The document details a project on the design and fabrication of a poka-yoke pneumatic fixture for milling and shaper machines, submitted by a group of mechanical engineering students at Mahakal Institute of Technology & Science. It emphasizes the importance of work holding in industrial automation, outlining the advantages of pneumatic systems, such as safety, efficiency, and environmental friendliness. The report includes acknowledgments, methodology, and a thorough exploration of related concepts, tools, and design considerations for improving manufacturing processes.

1. DESIGN AND FABRICATION OF POKA YOKE
PNEUMATIC FIXTURE FOR MILLING AND SHAPER
MACHINE
A Project Report
Submitted By-
Arun Singh Rathore, Mohit Verma, Shubham Bagi, Shubham
Dhaneshree, Shubham Mathur, Shubham Singh Rathore.
Towards Partial Fulfillment for the Award of
Bachelor of Engineering (Mechanical Engineering)
Guided By-
Prof. Pankaj Gera
Department of Mechanical Engineering Mahakal Institute of Technology &
Science, Ujjain
Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal
2016-2017

2. MAHAKAL INSTITUTE OF TECHNOLOGY & SCIENCE, UJJAIN
(Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal M.P.)
(2016-2017)
CERTIFICATE
This is to certify that Mr Arun Singh Rathore, Mr. Mohit Verma, Mr. Shubham Bagi, Mr.
Shubham Dhaneshree and Mr. Shubham Mathur, Shubham Singh Rathore. Student of B.E.
(Mechanical Engineering Department) of this college has carried out Project “DESIGN AND
FABRICATION OF POKA YOKE PNEUMATIC FIXTURE FOR MILLING AND SHAPER
MACHINE.”
It is submitted towards partial fulfillment of the requirements for the award of Bachelor of
Engineering in Mechanical Engineering from Mahakal Institute of Technology & Science;
Ujjain affiliated to Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal (M.P.).
Prof. Pankaj Gera Prof. Santosh Vyas Prof. V.M. Shah
Project Guide Head of Department Director
M.I.T.S., Ujjain M.I.T.S., Ujjain M.I.T.S., Ujjain

3. ACKNOWLEDGEMENT
The successful completion of the project is the result of dedicated efforts of many people and
this report would be incomplete without giving due credit to them. This acknowledgement is
taken of small gratitude in recognition of the help provided by them.
We wish to express our heartfelt appreciation to all the people who had contributed to this
project, both explicitly and implicitly. First to all we want to thank our projects guide Prof.
Pankaj Gera for giving us this opportunity to work under his guidance. His empathy towards
us made our work easy. Many thank to him for encouraging and supporting us to complete this
project work. We are thankful to Prof. Santosh Vyas Head of the Department, Mechanical
Engineering and Prof. V.M Shah Director Mahakal Institute Of Technology & Science, Ujjain
for understanding our problem and shorting them out. We are thankful to staff of Mechanical
Engineering Department for letting us know about problem of industry and encouraging us to
work on it. In the last but not least, we are also thankful to all the persons and colleagues who
have helped us directly or indirectly during this project.
Arun Singh Rathore
Mohit Verma
Shubham Bagi
Shubham Dhaneshree
Shubham Mathur
Shubham Singh Rathore

4. DECLARATION
We final year students of B.E. (Mechanical Engineering) hereby declare that
major project work titled as “DESIGN AND FABRICATION OF POKA YOKE
PNEUMATIC FIXTURE FOR MILLING AND SHAPER MACHINE” is
original to the best of our knowledge and has not been submitted in any institute
or university under Bachelor of Engineering program.
NAMES & SIGNATURES OF STUDENTS WITH DATE
1. Arun Singh Rathore
2. Mohit Verma
3. Shubham Bagi
4. Shubham Dhaneshree
5. Shubham Mathur
6. Shubham Singh Rathore

5. ABSTRACT
As the modern industries are shifting towards the automation, most of the industrial production
is held by the aid of robots and in such boom of modernization the main problem that was face
by the industries is to held work piece and proper position during machining work. Because of
heavy machineries cutting forces and due to little care needed on the automation work quality
of the automation fabricated product is little bit lesser than expectation. Hence it is must to
design a rigid and efficient work holding device called jigs and fixtures. Work holding and
releasing is the most essential act to carry out machining to hold the job in proper position. To release
the job quickly and hold the job rigidly, to prevent the vibrations of the job while the machining is
carried out we are using mechanical work holding devices. In this project we are dealing with pneumatic
fixture used in milling or shaper machines. In pneumatic type piston cylinder arrangement one end of
piston rod is connected to the movable jaw and the piston slides in the cylinder. Here the air actuates
the movement of the piston this in turn actuates the movable jaw. Here the principle movement is only
a reciprocating movement. Pneumatic systems are safer than electromotive systems because they
can work in inflammable environment without causing fire or explosion. Apart from that,
overloading in pneumatic system will only lead to sliding or cessation of operation. Unlike
electromotive components, pneumatic components do not burn or get overheated when
overloaded. The operation of pneumatic systems does not produce pollutants. The air released
is also processed in special ways. Therefore, pneumatic systems can work in environments that
demand high level of cleanliness. And use of pneumatic systems in turn reduces the
manufacturing times of jobs by a significant amount, hence increasing the production
efficiency.
Keywords: Jigs, Fixtures, Pneumatic Vice, Job.

6. CONTENTS page no.
Acknowledgement i
Abstract ii
CHAPTER 1: Introduction 1-10
1.1 Pneumatics and Compressed Air 2
1.2 Poka-Yoke 5
1.3 Jigs and Fixtures 8
CHAPTER 2: Literature Review 11-13
2.1 Principle of Locations 11
2.2 Design Considerations in Fixtures 12
2.3 Clamping Approach 12
CHAPTER 3: Apparatus and Tool Used 14-23
3.1 Compressor 14
3.2 Cylinder 17
3.3 Direction Control Valve 18
3.4 Pressure and Flow Control Valve 21
CHAPTER 4: Methodology 24-28
4.1 Design Criteria for Fixtures 24
4.2 Making of Fixtures 25
4.3 Material Selection 27
CHAPTER 5: Result and Analysis 29-35
Conclusion 36
References 37

