IE S COLLEGE OF ENGINEERING CHITTILAPPILLY, THRISSUR Dt., KERALA–680 551, www.iesce.info MINI PROJECT REPORT ON DESIGN & FABRICATION OF LAWN MOWER CYCLE Submitted By ABDUL SAMAD P.R (ISAMEME002) ABHAY VISHNU V.S (ISAMEME004) JAFEER P.A (ISAMEME022) KIRAN JOSEPH (ISAMEME026) MOHAMED HUWAIS (ISAMEME034) DEPARTMENT OF MECHANICAL ENGINEERING APRIL 2015 Department of Mechanical Engineering CERTIFICATE Certified that this is a bonafide record of the Mini Project Work titled “DESIGN AND FABRICATION OF LAWN MOWER CYCLE” Done by, ABDUL SAMAD.P.R (ISAMEME002) ABHAY VISHNU.V.S (ISAMEME004) JAFEER.P.A (ISAMEME022) KIRAN JOSEPH (ISAMEME026) MOHAMMED HUWAIS (ISAMEME034) of pre final year B Tech Mechanical Engineering in partial fulfillment of the requirement for the award of Bachelor of Technology Degree in Mechanical Engineering under the University of Calicut during the year 2012-2016. __________ Mr. Nandan K Kuttan Asst. Professor (Guide) ____________ Dr. U. Mohammed Iqbal Head of the Department Submitted for the Mini Project Viva-Voce Examination held on _ _ _ _ _ _ _ _________ Examiner I __ ______ Examiner II ACKNOWLEDGMENT We first of all we thank almighty for his blessing showered upon us in enabling us to complete this project on time. We thank Prof. Dr.V Jayaraman (Principal of, IES College of Engineering) for giving us a chance to fabricate this Mini project. We would like to thank our project guide Mr. Nandan K Kuttan, (Asst. Professor, IESCE) for giving us apt guidance. We would also like to extend our gratitude towards Dr. U. Mohammed Iqbal, (Head of the Department) for his invaluable support &suggestions throughout this project. We would also like to thank our project in charge Mr. Rinto K Anto, (Asst. Professor, IESCE) and Mr. Anil D Koola, (Asst. Professor, IESCE) for their continuing support in this endeavour. We would like to thank Mr. Febin V, (Lab Instructor, IESCE) for his valuable time and suggestions for fabrication of our project. Many people, especially our classmates and family members, who have made valuable comment suggestions on this proposal which gave us an inspiration to improve our project. We thank all the people for their help directly & indirectly to complete our project. i TABLE OF CONTENTS CHAPTER NO. Chapter 1 Chapter 2 Chapter 3 TITLE PAGE NO. List of Figures iv List of Tables v Abstract iv INTRODUCTION 1-3 1.1 Relevance 2 1.2 History 2 1.3 Project Plan 3 LITERATURE REVIEW 4-24 2.1 The basics in grass cutting 4 2.2 Types of lawn mowers 6 2.3 Reel Mower Parts 14 2.4 Factors effecting clip 15 2.5 Set-up and Adjustments 19 2.6 Sharpening 23 COSTRUCTION DETAILS 25-30 3.1 Selecting Required Cycle Frame 25 3.2 Mower Frame 26 3.3 Reel 26 3.4 Bed Knife 27 3.5 Main wheel with internal gears 28 3.6 Trolley Wheels 29 3.7 Balancing Wheels 29 ii 1 Conclusion 39 7.Chapter 4 WORKING PRINCILE 31 Chapter 5 DESIGN CALCULATIONS 32-34 5.1 Spur & pinion Gear parameters 32 5.1 Discussion 35 6.3 The Cutting blades Design 33 5.5 Estimate 37 CONCLUSION & FUTURE SCOPE 39 7.4 Design 36 6.2 Future Enhancements 39 REFERENCE 40 iii .2 Applications 35 6.4 Performance test and evaluation 34 Chapter 6 Chapter 7 RESULTS & DISCUSSIONS 35-38 6.3 Advantages 35 6.2 Deign Specification 33 5. 18 Cutting path 19 Figure 2.19 Single point reel to bedknife adjust 21 Figure 2.16 Side view showing bedknife during grass cutting 18 Figure 2.7 Balancing wheel and frame 29 Figure 3.10 Zero turn mower 13 Figure 2.9 A tractor-pulled mower 12 Figure 2.8 Lawn mower cycle after construction 30 Figure 6.5 A rotary mower (viewed from underneath) 9 Figure 2.21 Sharpening of blades 23 Figure 2.11 Bed knife 14 Figure 2.12 Clip and the shear point 15 Figure 2.15 Clip distance and shear points 17 Figure 2.7 Hover mower 11 Figure 2.14 Grass cutting process showing HOC 16 Figure 2.22 Lapped Surfaces 24 Figure 3.4 Bed Knife 28 Figure 3.1 Mulching 4 Figure 2.8 Robotic mower 12 Figure 2.3 Bagging 5 Figure 2.5 Pinion Gear & Main wheel 28 Figure 3.2 Spreading 5 Figure 2.20 Cutting unit dulling curve 22 Figure 2.6 Trolley wheels for supporting mower 29 Figure 3.1 View of mower Assembly 36 iv .13 Illustration of actual grass cutting process 16 Figure 2.6 A Cordless electric mower 10 Figure 2.1 Different Body Position 25 Figure 3.4 Push lawn reel mower 6 Figure 2.2 Mower Frame 26 Figure 3.LIST OF FIGURES Figure No.3 Reel: Helix shaped Spiral Blades 27 Figure 3. Name PageNo.17 Front view of Reel mower showing Helix angle 18 Figure 2. Figure 2. 1 Cost estimation 37 Table 6.2 Materials used 38 v . Table 6. Name Page No.LIST OF TABLES Table No. powered Mower cycle. Dept. The pushing force required for moving the reel mower is obtained from the motion of a bicycle. It also aims to design a pedal. Between the two front wheels a cutting mechanism is made with internal spur gear system which transfers the torque to the mower spiral mechanism. The Mower cycle consists of three main wheels with two of the wheels at the front.Lawn Mower Cycle Mini Project ABSTRACT The design objective is to come up with an apparatus for cutting grass that is portable. easy to operate and maintain. durable. Chittilappilly . of Mechanical Engineering vi IESCE. The cutting mechanism is made of a flat blade rigidly fixed to the frame behind the spiral arrangement which is configured to contact at least one reel bar of the spiral blades during the rotation of the spiral mechanism. The Lawn mower cycle is peddle powered. This project attempts to combine a cycle and a mower. the rotating blades come in contact with a stationary bar called the bed knife and placed parallel to the ground. So our design objective is to come up with a Lawn mower cycle that is durable. The reel (cylindrical) mowers seem to be better. they achieve clean cut by scissors action. mode of operation and power. The mower is adjusted to various cutting heights. The power required to push the mover is obtained from a chain-driven cycle. Dept. There are primarily two types of mowers namely (i) the