PROJECT REPORT ONTITLE OF THE PROJECT Submitted For The Partial fulfillment of Diploma In Mechanical Engineering Submitted by Ajinkya S. Khedekar : 134110001 Raj V. Patel : 134110007 Prasad C. Ghadashi : 134110018 Vikram H. Mane : 134110076 Year 2015-2016 Under The Guidance of Prof. K.P.Kudalkar VEERMATA JIJABAI TECHNOLOGICAL INSTITUTE MATUNGA, MUMBAI-400019 ACKNOWLEDGEMENT Pedal Powered Hacksaw Machine Page 1 “Project” is a very crucial part of every engineering student. To think of something new and different and bringing that imagination into practical is a very tedious job. It was not that easy for us too. But it was due to the kind co-operation & valuable guidance rendered to us by the people we would like to mention; it became easier for us to complete our project successfully. We take the great pleasure to present this project report on “Pedal Powered Hacksaw Machine”. We have taken great care that the information provided by is satisfactorialy enough and correct, but even then we welcome any correction. Written words have an unfortunate tendency to degenerate genuine gratitude into a formality. However, it is the only way to record one’s feelings permanently. Hence we take this opportunity to express our heartfelt thanks to all those who have been associated with our project. First of all, We are thankful to our project guide Prof. K.P.Kudalkar whose constant encouragement, presious guidance and full-fiedge co operation has lead to the success of this project. We would like to thank each other for actively participating and making this project what it is today. It was a full-blooded effort of our whole team without whom our project would have not been fruitful. We would like to thank almighty for making our project a full-fledged success. We would like to express our special thanks to our Department. CERTIFICATE Pedal Powered Hacksaw Machine Page 2 This is to certify that all the students of this group as mentioned earlier have successfully completed project report on “Pedal Powered Hacksaw Machine”, is found to be satisfactory and approved for the partial fulfillment of Diploma in Mechanical Engg. under the guidance of Prof.K.P.Kudalkar during the academic year 2015-2016 as prescribed by VJTI Mumbai. INTERNAL EXAMINER EXTERNAL EXAMINER Date:Place:- Pedal Powered Hacksaw Machine Page 3 Contents Chapter Page No 1 Abstract 5 2 Introduction 6 3 Future scope of the Project 7 4 Subjects Discussed 10 5 Sketch of Pedal Operated Hacksaw Machine 16 6 Main Components of Pedal Operated Hacksaw 17 7 Machine Working Principle 36 8 Advantages and Disadvantages 37 9 Calculations 38 10 References 41 Pedal Powered Hacksaw Machine Page 4 Moreover. PVC etc. Importance of this project lies in the very fact that it is green project and helps us to reduce our electricity need. The objective of the modal is using the conventional mechanical process which plays a vital role. The power hacksaw machine. The main aim is to reduce the human effort for machining various materials such as wooden blocks. Pedal Powered Hacksaw Machine Page 5 . if we want we can generate electricity with our project by connecting it to dynamo. Secondly. This project consists of a crank and slider mechanism. PVC materials. In the mechanism pedal is directly connected to the hacksaw through crank and slider mechanism for the processing of cutting the wooden blocks. steel. diode and battery.ABSTRACT :Pedal powered hacksaw machine is a machine which can be used for industrial applications and Household needs in which no specific input energy or power is needed. which runs on human power. this cutter can be used and transferred to our working place easily. works on the principle of the conversion of rotational motion to oscillatory motion. metal bars. A saw may be worked by hand. The cutting edge of a saw is either a serrated blade or an abrasive. Some third world development projects currently transform used bicycles into pedal powered tools for sustainable development. At the rate of ¼ HP. Some applications include pedal powered laptops. Pedal Powered Hacksaw Machine Page 6 . Many devices can be run right away with mechanical energy. water. continuous pedalling can be served for only short periods. An individual can generate four times more power (1/4 HP) by pedalling than by hand-cranking. Less commonly pedal power is used to power agricultural and hand tools and even to generate electricity. This technology is most commonly used for transportation and has been used to propel bicycles for over a hundred years.INTRODUCTION :Pedal power is the tr.ansfer of energy from a human source