7. LIST OF FIGURES
Figure Description Page no.
Figure 1.1 An example of Poka-Yoke 6
Figure 1.2 Jigs 8
Figure 1.3 Fixtures 9
Figure 2.1 Scheme of 3-2-1 Fixture Setup 11
Figure 2.2 Layout of Working 12
Figure 2.3 Fixture Design for the Sample Part 13
Figure 3.1 Regular Reciprocating Compressor 14
Figure 3.2 Double Acting Cylinder 18
Figure 3.3 Direction Control Valve 20
Figure 3.4 Pneumatic Flow Control Valve 21
Figure 3.5 Pressure control valve 22
Figure 3.6 PU tubes 23
Figure 4.1 Forces impact on work holding design 24
Figure 4.2 Locating Pins 25
Figure 4.3 Pneumatic Power Clamp 26
LIST OF TABLES
Table no. Name of table Page no.
4.1 List of Component Used 28
5.1 Maximum clamping force calculations 31
5.2 Table Comparative Analysis 34

8. CHAPTER 1
INTRODUCTION
One of the most time-consuming and labor extensive processes in the manufacturing of a
mechanical part is the process of work holding or fixturing. It is often remarked that only
approximately 10-15% of the overall time required to produce a part is spent
Actually on cutting or drilling a work piece; the other time is spent primarily planning for
executing part setup or work holding which is still performed by highly skilled Machinists
based on their experience. Recently, industries have begun to experience Difficulty finding
highly skilled machinists because the number of apprentices is decreasing and it is likely that
the situation will worsen in the future. As a result of this trend together with the increasing
power of computation speed, there has been a vast activity devoted to analyze the stability of
fixturing and to automate fixture designs via CAD techniques. A fixture may constrain the
motion of work pieces in two different ways. One, form closure, is purely kinematics, in which
the geometry of the contacting rigid parts prevents motion regardless of the magnitude of the
applied force. The other, force closure, involves the use of friction to assist in the freedom of
motion of a kinematically under constrained object. Most analyses focused on the stability of
the final fixture configurations and were less concerned on the sequence of placing the fixels.
Based on the theories of grasping planar objects demonstrated that improper sequence of
placing the fixels will result in the rotation of the planar work pieces. Instead of focusing on
the fixturing of planar work pieces which ignores the sequence of placing the overhead clamp
that is consider the fixturing of prismatic work pieces which are polyhedral objects with all
outer boundary faces either parallel or perpendicular to the fixture base plate. It is shown that
proper sequences of placing clamps can actually relax the stringent requirement in the
positioning accuracy of the fixels. So, in order to design a complete set or perfect jigs and
fixtures, the determination about all the factors which are influence the jigs and fixtures during
machining process is important. The factors are force, pressure, weight, cutting speed and
others.
1.1Pneumatics and Compressed Air
Pneumatics (pronounced new-MATT-ix) is an aspect of physics and engineering that is concerned
with using the energy in compressed gas to make something move or work. “Pneumos” means “Air”

9. and “Tics” means “Technology Pneumatics is using air to push/pull things or suck them up. The origins
of pneumatics trace back to the first century when the Greek mathematician Hero of Alexandria created
mechanical systems powered by wind and steam and documented his processes. Today, pneumatics
plays an important role in manufacturing and mechatronics.
With pneumatics, valves control the flow of energy from pressurized gas, which is often
simply compressed air. The device that converts energy from the pressurized gas into motion is called
a pneumatic actuator. Pneumatic actuators are often powered by electric compressors and are capable
of producing either linear or rotary motion. A nail gun is an example of a linear pneumatic actuator.
When the user pulls the nail gun's trigger, a valve opens and compressed air is released with enough
force to drive the nail into a solid surface. In manufacturing, pneumatic technology and
automated solenoid valves can be used in an assembly line to move process and package product.
An incredible range of manufacturing systems use the force and power of fluids such as water, oil and
air. Powered clamps open and close with the force of pressurized air or oil, large presses shape and form
metal with hydraulic pressure, and assembly torque tools fasten components with pressurized air. In
each example, fluid power provides the energy necessary to exert significant mechanical forces.
Systems that use air are called pneumatic systems while systems that use liquids like oil or water are
called hydraulic system. Pneumatic systems are similar to hydraulics in function, but hydraulic systems
use liquid to power movement and work instead of gas. Pneumatic systems are simpler to design and
simpler to manage than hydraulic systems, but hydraulic systems are capable of greater pressures: up
to 10,000 PSI (pounds per square inch) with hydraulics, compared to about 100 PSI with pneumatics.
In general pneumatic systems are more sustainable than hydraulic systems because air can be exhausted
into the atmosphere, while hydraulic fluid must be exhausted into a fluid reservoir and eventually
disposed of.
Both these systems (hydraulic and pneumatic) are used in industry as per need and convenience.
Pneumatic systems in fixed installations, such as factories, use compressed air because a sustainable
supply can be made by compressing atmospheric air. The air usually has moisture removed, and a small
quantity of oil is added at the compressor to prevent corrosion and lubricate mechanical components.
Advantages of Pneumatic Systems
Pneumatic control systems are widely used in our society, especially in the industrial sectors for the
driving of automatic machines. Pneumatic systems have a lot of advantages.
1. High effectiveness

10. Many factories have equipped their production lines with compressed air supplies and movable
compressors. There is an unlimited supply of air in our atmosphere to produce compressed air.
Moreover, the use of compressed air is not restricted by distance, as it can easily be transported
through pipes. After use, compressed air can be released directly into the atmosphere without the
need of processing.
2. High durability and reliability
Pneumatic components are extremely durable and cannot be damaged easily. Compared to
electromotive components, pneumatic components are more durable and reliable.
3. Simple design
The designs of pneumatic components are relatively simple. They are thus more suitable for use in
simple automatic control systems.
4. High adaptability to harsh environment
Compared to the elements of other systems, compressed air is less affected by high Temperature,
dust, corrosion, etc.
5. Safety
Pneumatic systems are safer than electromotive systems because they can work in inflammable
environment without causing fire or explosion. Apart from that, overloading in pneumatic system
will only lead to sliding or cessation of operation. Unlike electromotive components, pneumatic
components do not burn or get overheated when overloaded.
6. Easy selection of speed and pressure
The speeds of rectilinear and oscillating movement of pneumatic systems are easy to adjust and
subject to few limitations. The pressure and the volume of air can easily be adjusted by a pressure
regulator.
7. Environmental friendly
The operation of pneumatic systems does not produce pollutants. The air released is also processed
in special ways. Therefore, pneumatic systems can work in environments that demand high level of
cleanliness. One example is the production lines of integrated circuits.
8. Economical

