Proposal abebaw1 tefa

Defense University, College of Engineering
Project Proposal
On
Design and Fabrication of Plasma Cutter Tubing Notcher
PreparedBy:
Name Id.No.
Medeset Kuma EDED /229/06
Nigussie Beyene EDED /242/06
Tefera Megeres EDED /258/06
Tilahun Tsige EDED /264/06
Yazachew Yeneneh EDED /273/06
Supervisor: Capt. Abebaw Mekonen
MARCH, 2018
BISHOFTU

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List of figure page
Figure 2.1 Plasma - The Fourth State of Matter ……………………………………….… 5
Figure 2.2 Plasma Arc Cutting ………………………………………………………..… 10
Figure 2.3 Component Parts of a Plasma Arc Torch …………………………………..…11
Figure 2.4 Functions of gas in Plasma Arc cutting …………………………….…….......12
Figure 2.5 the principle of the plasma cutting …………………………….………………12
Figure 2.6 Air Plasma ……………………………………………………………………...14
Figure 2.7 Plasma Arc Setup …………………………………………………………..…...16
Figure 2.8 Plasma Arc Cutter Systems ………………………………………………….….17
Figure 3.1 compression spring nomenclature ………..…………………………….……..…33
Figure 3.2 Force acting on the sunk key…………………………………………………………35
Figure 3.6 Radial and thrust ball bearing……………………………………………………….40
Figure 3.7 Radial ball bearings…………………………………………………………………..41

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List of table
List of table page
Table 2.1 Gas selection chart ……………………………………………………..……11
Table2.2 Variation of Cutting Speed with Typical Gas-type and Current ………..…….13
Table 2.3 Cutting depths with Plasma ………………………………………………..14
Table 2.4 Summary for gas selection …………………………………………………..21
Table 3.1 Values of allowable shear stress, Modulus of elasticity and Modulus of rigidity for
various spring materials………………………………………………………………………….30
Table 3.2 allowable shear stress (τ) and modulus rigidity (G) and modulus elasticity (E)...…31
Table 3.3 Proportions of standard parallel tapered and gib head keys …………………………….
Table 4.1 Surface cutting speeds in meters per minute …….……………………………….….
Table 4.2 Feed rates for turning/boring in millimeters per Revolution ………………..……….
Table 4.3 Feed rates for milling in millimeters per tooth …………………………………….
Table 4.4 Feed rates for HSS and carbide drills ……………………………………………….
Table 4.5 Typical depths of cut for turning/boring with carbide tooling …………………….
Table 4.6 Operation list for machine components …………….…………………………...….
Table 4.7 Operation list for pulley ……………………………….………….…………….…
Table 4.8 Operation list for nut………………………………………………………
Table 4.9 Operation list for square pipe (RHS)…………………………………….

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CHAPTER ONE
Introduction
Plasma is a state of matter like a solid, liquid or gas. Adding heat to material causes the
molecules in it to vibrate or move more quickly. When a solid is heated, the molecules start to
vibrate more vigorously. Eventually the solid turns to a liquid and the molecules actually move
around and collide with each other. As more energy or heat is added the motion becomes faster
and more vigorous still and eventually the molecules move so quickly and collide so
energetically (violently) that they separate and form a gas. If still more energy is added to the gas
the molecules travel faster and thus collide with each other more violently and the gas changes to
a plasma. An atom consists of a positively charged core and is surrounded by negatively charged
electrons. The molecules in a gas can be either individual atoms or collections of such atoms that
are very closely connected. When a plasma is formed, the collisions between the molecules
eventually get so violent that, at first, the molecules will break up into the individual atoms and
eventually some of the atoms will separate from, or lose, some of their electrons from their outer
shell. When a critical number of atoms lose electrons the gas changes to plasma.
When kinetic energy in a gas is increased, some of the electrons are freed from the atoms outer
shell and a plasm When an atom releases electrons it becomes an ion. When enough energy is
added to a gas that there is a balance between the number of atoms releasing electrons and those
naturally recombining with free electrons, the gas is said to be ionized. This ionized gas is a
plasma. In a plasma, there is an important fraction of ionized atoms at any given time, so there
are always ions and electrons that are separate and free. The energy input into the gas has to be
ongoing otherwise the gas will eventually cool enough that the electrons will mate back with the
ionized atoms. When this happens, the plasma returns to a gas state.
1.1Background
Plasma cutting grew out of plasma welding in the 1960s, and emerged as a very productive way
to cut sheet metal and plate in the 1980s.[2] It had the advantages over traditional "metal against
metal" cutting of producing no metal chips, giving accurate cuts, and producing a cleaner edge
than oxy-fuel cutting. Early plasma cutters were large, somewhat slow and expensive and,
therefore, tended to be dedicated to repeating cutting patterns in a "mass production" mode.

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As with other machine tools, CNC (computer numerical control) technology was applied to
plasma cutting machines in the late 1980s into the 1990s, giving plasma cutting machines greater
flexibility to cut diverse shapes "on demand" based on a set of instructions that were
programmed into the machine's numerical control.[3] These CNC plasma cutting machines were,
however, generally limited to cutting patterns and parts in flat sheets of steel, using only two
axes of motion (referred to as X Y cutting).
1.2 Statement of the problem
At present time plasma cutter and tube notcher problems clearly have been seen in our country in
many industries. These machines are not used because of high foreign currency to import. Most part
fabrication and assembling firms are cut pipes using hacksaw, manual grinder and arc cutting by
rotating the pipe. But it is difficult to notch the pipe manually to the required dimension, surface
finish and geometrical tolerance. So that it is difficult to achieve accurate and quality parts.
Besides the above mentioned problems, our college either in the regular, short term training or
continuing education programs, the machines are highly required because from the data of the
previous demand. Thus, this project intends to address and give solutions by designing and
fabricating of plasma cutter and tube notcher.
1. 3 Objectives
1.3.1 General Objectives
The general objective of this project is to design & manufacturing plasma cutter tubing notcher
which should be capable of performing different profile of notch.
1.3.2 Specific Objective
To specify objectives of this project are: -
 To develop the technical data related to manufacturing of plasma cutter tubing notcher
machine.
 Develop different design concept.
 To perform detail design and analysis of plasma cutter tubing notcher parts.
 To prepar details and assembly drawing using CAD.
 To prepared a manufacturing processes planes for a specific part.
 To fabricate using the available manufacturing facilities.

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1.4 Scope of the Study
The scope of study is limited to the design of plasma cutter tubing notcher, fabricating of plasma
cutter tubing notcher and model some components using CAD or CATIA software. After that to
prepare a manufacturing processes plan and fabricate the product.
1.5 METHODOLOGY
To achieve the objective, a detailed review of published literatures as well as all those available
data and physical component form in the industries are crucial. Some of these items are
collected. So the study targets the objectives through the following ways or approach:
 Literature review from international journal, books and conference papers and materials
as well as technical input from the expected relate to the project is reviewed.
 Data collection from manual or catalogues, industry visit and interviews.
 Working product data detail assessment and analysis as per standard procedure.
 Working manufacturing process plan, fabrication some of parts and assembly.
 Applying important manufacturing procedure and calculations
 Material selection.
 Data collecting, analyzing and interpreting before coming to the real work.
 Conclusion and recommendation.

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CHAPTER TWO
Literature Review
The Fourth State of Matter the first three states of matter are solid, liquid and gas. For the most
commonly known substance, water, these states are ice, water and steam. If you add heat energy,
the ice will change from a solid to a liquid, and if more heat is added, it will change to a gas
(steam). When substantial heat is added to a gas, it will change from gas to plasma, the fourth
state of matter.
Fig 2.1Plasma - The Fourth State of Matter
The scientist who discovered electromagnetism, Michael Faraday, began asking this at the start
of the 19th century, discovering a phenomenon that only got its name in 1923 thanks to
New York chemist Irving Langmuir: plasma. Plasma is an electrically conductive gas that can
reach temperatures of several 10,000°K. We witness it in stunning natural phenomena such as
lightning and aurorae. We even see it when we look up to the sky on a normal day: the sun, stars
and even the “empty space” between celestial bodies is made of plasma. It can only be used
when it is artificially created. Plasma cutting is a thermal fusion cutting process that takes
advantage of the electrical conductivity of the plasma gas and processed material. It was
developed in the 1950s, building on knowledge of arc welding. The aim was to create a cutting
technique for high-alloy steel, aluminium and copper.