through the use of a foot pedal and crank system. or powered by steam. However. pedal powered grinders and pedal powered water wells. As a consequence of the brainstorming exercise. This project concentrates on pedal powered hacksaw machining. it was apparent that the primary function of pedal power one specific product was particularly useful: the bicycle. pedalling at half this power (1/8 HP) can be sustained for close to 60 minutes but power capability can depend upon age. electric or other power. An abrasive saw uses an abrasive disc or band for cutting. A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. rather than a serrated blade. approximately 10 minutes. Future Scope of Pedal Powered Hacksaw Machine:- Rice Threshing Pedal Powered Hacksaw Machine Peanut shelling Page 7 . Winnoving Corn Shelling Pedal Powered Hacksaw Machine Page 8 . Operating a wood working lathe Pedal Powered Hacksaw Machine Page 9 . its practical use was largely confined to low-power domestic applications for over a century. in which it is more efficient and safer than a comparable steam engine. This engine is currently exciting interest as the core component of micro combined heat and power (CHP) units. the Stirling engine is a closedcycle regenerative heat engine with a permanently gaseous working fluid. in this context. More specifically. Because the Stirling engine is compatible with alternative and renewable energy sources it could become increasingly significant as the price of conventional fuels rises. Originally conceived in 1816 as an industrial prime mover to rival the steam engine. it has a low power-to-weight ratio rendering it more suitable for use in static installations where space and weight are not at a premium. and its ability to use almost any heat source. However. means a thermodynamic in which the working fluid is permanently contained within the system.SUBJECTS DISCUSSED :1. Stirling Engine : A stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas (the working fluid) at different temperatures. Closed cycle . Pedal Powered Hacksaw Machine Page 10 . quiet operation. known as the regenerator. such that there is a net conversion of heat energy to mechanical work. and regenerative describes the use of a specific type of internal heat exchanger and thermal store. The Stirling engine is noted for high efficiency compared to steam engines. The inclusion of a regenerator differentiates the Stirling engine from other closed cycle hot air engines. and also in light of concerns such as peak oil and climate change. The heat energy source is generated external to the Stirling engine rather than by internal combustion as with the Otto cycle or Diesel cycle engines. so we have to find more ways to get useful energy. Many industries use furnaces for production processes. Pedal Powered Hacksaw Machine Page 11 . But as the cost of the project is very high. We can use this excess heat to run the sterling engine and hence produce electricity. in which most of the heat is lost. so we decided to reject it. Energy saved is energy produced.The energy crisis is increasing day by day. 2. We always see that road lights continuously glow whether vehicles are on the road or not. Pedal Powered Hacksaw Machine Page 12 . We can use this simple concept to the project. When vehicle pass through first sensor it sends the signal to the microcontroller that the vehicle is passing along that particular distance then light will glow for that particular time and when vehicle goes out from the second sensor. We can connect one mechanical rod with the dynamo and fit this rod on the surface of the road . When dynamo move. and with the help of this voltage we can light the bulb. we can generate voltage. In actual practice with the help of this voltage we can charge the battery and then we can use this voltage to light the small bulb. If we install this unit to the any small flyover then with the help of this mechanism. We can use two sensors between some distances.Electricity Generation Using Speed Breaker :In this model we show that how we can generate electricity from the busy traffic. Different types of basic electronics components has been used to get the desired output like capacitor. resister etc. Conversion of the mechanical energy into electrical energy is widely used concept. The second part of the project is the efficient use of energy by using simple electronics. It is a mechanism to generate power by converting the potential energy generated by a vehicle going up on a speed breaker into rotational energy.When any vehicle moves from this roller then due to