reel mowers. Rotary mowers are often powered either by an internal combustion engine or an electric motor and are generally moved manually. The power source riding mowers for example are usually powered by a gasoline engine and are ridden and steered by the operator but they are costly. Chittilappilly . of Mechanical Engineering 1 IESCE. cost efficient & easy to operate. and (ii) the rotary mowers. They vary in size.Lawn Mower Cycle Mini Project CHAPTER 1 INTRODUCTION Lawn mower is an essential tool for the maintenance of yards. As the mower moves forward. with the engine only spinning the cutting blades. Made of blades on a revolving cylinder. Grass is held by the shearing action of the reel blades against the bed knife. motorized mowers appeared as light weight petrol engines and small steam power units became available. It was called ‗Silens Messor‘ meaning silent cutter. By mid 1850. Therefore. In 1832.1 RELEVANCE The main aim of our project is to come up with a cost efficient lawn mower. Budding realized that a similar concept could be used to cut grass if the mechanism is mounted in a wheel frame to enable the blades rotate close to the lawns surface. Walk behind mowers are designed to be pushed by the operator and typically run on gasoline or electricity. it is strenuous.2 HISTORY The first lawn mower was invented in 1830 by Edwin Beard Budding . there is the need to develop a low cost mower which can take care of this operation easily. The objective of the study is to design and develop a locally fabricated peddle powered spiral blade lawn mower affordable by common man 1. A lawn mower is a machine used for cutting grass or lawns. Ransoms of Ipswich (under license) began the making of Budding‘s mower. These early machines were made of cast iron and featured a large rear roller with a cutting cylinder (reel) in the front. By late 1890. A lawn is any area of grass. the conventional methods of grass cutting involved the use of cutlasses which never met the maximum satisfaction. Cast iron gear wheel transmitted power from the rear roller to the cutting cylinder. time and labour intensive.He was said to obtain the idea after watching a machine in a local cloth mill which used a cutting cylinder mounted on a bench to trim clothes for a smooth finish after weaving. Chittilappilly . Thomas Green developed a mower which used chains to transmit power from the rear roller to the cutting cylinder. More so. The machines were found comparatively lighter and quieter than the gear driven machines that preceded them.Lawn Mower Cycle Mini Project 1. Modern gas powered and electric powered lawn mowers cut grass with a single blade revolving at a high speed parallel to the ground. in areas like ours. This company is today the world‘s largest manufacturer of lawn care equipment. of Mechanical Engineering 2 IESCE. mostly tough grass which is neatly cut like in a private garden or a public park. Generally. Dept. the recent innovation is the rotary hover mower. Today. new technology has brought new improved versions. Dept. This chapter explains the components and features of lawn mower cycle. 1. Colonel Edwin George produced the first gasoline powered mower in 1919.Lawn Mower Cycle Mini Project In US. Low emission gasoline engines with catalytic converters are introduced to help reduce air pollution. By 1960 the introduction of plastic components greatly reduced cost. Today. of Mechanical Engineering 3 IESCE. Then the later chapters deals with results and discussions. The mini project mainly consists of 7 Chapters. cost efficient & easy to operate. Electric powered mowers and rotary cutting machines emerged in the 1920‘s and 1930‘s. Improved muffling devices are also incorporated to reduce noise. The second chapter is literature review.3 PROJECT PLAN The design objective is to come up with a mower cycle that is durable. The third chapter is design part where we explain how we made the required machine. Chittilappilly . The first chapter is introduction part where we explain the basic concepts. The grass can be very sensitive and can be damaged if you cut too much at one time. of Mechanical Engineering 4 IESCE.Lawn Mower Cycle Mini Project CHAPTER 2 LITERATURE REVIEW 2. From then to June the grass has its high season.1 THE BASICS IN GRASS CUTTING Grass as most other plants grow during a certain period of the year. the grass starts to grow in April.1 Mulching When mulching you cut the grass in to small pieces that you leave on the ground to work as a natural fertilizer. drying the soil. If you want a lawn that you can walk on you should leave at least 4cm of the grass. Figure 2.1 Mulching Dept. 2. A good rule is to cut about one third of the grass length at a time. Here it really depends on what kind o a lawn you‘re aiming for. The negative side is that you will have to cut more often to let the mower cut the grass correctly. This can off course differ some depending on where in the world you are. For India. During this period you can cut the grass 1-2 times a week. You should take care not to cut the grass to short if the grass looks dry (turning somewhat yellow). mostly due to the sun.1. Then we come to the length. Chittilappilly . What you should think of is to take it easy in the beginning of the growth period as not to stress the grass. The grass is then entering a period of low growing rate. which means it‘s grows fast and strong. There are different approaches to cutting the grass all with advantages and disadvantages. Figure 2. If you cut the grass when it‘s long another downside can be that the cut grass can suffocate the living grass.3 Bagging Bagging involves a container that directly collects the grass for you to later empty at a pleasant spot. of Mechanical Engineering 5 IESCE. Figure 2. Depending on the amount of cut grass you might have to rake it together. Chittilappilly .2 Spreading 2.1. The downside is that it claims more energy from the mower or you to carry it around until you have emptied