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The first plasma cutting systems came onto the market in the 1960s. In the beginning, cut
surfaces were tapered and cut widths were still relatively large. Nevertheless, due to its high
cutting speed and relatively small heat-affected zone, the technology managed to become
established. The latter aspect ensures that plastic deformation is minimal; for this reason, plasma
cutting can also be employed in the construction steel industry.
Fine plasma jet cutting, developed as early as 1964, allowed for smaller cut widths and provided
the impetus required for the market share of plasma cutting among thermal cutting processes to
grow.
In the mid-1980s, plasma cutting took the plunge: with the help of the fluidising gas technique,
cutting could also take place underwater, which reduced noise pollution, radiation, dust exposure
and material distortion even further. With the fluidizing gas technique, the plasma jet is encased
by another gas, which supports it. This reduces cut width, improves cut quality and ensures
consistently high cut quality and longer service life. However, working underwater places
restrictions on cutting speed and material thickness.
Definition of Plasma
Plasma is an electrically conductive gas. The ionisation of gases causes the creation of free
electrons and positive ions among the gas atoms. When this occurs, the gas becomes electrically
conductive with current carrying capabilities. Thus, it becomes plasma.
Plasma in Nature
One example of plasma, as seen in nature, is lightning. Just like a plasma torch, the lightning
moves electricity from one place to another. In lightning, gases in the air are the ionisation gases.
Plasma Arc Cutting
Accurate cuts can be made in stainless steel and non-ferrous metals such as aluminium by
plasma arc cutting. The cuts are made by a high temperature, high velocity gas jet generated by
constricting an arc between a tungsten electrode and the component. The heat from the arc melts
the metal and the gas jet removes the molten metal from the cut. The arc operates in an inert
inner shield, whilst an outer shield provides protection for the cut surface. Argon, helium,
nitrogen and mixtures of these gases are used for both the inner and outer shields. Plasma arc
cutting is characterized by fast cutting speeds and is mainly used in mechanized systems. The

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cutting is accompanied by a high noise level which can be reduced by operating the torch under
water.
Fig 2.2: Plasma Arc Cutting
As for other arc processes plus there is a danger of severe electric shock from the high open
circuit voltage, up to 400 V for cutting. Dangerous fumes and noxious gases are formed when
using nitrogen mixtures so it is important to have adequate fume extraction. The intense arc
requires a darker shade of filter glass, at least 16 EW (BS 697). Intense high-frequency noise is
possible when cutting, especially with non-transferred arcs, of levels 110 dB which requires ear
muff protection.
Fig 2.3 Component Parts of a Plasma Arc Torch

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Plasma (Cutting) Gas Selection
 Selecting the proper gas for the material you are cutting is critical to get a
quality cut.
Fig 2.4 Functions of gas in Plasma Arc cutting
Plasma gas is also called the cutting gas. This is the gas that is ionised in the plasma
process and exits through the nozzle orifice. Examples of plasma gas are:
 Air
 Oxygen
 Nitrogen
 Argon-Hydrogen
2.2 Shield Gas Selection
The shield is the secondary gas in the plasma process. It surrounds the arc and is used to help
constrict the arc and cool torch. It creates and protects the cutting environment which among
other things affects the edge quality. Examples of shielding gas are:
 Air
 CO2
 Oxygen-Nitrogen
 Air-Methane
 Nitrogen

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 Methane
2.3 Selecting the Correct Gas
The cutting gas selected depends on the speeds and quality of cut desired. Several cutting gases
can be used in a plasma system to improve cut quality and speed. Nitrogen is widely used
because it is relatively inexpensive and can be used on many materials and thicknesses. Special
mixtures of argon and hydrogen can improve cutting speed and quality on thicker metals and
those other than carbon steels. Oxygen is used in combination with other gases to improve cut
quality by increasing heat, improving cutting speed, and/or reducing power requirements.
Compressed shop air is popular for many applications because it is inexpensive and provides
good quality cuts on thicknesses under 25mm, especially on carbon steels. Gas quality is critical
for the proper operation of plasma arc cutting systems and optimal cut quality. Any contaminates
can cause misfiring, poor cut quality or poor consumable life. Contaminates can be: gas
impurities, moisture, dirt, piping system contaminates or improper gases (i.e. Air in O2 systems-
leaks, not following proper purge procedures when changing gas). The table below gives a list of
the typical gases used for Plasma Arc cutting and the application that they are suitable for:
Table 2.1 Gas selection chart
Gas selection chart
System Material Plasma Gas Shield Gas
HyDefinition
Mild steel O2 O2&N2
Stainless steel
Up to "
4
1
Above "
4
1
Above "
4
1
*
Air Air
Air Air &methane
H35&N2 N2
Aluminum
Up to "
8
3
Up to "
2
1
Air CH4
H35&N2 N2

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Copper O2 O2&N2
MAX200&
HT2000
Mild Steel O2 Air
Stainless steel Air Air
Up to "
4
1
Above "
2
1
H35 N2
Aluminum Air Air
Copper O2 Air
HT4001 Mild Steel ** O2 H2O
Stainless Steel N2 H2O
Aluminium N2 H2O
*Only valid if equipped with six channel gas console (p/n: 078059 & 078061).
**O2 cutting is only for 340 amps maximum. Must use N2 for higher current.
Aluminium and stainless steels require non-oxidizing gases for good cutting results in both thin and
thick sections. Argon/hydrogen mixtures permit good cuts and high cutting rates because the
hydrogen increases the arc voltage and thermal conductivity of the mixture. Parallel kerfs, little
dross, oxide-free cut faces and minimal fumes result from the use of A/H2 mixtures.
Argon/Hydrogen/Nitrogen or A/N2 mixtures are used when machine cutting, but nitrogen is not
recommended for hand cutting due to the formation of poisonous oxides of nitrogen. Higher cutting
speeds are possible with this cheaper mixture with little loss of quality. The increase in cutting
efficiency is probably derived from the greater anodic voltage drop associated with the nitrogen gas.
When inert gases such as argon are used, the heat is derived from the electrical energy of the arc.
Carbon steels require an oxidizing gas for the best results; the exothermic iron-oxygen reaction
provides additional heat at the cutting point and so reduces the amount of electric power required.
Air has proved to be a most efficient gas.
Cutting Speeds for Plasma Arc Cutting
This should be as high as possible for economic reasons provided a narrow kerf and a clean cut at
top and bottom edges are produced. For a given electric power and gas mixture, there is an optimum
speed range for each type and thickness of material. Excess speed causes a decreased kerf width with

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an increased bevel but current intensity is the main factor determining kerf width. For manual
control and complicated machine cuts 1 m/min is a reasonable speed. In general speeds of several
metres/min are used for straight line and trimming cuts.
Table 2.2 Variation of Cutting Speed with Typical Gas-type and Current
Material Thickness
mm
Current
amps
Cutting
speed
Mm/min
Gas
Aluminium 1.5
5.0
12.0
25.0
40
50
400
400
1200
1500
3750
1250
A/H2
A/H2
A/H2
A/H2
Stainless steel
18/8
2
5
12
25
50
100
380
500
1600
2000
1500
625
A/H2
A/H2
A/H2
A/H2
Depth of Cut for Plasma Arc Cutting
Plasma cutting power sources are rated on their cutting ability and amperage. Therefore, for cut depths up
to 6mm thick material, a low amperage plasma cutter will suffice. For cut depths up to 12mm thick a
higher amperage machine will be required. Even though a smaller machine may be able to cut through a
given thickness of metal, it may not produce a quality cut. Instead, you may get a severe cut which barely
makes it through the plate and leaves behind dross or slag. Every unit has an optimal range of thickness --
make sure it matches up with what you need. In general, a 6mm machine has approximately 25 amps of
output, a 12mm machine has a 50-60 amp output while a 18mm to 25mm machine has 80 amps output. The
table below gives typical piercing and cutting depths for different materials
Table 2.3 Cutting depths with Plasma

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System Material Type Max Cut Capacity Max Pierce
Capacity
HD3070
Mild Steel 6mm 6mm
Stainless Steel 6mm 6mm
Aluminum 6mm 6mm
MAX200
Mild Steel 50mm 25mm
Aluminum 50mm 22mm
HT2000
Aluminum 50mm 22mm
HT4001
Aluminum 75mm 25mm
Plasma cutting is a process that is used to cut steel and other metals (or sometimes other materials) using
a plasma torch. In this process, an inert gas (Argon) is blown at high speed out of a nozzle and at the
same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning

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some of that gas to plasma. The plasma is sufficiently hot to melt the metal being cut and moves
sufficiently fast to blow molten metal away from the cut. Plasma can also be used for plasma arc
welding and other applications [3].
Plasma is typically an ionized gas. Plasma is considered to be a distinct state of matter, apart from gases,
because of its unique properties. Ionized refers to presence of one or more free electrons, which are not
bound to an atom or molecule. The free electric charges make the plasma electrically conductive so that
it responds strongly to electromagnetic fields [4].
The Arc type uses a two cycle approach to producing plasma. First, a high-voltage, low current circuit is
used to initialize a very small high intensity spark within the torch body, thereby generating a small
pocket of plasma gas. This is referred to as the pilot arc. The pilot arc has a return electrical path built
into the torch head. The pilot arc will maintain until it is brought into proximity of the work piece where
it ignites the main plasma cutting arc. Plasma arcs are extremely hot and are in the range of 15,000
degrees Celsius.
Oxy fuel cuts by burning, or oxidizing, the metal it is severing. It is therefore limited to steel and other
ferrous metals which support the oxidizing process.
Metals like aluminium and stainless steel form an oxide that inhibits further oxidization, making
conventional oxyfuel cutting impossible. Plasma cutting, however, does not rely on oxidation to work,
and thus it can cut aluminium, stainless and any other conductive material. While different gasses can be
used for plasma cutting, most people today use compressed air for the plasma gas. In most shops,
compressed air is readily available, and thus plasma does not require fuel gas and compressed oxygen
for operation.
Plasma cutting is typically easier for the novice to master, and on thinner materials, plasma cutting is
much faster than oxyfuel cutting. However, for heavy sections of steel (1inch and greater), oxyfuel is
still preferred since oxyfuel is typically faster and, for heavier plate applications, very high capacity
power supplies are required for plasma cutting applications [5] .
PRINCIPLE OF PLASMA ARC CUTTING
This process uses a concentrated electrical arc which melts the material through a high-temperature
plasma beam. All conductive materials can be cut. Plasma cutting units with cutting currents from 20 to

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1000 amperes to cut plates with inert gas, 5 to 160 mm thicknesses. Plasma gases are compressed air,
nitrogen, oxygen or argon/ hydrogen to cut mild and high alloy steels, aluminium, copper and other
metals and alloys [1].
The plasma arc process has always been seen as an alternative to the oxy-fuel process. In this part of the
series the process fundamentals are described with emphasis being placed on the operating features and
the advantages of the many process variants.
Fig 2.5 the principle of the plasma cutting
The plasma is additionally tied up by a water-cooled nozzle. With this energy densities up to
2x106 W/cm2 inside of the plasma beam can be achieved. Because of the high temperature the
plasma expands and flows with supersonic velocity speed to the work piece (anode). Inside the
plasma arc temperatures of 30 000oC can arise, that realize in connection with the high kinetic
energy of the plasma beam and depending on the material thickness very high cutting speeds on
all electrically conductive materials.