friction. then it generates a voltage and this voltage now connects to the bulbs. vehicle rotate the rod or roller and roller then move the dynamo. We can introduce a concept to avoid this wastage of light. Then the second sensor sends a signal to a microcontroller that vehicle has been passed through that particular path then light gets off automatically. When any vehicle pass from first sensor then first sensor becomes on. By using a LDR we can avoid a waste of light that glow in a day time. for that time the road lights gets on and when it pass from second sensor the second sensor become on and the first sensor gets off then the road light gets off.We have also used a light diode resistance(LDR) when LDR senses a light around it all the road lights gets off and when LDR senses there is a dark around it then LDR sends a signal to microcontroller then all the road lights gets on. Pedal Powered Hacksaw Machine Page 13 . The two sensors are made from the concept of electronics. it is difficult to achieve proper balance between speed and torque. Also. These sensors are called an infrared sensor which is made from photo diode and light emitting diode each. It gives low and non-uniform voltage. hence we decided against it. it will help people for comfortable boarding and alighting.3. 2. we use fans which needs electricity.If we reduce one seat from the row of three seats which is close to door. Since we cannot use this modification in rainy seasons. We can attach hollow structures on the roof of compartment as shown in figure which forces the air to come inside and flows through the windows and doors. Sufficient energy loss takes place in ventilation.Modification In Local Train’s Compartment :1. Pedal Powered Hacksaw Machine Page 14 . hence we decided to reject it.For ventilation in local compartments. we can make easy and eco-friendly ventilation system in the compartments using natural air flowing around the compartment due to movement of train. Harvesting etc. it speeds up the harvesting process. Two elements scissors type action. Crop Cutter:India is an agricultural country. Since. So for the development of our country. plucking and digging or a combination of these operations for removing the crop from under the ground or above the ground or removing the useful part or fruits from plants.4. There are many steps in agriculture field like Ploughing. Tearing action with a rough serrated edge High velocity single element impact with sharp edge. Pedal Powered Hacksaw Machine Page 15 .Harvesting action can be done by four ways: Slicing action with a sharp tool. In India harvesting is done by sickle which is time consuming process. hence we decided to reject it. the agricultural sector of our economy should be developed. Sowing. trials of this project are not possible in urban cities like Mumbai. By using crop cutter. picking. Harvesting is the operation of cutting. The economy of our nation is mostly dependent on agriculture. 5. Pedal Powered Hacksaw Machine :- Pedal Powered Hacksaw Machine Page 16 . Hacksaw 11. Clutch 8. Crank 5. Bearing Blocks 9. Connecting Rod 6. Flywheel 7. Blade Pedal Powered Hacksaw Machine Page 17 . Sprocket 3. Brake 10.Main Components of Pedal Powered Hacksaw Machine :1. Chain 4. Pedal 2. as it is known today.1. Pedal Powered Hacksaw Machine Page 18 . Pedal will be used to transfer our muscular energy to the large sprocket. The safety bicycle. Pedals usually consist of a spindle that threads into the end of the crank and a body. It provides the connection between the cyclist’s foot or shoe and the crank allowing the leg to turn the bottom bracket spindle and propel the bicycle's wheels. Pedal :A bicycle pedal is the part of a bicycle that the rider pushes with their foot to propel the bicycle. on which the foot rests or is attached. came into being when the pedals were attached to a crank driving a sprocket that transmitted power to the driven wheel by means of a roller chain. Pedals were initially attached to cranks connecting directly to the driven (usually front) wheel. that is free to rotate on bearings with respect to the spindle. Some sprockets used with timing belts have flanges to keep the timing belt centered. or even sprockets that mesh with a chain. Sprocket:A sprocket or sprocket-wheel is a profiled wheel with teeth. Sprockets and chains are also used for power transmission from one shaft to another where slippage is not admissible. Early automobiles were also largely driven by sprocket and chain mechanism. tracked vehicles. in which the pedal shaft carries a large sprocket-wheel. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passing over it. tape etc.2. sprocket chains being used instead of belts or ropes and sprocket-wheels instead of pulleys. which drives a chain. a maximum of efficiency being claimed for each by its originator. Larger sprocket will take the energy from pedal and transfer it to the smaller sprocket which will further transmit it to the shaft. motorcycles. which. It is distinguished from a gear in that sprockets are never meshed together directly. in turn. and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track. Pedal Powered Hacksaw Machine Page 19 . drives a small sprocket on the axle of the rear wheel . cogs. and differs from a pulley in that sprockets have teeth and pulleys are smooth. Sprockets are of various designs. They can be run at high speed and some forms of chain are so constructed as to be noiseless even at high speed. cars. Sprockets typically do not have aflange. Perhaps the most common form of sprocket may be found in the bicycle. Sprockets are used in bicycles. a practice largely copied from bicycles.track or other perforated or indented material. and efficient means of power transmission. It is distinguished from a gear in that sprockets are never meshed together directly. and differs from a pulley in that sprockets have teeth and pulleys are smooth.3. having two inner plates held together by two sleeves or bushings upon which rotate two rollers. consisting of two outer plates held together by pins passing through the bushings of the inner links. Construction of the Chain: There are actually two types of links alternating in the bush roller chain. cogs. or even sprockets that mesh with a chain. instead of separate bushings or sleeves holding the inner plates together. the outer links. reliable. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passing over it. Inner links alternate with the second type. The first type is inner links. It is a simple. It consists of a series of short cylindrical rollers held together by side links. Sprocket chain :Sprocket Chain: Roller chain or bush roller chain is the type of chain drive most commonly used for transmission A sprocket or sprocket-wheel is a profiled wheel with teeth. It is driven by a toothed wheel called a sprocket. The "bushingless" roller chain is similar in operation though not in construction. track or other perforated or indented material. the plate has a tube stamped Pedal Powered Hacksaw Machine Page 20 . with both the inner and outer plates held by pins which directly contacted the sprocket teeth. lubrication of roller chains is of primary importance for efficient operation as well as correct tensioning. The original power transmission chain varieties lacked rollers and bushings. This distributed the wear over a greater area. from the sliding friction against the bushings. The roller chain design reduces friction compared to simpler designs. Continuous. resulting in higher efficiency and less wear. This problem was partially solved by the development of bushed chains. clean. In a reciprocating engine. as long as the chain is sufficiently lubricated. Crank :A crank is a mechanical part able to perform a conversion between reciprocating motion and rotational motion. and the plates where they pivoted on the pins. however this configuration exhibited extremely rapid wear of both the sprocket teeth. This has the advantage of removing one step in assembly of the chain. however the teeth of the sprockets still wore more rapidly than is desirable. The addition of rollers surrounding the bushing sleeves of the chain and provided rolling contact with the teeth of the sprockets resulting in excellent resistance to wear of both sprockets and chain as well. with the pins holding the outer plates passing through bushings or sleeves connecting the inner plates. There is even very low friction. it translates reciprocating motion of Pedal Powered Hacksaw Machine Page 21 .into it protruding from the hole which serves the same purpose. Sprocket chain will transfer motion from the large sprocket to the small sprocket. 4. and sometimes a torsional or vibrational damper at the opposite end.the piston into rotational motion. In order to do the conversion between two motions. It is typically connected to a flywheel to reduce the pulsation characteristic of the four-stroke cycle. Pedal Powered Hacksaw Machine Page 22 . whereas in a reciprocating compressor. the crankshaft has "crank throws" or "crankpins". it converts the rotational motion into reciprocating motion. to which the "big ends" of the connecting rods from each cylinder attach. to reduce the torsional vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal. additional bearing surfaces whose axis is offset from that of the crank. Crank will convert rotary motion of shaft into the reciprocating motion which will further transmit to the hack saw assembly. 