it.2 Spreading Spreading means that the mower spread the cut grass directly on to the lawn.3 Bagging Dept.1. The downside is the extra work but on the other hand you will have grass to make fresh soil to use in your garden.Lawn Mower Cycle Mini Project 2. If more however.Lawn Mower Cycle Mini Project 2. white or brown discolouration as a result of leaf shredding. If the gap between the blades is less than the thickness of the grass. the rotating blades come in contact with a stationary bar called the bed knife and placed parallel to the ground. Figure 2. the grass will slip through. weeds and parasites.4 Push lawn reel mower Dept. The cut of a well-adjusted cylinder mower is straight and definite. This clean cut promotes healthier. Lawn cut with a cylinder mower is less likely to result in yellow.1 Reel (cylinder )mowers The reel (cylindrical) mower is made of blades on a revolving cylinder.2 TYPES OF LAWN MOWERS 2. Grass is held by the shearing action of the reel blades against the bed knife. Of all the mowers. it is not necessary for the blades of the spinning cylinder to contact the horizontal cutting bar. they achieve clean cut by scissors action. and this allows the grass to heal more quickly. of Mechanical Engineering 6 IESCE. thicker and more resilient lawn growth that is more resistant to disease. While the cutting action is often likened to that of scissors.2. Chittilappilly . a properly adjusted reel mower makes the cleanest cut of the grass. As the mower moves forward. as if cut with a pair of scissors. a clean cut can still be made. The mower is adjusted to various cutting heights. but normally ten. both in noise and air pollution. the wheels. and these models are able to cut grass which has grown too long for ordinary push mowers. was a powered version of the traditional side-wheel push mower. or any combination of these. On petrol machines the engine drives both the cylinder and the rear roller. As the mower is pushed along. usually through a belt.Lawn Mower Cycle Mini Project There are many variants of the cylinder (reel) mower. Push mowers (illustrated) have no engine and are usually used on smaller lawn areas where access is a problem. An internal combustion engine sat atop the reel housing and drove the wheels. Some variants have only three blades in a reel spinning at great speed. as in the push mower. Greens mowers are used for the precision cutting of golf greens and have a cylinder made up of at least eight. One type of reel mower. where noise pollution is undesirable and where air pollution is unwanted. Riding reel mowers are also produced. Typical cutting widths are 10 to 16 inches (410 mm). animal sanctuaries and exclusive hotel groups. the wheels drive gears which rapidly spin the reel. Advances in materials and engineering have resulted in these mowers being very light and easy to operate and manoeuvre compared with their predecessors while still giving all the cutting advantages of large professional cylinder mowers. of Mechanical Engineering 7 IESCE. The wheels in turn drove the reel. Chittilappilly . Much smaller and lighter variants of the roller mower are sometimes used for small patches of ornamental lawns around flower beds. The machine has a roller before and after the cutting cylinder which smooths the freshly cut lawn and minimizes wheel marks. Dept. A gasoline engine or electric motor can be added to a cylinder mower to power the cylinder. Due to the weight. Gang mowers are used over large areas of turf such as sports fields or parks. blades. 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. A typical arrangement on electric powered machines for residential lawns is for the motor to power the cylinder while the operator pushes the mower along. are also strong selling points. the engine also propels the mower. which was used on residential lawns. the roller. something not lost on many international zoos. and these have no engine. now largely obsolete. Their distinct environmental benefits. The electric models can be corded or cordless. 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. the cutting reels are ahead of the vehicle's main wheels. Blade reel/cylinder — consist of numerous (3 to 7) spiral blades that are attached to a rotating shaft. Body frame — the main structural frame of the mower onto which the other parts of the mower are mounted. Push handle — the "power source" of a manually operated reel mower. although some modern rotaries are fitted with a rear roller to provide a more formal striped cut. so that the grass can be cut before the wheels push the grass over onto the ground. Generally.2. creating a scissor-like cutting motion. but it can be propelled by a hydraulic motor.Lawn Mower Cycle Mini Project Typically. Cutter deck housing — this houses the blade and the drive system of the mower. 6. 2. wheels and blade chamber. 3. reel mowers have two wheels. Chittilappilly . 2. It is shaped to effectively eject the grass clippings from the mower. 4. Bed knife — is the stationary cutting mechanism of a cylinder/reel mower. Motor — the power source of a reel mower that is powered by gasoline or electric. Wheels — these help propel the mower in action. 2. The blades rotate. This is particularly prevalent if the blades become clogged or blunt. This is a sturdy T-shape handle that is connected to the frame. This is a fixed horizontal blade that is mounted to the frame of the mower. These machines will also tend to cut lower (13 mm) than a standard four-wheeled rotary. Blade mounting and drive system — the blade of a rotary mower is usually mounted directly to the crankshaft of its engine. The main parts of a rotary mower are: 1. Dept. of Mechanical Engineering 8 IESCE. 5. This tends to result in a rougher cut and bruises and shreds the grass leaf resulting in discolouration of the leaf ends as the shredded portion dies. The reels are often hydraulically powered. Most rotary mowers need to be set a little higher than cylinder equivalents to avoid scalping and gouging of slightly uneven lawns. The main parts of a cylinder or reel mower are: 1. 