation.

4) Red LED is on: - Battery is being charged.

5) Green LED is on: - charge process completed.

6) If the charger is connected to a power socket without a battery, the

Green LED is on.

3.5.6 Maintenance:-

Caution! Before carrying out maintenance or cleaning work:

1) Remove the contact key.

2) Remove the battery.

3) Do not touch rotating blades.

3.5.7 Replacing the cutting blade:-

To replace the blade, proceed as follows:

1) Loosen the nut and washer please in the middle of the blade.

2) Remove the old blade and replace it with a new Cutting knife.

3) Place washer and then nut and tighten everything tight.

4) Check to see if the blade can rotate freely.

3.5.8 Replacing Fuses:-

To replace the fuse, turn down the safety button with the Marked "FUSE" in the

direction indicated. Remove the old fuse and replace with a new one. Then,

turn the locking button re-tighten.

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3.5.9 Cleaning Blade:-

Grass collector and underbody should be cleaned after used each time. Use a

piece of wood and a cleaning rag. Caution! Wear gloves when doing this work.

Never use water jet or high pressure cleaning. Aggressive or corrosive cleaners

should not be used.

3.5.10 Dispose of batteries:-

Don’t throw the batteries into the garbage, fire or water since 01.10.1998, all

used batteries are not allowed to be thrown into the trash. The batteries need

to be handled-bring back to the Battery-box or to the local collection

communities. Please help to do anything that benefits our environment: Talk to

your relatives, acquaintances and friends.

3.5.11 Dispose-Recycling:-

Dispose your tool environmentally. Electric tools are not allowed to be disposed

into household rubbish. Send the tool to an appropriate collection facility-inquire

your local authority about this. The plastic and metal parts can be sorted

separately and thus be recycled.

29

Chapter 4

RESULTS AND DISCUSSIONS

4.1 Results:-

1) The area of cut (battery duration) depends on lawn conditions, grass

density, moisture content, grass length and height of cut.

2) Switching the product on and off frequently during cutting will also

reduce the area of cut (battery duration).

3) To improve the area of cut (battery duration) it is recommended to cut

more frequently, raise the cutting height and walk at a normal pace.

4) The maximum cutting height is 3.5 inch.

5) The run time is 45 min. / fully charged batteries.

4.2 Discussions:-

Below 40 degrees of inclination angle of the push handle, the mower handle

becomes very uncomfortable to handle and pushing the mower becomes quite

difficult. At an angle of 45 degrees, the handle is found most convenient in terms

of freedom in moving the mower.

In future we can add the Remote sensors to the Lawn Mower to operate it by

the remote control.

30

REFERENCES

(1) Kinnander, Ola (October 25, 2012). "Rise of the Lawn-Cutting

Machines". Bloomberg Businessweek.

(2) Everett G., "Improvement in Lawn-Mowers", published 23 February

1869, see Page 1.

(3) The Old Lawnmower Club. "Mower History".

Retrieved 2011-04-23.

(4) "The Hall & Duck Trust: Lawn Mower History Part 2". Hdtrust.co.uk.

Retrieved 2011-04-23.

(5) Australian Broadcasting Corporation's Radio National Ockham's

Razor, first broadcast 6 June 2010.

(6) Hessayon, D.G. (2007) the Lawn Expert. Tran’s world Publishers,

London.

(7) "Instruction Manual", web: MM Home-PDF.

(8) "OM, Black Bear ZTR", 2008, web: Deter-manual.

(9) Hollis, Scott. "Cordless electric lawn mowers: these battery-powered

machines are clean, quiet and easy to maintain." Mother Earth News

209 (April–May 2005): 67(4). General Reference Center Gold. Gale.

Fairfax County Public Library. 7 Apr. 2009.