11. As pneumatic components are not expensive, the costs of pneumatic systems are quite low.
Moreover, as pneumatic systems are very durable, the cost of repair is significantly lower than that
of other systems.
Compressed Air
Compressed air is a gas, or a combination of gases, that has been put under greater pressure than the air
in the general environment. This compressed air possesses great amount of energy which can be utilized
to do a great deal of work and operations in an industry; like lifting, moving or holding of humongous
objects to perform various mechanical operations upon them. To understand how compressed air is able
to do things, let’s think of a ball. If we blow up the ball so that it is full, it will contain a lot of compressed
air. If we bounce the ball, it will bounce very high. However, if the ball is burst then the compressed air
will escape and the ball will not bounce as high. Quite simply, the ball bounces because it is using the
energy stored in the compressed air.
It serves many domestic and industrial purposes. Current applications using compressed air are
numerous and diverse, including jackhammers, tire pumps, air rifles, and aerosol cheese. According to
proponents, compressed air also has a great potential as a clean, inexpensive, and infinitely renewable
energy source. Its use is currently being explored as an alternative to fossil fuels.
In 1991, the first compressed air energy storage (CAES) plant in the United States opened in McIntosh,
Alabama. The world's largest CAES plant, planned for Norton, Ohio, is expected to store sufficient
energy to provide electric power for 675,000 homes for two days. Another product that uses compressed
air is the so-called "air car" currently in development by several manufacturers, and expected to be on
the market within the next few years. According to "How Stuff Works," one such car, the e-Volution,
will run 120 miles without refueling, at a cost of about 30 cents. Compressed air in spray cans
(sometimes called canned air) is often used to clean things that are especially delicate or sensitive, such
as keyboards or the inside of computer cases. This explains that compressed air usage in cost effective
and easy.
Although in industry, compressed air is so widely used that it is often regarded as the fourth utility, after
electricity, natural gas and water. However, compressed air is more expensive than the other three
utilities when evaluated on a per unit energy delivered basis. A large number of operations are
performed in industries with the help of compressed air. Compressed air generations in industries
accounts for up to 10% of total industrial electricity consumption. Hence it is optimal to use compressed
air for making a vice for holding jobs and to operate pneumatic machines as it is in abundance and can
be manufactured easily.

12. 1.2 Poka-Yoke
Poka-yoke [poka joke] is a Japanese term that means "mistake-proofing" or “inadvertent error
prevention”. The key word in the second translation, often omitted, is "inadvertent". There is
no Poka Yoke solution that protects against an operator’s sabotage, but sabotage is a rare
behavior among people. A poka-yoke is any mechanism in a lean manufacturing process that
helps an equipment operator avoid (yokeru) mistakes (poka). Its purpose is to eliminate product
defects by preventing, correcting, or drawing attention to human errors as they occur. The
concept was formalized, and the term adopted, by Shigeo Shingo as part of the Toyota
Production System. It was originally described as baka-yoke, but as this means "fool-proofing"
(or "idiot-proofing") the name was changed to the milder poka-yoke.
More broadly, the term can refer to any behavior-shaping constraint designed into a process to
prevent incorrect operation by the user.
A simple poka-yoke example is demonstrated when a driver of the car equipped with a manual
gearbox must press on the clutch pedal (a process step, therefore a poka-yoke) prior to starting
an automobile. The interlock serves to prevent unintended movement of the car. Another
example of poka-yoke would be the car equipped with an automatic transmission, which has a
switch that requires the car to be in "Park" or "Neutral" before the car can be started (some
automatic transmissions require the brake pedal to be depressed as well). These serve as
behavior-shaping constraints as the action of "car in Park (or Neutral)" or "foot depressing the
clutch/brake pedal" must be performed before the car is allowed to start. The requirement of a
depressed brake pedal to shift most of the cars with an automatic transmission from "Park" to
any other gear is yet another example of a poka-yoke application. Over time, the driver's
behavior is conformed to the requirements by repetition and habit.

13. Fig 1.1 an example of Poka-Yoke
Poka-yoke can be implemented at any step of a manufacturing process where something can
go wrong or an error can be made. For example, a fixture that holds pieces for processing might
be modified to only allow pieces to be held in the correct orientation, or a digital counter might
track the number of spot welds on each piece to ensure that the worker executes the correct
number of welds.
Shigeo Shingo recognized three types of Poka-yoke for detecting and preventing errors in a
mass production system:
1. The contact method identifies product defects by testing the product's shape, size, color,
or other physical attributes.
2. The fixed-value (or constant number) method alerts the operator if a certain number of
movements are not made.
3. The motion-step (or sequence) method determines whether the prescribed steps of the
process have been followed.
Either the operator is alerted when a mistake is about to be made, or the poka-yoke device
actually prevents the mistake from being made. In Shingo's lexicon, the former implementation
would be called a warning poka-yoke, while the latter would be referred to as a control poka-
yoke.

14. Shingo argued that errors are inevitable in any manufacturing process, but that if appropriate
poka-yokes are implemented, then mistakes can be caught quickly and prevented from resulting
in defects. By eliminating defects at the source, the cost of mistakes within a company is
reduced.
A methodic approach to build up poka-yoke countermeasures has been proposed by the
Applied Problem Solving (APS) methodology, which consists of a three-step analysis of the
risks to be managed:
1. identification of the need
2. identification of possible mistakes
3. management of mistakes before satisfying the need
This approach can be used to emphasize the technical aspect of finding effective solutions
during brainstorming sessions.
Benefits of Poka Yoke implementation
 Less time spent on training workers;
 Elimination of many operations related to quality control;
 Unburdening of operators from repetitive operations;
 Promotion of the work improvement-oriented approach and actions;
 A reduced number of rejects;
 Immediate action when a problem occurs;
 100% built-in quality control.
1.3Jigs and Fixtures
The jigs and fixtures are the economical ways to produce a component in mass. So jigs and fixtures are
used and serve as one of the most important facility of mass production system. These are special work
holding and tool guiding device. Quality of performance of a process is largely influenced by the quality
of jigs and fixtures used for this purpose. What makes a fixture unique is that each one is built to fit a
particular part or shape. The main purpose of a fixture is to locate and in the cases hold a work piece
during an operation. A jig differs from a fixture in the sense that it guides the tool to its correct position
or towards its correct movement during an operation in addition to locating and supporting the work
piece.