2.Lawn Mower Cycle Mini Project 3. running on gasoline (petrol) or other liquid fuels. 4. with a mulching blade that rotates around the center. Gasoline mowers have the advantages over electric mowers of greater power and distance range.5 to 6. Chittilappilly . although an electric starter is offered on some models. They do create pollution due to the combustion in the engine. Dept. Some mowers have a throttle control on the handlebar with which the operator can adjust the engine speed. Wheels — rotary mowers generally feature a set of four wheels. Power generally ranges from two to seven horsepower (1. Internal combustion engines used with lawn mowers normally have only one cylinder. and changing the engine oil. and their engines require periodic maintenance such as cleaning or replacement of the spark plug and air filter. Such engines are usually four-stroke engines. two front wheels and two rear wheels. thus creating a sucking and tearing action. pre-set engine speed. used for their greater torque.3 Gasoline mower Most rotary push mowers are powered by internal combustion engines. of Mechanical Engineering 9 IESCE. 5. The engines usually have a carburetor and require a manual pull crank to start them. (although a number of older models used two-stroke engines). The blade features edges that slightly curved up to generate a continuous air flow as the blade rotates. Other mowers have a fixed. Engine — may be powered by gasoline or electricity.5 A rotary mower (viewed from underneath). Mower blade — a rotary mower generally has one blade that rotates horizontally. Figure 2. 2.75 kW). Figure 2. typically producing less than 75 decibels. while a gasoline lawn mower can be as loud as 95 decibels or more. Cordless mowers have the maneuverability of a gasoline powered mower and the environmental friendliness of a corded electric mower. Corded electric mowers are limited in range by their trailing power cord. Chittilappilly . There is the additional hazard with these machines of accidentally mowing over the power cable. which stops the mower and may put users at risk of receiving a dangerous electric shock. Cordless electric mowers are powered by a variable number (typically 1-4) of 12-volt rechargeable batteries.6 A Cordless electric mower Dept.4 Electric mower Electric mowers are further subdivided into corded and cordless electric models.Lawn Mower Cycle Mini Project 2. Both are relatively quiet. Installing are sidual-current device (GFCI) on the outlet may reduce the shock risk. which may limit their use with lawns extending outward more than 100–150 feet (30–45 m) from the nearest available power outlet. of Mechanical Engineering 10 IESCE.2. but are more expensive and come in fewer models. are usually self-docking and contain rain sensors. Multiple robotic mowers can be used to mow an even larger area. so they are often used by golf course greens keepers and commercial landscapers Figure 2. The robot uses this wire to locate the boundary of the area to be trimmed and in some cases to locate a recharging dock.7 Hover mower (underside view). The operator can then easily move the mower as it floats over the grass. The most significant disadvantage. Robotic lawn mowers are increasingly sophisticated.6 Robotic mower A robotic mower is contained by a border wire around the lawn that defines the area to be mowed. and high-weeded areas. is the cumbersome usability in rough terrain or on the edges of lawns. Dept. thereby creating an air cushion that lifts the mower above the ground.Lawn Mower Cycle Mini Project 2. 2. waterfronts. nearly eliminating human interaction for mowing grass.5 Hover mower Hover mowers are powered rotary push lawn mowers that use an impeller above the spinning blades to drive air downward. as the lifting air-cushion is destroyed by wide gaps between the chassis and the ground.000 m2) of grass.2. however.2. Chittilappilly . Robotic mowers are capable of maintaining up to 5 acres (20. of Mechanical Engineering 11 IESCE. Hover mowers are necessarily light in order to achieve the air cushion and typically have plastic bodies with an electric motor. Hover mowers are built to operate on steep slopes. Lawn Mower Cycle Mini Project Figure 2. The attachments can simply function by the movement of the tractor similar to manual push cylinder mowers.9 A tractor-pulled mower Dept.2. of Mechanical Engineering 12 IESCE. Chittilappilly .7 Tractor pulled mower These are usually in the form of an attachment to a tractor.8 Robotic mower 2. They are commonly mounted on either the side or the back of the tractor. Figure 2. but also sometimes may have powered moving blades. The mower can pivot around a point midway between the drive wheels (the classic z-turn). fuel type (gasoline or diesel). the large drive tires rotate independently of each other based on the driver's input. Chittilappilly . Most current models have four wheels: two small swiveling front tires and two large drive tires in the back. Bush Hog mowers sometimes come with a small. A z-turn mower typically drives faster and costs more than a similarly sized conventional riding mower that has steerable front wheels. Figure 2. size of cutting decks. a z-turn) is a standard riding lawn mower with a turning radius that is effectively zero. Both commercial duty and homeowner models exist. with varying engine power options. Reversal of the direction of travel can be accomplished by causing both wheels to rotate in reverse. Different brands and models achieve this in different ways. or it can pivot around either one of the drive wheels if one is stationary.2. and prices. pivoting fifth wheel mounted in the center behind the driver.Lawn Mower Cycle Mini Project 2.10 Zero turn mower Dept. Instead of controlling the swiveling tires to steer the machine. of Mechanical Engineering 13 IESCE. but hydraulic speed control of each drive wheel is the most common method. They may rotate in opposite directions. or it can turn in a circle of any radius.8 Zero-turn riding lawn mower A zero-turn riding lawn mower (colloquially. When properly maintained and operated. and in close relationship with each other.11 Bed knife The cutting action requires that the bed knife and reel blades be sharp. 