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The term for advisable state of plasma arc is called stability of arc too. The stability of arc is
keeping the plasma jet in desired form. It is possible to be provided by [1]:
a) Shape of Plasma Torch,
b) Streaming Jet,
c) Water.
We must monitor these parameters:
 Temperature and electrical conducting,
 Density of plasma jet,
 Diameter of plasma beam,
 Degree of the plasma beam focusing in output from nozzle.
For the cutting process first of all a pilot arc ignition by high voltage between nozzle and
cathode takes place. This low- energy pilot arc prepares by ionization in parts the way between
plasma torch and work piece. When the pilot arc touches the work piece (flying cutting, flying
piercing), the main arc will start by an automatic increase in power
The basic principle is that the arc formed between the electrode and the work piece is
constricted by a fine bore, copper nozzle. This increases the temperature and velocity of the
plasma emanating from the nozzle. The temperature of the plasma is in excess of 20 000°C and
the velocity can approach the speed of sound. When used for cutting, the plasma gas flow is
increased so that the deeply penetrating plasma jet cuts through the material and molten material
is removed in the efflux plasma.
The process differs from the oxy-fuel process in that the plasma process operates by using the
arc to melt the metal whereas in the oxy-fuel process, the oxygen oxidizes the metal and the heat
from the exothermic reaction melts the metal. Thus, unlike the oxy-fuel process, the plasma
process can be applied to cutting metals which form refractory oxides such as stainless steel,
aluminium, cast iron and non-ferrous alloys.
The power source required for the plasma arc process must have a drooping characteristic and a
high voltage. Although the operating voltage to sustain the plasma is typically 100 to 160V, the

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open circuit voltage needed to initiate the arc can be up to 400V DC. On initiation, the pilot arc
is formed within the body of the torch between the electrode and the nozzle. For cutting, the arc
must be transferred to the work piece in the so-called 'transferred' arc mode. The electrode has a
negative polarity and the work piece a positive polarity so that the majority of the arc energy
(approximately two thirds) is used for cutting.
In the conventional system using a tungsten electrode, the plasma is inert, formed using either
argon, argon-H2 or nitrogen. However, as described in Process variants, oxidizing gases, such as
air or oxygen can be used but the electrode must be copper with hafnium. The plasma gas flow is
critical and must be set according to the current level and the nozzle bore diameter. If the gas
flow is too low for the current level, or the current level too high for the nozzle bore diameter,
the arc will break down forming two arcs in series, electrode to nozzle and nozzle to work piece.
The effect of ‘double arcing’ is usually catastrophic with the nozzle melting. The quality of the
plasma cut edge is similar to that achieved with the oxy fuel process. However, as the plasma
process cuts by melting, a characteristic feature is the greater degree of melting towards the top
of the metal resulting in top edge rounding, poor edge squareness or a bevel on the cut edge. As
these limitations are associated with the degree of constriction of the arc, several torch designs
are available to improve arc constriction to produce more uniform heating at the top and bottom
of the cut.
The process variants have principally been designed to improve cut quality and arc stability,
reduce the noise and fume or to increase cutting speed. The inert or uncreative plasma forming
gas (argon or nitrogen) can be replaced with air but this requires a special electrode of hafnium
or zirconium mounted in a copper holder, by shearing . The air can also replace water for cooling
the torch. The advantage of an air plasma torch is that it uses air instead of expensive gases. It
should be noted that although the electrode and nozzle are the only consumables, hafnium tipped
electrodes can be expensive compared with tungsten electrodes.
Although the electrode and nozzle are the only consumables, hafnium tipped electrodes can be
expensive compared with tungsten electrodes.
Fig 2.6: Air Plasma

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This relatively new process differs from conventional, dry plasma cutting in that water is injected
around the arc. The net result is greatly improved cut quality on virtually all metals, including
mild steel. Today, because of advances in equipment design and improvement in cut quality,
previously unheard of applications, such as multiple torches cutting of mild steel, are becoming
common place [6].
Shielding and Cutting Gases for Plasma Cutting
Inert gases such as argon, helium, and nitrogen (except at elevated temperatures) are used with tungsten
electrodes. Air may be used for the cutting gas when special electrodes made from water-cooled copper
with inserts of metals such as hafnium are used. Recently, PAC units shielded by compressed air have
been developed to cut thin-gauge materials.
Almost all plasma cutting of mild steel is done with one of three gas types:
1. Nitrogen with carbon dioxide shielding or water injection (mechanized)
2. Nitrogen-oxygen or air
3. Argon-hydrogen and nitrogen-hydrogen mixtures
The first two have become standard for high-speed mechanized applications. Argonhydrogen and
nitrogen-hydrogen (20 to 35 percent hydrogen) are occasionally used for manual cutting, but the
formation of dross, a tenacious deposit of resolidified metal attached at the bottom of the cut, is a
problem with the argon blend. A possible explanation for the heavier, more tenacious dross formed with
argon is the greater surface tension of the molten metal. The surface tension of liquid steel is 30 percent

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higher in an argon atmosphere than in one of nitrogen. Air cutting gives dross similar to that formed in a
nitrogen atmosphere. The plasma jet tends to remove more metal from the upper part of the work piece
than from the lower part. This results in nonparallel cut surfaces that are generally wider at the top than
at the bottom. The use of argon-hydrogen, because of its uniform heat pattern or the injection of water
into the torch nozzle (mechanized only), can produce cuts that are square on one side and bevelled on
the other side. For base metal over 3 inches thick, argon-hydrogen is frequently used without water
injection [2].
Plasma Gas Selection
Air Plasma
1. Mostly used on ferrous or carbon based materials to obtain good quality a faster cutting speeds. 2.
Only clan, dry air is recommended to use as plasma gas. Any oil or moisture in the air supply will
substantially reduce torch parts life. 3. Air Plasma is normally used with air secondary.
2. Nitrogen Plasma
1. Can be used in place of air plasma with air secondary.
2. Provides much better parts life than air
3. Provides better cut quality on non-ferrous materials such as stainless steel and aluminium.
4. A good clean welding grade nitrogen should be used.
Argon/Hydrogen Plasma
1. A 65% argon/35% hydrogen mixture should be used.
2. Recommended use on 19mm and thicker stainless steel. Recommended for 12mm and thicker
non-ferrous material. Ar/H2 is not normally used for thinner non-ferrous material because less
expensive gases can achieve similar cut quality.
3. Provides faster cutting speeds and high cut quality on thicker material to offset the higher cost
of the gas.
4. Poor quality on ferrous materials.
Oxygen Plasma

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1. Oxygen is recommended for cutting ferrous metals. 2. Provides faster cutting speeds. 3.
Provides very smooth finishes and minimizes nitride build-up on cut surface (nitride build-up
can cause difficulties in producing high quality welds if not removed).
Secondary Gas Selection for Plasma Cutting
Air Secondary
1. Air secondary is normally used when operating with air plasma and occasionally with nitrogen
plasma.
2. Inexpensive - reduces operating costs
3. Improves cut quality on some ferrous materials
CO2 Secondary
1. CO2 secondary is used with nitrogen or Ar/H2 plasma.
2. Provides good cooling and maximizes torch parts life.
3. Usable on any ferrous or non-ferrous material
4. May reduce smoke when used with Ar/H2 plasma.
Table 2.4 Summary for gas selection
Gas Material
Thickness
Material
Carbon
Steel
Stainless
Steel
Aluminum
Air Plasma
Air Secondary
Gage
Gage to
12mm
12mm and Up
Good /
Excellent
Excellent
Excellent
Good /
Excellent
Good
Fair
Good /
Excellent
Good
Fair
Nitrogen
Plasma
Air Secondary
Or CO2
Secondary
Gage
Gage to
12mm
12mm and Up
Good /
Excellent
Good /
Excellent
Good /
Excellent
Good /
Excellent
Good /
Excellent
Good /
Excellent
Good /
Excellent
Good /
Excellent
Good /

