PNEUMATIC PUNCHING MACHINE Introduction
Pneumatic systems operate on a supply of compressed air which must be made available in sufficient quantity and at a pressure to suit the capacity of the system. When the pneumatic system is being adopted for the first time, however it wills indeed the necessary to deal with the question of compressed air supply.
The key part of any facility for supply of compressed air is by means using reciprocating compressor. A compressor is a machine that takes in air, gas at a certain pressure and delivered the air at a high pressure.
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WORKING PRINCIPLE ur pro!ect works on the following three basic b asic principles. 1.
Air can flow.
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Air can be compressed.
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$if $iffer ference ence in air air pr pressu essurre can can caus causee mov movem emen ent. t.
The main ob!ectives of our pro!ect is to punch ob!ect with the help of air. %nitially we press the lever manually and the force is transmitted from the lever to the cylinder &'yringe(1) through a link. The air in the cylinder &'yringe(1) gets compressed and e*erts force force through through the pipe pipe to the ne*t cylind cylinder er &'yrin &'yringe(" ge(")) where where the punchin punching g tool tool is connected and hence the ob!ect is punched due to air pressure.
Thus the pro!ect is easy to operate o perate due to its simple mechanism.
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PROJECT LAYOUT
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PROJECT PICTURES
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ADVANTAGES
%t reduces the manual work
%t reduces the production time
/niform application of the load gives perfect removing of the bearing.
$amages to the bearing due to the hammering is prevented
%t occupies less floor space
0ess skilled operator is sufficient
LIMITATIONS
%nitial cost is high
2ylinder stroke length is constant
'pecific 'i3e punching operation only.
2an work only on thin papers 4 sheets.
APPLICATIONS
Pressing peration in all industries
Paper punching industries
0eather washer operation in all industries.
'heet 5etal Punching.
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PNEUMATICS Pneumatics is a section of technology that deals with the study and application of pressuri3ed gas to produce mechanical motion.
Pneumatic systems are e*tensively used in industry, where factories are commonly plumbed with compressed air or compressed inert gases. This is because a centrally located and electrically powered compressor that powers cylinders and other pneumatic devices through solenoid valves is often able to provide motive power in a cheaper, safer, more fle*ible, and more reliable way than a large number of electric motors and actuators.
Pneumatics also has applications in dentistry, construction, mining, and other areas.
Com!ri"on to #$dr!u%ic"
7oth pneumatics and hydraulics are applications of fluid power. Pneumatics uses an easily compressible gas such as air or a suitable pure gas, while hydraulics uses relatively incompressible liquid media such as oil. 5ost industrial pneumatic applications use pressures of about 68 to 188 pounds per square inch &8 to -98 kPa). :ydraulics applications commonly use from 1,888 to ,888 psi &-.9 to #+ 5Pa), but speciali3ed applications may e*ceed 18,888 psi &-9 5Pa).
Ad&!nt!'(" o) n(um!tic" •
'implicity of $esign And 2ontrol
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5achines are easily designed using standard cylinders ; other components. 5achines operate by simple < ( == type control.
R(%i!*i%it$
Pneumatic systems tend to have long operating lives and require very little maintenance.
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7ecause gas is compressible, the equipment is less likely to be damaged by shock. The gas in pneumatics absorbs e*cessive force, whereas the fluid of hydraulics directly transfers force.
Stor!'(
2ompressed gas can be stored, allowing the use of machines when electrical power is lost.
S!)(t$ •
>ery low chance of fire &compared to hydraulic oil).
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5achines can be designed to be overload safe.