2. of Mechanical Engineering 14 IESCE. Dept.3 REEL MOWER PARTS There are three main structural members in a reel cutting unit: 1. The BEDKNIFE is attached to the bedbar and the assembly is mounted to the main frame in a manner that allows for paralleling and adjustment to the reel. The REEL consists of varying numbers of helix shaped blades attached to support spiders which are mounted on a rotating shaft. the bedbar assembly and reel with its drive mechanism. The FRAME supports the rollers. belt driven or ground driven. matched. A reel mower cuts grass with a scissors-like shearing action as the moving helix shaped blades pass over the stationary bedknife. It is essential that they be adjusted and operated with this in mind. which can be hydraulic. 3. Figure 2. It cannot be overstated that reel mowers are precision tools. reel mowers provide superior quality of cut.Lawn Mower Cycle Mini Project 2. Chittilappilly . Lawn Mower Cycle Mini Project 2. you must understand the concept of clip and the shear point. The diameter of the reel 2. A shear point is any single point of contact made between the reel blade and bed knife.4 FACTORS AFFECTING CLIP 1. Chittilappilly . The ground speed By following the blade path through two ―clips‖ as the machine moves forward we can illustrate the actual process of cutting grass. Dept.3. Each blade path has one-half clip in which to cut all the grass. The bedknife pushes grass toward the shear point while the reel blade gathers it in front.12 Clip and the shear point 2.1 Reel Mower Clip To understand reel cutting theory. of Mechanical Engineering 15 IESCE. Figure 2. The number of reel blades 3. The speed of the reel 4. Clip is the forward distance traveled between successive blade contacts at one shear point. Chittilappilly . clip is that both measurements should be within 20% of each other. Reel blades may contact the grass in this area several times prior to the actual gathering of the grass. Figure 2. The general rule of thumb concerning height of cut vs. Dept. yet tall enough to be within the blade path is less likely to be cut.14 Grass cutting process showing HOC Grass extending beyond the forward half clip. of Mechanical Engineering 16 IESCE. The best results will be obtained when height of cut is equal to or close to the clip.Lawn Mower Cycle Mini Project Figure 2.13 Illustration of actual grass cutting process Note that the grass outside of the forward half clip is not easily gathered. This is the so called ―fanning‖ process. Figure 2. of Mechanical Engineering 17 IESCE. Chittilappilly .Lawn Mower Cycle Mini Project This process is more a mechanical striking of the grass that it is of the commonly thought effect of a blowing action.15 Clip distance and shear points Dept. The grass is physically cut at an angle to the bedknife.Lawn Mower Cycle Mini Project The importance of the bedknife front angle is visible from the side view. Dept. of Mechanical Engineering 18 IESCE. Note that (from Figure 2. The shear point moves down the bedknife as the bedknife moves forward.17 Front view of Reel mower showing Helix angle Cutting path: Another term known as ―the cutting path‖ is the result of the helix angle and the forward motion of the cutting unit.16 Side view showing the bedknife during grass cutting Figure 2. Figure 2. Chittilappilly .16) the proper angle allows the grass behind the bedknife front edge to be more effectively cut. Dept. accurate height of cut tools and proper instruction are essential for setting up a cutting unit. Grass tends to thicken at the normal maintained height of cut. An error of .18 Cutting path Other factors which affect reel mowing are the grass density and the grass acclimation or grain.25 mm. 3. or from one cutting unit to another. The cutting edges on the reel blades and bedknife must be straight and sharp. The bedknife should be positioned against the reel with light contact. Chittilappilly . The denser the grass.5 SET-UP AND ADJUSTMENTS Reel mower performance depends on proper set–up and adjustment procedures. most require the same basic procedures. A surface plate. Although there are design variations in cutting units. The basic requirements for good performance of reel mowers are: 1.010 inch or .Lawn Mower Cycle Mini Project Figure 2. 2. Grass density and grain can often override other factors we have discussed regarding the cutting action. 2. of Mechanical Engineering 19 IESCE. the easier it is for the bedknife and reel to gather it. The bedknife must be exactly parallel with the reel. in height end–to–end. is visible as a mismatch on many golf course greens. start or change a cultural practice. Roller Parallelism 5. color variations in the turf may appear in the form of a streak.5. To correct problems. This bedknife leveling mechanism could may be an eccentric pivot bolt on one end of the bedbar. Effective height of cut is the actual height the grass has been cut. This is due to the effective height of cut being too low for the existing turf conditions. cutting unit accessories and turf conditions. Dept. or a capscrew / jam nut assembly. Attitude Adjustment 4. the more predictable and smooth the turf surface must be. To accurately maintain height of cut and performance. Effective height of cut will be different than the bench set height of cut. Making an accurate height measurement on the turf is difficult due to many variables. Bedknife to Reel Adjustment 3. ―sponginess‖ or attempting to cut off too much grass height may not always be overcome by adjusting the machine. of Mechanical Engineering 20 IESCE. Turf conditions such as excessive thatch. the more critical these factors