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Excellent
Ar/H2 Plasma
N2 or CO2
Secondary
Gage to 6mm
6mm to
30mm
12mm and Up
NR
NR
NR
NR
Good
Good /
Excellent
NR
Excellent
Excellent
Plasma cutting capability
Plasma is an effective means of cutting thin and thick materials alike. Hand held torches can usually cut
up to 2 in (48 mm) thick steel plate, and stronger computer controlled torches can pierce and cut steel up
to 12 inches (300 mm) thick. Formerly, plasma cutters could only work on conductive materials,
however new technologies allow the plasma ignition arc to be enclosed within the nozzle thus allowing
the cutter to be used for non-conductive work pieces. Since plasma cutters produce a very hot and much
localized cone to cut with they are extremely useful for cutting sheet metal in curved or angled shapes.
In this work, Plasma Arc Cutter was utilized to perform Stainless Steel (316 L) material cutting. The
system and the process are the important elements when utilizing plasma arc cutting. It is important to
know current plasma arc cutting research areas to plan the direction of this work so that this work would
contribute information that will be useful in future.
Fig 2.7 Plasma Arc Setup

22
SYSTEM
Plasma arc cutting can increase the speed and efficiency of both sheet and plate metal cutting
operations. Manufacturers of transportation and agricultural equipment, heavy machinery,
aircraft components, air handling equipment, and many other products have discovered its
benefits. Basically Plasma Arc Cutter comprises of 8 major parts such as air compressor, AC
plug, power supply, plasma torch, ground clamp, electrode, nozzle and work piece [2].
Figure 2.8: Plasma Arc Cutter System
2.4 Arc starting circuit
The arc starting circuit is a high frequency generator circuit that produces an AC voltage
of 5,000 to 10,000 volts at approximately 2 megahertz. This voltage is used to create a
high intensity arc inside the torch to ionize the gas, thereby producing the plasma [7].
This project title is to design and fabricate plasma cutter tubing notcher machine. It is more focus to
create the upgrade idea for semi automatic plasma cutter tubing notcher machine. The movable semi
automatic nozzle has two common functions. The first is to cut circular pipe and the second function is
to cut Irregular shape .This plasma cutter is suitable for mass production. This is because of
multifunction used. It also can use for the small business and large manufacturing industry. The main
idea for this cuter is a multifunction plasma cutter tubing notcher machine that is not available in our

23
market now. From this idea we were add more function and the design is different from the other plasma
cutter tubing notcher machine that has in the market.
In our daily life there is a high demand of equipment’s such as manufacturing, household, channels,
frames, and house equipment like tables, chairs and so on. These equipment’s attract the investors to
invest in the production those materials to fulfill the demand of their customers. The main purpose of
this project is to design and manufacture of plasma cutter tubing notcher machine.
2.2Types of plasma cutter tubing notcher
According to the need of investment there are different types of machine those are:
a) Manual plasma cutter tubing notcher
b) Semi automatic plasma cutter tubing notcher
c) Automatic plasma cutter tubing notcher
a) Manual plasma cutter tubing notcher
The original method of Manual plasma cutter tubing notcher began with human power. Although
Manual plasma cutter tubing notcher by hand is very economical, it is not conductive to higher
production rate, quality or repeatability. Operation of this machine requires that the operator
place the tube notcher in the tooling area at the proper cutter position, actuate the tooling into
position, and physically, the machine mechanism to produce the cutter. Basic machines have a
gage or adjustable stop which serves as guide line to produce a desired angel of cutter. When
more than one cutter per part is to be produced, the operator must index the part to the next cutter
point and repeat the process to the desired second cutter angle.
Advantages ofPlasma Arc Cutting
Following are the advantages of Plasma Arc Cutting:
➨Any metals can be cut.
➨The cutting is faster (about 5 to 10 times) than Oxy-fuel.
➨It leaves narrower kerf.

24
➨Higher thickness ability of 150mm.
➨Easy to automate
Disadvantages ofPlasma Arc Cutting
Following are the disadvantages of Plasma Arc Cutting:
➨Larger heat affected zone.
➨Rough surfaces
➨Difficult to develop sharp corners.
➨Smoke and noise gets generated.
➨The method often results into burr.
➨High initial cost of investment.
b) Semi Automatic plasma cutter tubing notcher
Semi-automatics plasma cutter tubing notcher characterized as fundamentally use electrical
power to cut or notched circular pipe. The most basic semi automatic plasma cutter tubing
notcher have a control mechanism by Stops either a physically set limit switch or electronic
really logic system. This machine can require manual positioning of the link or provide powered
tool positioning via the control panel. The operator actuates the cycle via push button and the
machine cutter tubing notcher to the present angle. After the cutting is made, the operator
physically indexes the part forward to the next cutter tubing notcher position, actuates the return
sequence and repeats the process.
c) Automatic plasma cutter tubing notcher
Automatic plasma cutter tubing notcher machine are called PLC plasma cutter tubing notcher
machine, which are programming control logic plasma cutter tubing notcher. Modern PLC
technology is linked with servo-mechanical control offers an excellent method for controlling the
three plasma cutter tubing notcher axis. PLC plasma cutter tubing notcher mechanics operates
very similar to the other draw plasma cutter methods. The difference is that servo drives control
the distance between cutter and plane of torch. Tooling movement and sequencing, part storage

25
data, and other items are controlled by the plc automatically. But the drawback of automatic PLC
plasma cutter tubing notcher machine is required programming skill, need high maintenance and
electrical power.
When we came to our project, it is one of the semi automatically operated plasma cutter tubing
notcher. It is multipurpose plasma cutter tubing notcher. The entire above listed plasma cutter
tubing notcher. have their own drawbacks. For example need high capital expenditure, require
plc skill, need high maintenance cost etc. To reduce those above mentioned drawback, our
project is preferable because it can be produce easily and it can be cut irregular noche. So when
we compare this project with above listed plasma cutter tubing notcher, this machine entirely
different.
Those are:
I. It needs less space.
II. It cannot be needs skill.
III. Manufacture by local materials.
IV. Can be cut irregular shape.
V. Low labor rate and initial investment.
VI. The part easily replaced when damaged.
VII. It is portable.
VIII. Maintenance cost is less.
IX. No wastage of materials
X. Reduce foreign currency.
. SCOPE OF FUTURE WORK
Based on result and discussion summary, this project had archive it main objective but an
improvement still can done to improve more on the Metal Removal Rate (MRR) and Surface
Roughness (Ra) of parts by features. Some of the suggestions to improve the result include the
replication of the model which can reduce the variations of the data and increase the reliability of
the data. Based on this work many improvements can be made and the scope can also be
widened. Following are suggestion for future work:
 Using Plasma Arc Cutting system, add the parameter such as Kerf, Voltage, angle,
material dimension, and change advance material such as brass and bronze then compare
the result obtained.

26
 Using other methodology in the same material of study to compare the results obtained
such as Response Surface Methodology, Grey Relational Analysis, and Genetic
Algorithm etc.
 Study for manual calculation for other method in DOE to improve knowledge and skills.
 No interaction is considered so we can consider interaction by applying L27 or L32 with
3-level design this will improve optimum condition as compare to L16 considered in this
work.
 Also side clearance and thermal effect on material and work piece like Heat
Affected Zone (HAZ) can also be considered to study the effect on properties of work piece.
SUMMARY
Objective of this study is to find out optimal condition of Plasma Arc Cutting Machine for
maximizing MRR and minimizing Surface Roughness (Ra). For this 16 specimens of Stainless
Steel material were prepared which were easily and cheaply available in the scrap yard of
Fabrication Division of BHEL, Bhopal. The mechanical properties of Stainless Steel (316L) are
given in appendix B .Machining process is carried out on Plasma Arc Cutting Machine number
B/0/2163 which is available in the Fabrication Division of BHEL, Bhopal. I considered MRR
and Surface Roughness (Ra) as two most important outputs.
As per literature review Gas Pressure, Current Flow Rate, Cutting Speed and Arc Gap were
considered as most important parameters. In order to perform minimum experiments Taguchi
method has been employed. For this L16 orthogonal array is considered .Experiment results and
various response graph for MRR and SR (Ra) were obtained and there optimum value were also
considered. In chapter 6 mathematical modeling were done .For this I consider regression
analysis. Mathematical equation both for MRR and SR (Ra) were obtained by regression
analysis.
DISCUSSION
 As per analysis, the significant parameter for optimum MRR calculation is
Cutting Speed and the significant parameters for Surface Roughness calculation are Gas
Pressure, Current and Cutting Speed.
 Although some parameters are not significant but we able to improve MRR and Surface
Roughness.
 As per regression analysis the mathematical models of first order for MRR and

27
SR (Ra) is showing significant results.
 Table 4.2 shows the analysis result for MRR. In this case speed is significant model term.
In the model term graph for speed is increase for MRR. It can determined that when the
level of the factor increased, the MRR response also increase significantly. Values greater
than 0.1000 indicate the model terms are not significant. Speed factor are most important
to measured maximize Metal Removal Rate (MRR) for Stainless Steel (316L) Material.
Another factor influence for MRR is equipment system and environments. The
equipment systems, torch vibration, nozzle gag (blocking air), and working table area are
each factors influence MRR.
 Table 4.7 shows the ANOVA result for Ra. P values less than 0.0500 indicate model
terms are significant. In this case there are Gas Pressure, Current and Cutting Speed are
significant terms. In the main effect term graph for pressure and current are increased for
minimizing Ra, and the speed is decreased for minimizing Ra.
CONCLUSION
This thesis has presented an application of the Taguchi method to the optimization of the
machining parameters of Plasma Arc Cutting Machine. As shown in this study, the Taguchi
method provides a systematic and efficient methodology for determining optimal parameters
with far less work than would be required for most optimization techniques. The confirmation
experiments were conducted to verify the optimal parameters. It has been shown that Material
Removal Rate (MRR) and Surface Roughness (Ra) can be significantly improved in the Plasma
Arc Cutting process using the optimum level of parameters.
Plasma Arc Cutting Machine is widely utilized in BHEL, Bhopal to cut materials such as
Stainless Steel and Nickel-Base Alloys. This is the basis work where Plasma Arc Cutting was
utilized to perform the material removal process at finishing stage. The Plasma Arc Cutting
(PAC) machining of Stainless Steel (316L) has been performed with the application of
combination with design of experiment (DOE).
The PAC parameters studied were how to have setting for the parameter such as Gas Pressure,
Current flow, Cutting Speed and Arc gap of machine. From ANOVA of MRR we can say that
some parameters are not making any significant effect .This is because we must take large
number of observations either by considering L27 0r L32 orthogonal array with 3 level designs.