Pn(um!tic %o'ic
Pneumatic logic systems &sometimes called air logic control) are often used to control industrial processes, consisting of primary logic units such as? •
And /nits
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r /nits
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@elay or 7ooster@ /nits
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0atching /nits
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@Timer@ /nits
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'orteberg relay
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=luidics amplifiers with no moving parts other than the air itself
Pneumatic logic is a reliable and functional control method for industrial processes. %n recent years, these systems have largely been replaced by electrical control systems, due to the smaller si3e and lower cost of electrical components. Pneumatic devices are still used in processes where compressed air is the only energy source available or upgrade cost, safety, and other considerations outweigh the advantage of modern digital control.
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PUNCHING %ntroduction Punching is a metal forming process that uses a punch press to force a tool, called a punch, through the workpiece to create a hole via shearing. The punch often passes through the work into a die. A scrap slug from the hole is deposited into the die in the process. $epending on the material being punched this slug may be recycled and reused or discarded. Punching is often the cheapest method for creating holes in sheet metal in medium to high production volumes. When a specially shaped punch is used to create multiple usable parts from a sheet of material the process is known as blanking. %n forging applications the work is often punched while hot, and this is called hot punching.
Proc(""
Punch tooling &punch and die) is often made of hardened steel or tungsten carbide. A die is located on the opposite side of the workpiece and supports the material around the perimeter of the hole and helps to locali3e the shearing forces for a cleaner edge. There is a small amount of clearance between the punch and the die to prevent the punch from sticking in the die and so less force is needed to make the hole. The amount of clearance needed depends on the thickness, with thicker materials requiring more clearance, but the clearance is always less than the thickness of the workpiece. The clearance is also dependent on the hardness of the workpiece. The punch press forces the punch through a workpiece, producing a hole that has a diameter equivalent to the punch, or slightly smaller after the punch is removed. All ductile materials stretch to some e*tent during punching which often causes the punch to stick in the workpiece. %n this case, the punch must be physically pulled back out of the hole while the work is supported from the punch side, and this process is known as stripping. The hole walls will show burnished area, rollover, and die break and must often be further processed. The slug from the hole falls through the die into some sort of container to either dispose of the slug or recycle it.
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Punc#in' C#!r!ct(ri"tic" •
Punching is the most cost effective process of making holes in strip or sheet metal for average to high fabrication
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%t is able to create multiple shaped holes
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Punches and dies are usually fabricated from conventional tool steel or carbides
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2reates a burnished region roll(over, and die break on sidewall of the resulting hole.
G(om(tr$
The workpiece is often in the form of a sheet or roll. 5aterials for the workpiece can vary, commonly being metals and plastics. The punch and die themselves can have a variety of shapes to create an array of different shaped holes in the workpiece. 5ultiple punches may be used together to create a part in one step.
E+uim(nt
5ost punch presses are mechanically operated, but simple punches are often hand( powered. 5a!or components of this mechanical press are the frame, motor, ram, die posts, bolster, and bed. The punch is mounted into the ram, and the die is mounted to the bolster plate. The scrap material drops through as the workpiece is advanced for the ne*t hole. A large computer controlled punch press is called a computer numerical controlled turret. %t houses punches and their corresponding dies in a revolving inde*ed turret. These machines use hydraulic, pneumatic, or electrical power to press the shape with enough force to shear the metal.
,orc("
The punch force required to punch a piece of sheet metal can be estimated from the following equation?
1"
Where t is the sheet metal thickness, 0 is the total length sheared &perimeter of the shape), and /T' is the ultimate tensile strength of the material.
$ie and punch shapes affect the force during the punching process. The punch force increases during the process as the entire thickness of the material is sheared at once. A beveled punch helps in the shearing of thicker materials by reducing the force at the beginning of the stroke. :owever, beveling a punch will disort the shape because of lateral forces that develop. 2ompound dies allow multiple shaping to occur. /sing compound dies will generally slow down the process and are typically more e*pensive than other dies. Progressive dies may be used in high production operations. $ifferent punching operations and dies may be used at different stages of the operation on the same machine.