are. spongy or varies in density. change cutting unit configuration or raise the bench set height of cut. Reel Bearings 2. The lower your height of cut. Chittilappilly . routinely check the following components: 1. Remember that the ―effective‖ or actual height of cut depends on cutting unit weight.Lawn Mower Cycle Mini Project There are many factors that can affect quality of cut. A true base is simply not present. It is important to remember that the lower the height of cut.1 Reel to Bedknife adjustment Single point adjust cutting units also have an adjustment mechanism on one end of the bedknife for adjusting the bedknife parallel to the reel. Height of Cut 2. If the surface is uneven. including condition of the mowing equipment and agronomic factors. Properly adjusting the bedknife to the reel is one of the most effective preventive maintenance practices for reel mowers. Dept. Dulled cutting edges cannot be corrected immediately by adjustment or over– tightening. then cut paper strips to check blade sharpness. Chittilappilly . Put the cutting unit on the turf and check for light bedknife to reel contact and free reel rotation. A light contact adjustment. This requires that the adjustment be checked frequently at a predetermined time interval. This is true even if all other set–up procedures are correct. of Mechanical Engineering 21 IESCE. If the cutting edges on the reel blades and bedknife are not straight and sharp the mowing results may not be acceptable. Do not wait until the quality of cut has deteriorated to check the bedknife to reel adjustment. if maintained. The amount of contact and how frequently it is checked are major factors in performance.19 Single point reel to bedknife adjust Adjust the bedknife against the reel to evenly pinch one paper thickness across the entire width of the bedknife. Do a final adjustment of bedknife to reel contact if necessary.Lawn Mower Cycle Mini Project Figure 2. will help keep cutting edges sharp on the reel and bedknife. rear. A small angle (flat attitude) can have most or all of the bedknife riding ON the turf. or both rollers. The result may be better or worse depending on several factors The result may be better or worse depending on several factors.Lawn Mower Cycle Mini Project Figure 2. Dept. Chittilappilly . A large angle is also referred to as an aggressive bedknife attitude. This can change the after cut appearance of the grass. it is important to note that the reel to bedknife shear point changes relative to the center line of the reel. A height of cut change is NOT necessarily part of a change to the bedknife attitude.20 Cutting unit dulling curve The cutting unit attitude is the angle between the bottom of the bedknife and the ground plane under the cutting unit. This can influence after cut appearance. Bedknife attitude is adjusted by changing the height of the front. of Mechanical Engineering 22 IESCE. As the bedknife attitude is changed. 3. Optimize cutting unit performance. Allow the tractor to run most efficiently. Provide excellent finished appearance of the turf. 6. If the reel is not adjusted or ground to a cylinder shape again. Extend the life of the mower. Of course. and the edge of the bedknife should be checked for damage visually & by carefully feeling the edges. Chittilappilly . All reels eventually become tapered with use. When light contact is not maintained. 2. of Mechanical Engineering 23 IESCE. 5. Rounded edges on the reel blades and bedknife will cause the grass blades to be pinched and torn. Maximize operator mowing time. Reel blades. and never slide your fingers down the edges lengthwise. a mismatch in the height cut between adjacent reels can result.21 Sharpening of blades Dept.6 SHARPENING Cutting units should be kept as sharp as possible to: 1. Sharpening will also be required if the reel is ―cone shaped‖ (tapered). rather than sheared off cleanly. dull edges will soon result. 4.Lawn Mower Cycle Mini Project 2. Promote growth of healthy grass. this should only be done when it is certain that the reel cannot be started. Figure 2. Occasionally run a file or facing grinder across the front edge to remove this burr to extend the cutting performance of the machines. As the reel blades run against the bedknife a slight burr will appear at the front cutting edge surface the full length of the bedknife. you may not want to grind the reels and install new bedknives. Lapping is not intended to be a reconditioning process to correct severely nicked or rounded blades. If. Lapping must be done after single blade grinding. It should also make the most sense for the anticipated use.Lawn Mower Cycle Mini Project There are several methods that may be used to sharpen a cutting unit. Figure 2. it is time to grind the reel. if you are about to mow greens that have been core aerated or topdressed. For example. Chittilappilly . rifling or taper. This is done to establish a ―land area‖ and to insure a perfect match between the bedknife and the reel edge. after 5 minutes of lapping. the edge is not restored. of Mechanical Engineering 24 IESCE. The one that you choose will depend upon the condition of the cutting unit.22 Lapped Surfaces Dept. The speed of a lawnmower is not that high so the aggressive style presented below is a bit too much even if it is effective considering the amount of energy that you can provide from that position. Chittilappilly . Getting the right impression of the product as well as considering the way it is being used is important.1 SELECTING REQUIRED CYCLE FRAME Different products come in different styles. both when it comes to emotional aspects but also ergonomics and user interaction. An honest expression with good ergonomically & mechanical possibilities is the position we chose to work with. One product category where this is a fact is the bicycle category.Lawn Mower Cycle Mini Project CHAPTER – 3 CONSTRUCTION DETAILS 3. Hence after necessary research a bicycle frame which gives a formal body position was chosen.1 Different Body Position Dept. Figure 3. If we see to the demanded speed and wanted input power the formal style is the one best suited for our project. of Mechanical Engineering 25 IESCE. The frame supports the Trolley wheels. The reel is made up of six smaller blades of sizes 310mm x 25mm x 2mm and is made of steel materials. 