28
Mathematical equation for MRR of first order is of R-sq of 71.2% and for Surface Roughness
(Ra) is of R-sq 77.5% which is acceptable.
CHAPTER THREE
Material selection and design
3.1 Introduction
Mechanical design of the parts of the Plasma cutter and tube notcher will be present in this
chapter. It is known that design is the first activity that has to be done before manufacturing of
parts; we have done all design calculations of the Plasma cutter and tube notcher element in
scientific approaches. The important design and materials of each construction parts of the
machine. Sometimes the strength required of an element in a system is an important factor in the
determination of the geometry and the dimensions of the element. In such a situation
we say that strength is an important design consideration. When we use the expression
design consideration, we are referring to some characteristic that influences the design
of the element or, perhaps, the entire system. Usually quite a number of such characteristics must
be considered and prioritized in a given design situation. Some of the important ones are as
follow.
1. Strength/stress
2. Control
3. Safety
4. Manufacturability
5. Cost
6. Life
7. Marketability
8. Maintenance

The important design and materials machine part are listed as follows
1. Spring
2. Key
3. Shaft
4. pulley
5. Belt
6. Design Load of machine
3.2 Spring design
Table 3.1 Values of allowable shear stress, Modulus of elasticity and Modulus of rigidity for
various spring materials.
Material Allowable shear stress () MPa Modulus of
rigidity (G)
kN/m
Modulus
of
elasticity
(E)
kN/mm
2
Severe
Average
service
service
Light
service
1. Carbon steel
(a) Upto to 2.125 mm dia.
(b) 2.125 to 4.625 mm
(c) 4.625 to 8.00 mm
(d) 8.00 to 13.25 mm
(e) 13.25 to 24.25 mm
( f ) 24.25 to 38.00 mm
2. Music wire
3. Oil tempered wire
4. Hard-drawn spring wire.
5.Stainless-steel wire
6. Monel metal
7.Phosphor bronze
8 . Brass
420
385
336
294
252
224
392
336
280
280
196
196
140
525
483
420
364
315
280
490
420
350
350
245
245
175
651
595
525
455
392
350
612
525
437.5
437.5
306
306
219
80
70
44
44
35
210
196
105
105
100

52
Our spring material is Carbone steel diameter of spring wire is Ф2.5 mm which is used for
light service. Allowable share stress is τ=595 Mpa, modules of rigidity (G) =80kg/m2,
module of elasticity (E) =210KN/mm2
Nomenclatures of springs
D=mean diameter of spring coil, =20mm
d=diameter of spring wire=2.5 mm
n=number of active coils, =25
Wi = initial axial tensile load on the spring
W=maximum axial tensile load on the spring, =100N
G= modulus of rigidity for the spring material of the spring wire.
τ = maximum shear stress induced in the wire
C= spring index =D/d
p=pitch of the coil
LF=free length of spring
δ= deflection of the spring, as a result of an axial load W.
n’=total number of coils
LS=solid length of spring
From the above characteristics we should do directly with the dimensions, the material, the
processing, and the assembling of the elements of the system. Several characteristics may
be interrelated, which affects the configuration of the total system.
Table3.2 allowable shear stress (τ) and modulus rigidity (G) and modulus elasticity (E)
No Material Allowable shear stress (τ) MPa Modulus of
rigidity(G)
kN/m2
Modulus of
elasticity(E)
kN/mm2
Severe
service
Average
service
Light
service
1 Oil tempered wire 336 420 525 80 210
2 2.Hard-drawn spring wire 280 350 437.5 80 210
3 3.Stainless-steel wire 280 350 437.5 70 196

52
Solid length of the spring
LS = n'.d
Where n' = Total number of coils=25, and
d = Diameter of the wire 2.5mm.
LS=25*2.5mm
= 62.5mm
Free length of the spring,
In designing a tension spring the minimum gap between two coils when the spring is in the
Free State is taken as 1 mm. Thus the free length of the spring,
LF = n’d + (n – 1)
And pitch of the coil, p = LF/ n– 1
LF = 25*2.5mm + (25 – 1)
=86.5mm
Spring index, C = D / d
Where D = Mean diameter of the coil=20mm, and
d = Diameter of the wire=2.5mm.
C = 20mm / 2.5mm
=8mm
mm
dG
nDW
0512.0
5.2*10*80
25*20*100
*8
*
**
*8 46
3
4
3


Spring rate,
k = W / δ
Where W = Load=100, and
δ = Deflection of the spring=0.0512.
k = 100 / 0.0512
k=1953.125
Pitch of the coil, p =
1n'-
lengthFree

52
, p =
1-25
86.5
=
24
86.5
P=3.6mm
The pitch of the coil may also be obtained by using the following relation, i.e.
Pitch of the coil, p = d
n'
LS-LF
Where LF = Free length of the spring,
LS = Solid length of the spring,
n' = Total number of coils, and
d = Diameter of the wire.
p = d
n'
LS-LF
p = 5.2
25
62.5-86.5

p =3.46mm
In choosing the pitch of the coils, the following points should be noted :
(a) The pitch of the coils should be such that if the spring is accidently or carelessly
compressed,
the stress does not increase the yield point stress in torsion.
(b) The spring should not close up before the maximum service load is reached.
Fig.3.1 compression spring nomenclature
Shear stress factor

52
KS=
C2
1
1
Where KS = Shear stress factor
C=spring index =8
KS=
8*2
1
1 =
16
17
Ks =1.06 N/mm
2
33max
/68.345
)5.2(*
20*100*8
*06.1
*
**8
*
mmN
d
DW
Ks




Note: the total number of turns of a tension helical spring must be equal to the number of
turns (n) between the points where the loops start plus the equivalent turns for the loops. It
has been found experimentally that have turn should be added for each loop [7]. Thus for
spring having on loops on both ends, the total number of active turns,
n’= n+1=18+1=19mm
3.5 design of Key
Table 3.3 Proportions of standard parallel tapered and gib head keys.
Shaft diameter
(mm) up to and
Including
Key cross section Shaft diameter
(mm) up to and
Including
Key cross section
Width
(mm)
Thickness
(mm)
Width
(mm)
Thickness
(mm)
6
8
10
12
17
22
30
38
44
50
58
2
3
4
5
6
8
10
12
14
16
18
2
3
4
5
6
7
8
8
9
10
11
85
95
110
130
150
170
200
230
260
290
330
25
28
32
36
40
45
50
56
63
70
80
14
16
18
20
22
25
28
32
32
36
40

52
65
75
20
22
12
14
338
440
90
100
45
50
Shaft diameter of motor is =Ф17mm
Revolution Per minute (RPM) =25
The square key is design as per the table. We find that for a shaft Ф17
Width of key (W) =6mm
Thickness of key (T) =6mm
The length of key is obtained by considering the key is in shearing and crushing stresses for
the mild steel key 56mpa and 112mpa respectively.
Let L=length of key, consider shearing of the key we know that sharing strength of the key.
Solution. Given: d = 17 mm; τ = 56 MPa = 56 N/mm2; σc = 112 MPa = 112 N/mm2
The rectangular key is designed as discussed below:
We find that for a shaft of 17mm diameter,
Width of key, w = 6 mm.
And thickness of key, t = 6 mm.
The length of key is obtained by considering the key in shearing and crushing.
Let l = Length of key.
Considering shearing of the key. We know that shearing strength (or torque transmitted) of the
key,
Considering the failure of key due to shearing, T=L*w*τs*d/2,
T=L*6*56*17/2
T=2856L N.mm -------------- (equ.1)
Torsion shearing strength (or torque transmitted) of the shaft
3
max **
16
dT 