15. Figure 1.2 Jigs
An example of jig is when a key is duplicated; the original key is used as base for the path reader which
guides the movement of tool to make its duplicate key. The path reader of a CWC machine here works
as a jig and the original is called template. Sometimes the template and jig both are the name of same
part of a manufacturing system.
A fixture is a device used to locate, clamp and support a work piece during machining,
assembly or inspection. The most important criteria’s for fixturing are work piece stability,
position accuracy and work piece deformation. A good fixture design is one that minimizes
work piece geometric error. Work piece location principles are defined in terms of 3-2-1
fixturing which is widely used work piece location method for prismatic parts. Force analysis
is concerned with checking whether the forces applied by the fixture and clamping are
sufficient to maintain static equilibrium.

16. Fig. 1.3 Fixtures
Fixtures must correctly locate a work piece in a given orientation with respect to a cutting tool
or measuring device, or with respect to another component, as for instance in assembly or
welding. Such location must be invariant in the sense that the devices must clamp and secure
the work piece in that location for the particular processing operation. There are many standard
works holding devices such as jaw chucks, machine vises, drill chucks, collets, etc. which are
widely used in workshops and are usually kept in stock for general applications. Fixtures are
normally designed for a definite operation to process a specific work piece and are designed
and manufactured individually.
Purpose and advantages of Jigs and Fixtures
Following the purpose and advantages of jigs and fixtures:
(a) It reduces or sometimes eliminates the efforts of marking, measuring and setting of work piece on a
machine and maintains the accuracy of performance.
(b) The work piece and tool are relatively located at their exact positions before the operation
automatically within negligible time. So it reduces product cycle time.
(c) Variability of dimension in mass production is very low so manufacturing processes supported by
use of jigs and fixtures maintain a consistent quality.

17. (d) Due to low variability in dimension assembly operation becomes easy, low rejection due to les
defective production is observed.
(e) It reduces the production cycle time so increases production capacity. Simultaneously working by
more than one tool on the same work piece is possible.
(f) The operating conditions like speed, feed rate and depth of cut can be set to higher values due to
rigidity of clamping of work piece by jigs and fixtures.
(g) Operators working become comfortable as his efforts in setting the work piece can be eliminated.
(h) Semi-skilled operators can be assigned the work so it saves the cost of manpower also.
(i) There is no need to examine the quality of produce provided that quality of employed jigs and fixtures
is ensured.
Importance of Fixtures in Manufacturing
The use of fixtures has two fold benefits. It eliminates individual markings positioning and frequent
checking before machining operation starts, thereby resulting in considerable saving in set-up time. In
addition, the usage of work holding devices saves operator labor through simplifying locating and
clamping tasks and makes possible the replacement of skilled workforce with semiskilled labor, hence
effecting substantial saving in labor cost which also translates into enhanced production rate.
Furthermore, the use of well-structured fixtures with higher locating and clamping rigidity would allow
for increase in cutting speeds and feeds, thereby reducing tm, hence improving production rate. Besides
improving the productivity in Terms of the rate of production, there are also other benefits accrued
through the use of Fixtures, they are: It Increases machining accuracy because of precise location with
fixtures.

18. CHAPTER 2
LITERATURE REVIEW
2.1 Principles of Locations
Guohua Qin et al., (2006), focuses on the fixture clamping sequence. It consists of two parts:
a. For the first time he evaluated varying contact forces and work piece position errors in each
clamping step by solving a nonlinear mathematical programming problem. This is done by
minimizing the total complementary energy of the work piece-fixture system. The prediction
proves to be rigorous and reasonable after comparing with experimental data and referenced
results.
b. The optimal clamping sequence is identified based on the deflections of the work piece and
minimum position error. Finally, to predict the contact forces and to optimize the clamping
sequence three examples are discussed.
Fig. 2.1 Scheme of 3-2-1 Fixture Setup (Guohua Qin, Weihong, Zhang Min Wan, 2006)
First mathematical modeling for clamping sequence is done then he determined the contact
forces in clamping sequence as shown in Figure 1. After that he optimized of clamping
sequence for higher stiffness work pieceand low stiffness work piece. He found that with the
use of optimal clamping sequence, good agreements are achieved between predicted results
and experimental data and the work piece machining quality can be improved.
2.2 Design Consideration in Fixtures
The importance of fixture design automation is emphasized by Djordje Vukelic (Michael
Stampfer, 2008). General structure of the automated design system is shown in Figure 2 with
a highlight on the fixture design systems and their main characteristics.

19. It also shows a structure and a part of output results of the automated modular fixture design
system. The expert systems have been mostly used for the generation of partial fixture
solutions, i.e. for the selection of locating and clamping elements.
Fig. 2.2: Layout of Working (Michael Stampfer, 2008)
Shrikant et al., (2013), discussed various design and analysis methods in the context of to
improve the life of fixture; different fixture geometries are compared experimentally and are
selected. The proposed eccentric shaft fixture will fulfilled researcher Production target and
enhanced the efficiency, fixture reduces operation time and increases productivity, high quality
of operation.
2.3 Clamping Approach
J Cecil proposed an innovative clamping design approach is described in the context of fixture
design activities. The clamping design approach involves identification of clamping surfaces
and clamp points on a given work piece. This approach can be applied in conjunction with a
locator design approach to hold and support the work piecework piece correctly with respect
to the cutting tool. Detailed steps are given for automated clamp design. Geometric reasoning
techniques are used to determine feasible clamp faces and positions. The required inputs
include CAD model specifications, features identified on the finished work piece, locator
points and elements.

