Post on 15-Aug-2015
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CHAPTER 1
INTRODUCTION
1.1 INTRODUCTION Mechanical engineering without production and manufacturing is
meaningless and inseparable. Production and manufacturing process deals
with conversation of raw materials inputs to finished products as per required
dimensions specifications and efficiently using recent technology.
CHAPTER 1 is the introduction chapter of this project. Generally, it discuss
about the project background, problem statement, the objective, scope of
project, projectflow and project Gantt chart.
1.2 BACKGROUND Imagine two plain wheels fixed rigidly to two parallel shafts and pressed
tightly in contact witheach other. If one wheel is rotated about its axis, the
other wheel will also rotate due to thefriction between them. The rotary
motion is thus transmitted from one shaft to another. Thesurfaces of the two
wheels will move at the same speed if there is no slipping. It is obvious that
with the increase in Load to be transmitted, the wheels will begin to slip on
each other.To prevent slipping slots may be cut on the cylindrical surfaces of
the wheels and projectionsadded between them. These slots and projections
form the teeth, and wheels with such teeth arecalled toothed wheels or gears.
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Fig1.2.1 (Gear terminology)
1.3 PROBLEM STATEMENT Lathe is suitable for operations like turning, boring, facing taper turning,
thread cutting, knurling, etc. but not suitable for operations like key way
cutting etc. Because in a conventional lathe as soon as the machine is
switched on, the workpiece fixed to the chuck rotates. This is a major
limitation of the conventional lathe keeping in view of the present project
work.
Gear cutting is a specialized form of milling, and the lathe is quite suited to
this job for smaller work (6" diameter or so) with the help of attachment.
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1.4 OBJECTIVE The objective of this project is:
Our project design and fabrication of gear cutting attachment is used to cut
gear or splines over the cylindrical job.
Our main aim is to prove lathe as a versatile machine and with the help of gear cutting attachment the object is possible by lathe itself.
1.5 SCOPE
i. To cut gears without milling machine.
ii. To cut splines over shafts.
iii. To cut key ways & slots.
1.6 FLOW CHART
The project starts identify the problem. It is a first step for the project flow in
order tofind the problem in conventional lathe . This step helps to create a
different design to improve the product.After identify the problem for the
project, project continues with identify the objective. The objective is very
important in every work because every procedure to make a project will
depend on it. It will help to know the main point to make the project success
or not. The project continues with identify the scope of the project because
this scope can help the progress to create the new product design for the
project and to make sure the method chose will be within the range of
achievable objective. Next continue it with literature review and research
about the title. This consist a review of the design and type of safety. These
tasks have been done through research on the internet. From the flow chart,
start to design new concept. Use datum as reference. Then improve the
design. Try to come with several concepts. Then compare the criteria from
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each design which the most best. If the design chosen still needed to be
improved go back to the previous steps. If no improvement is needed go to
next step. Produce the drawing together with dimension of the product and the
type of material needed. After completing the previous task, start the
fabrication process. Gather the parts needed for the project to proceeds the
fabrication process. Here come the testing and evaluation process. During the
testing, if problem occur, the process of fabrication will step back to the
previous process. The reason to step back is to fix the error. After all part had
been joined together and no error, here comes the phase of result and
discussion. Beside, how to achieve objective and solve problem statement of
the project will be discuss in this phase.
Fig1.6.1 (flow chart)
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1.7 GANTT CHART Gantt chart is an importance to guide work process during this project. With
gantt chart what need to be done first can be plan accordingly. Other than
that, this project will run smoothly and finish on time.
MONTHTaskData collection
Establish target
Basic darwing of componants
Assembly drawing and design
Analysis of Design
material selection
Fabrication of componants
Part assembly
Finishing
Design testing
Final presentation
Report
PlanningActual
february march aprilseptember october november december janurary
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CHAPTER 2
LITERATURE REVIEW
2.1 INTRODUCTION CHAPTER 2 is the literature review of the project. In this chapter, various
literatures on gear cutting attachment in lathe, basic principles which use for
fabrication of attachment, fabrication planning& machine used for fabrication
are described.
2.2 LITERATURE REVIEW
i.Keyway &GEAR-CUTTING ATTACHMENTS TO LATHES on Jan.
30, 1940 by T. E. SMITH. (USA Patent No. 2188447 A)–
First of all T.E.SMITH proposed the principle of gear and keyway cutting
attachment on lathe machine. He used a separate motor for rotating cutting
tool and indexing was done on lathe chuck. This attachment was very
complex and large in construction
ii.GEAR CUTTING ATTACHMENT by John w. Barons, Baltimore,
"Application Serial No.‘131,002 .” John w. barons Baltimore used screw for giving feed while T.E.SMITH used intermittent
feed device..
iii.MILLING ATTACHMENT FonLÀfrHEsJoseph C. Harbison, Eldorado, Ill.,
assignor offorty-three and onefthird per cent to . ObeRoberts, Eldorado, Ill.