5. they form a simple mechanism that converts reciprocating motion into rotating motion. before the development of engines.e. they were first used in this way. Earlier mechanisms. Together with the crank. Historically. i. Connecting rods may also convert rotating motion into reciprocating motion. Pedal Powered Hacksaw Machine Page 23 . piston pushing and piston pulling. Connecting Rod :The connecting rod connects the piston to the crank or crankshaft. it may transmit either a push or a pull and so the rod may rotate the crank through both halves of a revolution. As a connecting rod is rigid. the connecting rod is only required to push. Flywheels have an inertia called the moment of inertia and thus resist changes in rotational speed. such as automotive engines.such as chains. a flywheel releases stored Pedal Powered Hacksaw Machine Page 24 . and hence its stored energy. Energy is transferred to a flywheel by the application of a torque to it. The amount of energy stored in a flywheel is proportional to the square of its rotational speed. thereby increasing its rotational speed. These are of a distinctly different design from earlier forms of connecting rods. We are using the connecting rod to convert the rotary motion of crank into reciprocating motion and supplied it to the hack saw assembly.Flywheel: A flywheel is a rotating mechanical device that is used to store rotational energy. could only pull. Today. In a few two-stroke engines. Conversely. used in steam engines and steam locomotives. 6. connecting rods are best known through their use in internal combustion piston engines. at rates that exceed the abilities of the energy source. torque from the engine. thereby decreasing the flywheel's rotational speed. the angular momentum of a flywheel is purposely Pedal Powered Hacksaw Machine Page 25 . For example. flywheels are used in reciprocating engines because the energy source. This is achieved by collecting energy in the flywheel over time and then releasing the energy quickly. Controlling the orientation of a mechanical system.energy by applying torque to a mechanical load. is intermittent. In such applications. Delivering energy at rates beyond the ability of a continuous energy source. Common uses of a flywheel include: Providing continuous energy when the energy source is discontinuous. As our hack saw assembly is inclined. Pedal Powered Hacksaw Machine Page 26 . Flywheels are typically made of steel and rotate on conventional bearings. these are generally limited to a revolution rate of a few thousand RPM. Some modern flywheels are made of carbon fibre materials and employ magnetic bearings. Flywheel will store the energy during downward stroke and supply the stored energy during upward stroke to lift up the hack saw assembly. Additionally. we have to provide more energy to lift up the hack saw assembly.transferred as a torque to the attaching mechanical system when energy is transferred to or from the flywheel. their disposal is more eco-friendly. thereby causing the attaching system to rotate into some desired position.000 RPM. enabling them to revolve at speeds up to 60. Carbon-composite flywheel batteries have recently been manufactured and are proving to be viable in real-world tests on mainstream cars. one shaft is driven by a motor and the other drives a drill chuck. we will release the clutch so that it will get engaged and will connect the flywheel and crank. one shaft is typically attached to an engine or other power unit (the driving member) while the other shaft (the driven member) provides output power for work. or unlocked and spinning at different speeds (disengaged). for instance.7. Pedal Powered Hacksaw Machine Page 27 . While typically the motions involved are rotary. The clutch connects the two shafts so they may be locked together and spin at the same speed (engaged). linear clutches are also possible. especially from driving shaft to driven shaft.g. Clutches are used whenever the transmission of power or motion must be controlled either in amount or over time (e. In a torque-controlled drill.. As the speed of the flywheel increases.Clutch: A clutch is a mechanical device that engages and disengages the power transmission. In these devices. clutches control whether automobiles transmit engine power to the wheels). clutches connect and disconnect