20. Fig. 2.3: Fixture Design for the Sample Part (J Cecil, 2008)

21. CHAPTER 3
APPARATUS AND TOOL USED
There were various tools used while designing and making our projects. These are as follows:
3.1 COMPRESSOR
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.
An air compressor is a specific type of gas compressor. You'll find air compressors used in a wide range
of situations—from corner gas stations to major manufacturing plants. And, more and more, air
compressors are finding their way into home workshops, basements and garages. Models sized to
handle every job, from inflating pool toys to powering tools such as nail guns, sanders, drills, impact
wrenches, staplers and spray guns are now available through local home centers, tool dealers and
mail-order catalogs.
Fig 3.1 Regular Reciprocating Compressor
Like a small internal combustion engine, a conventional piston compressor has a crankshaft, a
connecting rod and piston, a cylinder and a valve head. The crankshaft is driven by either an
electric motor or a gas engine. While there are small models that are comprised of just the pump

22. and motor, most compressors have an air tank to hold a quantity of air within a preset pressure
range. The compressed air in the tank drives the air tools, and the motor cycles on and off to
automatically maintain pressure in the tank.
The big advantage of air power is that each tool doesn't need its own bulky motor. Instead, a
single motor on the compressor converts the electrical energy into kinetic energy. This makes
for light, compact, easy-to-handle tools that run quietly and have fewer parts that wear out.
Compressors are similar to pumps: both increase the pressure on a fluid and both can transport
the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of
a gas. Liquids are relatively incompressible; while some can be compressed, the main action
of a pump is to pressurize and transport liquids.
An air compressor is a device that converts power (using an electric motor, diesel or gasoline
engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of
several methods, an air compressor forces more and more air into a storage tank, increasing the
pressure. When tank pressure reaches its upper limit the air compressor shuts off. The
compressed air, then, is held in the tank until called into use. The energy contained in the
compressed air can be used for a variety of applications, utilizing the kinetic energy of the air
as it is released and the tank depressurizes. When tank pressure reaches its lower limit, the air
compressor turns on again and re-pressurizes the tank.
Compressors can be classified according to the pressure delivered:
1. Low-pressure air compressors (LPACs), which have a discharge pressure of 150 psi or
less
2. Medium-pressure compressors which have a discharge pressure of 151 psi to 1,000 psi
3. High-pressure air compressors (HPACs), which have a discharge pressure above 1,000
psi
They can also be classified according to the design and principle of operation:
1. Rotary Screw compressors
2. Turbo or Axial Compressors.

23. There are other design types of compressors also, but the general type is given above. These
are also differentiated on the basis of method of displacement of air in the compressors.
There numerous methods of air compression, divide it into either positive-displacement or roto-
dynamic types.
Positive displacement
Positive-displacement compressors work by forcing air into a chamber whose volume is
decreased to compress the air. Once the maximum pressure is reached, a port or valve opens
and air is discharged into the outlet system from the compression chamber. Common types of
positive displacement compressors are:
 Piston-type: air compressors use this principle by pumping air into an air chamber
through the use of the constant motion of pistons. They use one-way valves to guide air
into a cylinder chamber, where the air is compressed.
 Rotary screw compressors: use positive-displacement compression by matching two
helical screws that, when turned, guide air into a chamber, whose volume is decreased
as the screws turn.
 Vane compressors: use a slotted rotor with varied blade placement to guide air into a
chamber and compress the volume. A type of compressor that delivers a fixed volume
of air at high pressures.
Dynamic Displacement
Dynamic displacement air compressors include centrifugal compressors and axial compressors.
In these types, a rotating component imparts its kinetic energy to the air which is eventually
converted into pressure energy. These use centrifugal force generated by a spinning impeller
to accelerate and then decelerate captured air, which pressurizes it.
Compressor The compressor works best when there is no air pressure in the system to resist
the pump. As the pressure increases the compressor labours longer to get more pressurized air
into the system. When at first the system is empty, the compressor can move a lot of air, but as
pressure builds up the compressor takes longer and longer to stuff more air in.
3.2 CYLINDER

24. Pneumatic cylinder(s) (sometimes known as air cylinders) are mechanical devices which use
the power of compressed gas to produce a force in a reciprocating linear motion. Like hydraulic
cylinders, something 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 object to be moved. Engineers
sometimes prefer to use pneumatics because they are quieter, cleaner, and do not require large
amounts of space for fluid storage.
Because 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. For example, in the mechanical puppets of the Disney Tiki Room, pneumatics are
used to prevent fluid from dripping onto people below the puppets.
Single-acting cylinders
Single-acting cylinders (SAC) use the pressure imparted by compressed air to create a driving
force in one direction (usually out), and a spring to return to the "home" position. More often
than not, this type of cylinder has limited extension due to the space the compressed spring
takes up. Another downside to SACs is that part of the force produced by the cylinder is lost
as it tries to push against the spring
Double-acting cylinders
Double-acting cylinders (DAC) uses the force of air to move in both extends and retracts
strokes. They have two ports to allow air in, one for outstroke and one for in stroke. Stroke
length for this design is not limited; however, the piston rod is more vulnerable to buckling and
bending. Additional calculations should be performed as well.

25. Fig. 3.2 Double Acting Cylinder
Many hydraulic and pneumatic cylinders use them where it is needed to produce a force in both
directions. A double-acting hydraulic cylinder has a port at each end, supplied with hydraulic
fluid for both the retraction and extension of the piston. A double-acting cylinder is used where
an external force is not available to retract the piston or where high force is required in both
directions of travel.
3.3 DIRECTION CONTROL VALVE
DIRECTIONAL VALVES As the same name implies, directional valves start, stop, and
control the direction of fluid flow. Although they share this common function, directional
valves very considerably in construction and operation.
There are basically three types of valves employed in hydraulic systems:
a. Directional control valves
b. Flow control valves
c. Pressure control valves
a. Directional control valves:- Directional control valves are used to control the distribution of
energy in a fluid power system. They provide the direction to the fluid and allow the flow in a
particular direction. These valves are used to control the start, stop and change in direction of
the fluid flow. These valves regulate the flow direction in the hydraulic circuit.
Directional control valves can be classified in the following manner:
1. Type of construction:
• Poppet valves
• Spool valves
2. Number of ports:
• Two- way valves
• Three – way valves
• Four- way valves.