C$%ind(r"
B =orce C Pressure Area D "E diameter piston D Area C #.1+ 1" C #.1+ in" D Pressure C -8 psi D #.1+ in" -8 psi C 166 lbs D =orce while e*tending greater than while retracting B 5ain decisions? 0ength and diameter D $iameter based on required force D 0arger diameter? more force, but more air %ntroduction 2omponents 5echanisms esources
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T#( T#r(( Princi%("
There are three scientific principles involved in each type of fluid systems. These include the following?
1) =luids can be compressed
") =luids can flow
#) Pressure differences can cause movement
F=luids can flowE relates to my sub!ect because for pneumatic systems to work, it needs the compressed air to flow through something in order to do a !ob right.
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LIST O, COMPONENTS - ACCESSORIES USED IN THE PROJECT 1.
Punching Tools
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Pneumatic 2ylinder
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0ever
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'procket
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Wooden 'urface 4 =rame
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2lamp 4 $ies &5ale 4 =emale)
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'pring
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PNEUMATIC CYLINDER
Pneumatic cylinders &sometimes known as air cylinders) are mechanical devices which use the power of compressed gas to produce a force in a reciprocating linear motion.?6 0ike hydraulic cylinders, pneumatic cylinders use the stored potential energy of a fluid, in this case compressed air, and convert it into kinetic energy as the air e*pands in an attempt to reach atmospheric pressure. This air e*pansion forces a piston to move in the desired direction. The piston is a disc or cylinder, and the piston rod transfers the force it develops to the ob!ect to be moved. ?6 Gngineers prefer to use pneumatics sometime because they are quieter, cleaner, and do not require large amounts of space for fluid storage.
7ecause the operating fluid is a gas, leakage from a pneumatic cylinder will not drip out and contaminate the surroundings, making pneumatics more desirable where cleanliness is a requirement. =or e*ample, in the mechanical puppets of the $isney Tiki oom, pneumatics are used to prevent fluid from dripping onto people below the puppets.
O(r!tion G(n(r!%
nce actuated, compressed air enters into the tube at one end of the piston and, hence, imparts force on the piston. 2onsequently, the piston becomes displaced &moved) by the compressed air e*panding in an attempt to reach atmospheric pressure. 1-
Comr(""i*i%it$ o) '!""("
ne ma!or issue engineers come across working with pneumatic cylinders has to do with the compressibility of a gas. 5any studies have been completed on how the precision of a pneumatic cylinder can be affected as the load acting on the cylinder tries to further compress the gas used. /nder a vertical load, a case where the cylinder takes on the full load, the precision of the cylinder is affected the most. A study at the
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Pneumatic systems are often found in settings where even rare and brief system failure is unacceptable. %n such situations locks can sometimes serve as a safety mechanism in case of loss of air supply &or its pressure falling) and, thus,remedyJremedyKK or abate any damage arising in such a situation. $ue to the leakage of air from input or output reduces the pressure and so the desired output.
T$("
Although pneumatic cylinders will vary in appearance, si3e and function, they generally fall into one of the specific categories shown below. :owever there are also numerous other types of pneumatic cylinder available, many of which are designed to fulfill specific and speciali3ed functions.
Sin'%(.!ctin' c$%ind(r
'ingle(acting cylinders &'A2) use the pressure imparted by compressed air to create a driving force in one direction &usually out), and a spring to return to the LhomeL position. 5ore often than not, this type of cylinder has limited e*tension due to the space the
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compressed spring takes up. Another downside to 'A2s is that part of the force produced by the cylinder is lost as it tries to push against the spring. 7ecause of those factors, single acting cylinders are recommended for applications that require no more than 188mm of stroke length ?6
Dou*%(.!ctin' c$%ind(r"
$ouble(acting cylinders &$A2) use the force of air to move in both e*tend and retract strokes. They have two ports to allow air in, one for outstroke and one for instroke. 'troke length for this design is not limited, however, the piston rod is more vulnerable to buckling and bending. Addition calculations should be performed as well. ?69
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SPROCKET
A sprocket or sprocket(wheel is a profiled wheel with teeth, cogs, or even sprockets that mesh with a chain, track or other perforated or indented material. The name @sprocket@ applies generally to any wheel upon which are radial pro!ections that engage a chain passing over it. %t is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley in that sprockets hav e teeth and pulleys are smooth.