two rotating shafts (drive shafts or line shafts). In the simplest application. When we will start the machine. electric screwdrivers limit how much torque is transmitted through use of a clutch. locked together but spinning at different speeds (slipping). we will press the clutch lever so that clutch will get disengaged and prevent the connection of flywheel and crank. as little slippage (difference in speeds) as possible between the two members is desired. The purpose of friction clutches is to connect a moving member to another that is moving at a different speed or stationary. often to synchronize the speeds. and/or to transmit power.Friction clutches: The vast majority of clutches ultimately rely on frictional forces for their operation. Pedal Powered Hacksaw Machine Page 28 . Usually. to support) another. and reduces friction between moving parts. size. the motions allowed.8. it may prevent a motion by controlling the vectors of normal forces that bear on the moving parts. The term "bearing" is derived from the verb "to bear". for example. brakes. cut or formed into a part. with varying degrees of control over the form. such as by minimizing friction. Bearing blocks will be used to provide support to the rotating shaft on which flywheel. crank. or. their manufacture requires some of the highest standards of current technology. The simplest bearings are bearing surfaces. clutch. Many bearings also facilitate the desired motion as much as possible. The most sophisticated bearings for the most demanding applications are very precise devices. roughness and location of the surface. Pedal Powered Hacksaw Machine Page 29 . Bearing Blocks :A bearing is a machine element that constrains relative motion to only the desired motion. The design of the bearing may. provide for free linear movement of the moving part or for free rotation around a fixed axis. and sprocket are mounted.. Bearings are classified broadly according to the type of operation. Other bearings are separate devices installed into a machine or machine part. a bearing being a machine element that allows one part to bear (i. or to the directions of the loads (forces) applied to the parts.e. such as drag racing cars with both wheel brakes and a parachute. or rail. for example by transferring the energy to a rotating flywheel. Most brakes commonly use friction between two surfaces pressed together to convert the kinetic energy of the moving object into heat. but may also take other forms such as the surface of a moving fluid (flaps deployed into water or air). For example. Brake :A brake is a mechanical device that inhibits motion. Some vehicles use a combination of braking mechanisms. Pedal Powered Hacksaw Machine Page 30 . which may be stored for later use. slowing or stopping a moving object or preventing its motion. Eddy current brakes use magnetic fields to convert kinetic energy into electric current in the brake disc. or airplanes with both wheel brakes and drag flaps raised into the air during landing. Brakes are generally applied to rotating axles or wheels. Other methods convert kinetic energy into potential energy in such stored forms as pressurized air or pressurized oil. fin. regenerative braking converts much of the energy to electrical energy.9. though other methods of energy conversion may be employed. which is converted into heat. Still other braking methods even transform kinetic energy into different forms. Pedal Powered Hacksaw Machine Page 31 . if we have to stop the machine in case of emergency.Magnetic brake system: Disclosed is a magnetic brake system for a vehicle. a braking sensor for detecting whether a brake pedal is applied. Sometimes. a magnetic polarity sensor for detecting magnetic polarity of the brake disk solenoids. comprising: a plurality of brake disk solenoids for generating the magnetic force. the wheel speed sensor and the magnetic polarity sensor. a plurality of brake pad solenoids for generating the magnetic force. a wheel speed sensor for detecting wheel speed. then we will press the brake lever so that it will decrease the speed of the hack saw assembly. and a control unit for controlling the brake pad solenoids using signals from the braking sensor. plumbers and electricians often cut plastic pipe and plastic conduit with them. There are hand saw versions and powered versions (power hacksaws). Most hacksaws are hand saws with a C-shaped frame that holds Pedal Powered Hacksaw Machine Page 32 . originally and principally for cutting metal.10. such as plastic and wood. They can also cut various other materials. for example. HackSaw :A