26. 3. Number of switching position:
• Two – position
• Three – position
4. Actuating mechanism:
• Manual actuation
• Mechanical actuation
• Solenoid actuation
• Hydraulic actuation
• Pneumatic actuation
• Indirect actuation
b. Flow control valves: -The flow control valves work on applying a variable restriction in the
flow path. Based on the construction; there are mainly four types viz. plug valve, butterfly
valve, ball valve and balanced valve.
Fig. 3.3 Direction Control Valve
c. Pressure control/relief valves:-The pressure relief valves are used to protect the hydraulic
components from excessive pressure. This is one of the most important components of a
hydraulic system and is essentially required for safe operation of the system. Its primary

27. function is to limit the system pressure within a specified range. It is normally a closed type
and it opens when the pressure exceeds a specified maximum value by diverting pump flow
back to the tank. The simplest type valve contains a poppet held in a seat against the spring
force.
The direction control valve that has been used by us in this project is a 5*2 Manual Head lever
Valve.
3.3 PRESSURE AND FLOW CONTROL VALVE
Pressure-control valves are found in virtually every hydraulic system, and they assist in a
variety of functions, from keeping system pressures safely below a desired upper limit to
maintaining a set pressure in part of a circuit. Types include relief, reducing, sequence,
counterbalance, and unloading. All of these are normally closed valves, except for reducing
valves, which are normally open. For most of these valves, a restriction is necessary to produce
the required pressure control. One exception is the externally piloted unloading valve, which
depends on an external signal for its actuation.
Pneumatic Pressure and Flow Control Valves
Pneumatic valves circulate air throughout a larger pneumatic system by either allowing or
inhibiting the flow of pressurized air, whose force is then used to power a device.
Fig. 3.4Pneumatic Flow Control Valve

28. Because valves can have varying numbers of entryways for air, creating different flow patterns,
valves are classified according to the number of ports they possess and the flow-paths they
create. Additionally, because they can move air in a variety of ways they can suit a variety of
applications. Aside from the commonly used directional control valves, there are valves that
are designed to serve more specific purposes, such as pressure regulator, venting-type regulator
valves, and needle valves. Pressure and venting-type valves both help control pressure, whereas
needle valves help control the flow within a pneumatic system.
Pressure Regulators
A pressure regulator is responsible for preventing pressure fluctuation by controlling pressure
as it is coursed through an actuator or another part of a pneumatic system. In order to air
pressure within an appropriate pressure range, the pressure should be set low enough so that it
can fluctuate between 3 and 5 psi without altering the minimum and maximum pressure system
requirements. In certain applications, a pressure regulator valve must ensure that air-pressure
output stays at a constant regardless of changes in pressure at earlier points in the system and
changes in flow. Other applications require pressure regulators to lower pressure so that air
isn’t wasted while still meeting the basic pressure requirements of the device.
Fig. 3.5 Pressure Control Valve

29. Pressure regulators work with sensors to monitor the pressure as it expands as it moves through
a pneumatic system. Once the pressure has reached the maximum level of expansion, a sensor
is triggered by the high pressure, which in turn signals to the pressure valve to close thus cutting
off pressure. As a result of the pressure valves opening and closing in response to pressure
levels, pressure is kept at a relatively constant level as it reaches the actuator or other pneumatic
device.
3.5 Pneumatic Tubes
Pneumatic tubes (or capsule pipelines; also known as Pneumatic Tube Transport or PTT)
are systems that propel cylindrical containers through networks of tubes by compressed air or
by partial vacuum. They are used for transporting solid objects, as opposed to conventional
pipelines, which transport fluids. Pneumatic tube networks gained acceptance in the late 19th
and early 20th centuries for offices that needed to transport small, urgent packages (such as
mail, paperwork, or money) over relatively short distances (within a building, or, at most within
a city). Some installations grew to great complexity, but were mostly superseded. In some
settings, such as hospitals, they remain widespread and have been further extended and
developed in recent decades.
Fig. 3.6 PU tubes

30. CHAPTER 4
METHODOLOGY
In design methodology the whole study of arrangements are taken in account. We divide the
whole project or research into various steps in which the whole model of project is
manufactured. These steps based on principles and concepts of production technology, which
are used as follows.
4.1 Design criteria for Fixtures
A work holding device is a tool that establishes a relationship between the work piece and the
machine tool. Every work holding device is designed to securely support, locate, and hold the
work piece as it sustains machining forces, as shown in Figure 4.1. However, many variables
affect the design of an effective customized fixture for any given machining operation. The
responsibility of the designer is to create a fixture that is sturdy, easy to use, and inexpensive.
An effective fixture also reduces nonproductive time spent on tasks other than machining. The
designer plays a crucial role in maintaining quality while increasing production.
Fig. 4.1 Machining forces impact workholding design
4.2 Making of Fixture

31. After the base plate is selected, the designer must choose the appropriate components for
supporting the workpiece. Besides size and shape, the material of the workpiece will greatly
affect workholding design. A workpiece made of aluminum or other soft material will generate
less cutting forces. However, softer materials may distort and bend, especially while cutting.
Extra support may be necessary to prevent this distortion during machining.
With high-carbon steels, tool steels, or other harder materials, the designer must anticipate
greater cutting forces. Harder materials experience less distortion. However, supporting
components must be able to resist these increased cutting forces. Supports must also be able to
withstand the wear encountered by the loading and unloading of parts. Regardless of the
material, the workpiece must always be supported near the location of the machining. In this
project, the material that is used for supporting is mild steel for making the fixture, bed and for
fasteners.
Locating Pins
Locating pins are used to hold the workpiece at its desired place or to align it in order to perform
operations on it. Locating pins are a great way to make sure the parts you are putting together
fit the way you want them to fit. Drill two holes opposite each other in each part; install a
cylindrical locating pin, and presto! Your parts are aligned exactly the way you want.
There are two ways for locating an object, internal locating and external locating. If internal
holes are not feasible, the designer can locate the part externally using the 3-2-1 method, as
demonstrated in Figure 4.2.
Fig. 4.2 External Location requires location on several surfaces.
According to the 3-2-1 method, the workpiece must be supported by at least three points from
below. The rest buttons accomplish this task. The workpiece must also be located along an axis
by two points, which is satisfied by the two locating pins at the top and right. Finally, the
workpiece must be located along an axis perpendicular to the previous axis by a single point.
This method is implemented as an option for locating the workpiece in our project.