52
3
17*56*
16

T
T=53993.87------------------ (equ.2)
From equ.1and equ.2
L=
2856
53993.87
L=18.9mm
Now consider crushing of the key. We know that shear strength (torque transmitted)
of the key
2
**
2
*
dt
lT ck
mmLNLT .2856
2
17
*112*
2
6
*  -------------- (equ.3)
From equ.2 and equ.3
L=
2856
53993.87
=18.9mm, then the same value and take one of the two value length of key.
L=18.9mm  19 mm
Design of pulley
The velocity ratio of a belt drive may also be obtained as discussed below.
The prepared velocity of the belt on the driving pulley
V1 = sm/
60
N1*d1*
,
And prepared velocity of the belt on the driving pulley
V2 = sm/
60
N2*d2*
When there is no slip, then V1=V2

52
sm/
60
N1*d1*
= sm/
60
N2*d2
OR
d2
d1
N1
N2

Our pulley is: - Our motor RPM= 25RPM
Maximum presumable tension in belt (T) =1KN
Coefficient of friction between the belt and pulley is (  ) =0.25
Distance between center of pulley(X) =700mm
d1=80mm
d2=200mm
N1=25 RPM
smN /N1*
d2
d1
2  smN /25*
200
80
2  N2=10 RPM
Length of belt
L=  2x*r2)(r1* sm
rr
/
60
N2*d2*)21( 
 2x*r2)(r1*
X
r2)2+(r1
 (700)*2*)001(40*14.3
700
)2001(40
L=1867.6mm
Angle of contact for open belt driven
ፀ= (180-2 )
But the value  is given by

52
Sin  = (
X
r1)-(r2
)
 =(
700
40)-(100
)
 =4.90
Where r1=radius of large pulley
R2= radius of small pulley
(180-2 ) but  =4.9
2 ፣2*4.9=9.8  10
ፀ= (180-9.8)
ፀ= 170
Power transmitted
T1=transmit in the right side of belt
T1=transmit in the slack side the belt
*
T2
T1
 eµፀ
*9.2*
T2
T1
 1018
T2=
𝑇1
2.98∗1018
T1=1000 N

52
T2=
1000𝑁
2.98∗1018
T2=3.345*10−16N
Velocity of belt, V=
60
N1*d1*
=
60
25*08*14.3
V=104.66m/s
Power transmit ion
P= V*T2)(T1
P= *3.345(1000N 10-16)*104.66
P=104.66KN
Weight of the cutting part
W1= cutting part
W=mg
W1=1.5kg*9.81m/s (Weight of the cutting part)
= 147.15N
Weight of the volume
W=10kg*9.81m/s
=98.1N
Total mass=25kg
Total Weight 245.25N
Assumption is required for softy
Late take 10% of the total mass =2.5kg
Weight for softy
W=2.5kg*9.81m/s

52
=24.525N
Total weight=24.525+245.25
= 269.775N
W=98.1 W= 147.15N
A
200 600 200
RA RB
∑MA=0
RB= RB*1000 = (147.15*800) + (98.1N*200)
= (147.15*800) + (98.1N*200)
=117720+19620
RB=
1000
137340
 =137.34 N
∑MB=0
∑MB=0, RA*1000= (98.1*800)+(147.15*200)
, RA*1000=78480+29430

1000
1000*RA
1000
29430+78480

1000
107910

RA=107.91Nm
A B

52
Free body diagram of segment CB.
147.15
M V C B
200 RB 98.1N
∑v=0
V=147.15-137.34 RA 200
=9.81
∑Mc=0, M=137.34*200
=2746.8Nm ∑v=0
∑Mc=0
, RA*200
107.91N*200 =-21582Nm
We know the maximum bending moment is at D
There for maximum bending moment M=2746.8Nm. Our shaft cross section is
50mm*50mm*2mm rectangular tube.
Y
X b
B
12
44
hb
I
I
MY 

520832
12
6250000
I
25
2

b
Y

52
520832
25*8.2746
I
MY

 =0.1318N/mm2

52
CHAPTOR FOURE
MANUFACTURING PRINCILE AND PROCESS PLANNING
4.1 INTRODUCTION
Manufacturing is the transformation of raw material into finished goods for sale, or
intermediate process involving the production or finishing of semi -manufacture.
For an organization to manufacture a product that meets the design specifications, the
manufacture of each component part of each the product must be thoroughly planned.
However, merely ensuring that the product meets the design specification and the required
quality is not enough. The manufacture of the product must be cost-effective, that is,
maximize the added value, and meet the agreed deadlines, that is, be completed on time.
Therefore, though process planning the manufacturing engineer is responsible for ensuring
that the product is manufactured to the correct specification at the lowest possible cost and
completed on time. [Process p]
4.2 Aims and objectives
The main aims of this chapter are to describe process planning.
 Identify the functions involved in product design and manufacture;
 Define the process planning activity;
 Identify and describe the main tasks undertaken during process planning;
 Identify and describe used in process planning;
 Identify and describe the main process planning documentation;
 Identify and describe the relationship between process planning and other
manufacturing functions.
4.3 Process planning
Process planning comprises the selection and sequencing of processes and operations to
transform a chosen raw material into a finished component. It is the act of preparing detailed
work instructions to produce a component.
This includes the selection of manufacturing processes and operations, production equipment,
tooling and. It will also normally include determining manufacturing parameters and
specifying criteria for the selection of quality assurance (QA) methods to ensure product
quality.
4.4 Preparing the process planning documentation
There are two documents involved in the preparation of the process plans.
These are:

52
 Routing sheets
 Operations list.
4.5 Routing sheets
It is name suggests, specifies the route the raw material follows through the body and frame
work shop floor. It usually lists the production equipment and tooling to be used.
4.6 Operations list
It is once the routing of a component has been established; the detailed plan for every
operation can be prepared using an operation list. This specifies in more detail each
individual operation. It is usually for an operation list to be prepared for each work station
listed on the routing sheet, although it may sometimes cover a group of machines in a work
cell.
There for the determination of detailed process plan for machining operation is critical. A
detail process plan contains the process route, process parameter and available machine and
tooling required for production etc.
The process plan involves the following activates
 Selection of blank and its manufacturing method
 Selection of machining method
 Determination of operation sequence
 Determination of work piece setting method
 Selection of machining equipment and tooling
 Determination of operating procedure
 Determination of dimension and tolerance
 Selection of machining condition and determination of time standards for each
operation.
4.7 Process parameters
The setting of these parameters logically follows on from the selection of appropriate
production equipment and tooling. In fact, once the machine tool and tooling have been
selected and cutting fluid specified for the part under consideration, there are only three other
parameters remaining that can influence the success of the machining. These are the cutting
speed, feed rate and depth of cut to be used for each operation. To accurately determine the
precise data for any machining operation can be difficult without knowledge of the exact
practicalities involved. As process planning relies heavily on the experience of the individual

52
preparing the plan and their knowledge of the processes, equipment and tooling available,
there may be instances when this is the case, for example, in cases where new production
equipment is purchased.
4.8 Surface cutting speeds
The cutting speed for a machining operation refers to the speed at which the cutting edge of
the tool passes over the surface of the work piece. It is invariably also referred to as the
surface speed. It is always considered as the maximum relative speed between the tool and
the work piece and is usually quoted in meters’ per minute (mmin-1). The cutting speed Vc is
subsequently used to calculate the time taken for the operation, that is, the machining time T.
4.9 Cutting speeds for turning, boring, milling and drilling
The maximum cutting speed can be calculated for processes where either the Work piece or
the tool rotate, that is, turning, boring, milling and drilling, by using the maximum rotational
speed N of the work piece/tool and the work piece/tool diameter D in the following equation:
1000
DN
vc


Where Vc is the surface cutting speed (mmin-1),
D the diameter of the cutter for milling/drilling or the work piece for turning/boring (mm)
and NR the revolutions of the cutter for milling/drilling or the work piece for turning/boring
(rpm).
In turning and boring where a taper is being machined, that is, the diameter is varying across
the cutting operation; the average diameter should be used.
Therefore:
2
21 dd
D


Where,
D is the average diameter of the work piece,
d1 the diameter of the Work piece at the start of the operation and
d2 the diameter of the work piece at the end of the operation.
The above also applies for calculating the cutting speeds for facing and parting-off operations
for turning.
4.10 Spindle speeds for turning, boring, milling and drilling
The actual spindle speed to be set, which will maintain the quoted surface speed, depends on
the diameter of the work piece D (for turning and boring) or the cutter (for milling and
drilling). Therefore, if a small diameter and a large diameter have to be machined at the same
surface speed, then the smaller diameter must rotate quicker. The equation presented to

52
calculate the cutting speeds can be used to calculate the spindle speed by simple transposition
as follows:
D
V
N C
R

1000
 , Where, NR= the revolutions of the cutter for milling/drilling or the work
piece for turning and boring (rpm),
VC=the surface cutting speed (mmin-1)
D= the diameter of the cutter for milling and drilling or the work
piece for Turning and boring (mm).
For turning and boring, the above equation holds true for the machining of a ‘constant’
diameter. However, in cases where the diameter is decreasing or increasing as the cutting tool
moves along the work piece, it does not hold true, that is, the spindle speed calculated is no
longer valid or efficient. Therefore, as a compromise the average diameter must be used.
Table 4.1: Surface cutting speeds in meters per minute
Part material Surface cutting speed (m/min)
HSS carbides
Low-carbon steel 20-110 60-230
Medium-carbon steels 20-80 45-210
Steel alloys (Ni-based) 20-80 60-170
Gray cast iron 20-50 60-210
Steel less steels 20-50 55-200
Chromium nickel 15-60 60-140
Aluminum 30-110 60-210
Aluminum alloys 60-370 60-910
Brass 50-110 90-305
Plastics 30-150 50-230
4.11 Feed rates for turning and boring
The feed rate of machining operation is defined as the speed at which the cutting tool
penetrates the work piece. This is usually stated in either millimeter per spindle revolution
(mm/rev) or as millimeter per minute (mm/min). The two most common tool materials used
for turning are high-speed steels (HSS) and carbides. It is common practice for manufacturers
to recommend feed rates in millimeters per spindle revolution fr (mmrev-1). Typical feed rates
fr are given for both materials in Table 4.2, which was compiled from various The above
feeds fr in mmrev-1 can be converted to mm/min(fm) by using the equation:

52
Nff rm 
Table 4.2: Feed rates for turning/boring in millimeters per Revolution
Part material Turning/boring feed rate fr (mmrev-1)
HSS Carbides
Low-carbon steels 0.15–0.45 0.15–1.1
Medium-carbon steels 0.15–0.4 0.15–0.8
Steel alloys (Ni-based) 0.1–0.3 0.1–0.75
Grey cast iron 0.1–0.4 0.1–1.0
Stainless steel 0.2–0.75 0.2–2.0
Chromium nickel 0.1–0.6 0.1–1.0
Aluminum 0.2–0.6 0.2–1.0
Aluminum alloys 0.1–0.3 0.1–1.0
Brass 0.15–8.0 0.15–1.5
Plastics 0.1–0.35 0.2–1.0
Table 4.3: Feed rates for milling in millimeters per tooth
Part material Milling feed rate ft (mm/tooth)
HSS Carbide
Face
mills
End mills
and slot drill
Face
mills
End mills
and slot drills
Low-carbon steels 0.2–0.5 0.1–0.25 0.1–0.75 0.15–0.40
Medium-carbon steels 0.2–0.5 0.1–0.25 0.1–0.75 0.15–0.40
Steel alloys (Ni-based) 0.2–0.8 0.15–0.4 0.3–1.2 0.2–0.5
Grey cast iron 0.15–0.65 0.075–0.3 0.15–0.75 0.075–0.4
Stainless steels 0.2–0.6 0.1–0.3 0.3–1.2 0.2–0.5
Chromium nickel 0.1–0.6 0.1–0.3 0.3–1.2 0.2–0.5
Aluminum 0.25–0.75 0.15–0.4 0.25–1.0 0.1–0.5
Aluminum alloys 0.25–0.75 0.15–0.4 0.25–1.0 0.1–0.5
Brass 0.25–0.5 0.1–0.25 0.25–0.65 0.1–0.4
Plastics 0.2–0.8 0.15–0.4 0.2–1.2 0.1–0.6
Table 4.4: Feed rates for HSS and carbide drills

52
Drill diameter (mm) Drilling feed rate fr (mmrev1)
HSS Carbide
2 0.05 0.15
4 0.10 0.15
6 0.12 0.15
8 0.15 0.18
10 0.18 0.25
12 0.21 0.25
14 0.24 0.28
16 0.26 0.32
18 0.28 0.32
20 0.30 0.32
Table 4.5: Typical depths of cut for turning/boring with carbide tooling
4.12 Setting process parameters
4.12.1General Information
The process parameter to be calculated is the spindle speeds, for all operations. This will be
calculated using the formula and guide lines provided. The feed rates for all operation will be
selected from standards tables provided above. The spindle speed for all operation are
calculated based on rough cuts only, but for finishing operations the spindle speeds for all
Part material Depth of cut (mm)
Low-carbon steels 0.5–7.6
Medium-carbon steels 0.25–7.6
Steel alloys (Ni-based) 0.25–6.5
Grey cast iron 0.4–12.7
Stainless steels 0.5–12.7
Chromium nickel 0.25–6.5
Aluminum 0.25–8.8
Aluminum alloys 0.25–8.8
Brass 0.4–7.5
Plastics 0.25–7.5

52
operations are higher compare to roughing operations. Finally, all calculation will be made on
the bases that low carbon steel tooling is being used in line with general recommendation.
4.13 Process parameters calculations
4.13.1 Part 1: shaft
Operation1: cut blank size to Φ55*603mm
For cutting blank size to Φ55*603 by hack saw, surface speed and feed rate are not important.
Operation 2: facing both sides to Φ55*600mm
For facing both sides of shaft to Φ55*600mm, of 340 rpm has been used and feed rate of
0.4mm/rev has been selected from table 4.2 for typical feed rates for turning or boring in
mm/rev.
I. Speed- a surface speed of 80m/min has been selected for HSS tool (cutter) from
table 4.1 for surface cutting speeds in m/min for diameter 30mm.
NR=1000*VC/πD=1000*80/π*55=463rpm
II. Feed-a feed rate of 0.4mm per revolution has been selected from table 4.2 for
typical feed rates for turning or boring in millimeters per revolution.
Operation3: turning diameter Φ55mm*80
I. Speed- surface speed of 60m/min has been selected from table 4.1 for surface
cutting speed in meters per minute.
NR =1000*Vc /πD= 1000*60/π*55=347rpm.
II. Feed- rate of 0.4mm per revolution has been selected for HSS cutter from the
table 4.2 for typical feed rates for turning or boring in millimeters per revolution
and for finish cut 0.2mm/rev.
4.13.2 Key way on the motor shaft
Operation 4: (Φ20*80) mm
I. Speed- surface speed of 70m/min has been selected from the table 4.1 for
surface cutting speeds in m/min
NR =1000*Vc /πD=1000*40/ π*20=637rpm
II. feed- feed rate of 0.3mm/rev has been selected for HSS cutter from table 4.3
for typical feed rates for milling in millimeters per tooth and for finish cut
0.1mm where length of key way is (40*8)mm
4.13.3 Part 2: pulley
Operation 1: cut blank size (Φ200*55) mm

52
For cutting blank size to (Φ200*55) mm by Plasma Cutter Tubing Notcher
power hack saw, surface speed and feed rate are not important.
Operation 2: facing both sides to (Φ200*55) mm
I. speed- surface speed of 70m/min has been select for HSS cutter
from the table 4.1 for surface cutting speeds in meters per minutes
for Φ100mm*83mm
NR =1000*Vc /πD=1000*70/ π*100 =222rpm
II. Feed-feed rate of 0.3 mm/rev has been selected from table 4.2 for
typical feed rates for facing in millimeters per revolution for rough
cut.
Operation 3: turning with (Φ200*60) mm
I. speed-surface speed of 80m/min has been selected HSS cuter from table 4.1 for
surface cutting speeds m/min for turning
NR =1000*Vc /πD=1000*80/π*100=255rpm
II. Feed-feed rate of 0.3 mm/rev has been selected from table 4.2 for typical feed
rates for facing in millimeters per revolution for rough cut and for finish cut
0.1mm.
Operation 3: boring hole (Φ30*80) mm
First operation is center drilling by using center drill.
I. Speed- surface speed of 60m/min has been selected from table 4.1 for surface
cutting speed in meters per minute.
NR =1000*VC /Pd= 1000*60/π30=637rpm.
 HSS Drill Bits: drill bit with 5mm, 8 mm, 14mm, 18mm, 20mm, 24mm, 28mm, and
30mm.
Operation 4: groove on pulley (Φ100*25) mm
I. Speed- a surface speed of 80m/min has been selected for HSS tool (cutter)
from table 4.1 for surface cutting speeds in m/min for diameter 30mm.
NR=1000*VC/πD=1000*80/π*94=270rpm
II. Feed-feed rate of 0.3 mm/rev has been selected from table 4.2 for typical
feed rates for groove in millimeters per revolution for rough cut and for
finish cut 0.1mm.
Where grooving of length 25mm depth of grooving 12.5 radius
4.13.4 Part 3: Key

52
For cutting blank size to length 80mm, width 10mm, and thickness 6mm profile
made by milling machine.
4.13.5 Part 4: square pipe (RHS)
Operation1: blank size of (50*30*3) mm
Cutting black size for body (1200*300*270) mm by power hack saw, surface
speed and feed are not rate important.
PROCESS PLAN FOR BEARING HOUSE
PROCESS PLAN
Part name;
Bearing
House
Material
Black
steel
Black size
 115mmX355m
Customer Quantity -01
Part no;01
Op.no Operation
description
Machine Toolin
g
Feed
(mm/min)
Speed
(RPM)
Planned time
Rem
arksSet-up
time
(min)
Machine
time(min) Total
Time
1 Black preparation
size ϕ115*355mm
Power
hacksaw
blade - - 2 10 12
2 Facing 2mm lathe
process
HSS 0.30 420 3 8 11 Both
side
3 Rough turning
ϕ112*351mm
lathe
process
HSS 0.4 420 5 14 19
4 Finish Turing
ϕ110mm350mm
lathe
process
HSS 0.20 960 4 10 14
5 Boring with
ϕ100mm20mm
lathe
process
Borin
g tool
0.32 640 6 13 19 Both
side
PROCESS PLAN FOR HOLLOW SHAFT