hacksaw is a fine-toothed saw. A screw or other mechanism is used to put the thin blade under tension. On hacksaws. as with most frame saws. Panel hacksaws forgo the frame and instead have a sheet metal body. the blade can be mounted with the teeth facing toward or away from the handle. usually a pistol grip. they can cut into a sheet metal panel further than a frame would allow. These saws are no longer commonly available. with pins for attaching a narrow disposable blade.a blade under tension. Pedal Powered Hacksaw Machine Page 33 . Some frame saws. and angle grinders fitted with metal-cutting blades and discs are now used for longer cuts in sheet metals. hacksaw blades should be set to be facing forwards. Power tools including nibblers. including Fret Saws and Piercing Saws. Such hacksaws have a handle. In normal use. jigsaws. but hacksaw blade holders enable standard hacksaw blades to be used similarly to a keyhole saw or pad saw. have their blades set to be facing the handle because they are used to cut by being pulled down against a horizontal surface. The frames may also be adjustable to accommodate blades of different sizes. cutting vertically downwards with work held in a bench vice. resulting in cutting action on either the push or pull stroke. Powered hacksaws may use large blades in a range of sizes. As hacksaw teeth are so small. with a minimum of three teeth in the material. The pitch of the teeth can be anywhere from fourteen to thirty-two teeth per inch (tpi) for a hand blade. with as few as three tpi for a large power hacksaw blade.11. Blade :Blades are available in standardized lengths. they are set in a "wave" set. usually 10 or 12 inches for a standard hand hacksaw. or small machines may use the same hand blades. The blade chosen is based on the thickness of the material being cut. As for other saws they are set from side to side to provide Pedal Powered Hacksaw Machine Page 34 . "junior" hacksaws are typically 150mm long. giving greatly improved cutting and tooth life. so care needs to be taken to prevent brittle fracture of the blade. which wore well and resisted breakage. These blades were first available in the 'All-hard' form which cut accurately but were extremely brittle. A softer form of high speed steel blade was also available. and were relatively soft and flexible. rather than alternate teeth set left and right. but the set of a hacksaw changes gradually from tooth to tooth in a smooth curve. but also wore out rapidly.a kerf or clearance when sawing. but was less stiff and so less accurate for precise sawing. which limits the usefulness of this otherwise popular saw. Since the 1980s. 'Low alloy' blades are still the only type available for the Junior hacksaw. This limited their practical use to benchwork on a workpiece that was firmly clamped in a vice. their use is now almost universal. Except where cost is a particular concern. without risk of breakage. Early blades were of carbon steel. Pedal Powered Hacksaw Machine Page 35 . Hacksaw blades are normally quite brittle. They avoided breakage. A strip of high speed steel along the tooth edge is electron beam welded to a softer spine. As the price of these has dropped to be comparable with the older blades. bi-metal blades have been used to give the advantages of both forms. For several decades now. this type is now obsolete. now termed 'low alloy' blades. hacksaw blades have used high speed steel for their teeth. When starting a cut with an all-hard blade. Use light feed pressure on soft materials and work with small cross sections. and with tungsten carbide teeth on steel alloy backs. The following “rule-ofthumb” can be followed for selecting the correct blade: Use a 4-tooth blade for cutting large sections or readily machined metals. theall-hard bladeis best for straight. Power Hacksaw blade :Blades are also made from tungsten and molybdenum steels. i) Flexible-back blades -should be used where safety requirements demand a shatterproof blade. These blades should also be used for cutting odd-shaped work if there is a possibility of the work coming loose in the vise. the blade could shatter and flying pieces cause injuries. Large sections and soft materials require a coarse-tooth blade. be sure the blade does not drop on the work when cutting starts. ii) All-hard blade -For a majority of cutting jobs. If it falls. apply heavy feed pressure on hard materials and large work. Pedal Powered Hacksaw Machine Page 36 . accurate cutting under a variety of conditions. The choice depends upon use. Blades are made in two principal types: flexible-back and all-hard. For