32. For any workholding assignment, the designer has numerous tools and components available.
Every workholding device must accurately support, locate, and hold the workpiece. Generally
manual clamps are used on small machines. Since, manual clamps may increase the time
required to load and unload a workpiece, this introduces a labor cost. Flat angle clamping bars
are used for clamping the workpiece. Another option for the designer is power clamping. If
power clamps such as the system in our project as shown in Figure 4.3 are used, the operator
can clamp the workpiece with a flick of a switch. Because they are driven by hydraulic power
or pneumatic power, the clamping force is always the same and is evenly distributed to all the
clamps. Most importantly, the time required for securing parts is greatly reduced. As
compressed gas for pneumatic components is easily available in industries, power clamping
turns out to be a cost effective when used large manufacturing.
Fig. 4.3 Pneumatic Power Clamp
Modern manufacturing is a race to produce the greatest number of high quality parts in the least
amount of time. As time increases, the cost of the part increases as well. As you might imagine,
the workholding setup plays a key role in reducing the time it takes to make a part.
An effective fixture can reduce nonproductive time. A fixture effectively secures more parts
with fewer clamps. Nonproductive time includes setup time spent setting up the fixture,
calculating tool offsets, and other tasks required to make the first good part. However,
nonproductive time also includes more general tasks such as loading and unloading the part,
part checking, tool changes, etc.

33. A basic truism of the shop is that if you are not producing chips, you are not making money.
An effective workholding setup reduces the amount of nonproductive time and helps keep a
machine running.
The responsibility of the tool designer is to create a fixture that is sturdy, easy to use, and
inexpensive. The design of the plate fixture begins with the selection of a base plate, which
acts as the tool body containing all the workholding components. Besides size and shape, the
material of the workpiece and the operations performed greatly affect workholder design.
First, supporting components are used to resist cutting forces and sustain wear. Second,
locating pins are strategically placed to prevent the workpiece from sliding. Finally, clamping
prevents the workpiece from lifting off the supports and out of the fixture. Clamps should be
secured over supports to prevent distortion of the workpiece.
These workholding steps are often best accomplished with the use of standard components.
Workholding components are generally hardened to resist wear and ground to precise
dimensions. An effective fixture can also be an opportunity to reduce nonproductive time and
increase overall efficiency.
4.3 Material Selection
The selection of material used depends upon the forces and vibrations generated while
operating on the workpiece. The materials selected are for two components namely, the base
of the project and the base plate of the fixture.
The base of the project is made of wooden ply; the whole project is assembled and fastened on
this ply.
Whereas the material of the base plate of the fixture is mild steel. Since the force generated by
a drill or a milling machine on the fixture is not very high hence the material should not be very
tough or brittle. Mild steel is chosen over other materials because it is rigid and resilient in
absorbing sudden loads and vibrations on fixture plate.
Other components used are incorporated by us from their OEM (original equipment
manufacturer for the components used).
These components are listed as follows.
S.No. Component Qty. Specifications

34. 1 Double Acting Cylinder 1 Pressure: 1.5-8 Kgf/cm2
2 Direction Control Valve 1 Pressure: 0.15-0.85 MPa
3 Pressure Control Valve 1 Pressure: 0-10 Kgf/cm2
4 Fluid flow Regulators 2 1/8 inch
5 Pneumatic Pipes 4 6mm,8mm
6 Silencers 2 1/8 inch
Table 4.1 List of Components Used.

35. CHAPTER 5
RESULTS AND ANALYSIS
FORCE
The fluid pushes against the face of the piston and produces a force. The force produce is given
by the formula.
F = PA
P is the pressure in N/m2 and A is the area the pressure acts on in m2.
This assumes that the pressure on the other side of the piston is negligible. The diagram shows
a double acting cylinder. In this case the pressure on the other side is usually atmospheric so if
p is a gauge pressure we need not worry about the atmospheric pressure.
Let A be the full area of the piston and a be the cross sectional area of the rod. If the pressure
is acting on the rod side, then the area on which the pressure acts is (A-a).
F= P A on the full area of piston.
F= P (A-a) on the rod side.
This force acting on the load is often less because of friction between the seals and both the
piston and piston rod.
SPEED
The speed of the piston and rod depends upon the flow rate of fluid. The volume per second
entering the cylinder inside. It follows then that.
Q m3/ s =Area * distance moved per second
Q m3/s=A*velocity (full side)
Q m3/s= (A-a)* velocity (rod side)
Note in calculus form velocity is given by v= A dx/dt this is useful in control applications.
In this case of air cylinders, it must be remembered that Q is the volume of the volume of
compressed air and this changes with pressure so any variation in pressure will cause a variation
in the velocity.
POWER
Mechanical power is defined as Force * velocity. This makes it easy to calculate the power of a cylinder.
The fluid power supplied is more than the mechanical power output because of friction between the
sliding parts.

36. CALCULATION
Diameter of the cylinder D=2R
Diameter of the connecting rod = d= 2r
Total stroke length of the cylinder = 80mm
Effective stroke length = 40 mm
F =Force exerted on work piece
F = P*A
F= (Pcomp – Patm) * π/4(D^2 –d^2)
Pressure Measurement
Considering P= 10 bar = 1.01 N/mm2=145.03 PSI
Diameter of piston = D= 25mm
Diameter of piston rod =d=10mm
A= (3.14 / 4) * (D2
–d2
)
= (3.14 / 4) * (252
-102
)
= 412.33 mm2
And P= F / A
0.068 = F / 412.33
F = 28.42 N =2.84kg
So, we have selected pneumatic cylinder move 2.8 Kg. Of force at 10 psi pressure.
5.1 Table for the maximum clamping force at different pressure variation
S no. Pcomp
psi
Pcomp
N/mm2
A=D2
-
d2
)
mm2
F=P*A
N
1 10 0.068 412.33 28.03
1 Bar = 100Kpa = 100KNm2
= 14.5 PSI

37. 2 15 0.103 412.33 42.46
3 20 0.137 412.33 56.48
4 25 0.172 412.33 70.92
5 30 0.206 412.33 84.93
The Sample required clamping force are :
Metal Removal Rate = d x Fr x Vc x 12 (in./ft.)
(Q) (cu.in./min.)
Where d = Depth of Cut (in.)
Fr = Feed Rate (in.)
Vc = Cutting Speed (sfm)
or Q = .060 in. x .010 in. x 1500 ft/min x 12 in./ft
= 10.8 cu. in./min
Horsepower required = metal removal rate x unit power
(Hp) (Q) (P)
or Hp = 10.8 (cu. in./min) x.3 (Hp/cu.in/min)
= 3.24 Hp
Resultant cutter force = Hp x 33000 / cutter speed (sfm)
(Fc) (ft-lbs/min/Hp)(Vc)
or Fc = (3.24 x 33000) / 1500 sfm
= 72 pounds
Clamping Force =
72lbs/.15
= 480 lbs=217.72 kg
DATA AVAILABLE FROM RESEARCH PAPER