52
PROCESS PLAN
Part name;
hollow shaft
Material
Mild
steel
Black size
 45mmX705m
Part no;02
Op.no Operation
description
Machine Tooli
ng
Feed
(mm/mi
n)
Speed
(RPM)
Planned time
Rema
rks
Set-up
time
(min)
Machine
time(min
)
Total
Time
1 Black preparation
size ϕ45*705mm
Power
hacksaw
blade - - 3 10 13
2 Facing 2.5mm lathe
process
HSS 0.25 420 4 15 19 Both
Side
3 Rough turning
ϕ41mm700mm
lathe
process
HSS 0.35 640 3 20 23
4 Finish Turing
ϕ40mm700mm
lathe
process
HSS 0.2 960 5 15 20
PROCESS PLAN FOR BUSH
PROCESS PLAN
Part name;
bush
Material
Mild steel
Black size
ϕ70*60mm
Part no;03
Op.No Operation
description
Machine Tooling Feed
(mm/
min)
Speed
(RPM)
Planned time
Rema
rks
Set-up
time
(min)
Machine
time(min
)
Total
Time
1 Black preparation
size ϕ70*60mm
Power
hacksaw
Blade - - 3 10 13
process
Facing
Tool
0.35 640 4 15 19 Both
Side
3 Rough Turing
ϕ66mm55mm
lathe
process
Roughi
ng
Turing
tool
0.30 420 6 12 18
4 Step Turing
Φ56mm41mm
lathe
process
Turing
Tool
0.35 640 4 15 19
5 Finish Turing
ϕ40mm700mm
lathe
process
Finishi
ng tool
0.25 960 5 13 18

52
6 Drilling
ϕ38mm55mm
lathe
process
Center
bit ϕ10,
ϕ20,
ϕ30,
ϕ38mm
0.25 340 3 25 28
7 Boring
ϕ40mm55mm
lathe
process
Boring
tool
0.25 640 5 20 25
8 Drilling ϕ5mm Drilling
machine
Drill bit
ϕ5
0.30 420 8 15 23
9 Taping M6*1 Manual
taping
Taping
M6*1
- - 3 15 18
PROCESS PLAN FOR PULLEY
PROCESS PLAN
Part name; bush Material
Aluminu
m
Black size
 205X65mm
Part no;04
Op.No Operation
description
Machin
e
Tooling Feed
(mm/
min)
Speed
(RPM)
Planned time
Rema
rks
Set-up
time
(min)
Machine
time(min
)
Total
Time
1 Black preparation
size  205X65mm
Power
hacksa
w
Blade - - 10 25 35
process
HSS 0.35 640 5 15 20 Both
Side
3 Rough Turing
ϕ201mm60mm
lathe
process
Roughi
ng
Turing
tool
0.30 420 6 15 21
4 Step Turing
Φ62mm28mm
lathe
process
Turing
Tool
0.35 640 4 15 19
5 Drilling
ϕ38mmX60mm
lathe
process
Center
bit ϕ10,
ϕ20,
ϕ30,
ϕ38mm
0.25 340 3 25 28
6 Boring
ϕ40mmX60mm
lathe
process
Boring
tool
0.25 640 5 20 25

52
7 Finish Turing
ϕ60mm30mm
lathe
process
Finishi
ng tool
0.25 960 5 13 18
8 Grooving lathe
process
Formin
g tool
0.30 420 8 15 23
9 Drilling ϕ5mm hole
on the part of
shoulder opposite
side
Drill
machin
e
Drill bit
ϕ5
0.30 420 8 15 23
taping
Taping
M6*1
- - 3 15 18
PROCESS PLAN FOR PULLEY
PROCESS PLAN
Part name;
bush
Material
Aluminum
Black size
 205X65mm
Part no;05
Op.No Operation
description
(mm/mi
n)
Speed
(RPM)
Planned time
RemarksSet-up
time
(min)
Machine
time
(min)
Total
Time
1 Black preparation
size  105X65mm
Power
hacksaw
Blade - - 10 25 35
process
HSS 0.35 640 5 15 20 Both
Side
3 Rough Turing
ϕ101mm60mm
lathe
process
Roughing
Turing
tool
0.30 420 6 15 21
4 Step Turing
Φ42mm28mm
lathe
process
Turing
Tool
0.35 640 4 15 19
5 Drilling
ϕ18mmX60mm
lathe
process
Center bit
ϕ10, ϕ20,
ϕ30,
ϕ38mm
0.25 340 3 25 28
6 Boring
ϕ20mmX60mm
lathe
process
Boring
tool
0.25 640 5 20 25

52
7 Finish Turing
ϕ40mm30mm
lathe
process
Finishing
tool
0.25 960 5 13 18
8 Grooving lathe
process
Forming
tool
0.30 420 8 15 23
9 Drilling ϕ5mm hole
on the part of
shoulder opposite
side
Drilling
machine
Drill bit
ϕ5
0.30 420 8 15 23
taping
Taping
M6*1
- - 3 15 18
PROCESS PLAN FOR VICE
PROCESS PLAN
Part name;
bush
Material
Mild steel
Black size Customer Quantity -01
Part no;06
Op.No Operation
description
(mm/mi
n)
Speed
(RPM)
Planned time
RemarksSet-up
time
(min)
Machine
time
(min)
Total
Time
1 Black preparation
size angle iron 
60X60mmX20
Power
hacksaw
Blade - - 10 25 35
2 Black preparation
(80*400*2)mm
Power
hacksaw
Blade - - 5 15 20 Both
Side
3 Black preparation
For square trade
Φ25mm20mm
Power
hacksaw
Blade 0.30 420 6 15 21
process
Facing
Tool
0.35 640 4 15 19
5 Turing
ϕ22mmX18mm
lathe
process
Turing
tool
0.25 340 3 25 28
6 Finish Turing
ϕ20mm18mm
lathe
process
Facing
tool
0.25 640 5 20 25
7 External trading
making square
lathe
process
Threadin
g tool
0.25 960 5 13 18
8 Welding
(Assembling )
Welding
machine

52
Chapter summery
In this chapter analyze all manufacturing analysis of the parts fabrication. From the drawing
interpretation up to documentation of the process, the part which fabricate with the
relationship of the surface roughness and geometric tolerance. It expresses how
manufacturing processes will perform by mentioning there sequence of process,
manufacturing parameters and calculate setting parameters, selection of tools and machine.
Based on this manufacturing processes planning and part fabrication.

52
CHAPTER FIVE
RESULT AND DISCUSSION
In this project the design analyses of plasma cutter and tube notcher and place operation has
been considered. The main challenge during the design and development of plasma cutter and
tube notcher type machine is obtaining the desired geometrical data and its variables analysis.
To achieve the plasma cutter and tube notcher machine is used. Future work is to be
fabrication and manufactured the complete body structure of the plasma cutter and tube
notcher, then the assembly of all the manufactured parts are to be done, so that the required to
cutting regular and irregular circular cutting to the target place.
During conducting the project work improper manufacturing and fabrication of machine parts
have been observed. The materials that are used to make the parts are mostly steel parts.

52
CHAPTER SIX
CONCLUSION AND RECOMMENDATIONS FOR FUTURE WORK
6.1 Introduction
This chapter summarizes, concludes and proposes the future work to be continued on the
theoretical and experimental study of plasma cutter and tube notcher application.
6.2 CONCLUSION
The project gives a brief idea about semi automatic Plasma Cutter Tubing Notcher machine
process. The conceptual design of Plasma Cutter Tubing Notcher machine system to be used
for irregular and regular pipe cutting. However, much scope for the system improvement in
the future is left to be considered such as increasing the develop rate and simplifying the
system design.
The machine has a complete design and is available for fabrication. To validate and evaluate
the actual performance, the machine has to be fabricated and tested. The fabrication was not
included in this study due to press of time and the unavailability of necessary materials.
6.3 RECOMMENDATION
Since the prototype of the design of semi automatic Plasma Cutter Tubing Notcher machine
was successful and future action is recommended to manufacturing to produce a large scale
and plc set up of this machine and need farther study on the abrasive type best for the
method of Plasma Cutter Tubing Notcher.
It is highly recommended that this project continue to fabrication stage and be tested and
evaluated in the presence of representatives from industry and our college.
It is recommended that design of experiments be used to scientifically determine the optimum
combinations of parameters so that the highest shelling efficiency could be achieved.

52
6.4 Limitation
Research work such as our own requires an ample data and information sources to produce a
good pack of documents. Comparing the old with the new approach is possible only when
sources are available. But, we have started our study with no provision of data on hand.
The scarcity of data should not be a limitation for addressing a problem we have seen in
Basic Metal Industry, according to this study. Results of our own would be the foundation for
incoming study. Of course, things would have been much better, had we been in a different
situation of having resource.
Books Referred and Websites
1. Hatala Michal Faculty of Manufacturing Technologies of the Technical University of
Košice Šturova The Principle of Plasma Cutting Technology and Six Fold Plasma
Cutting. 5th International Multidisciplinary Conference.
2. Parweld Plasma Process Synopsis September 2001 Release
3. Plasma Cutting, http://en.wikipedia.org/wiki/Plasma_cutting
4. http://www.aws.org/wj/2003/02/024/#A,
5. Plasma(Physics), http://en.wikipedia.org/wiki/Plasma_(physics)#History
6. Cutting Process, http://www.twi.co.uk/j32k/protected/band_3/jk51.html
7. Plasma Cutting, http://www.hypertherm.com/technology.htm

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