'prockets are used in bicycles, motorcycles, cars, tracked vehicles, and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. Perhaps the commonest form of sprocket is found in the bicycle, in which the pedal shaft carries a large sprocket(wheel which drives a chain which in turn drives a small sprocket on the a*le of the rear wheel. Garly automobiles were also largely driven by sprocket and chain mechanism, a practice largely copied from bicycles. 'prockets are of various designs, a ma*imum of efficiency being claimed for each by its originator. 'prockets typically do not have a flange. 'ome sprockets used with timing belts have flanges to keep the timing belt centered. 'prockets and chains are also used for power transmission from one shaft to another where slippage is not admissible, sprocket chains being used instead of belts or ropes and sprocket( wheels instead of pulleys. They can be run at high speed and some forms of chain are so constructed as to be noiseless even at high speed. 19
LEVER A lever is a machine consisting of a beam or rigid rod pivoted at a fi*ed hinge, or fulcrum. %t is one of the si* simple machines identified by enaissance scientists. The word comes from the =rench lever, Lto raiseL, cf. a levant. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the ideal mechanical advantage of the lever.
,orc( !nd %(&(r"
A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in the hinge or bending in the beam. %n this case, the power into the lever equals the power out, and the ratio of output to input force is given by the ratio of the distances from the fulcrum to the points of application of these forces. This is known as the law of the lever.
C%!""(" o) L(&(r
0evers are classified by the relative positions of the fulcrum and the input and output forces. %t is common to call the input force the effort and the output force the load or the resistance. This allows the identification of three classes of levers by the relative locations of the fulcrum, the resistance and the effort?
2lass 1? =ulcrum in the middle? the effort is applied on one side of the fulcrum and the resistance on the other side, for e*ample, a crowbar or a pair of scissors.
2lass "? esistance in the middle? the effort is applied on one side of the resistance and the fulcrum is located on the other side, for e*ample, a wheelbarrow or a nutcracker or a bottle opener.
2lass #? Gffort in the middle? the resistance is on one side of the effort and the fulcrum is located on the other side, for e*ample, a pair of twee3ers or the human mandible.
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These cases are described by the mnemonic Lfre 1"#L where the fulcrum is in the middle for the 1st class lever, the resistance is in the middle for the "nd class lever, and the effort is in the middle for the #rd class lever.
L!/ o) t#( L(&(r
The lever is a movable bar that pivots on a fulcrum attached to a fi*ed point. The lever operates by applying forces at different distances from the fulcrum, or pivot.
Assuming the lever does not dissipate or store energy, the power into the lever must equal the power out of the lever. As the lever rotates around the fulcrum, points farther from this pivot move faster than points closer to the pivot. Therefore a force applied to a point farther from the pivot must be less than the force located at a point closer in, because power is the product of force and velocity.
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SPRINGS DE,INITION ,OR SPRING0
'prings are elastic bodies &generally metal) that can be twisted, pulled, or stretched by some force. They can return to their original shape when the force is released. %n other words it is also termed as a resilient member. CLASSI,ICATION O, SPRINGS0
7ased on the shape behavior obtained by some applied force, springs are classified into the following ways? 'P%
:G0%2A0 'P%
0GA= 'P%
'P%A0 'P%
TG<'%< :G0%2A0
T'%< 'P%
'P%
I1 HELICAL SPRINGS0 DE,INITON0
%t is made of wire coiled in the form of heli*. CROSS.SECTION0
2ircular, square or rectangular CLASSI,ICATION0
1) pen coil springs &or) 2ompression helical springs ") 2losed coil springs &or) Tension helical springs 23 HELICAL TENSION SPRINGS0 CHARACTERISTICS0
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=igure1 shows a helical tension spring. %t has some means of transferring the load from the support to the body by means of some arrangement.