38. Shailesh S Pachbhai1* and Laukik P Raut2 “DESIGN AND DEVELOPMENT OF
HYDRAULIC FIXTURE FOR MACHINING HYDRAULIC LIFT HOUSING” ISSN 2278 –
0149 © 2014 IJMERR
Calculations for Existing Fixture
Followings are the data available from the Company
1) Time Required
Total number of shifts = 3
There are 3 Shift of 8 hours each.
Total working time in a shift is 7 hr 30 min i.e
450 min (30 minutes utilized in lunch break).
Total number of finished part in each shift =
32
Processing time = machining time + loading/
unloading time + part travel time (from pallet
to fixture or vice versa)
Machining time = 11.36 min
Loading time = 1.20 min
Unloading time = 1 min
Part travel time = 10 sec
Therefore, Processing time = 14.06 min
2) Cost of Operation
Cost of finished product = Rs. 345/- part
Cost of finished product/shift = Rs. 11040/-
Cost of finished product /day = Rs. 33120/-
There are 26 days of working in one month
Therefore,
Annual production cost of finished product =
Rs. 10333440/-
3) Machine Utilization
A measure (usually expressed as a percentage)
of how intensively a resources is being
used to produce a good or service (J Cecil,
2008).

39. Capacity = 3*8*1*6
= 144 machine hours
Hours available - hours down
Machine Utilization = —————————————— x 100
Hours available
= 91.66%
Calculations for New Proposed Fixture
1) Time Required
Total processing time includes machining
time, clamp actuation/de-actuation time and
part travel time.
According to standard specification of cylinder,
clamping will actuate in 5 sec.
Therefore,
Processing time = machining time + clamp
acting time + part travel time
v machining time = 11.36 min
clamp acting time = 0.10 min
part travel time = 0.10 min
Total number of finished parts per shift = 39
2) Cost of Operation
Cost of finished product per day = Rs.40365/-
Annual cost of finished part = Rs.1,25,93880/-
Annual increase in production cost of finished
part = Rs.22,60,440/-
3) Machine Utilization
Hours available - hours down
Machine Utilization = —————————————— x 100
Hours available
Machine hours = 144
Hours down = 9.5

40. S no. Parameter Existing
Fixture
Proposed
Fixture
1 Finished
part/Shift
32 parts 39 Parts
2 Production Cost Rs1,03,334440/- Rs 1,25,93880/-
3 Machinine
Utilization
91.66% 93.40%
4 Prossessing tie 14.06 min 11.56 min
5.2 Table Comparative Analysis

41. CAD Model of pneumatic Vice:-
Isometric View
Top View

42. CONCLUSION
The unique and novel design of proposed project automates the otherwise tedious task of
manually operating the vice and fixture to set the object for manufacturing operations with the
help of pneumatic clamp.
In industries our proposed system has a very vital application. With abundant supply of
compressed air, this project could serve as a cost effective vice or fixture, which can help reduce
non-productive time by speeding up the setup time.
Since there is minimal use of hands to manually operate the fixture component or workpiece,
this could help in reducing the accidental cases of hand getting trapped or injured in vice or in
any other mechanical component as everything is available at just a flick of a switch. It will
also improve error-proofing and the quality of manufactured workpiece.
The project is meant to produce a low cost pneumatic fixture as a work holding devices for
machining operations like filing, grinding, drilling. Etc. We designed a pneumatic fixture
which costs less than that available in the market. We tested our project on holding the work
pieces. Our pneumatic fixture is useful to do machining operations operation and 10 kgf/cm2
max pressure withstanding. We can do simple operations which is very useful and helpful to
do small works at our college. With a few extensions to this project it could serve well in
industries where pneumatic vices or fixtures are required to setup difficult to hold workpiece.
FUTURE SCOPE
1. Two cylinders side by side placed in the arrangement leads to hold a greater size work piece
for grinding operations also for higher thickness metals.
2. Two adjustable cylinders placed in opposite side results in the holding of all sizes work
piece.

43. REFERENCES
1. Guohua Qin, Weihong, Zhang Min Wan “Analysis and Optimal Design of Fixture Clamping
Sequence ASME for publication in the JOURNAL OF MANUFACTURING SCIENCE AND
ENGINEERING, 2006.
2. Michael Stampfer “Automated setup and fixture planning system for box-shaped Parts”
International Journal of Advance Manufacturing Technology 45:540–552 DOI
10.1007/s00170-009-1983-1, 2008.
3. Djordje Vukelic, Uros Zuperl & Janko Hodolic “Complex system for fixture selection,
modification, and design” Int J Adv Manuf Technol 45:731–748 DOI 10.1007/s00170-009-
2014-y, 2009
4. Weifang Chen ,Lijun Ni & Jianbin Xue “Deformation control through fixture layout design
and clamping force optimization” Int J Adv Manuf Technol 38:860–867 DOI 10.1007/s00170-
007-1153-2,2008
5. J. Cecil “A Clamping Design Approach for Automated Fixture Design” Int J Adv Manuf
Technol 18:784–789,2008
6. Nicholas Amaral · Joseph J. Rencis · Yiming (Kevin) Rong “Development of a finite element
analysis tool for fixture design integrity verification and optimization” Int J Adv Manuf
Technol 25: 409–419, 2005
7. Y. Wang, X. Chen. N, Gindy “Surface error decomposition for fixture development” Int J
Adv Manuf Technol DOI 10.1007/s00170-005-0270-z, 2007
8. Shrikant.V.Peshatwar, L.P Raut “Design and development of Fixture for eccentric shaft: A
Review” International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-
9622 Vol. 3, Issue 1, February 2013.
9. Shailesh S Pachbhai1* and Laukik P Raut2 “DESIGN AND DEVELOPMENT OF
HYDRAULIC FIXTURE FOR MACHINING HYDRAULIC LIFT HOUSING” ISSN 2278 –
0149 © 2014 IJMERR