3.2 Mower Frame The frame is the main structural unit of the mower onto which the other parts of the mower are mounted. of Mechanical Engineering 26 IESCE. The frame is that provides a base unit that all of the components /subsystems are mounted on.2 MOWER FRAME Figure 3.3 REEL The Reel consists of varying numbers of helix shaped blades attached to support spiders which are mounted on a rotating shaft. The Mower Frame is made of cast iron. The blades are mounted on the three spiders rigidly fixed to the shaft and are oriented at a helical angle of 12 degree to the horizontal on the circular spiders for efficient grass cutting. Chittilappilly .Lawn Mower Cycle Mini Project 3. Dept. the bedbar assembly and the reel with its drive mechanism. 4 BED KNIFE The Bedknife is attached to the bedbar and the assembly is mounted to the main frame in a manner that allows for paralleling and adjustment to the reel. Chittilappilly . As the movable blades on the reel pass by the bed knife. and determines the cutting width of the mower.Lawn Mower Cycle Mini Project Figure 3. The bed-knife is fixed to the machine frame behind the reel.6mm. Its edge is grinded with a front relief angle of 30 degree to make grass cutting easy in a scissor action with the reel.3 Reel: Helix shaped Spiral Blades 3. Dept. of Mechanical Engineering 27 IESCE. The slight space between the bed knife and the reel is adjusted by a precision screw mechanism The bedknife is also made of steel material of size 300mm x 55mm x 2. The bedknife takes up almost the entire distance between the wheels on each end. the grass trapped between the blades and the bed knife is sheared off. Figure 3. Chittilappilly .5 MAIN WHEEL WITH INTERNAL GEARS The pinion gear transfers the power from the rotation of the main wheel to the axle and spinning blades.5 Pinion Gear & Main wheel Dept. These gears are mounted on the mower frame. of Mechanical Engineering 28 IESCE.Lawn Mower Cycle Mini Project Figure 3. Driving gear has 72 teeth & the pinion gear has 13 teeth.4 Bed Knife 3. 6 Trolley wheels for supporting mower 3.7 Balancing wheel and frame Dept. Figure 3.S flat bars.S flat bars. Figure 3. of Mechanical Engineering 29 IESCE.6 TROLLEY WHEELS Trolley wheel acts as a support for the mower and it also helps in the movement of entire mower assembly. Rubber trolley wheel of 5. These wheels support mower cycle and also give an easiness to steer the mower cycle.7 BALANCING WHEELS A frame for balancing wheel is made of M.Lawn Mower Cycle Mini Project 3. Chittilappilly . Trolley wheels are attached to mower frame by means of M.5 inch diameter is used as balancing wheels. of Mechanical Engineering 30 IESCE.Lawn Mower Cycle Mini Project Figure 3. Chittilappilly .8 Lawn mower cycle after construction Dept. A shear point is any single point of contact made between the reel blade and bedknife. To understand reel cutting theory. Clip is the forward distance traveled between successive blade contacts at one shear point. of Mechanical Engineering 31 IESCE. Chittilappilly .Lawn Mower Cycle Mini Project CHAPTER – 4 WORKING PRINCILE OF LAWN MOWER CYCLE The cutting mechanism is made of a flat blade rigidly fixed to the frame behind the spiral arrangement which is configured to contact at least one reel bar of the spiral blades during the rotation of the spiral mechanism. Dept. The pushing force required to move the reel mower is given by the motion of bicycle. Each blade path has one-half clip in which to cut all the grass. The bedknife pushes grass toward the shear point while the reel blade gathers it in front. we must understand the concept of clip and the shear point. 54 Module for internal spur gear (driving gear) Module.1) T1 Where. of Mechanical Engineering 32 IESCE. 𝑑1 = pitch circle diameter of driving gear (m) 𝑇1 = Number of teeth on driving gear Dept. 𝜔1 = Angular velocity of driving gear (rads/s) 𝜔2 = Angular velocity of driven gear (rads/s) 𝑇1 = Number of teeth on driving gear 𝑇2 = Number of teeth on driven gear Gear ratio = T2 T1 = 13 72 = 0. Using the Gear ratio/ speed ratio relation ω1 ω2 = T2 ---------(5.5 ---------(5.2) Gear ratio is 1: 5.18055 ---------(5.3) Where. through the pinions on the shaft. Chittilappilly .Lawn Mower Cycle Mini Project CHAPTER – 5 DESIGN CALCULATIONS 5. M= 𝑑1 𝑇1 = 180 72 = 2.1 SPUR & PINION GEAR PARAMETERS The gear train of a reel mower consists of a driving internal spur gears fixed to each of the front wheels internally which transmits the torque from the wheels to the reel. Average forward speed of the machine = 0. The reel is made up of six smaller blades of sizes 310mm x 25mm x 2mm and is made of steel materials.5 ---------(5. the bed-knife and the reel. 𝑑2 = pitch circle diameter of driven gear (m) 𝑇2 = Number of teeth on driven gear 5. Cot i = i = 𝐶𝑜𝑡 −1 𝑛𝐿 ---------(5.Lawn Mower Cycle Mini Project Module for pinion gear (driven gear) Module.4) Where. Chittilappilly . Principles of farm machinery 1980). The above specifications were chosen for operational convenience (From Kepner. The blades are mounted on the three spiders rigidly fixed to the shaft and are oriented at a helical angle i.8m/s Speed of rotation of the blade = 1500rpm Number of helical blades = 6 Length of bed-knife = 300mm.08 degree Where.2 DEIGN SPECIFICATION The following were chosen as the design standards. 