best cutting action. Small or thin work and hard materials require a fine-tooth blade. Use the three-tooth rule at least three teeth must be in con-tact with the work.Selection of blade:Proper blade selection is important. If the information (proper torque for a given blade on a given machine) is not available. the following methods can be used: Tighten the blade until a low musical ring is heard when the blade is tapped lightly. A high pitched tone indicates that the blade is too tight. Use 10.Use a 6-tooth blade for cutting harder alloys and miscellaneous cutting. A dull thud means the blade is too loose. The shape of the blade pin hole can serve as an indicator of whether the blade is tensioned Pedal Powered Hacksaw Machine Page 37 . the blade must be properly tensioned. The blade must also lie perfectly flat against the mounting plates. Many techniques have been developed for properly mounting and tensioning blades. Mounting a Power Hacksaw blade:The blade must be mounted to cut on the power (back) stroke. Use a torque wrench and consult the manufacturer’s literature.and 14-tooth blades primarily on light duty machines where work is limited to small sections requiring moderate or light feed pressure. If long life and accurate cuts are to be achieved. The hacksaw is passed through the guide ways by means of maintaining the cutting axis. As the user operated the pedal. The power is transmitted to the crank and slider mechanism. Pedal Powered Hacksaw Machine Page 38 . When proper tension is achieved. the pin holes will become slightly elongated. the disc which is having an extended rod is connected to the sliding portion of the hacksaw directly by means of a linkage. The dead weight is for compressive force while the user operated the foot pedal. the hack saw cuts the various materials automatically with less power. This mechanism is used to rotate the crank disc. The blade will become more firmly seated after the first few cuts and will stretch slightly.properly. The blade will require re-tensioning (retightening) before further cutting can be done. WORKING PRINCIPLE It consists of the pedal arrangement which rotates the crank and through it slider consists of oscillating mechanism. including at construction sites and furniture units. Without human effort it’s not operated IV. DISADVANTAGES:I. Power saving as it is manually operated III.ADVANTAGES:I. or to cut metal for window panes. Comfortable then ordinary hacksaw VI. Time consuming as compared to electrical power hacksaw III. Easy machinery used IV. It could be used wherever metal cutting is done in small scales. It is portable VII. As it is pedal operated so good for health V. Time saving as compared to simple hacksaw II. Not fit for heavy production Pedal Powered Hacksaw Machine Page 39 . It’s totally manually operated II. of teeths on Driven Sprocket = T2 Pitch of the Chain = P Teeth Ratio = T1/T2 Velocity Ratio = (T1/T2 = N2/N1) R1 = P/2 cosec ( 180 / T1 ) R2 = P/2 cosec ( 180 / T2 ) Length of the chain = п (R1 + R2) + 2x + (R1 – R2)2/x Pedal Powered Hacksaw Machine Page 40 . of teeths on Driver Sprocket = T1 No.Calculations:Chain Driver Sprocket X Driven Sprocket Radius of Driver Sprocket = R1 Radius of Driven Sprocket = R2 No. Pedal Powered Hacksaw Machine Page 41 . F = Force applied by human in N r = Length of pedal arm Now.Input Power = 2 п N T / 60 where. The cutting force required = п x D x t x τs where D = Diameter of workpiece t = Cutting Depth τs = Shear strength of material In case of rectangular workpiece. B = Breadth of workpiece L = Length of workpiece Maximum power required = Fmax x V where. N = Sprocket speed in rpm T = Torque applied by human in Nm T=Fxr where. we can increase the torque by increasing the length of pedal from its centre. Fmax = 2 x (B+L) x t x τs where. V = velocity of blade SHEAR STRENGTH OF VARIOUS MATERIALS Pedal Powered Hacksaw Machine Page 42 . 8 to 41 119 to 203 245 to 812 20.Metal τs N/mm2 Carbon steel 0.10% C 0.5 420 to 490 98 to 266 Page 43 .20% C 0.30% C High strength low alloy steel Silicon Steel Stainless steel Aluminium alloys Copper and Bronze Lead alloys Magnesium alloys Nickel alloys Tin alloys Titanium alloys Zinc alloys Pedal Powered Hacksaw Machine 245 to 310 308 to 385 364 to 469 315 to 446 420 to 490 399 to 903 49 to 322 154 to 490 12.5 to 77. K Gupta. Theory of Machines By R. Khurmi and J. ‘A Textbook of Production Engineering ‘ by P. 2.S.1st multicolour edition .References: 1.C.Sharma Pedal Powered Hacksaw Machine Page 44 . Pedal Powered Hacksaw Machine Page 45 .
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