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%t stretches apart to create load.
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The gap between the successive coils is small.
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The wire is coiled in a sequence that the turn is at right angles to the a*is of the spring.
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The spring is loaded along the a*is.
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7y applying load the spring elongates in action as it mainly depends upon the end hooks as shown in figure". ,IGURE1TENSION HELICAL SPRING
,IGURE1TYPES O, END HOOKS O, A HELICAL E4TENSION SPRING
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APPLICATIONS0
1) Marage door assemblies ") >ise(grip pilers #) carburetors 53 HELICAL COMPRESSION SPRINGS0 CHARACTERISTICS0 •
The gap between the successive coils is larger.
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%t is made of round wire and wrapped in cylindrical shape with a constant pitch between the coils.
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7y applying the load the spring contracts in action.
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There are mainly four forms of compression springs as shown in figure#.. They are as follows? 1) Plain end ") Plain and ground end #) 'quared end +) 'quared and ground end Among the four types, the plain end type is less e*pensive to manufacture. %t tends to bow sideways when applying a compressive load. ,IGURE1COMPRESSION HELICAL SPRING
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APPLICATIONS0
1) 7all point pens ") Pogo sticks #) >alve assemblies in engines 63 TORSION SPRINGS0 CHARACTERISTICS0 •
%t is also a form of helical spring, but it rotates about an a*is to create load.
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%t releases the load in an arc around the a*is as shown in figure+.
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5ainly used for torque transmission
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The ends of the spring are attached to other application ob!ects, so that if the ob!ect rotates around the center of the spring, it tends to push the spring to retrieve its normal position.
,IGURE1TORSION SPRING APPLICATIONS0 •
5ouse tracks
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ocker switches
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$oor hinges
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2lipboards
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Automobile starters
73 SPIRAL SPRINGS0 CHARACTERISTICS0 •
%t is made of a band of steel wrapped around itself a number of times to create a geometric shape as shown in figure.
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%ts inner end is attached to an arbor and outer end is attached to a retaining drum.
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%t has a few rotations and also contains a thicker band of steel.
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%t releases power when it unwinds.
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PUNCHING TOOLS - ACCESSORIES A punch is a hard metal rod with a shaped tip at one end and a blunt butt end at the other, which is usually struck by a hammer. 5ost woodworkers prefer to use a ball(peen hammer for using punches. Punches are used to drive ob!ects, such as nails, or to form an impression of the tip on a workpiece. $ecorative punches may also be used to create a pattern or even form an image. Punches and dies are necessities in a metal shop. They will help to make work more efficient in the realm of modular home construction to auto body repair and restoration. Whether in need of a punch for a variety of metal work tasks or for more specific needs in auto body shops, variety of punches and dies, that are capable of punching through a variety of metals.
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CONCLUSION ur team has made this pro!ect with utmost dedication which will help common people. This pro!ect has been made for the first time and this the pneumatic punching machine can easily punch the papers, metals, plastics etc. %nitially we press the lever manually and the force is transmitted from the lever to the cylinder &'yringe(1) through a link. The air in the cylinder &'yringe(1) gets compressed and e*erts force through the pipe to the ne*t cylinder &'yringe(") where the punching tool is connected and hence the ob!ect is punched due to air pressure.
Thus the pro!ect is easy to operate due to its simple mechanism.
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RE,ERENCES •
www.engineering.world.edu4me
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www.blown(film(machine.com4mechanical(type(pneumatic(type(manual( punchingmachine.htm
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www.howstuffworks.com
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www.188pro!ects.org
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www.technocrats.com4pro!ects4mechanical(pro!ect4
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www.students#-8.in
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