5. The blades are in two sets. of Mechanical Engineering 33 IESCE. M= 𝑑2 𝑇2 = 32.310 2π × 0.3 THE CUTTING BLADES DESIGN The cutting blades are chosen as they appear in the spiral blade lawn mower. The helix inclination angle i for a cylinder having n partial helices is given by.052 ) = 11.5) 2𝜋r 𝑛𝐿 2𝜋r = Cot −1 ( 6 × 0.5 13 = 2. L=Length of the cylinder (m) r = radius of the cylinder (m) i = helix inclination angle (degree) Dept. of Mechanical Engineering 34 IESCE.7) = (4× 2)/90 = 0.8) t 0.248m2 /s Where. A land predominantly covered with grass was mapped out into a plot of area 4mx2m.08889 0. FC FCe × 100 %---------(5.2480 × 100 Where. A = Actual area covered by mower cycle (m2 ) t = Total time taken to cut the grass for a given area ( sec) Field efficiency.08889 m2 /s Where. FCe = A/t ---------(5.8 × 0. Theoretical field capacity.4 PERFORMANCE TEST AND EVALUATION The performance of the machine was evaluated through a field test.Lawn Mower Cycle Mini Project 5. FCt = Vt × Wt ---------(5.310 = 0 . Vt = Forward speed (m/s) 𝑊𝑡 = Theoretical width (m) Effective Field capacity. FCe = Effective Field capacity (m2 /s) FCt = Theoretical field capacity (m2 /s) Dept.6) = 0. Chittilappilly . This grass cutting machine can be used by both rural as well as urban dwellers. Dept. because there is proper gripping of the tyres in a dry condition of the soil. The Effective field capacity (FCe). 3. with an operating time of 90 seconds (1. Produce little noise. The machine was seen to be more effective when working in a dry soil condition. Chittilappilly .2 APPLICATION A lawn mower cycle is a machine used for cutting grass in lawns at the required height. They are less dangerous than rotary mowers. Are easy to transport and store. Theoretical field capacity ( FCt ) and field efficiency(%) are found out . 5.8m/s and the theoretical width of 0. 6. 4. The theoretical field capacity (FCt) of the machine was calculated to be 0.31m. of Mechanical Engineering 35 IESCE.1 DISCUSSION The performance test of lawn mower cycle is carried out on a lawn.84 %.08889 m2 /s and Field efficiency (%) as 35.248 m2 /s with a forward speed of 0.Lawn Mower Cycle Mini Project CHAPTER 6 RESULTS AND DISCUSSIONS A lawn mower cycle was designed. 6.The effective field capacity is obtained as 0. Require little maintenance. It is also affordable since the cost of production is low 6. 8. The mower is powered by the pushing force of cycle. Don't fill debris around the yard. 7.5 minutes) .3 ADVANTAGES 1. Don't stir up dust or emit harmful fumes. Low Cost 2. Are environmentally friendly. 6. fabricated and tested. Lawn Mower Cycle Mini Project 6. Chittilappilly .4 DESIGN Figure 6.1 View of mower Assembly Dept. of Mechanical Engineering 36 IESCE. 4025 37 IESCE. of Mechanical Engineering 300 Rs. Other expenses TABLE 6. Cost 1 Pinion Gear 2 nos 160 2 Main Gear Wheel 2 nos 750 3 Reel blades 1 nos 1050 4 Mower Frame 1 nos 600 5 M. Part Name Size/No. Elements of cost are the primary classifications of cost according to the factors upon which expenditure is incurred the elements of cost that constitute total cost of a product are: i.No. In order to compute the cost of each of these factors the cost of manufacturing is subdivided into what are known as elements of cost. Chittilappilly .5 ESTIMATE A manufacturing process concerned with conversion of raw materials into finished products with the help of labor and other services.S Rods 2 m length 250 6 Bicycle Parts 1 nos 500 7 M.1 COST ESTIMATION Sl. Material cost ii.S strips 1m length 105 8 Trolley Wheels 2 nos 70 9 Balancing Wheels 5 inch dia/ 2 nos 150 10 Nuts & Bolts 90 11 Workman ship a)MI2/2 nos b) M14/6 nos c) M18/2nos ----- Total Dept. Labor cost iii.Lawn Mower Cycle Mini Project 6. 2 MATERIALS USED No Parts Name Materials Used Quantity 1 Pinion Gear H. Steel 1 6 Trolley Wheels Rubber 2 7 Balancing Wheels Rubber 2 8 Nuts & Bolts Mild steel 10 Dept.S 2 2 Main Mower Wheel Cast iron 2 3 Reel blades Steel 6 4 Mower Frame Cast iron 1 5 Bicycle Frame G.Lawn Mower Cycle Mini Project TABLE 6.I.S. of Mechanical Engineering 38 IESCE. Chittilappilly . The machine is simply powered by the pushing force of a cycle.2 Back Wheel steering The back wheel steering can be added to this machine so that the lawn mower cycle can be easily turned in different angles.1 Energy storage The Lawn mower cycle can be modified to an electric hybrid lawn mower.1 CONCLUSION The aim of our project is to design. This project helped us to improve our practical knowledge and also to express a new idea on the work shop.2 FUTURE ENHANCEMENTS 7. 7. fabricate a lawn mower cycle. It would increase the overall capacity of the machine as more energy would be available. It is also affordable since the cost of production is low.2.Lawn Mower Cycle Mini Project CHAPTER 7 CONCLUSION AND FUTURE SCOPE 7. This does not have engine and is powered by a cycle. of Mechanical Engineering 39 IESCE. we feel that our aim and objectives of the project is fulfilled. This ensures a good control and making it possible to turn around hard corners and small obstacles. Dept. However by completing this project. Chittilappilly . getting its power from a battery and by human power given by pedaling. 7.2. 2010). Solar charged lawnmower (28th Jan. 3 No. of Mechanical Engineering 40 IESCE. R. (2005).Lawn Mower Cycle Mini Project REFERENCES 1. fabrication and evaluation of a spiral blade lawn mower 10. Nathan Fletcher.A. 2014 Design. J. R. Yong and Chow. October. Bloomberg Businessweek. Basil Okafor.O. 11th Edition. Principles of farm machinery 7. & Boroger. Optimum blade configuration for the cutting of soft solids.. Kepner. Chittilappilly . L . Fundamentals of Reel Mowers by TORO Commercial products 4. and Gopta. S. 2012).. (1997). European International Journal of Science and Technology Vol. 10. T. 8. New Delhi 6. Bainer. Nkakini. Atkins. 4 May. Kinnander. (2005).H. Machine Design. R. Design and Construction of an Improved Domestic Dept. Design project 9. 5. 2013 Simple Design of Self-Powered Lawn Mower 3. 2. Eurasia Publishing House Ltd. (1980).S. (2007) University Of Louisville . J.K. "Rise of the Lawn-Cutting Machines". E. International Journal of Engineering and Technology Volume 3 No. Jeremy. S. Khurmi. Ola (October 25. (1991).
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