Joseph c. Harbision eliminated the use of motor and replaced the chuck
indexing by compound indexing .Cutting tool was mounted on arbor and arbor
was mounted between chuck and tail stock
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2.3 BASIC PRINCIPLES GEAR PRODUCTION
Gears may be manufactured by casting, stamping, machining or by powder
metallurgical process. Out of all processes, the most common and accurate
method of production of gears is by machining. You are required to cut gears
on a Horizontal Milling Machine.Schematic diagram of this machine is given.
Fig 2.3.1
Cutting of a Spur Gear on a Milling Machine involves the following steps:
1.To determine the important dimensions and proportions of the gear tooth
element.
2.Mounting the cutter and the job on the machine.
3.Adjust the position of the table to the starting position.
4.Indexing.
5.Repeat the operation till the gear is complete.
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INDEXING
Indexing is an operation of dividing the periphery of a piece of work into any
number of equal parts, for e.g. this operation can be adopted for producing
hexagonal and square headed bolts, cutting spines on shafts, fluting drills and
in gear cutting. All these works require a holding device which will permit the
rotation of the work about the axis so that periphery of the work piece can be
divided equally and accurately. Such a work holding devices is known as DIVIDING HEAD OR INDEXING HEAD.
METHODS OF INDEXING:
i) Direct Indexing ii) Simple Indexing
iii) Compound Indexing iv) Differential Indexing
Direct Indexing: It is also called Rapid Indexing. This is used when a large
number of identical pieces are indexed by very small number of divisions.
Therapid plate is generally fitted to the front end of the spindle nose. The
plate has 24numbers of equally spaced holes. Into any one of which a spring
loaded pin is pushed to lock the spindle with the frame while indexing, the pin
is taken out and the spindle is rotated by hand. After the required position is
reached, it is again locked by the pin. Now the dividing head spindle and
work are also turned through the same part of revolution. With this type of
indexing with a plate of 24 holes, the periphery can be divided into
2,3,4,6,8,12 or 24 parts which are all factors of 24.
fig 2.3.2
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2.4 FABRICATION PLANNING & MACHINE USED IN
FABRICATION Lathe
A lathe is a machine tool which turns cylindrical material, touches a cutting
toolto it, and cuts the material. A material is firmly fixed to the chuck of a
lathe. The lathe is switched on and the chuck is rotated. And since the table
which fixed the byte can be moved in the vertical direction and the right-and-
left direction by operating some handles. In order to get an efficient process
and beautiful surface at the lathe machining, it is important to adjust a rotating
speed, a cutting depth and a sending speedas shown in Figure below. I plan to
use this process to reduce the diameter of the solid rod.
Fig 2.4.1 Fig 2.4.2
Milling
Milling is the most common form of machining, a material removal process,
which can create a variety of features on a part by cutting away the unwanted
material. The milling process requires a milling machine, workpiece, fixture,
and cutter. The workpiece is a piece of pre shaped material that is secured to
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the fixture, which itself is attached to a platform inside the milling machine.
The cutter is a cutting tool with sharp teeth that is also secured in the milling
machine and rotates at high speeds. By feeding the workpiece into the rotating
cutter, material is cut away from this workpiece in the form of small chips to
create the desired shape. Milling is typically used to produce parts that are not
axially symmetric and have many features, such as holes, slots, pockets, and
even three dimensional surface contours. For CNC milling machine, coding is
the important thing to run the machine. There are two ways to make a coding
that is using a simulator or master cam. CNC milling machine is more
accurate than conventional milling machine. Figure below is an example of
milling process. I plan to use conventional milling machine to produce head
holder for my project.
Drilling
There are many machines capable and used to drill, ream or thread holes in a
part. Drilling is the manufacturing process where a round hole is created
within a workpiece or enlarged by rotating an end cutting tool, a drill. Figure
below show the drilling process. I plan to use this process to make a hole for
screw and thread.
Welding
Welding is one of joining process that joint part together to be a product. In
faculty laboratory there has two type of welding that is metal inert gas
welding, MIG and arc welding. Arc welding uses a welding power supply to
create an electric arc between an electrode and the base material to melt the
metals at the welding point. They can use either direct (DC) or alternating
(AC) current, and consumable or non-consumable electrodes. While MIG
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welding uses high deposition rate welding process,wire is continuously fed
from a spool. MIG welding is therefore referred to as a semiautomatic
welding process. Figure below show the MIG welding process. I plan to use
this process to make a join between workpiece.
Welding(fig 2.4.3)
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CHAPTER 3
METHODOLOGY
3.1 INTRODUCTION CHAPTER 3 is the methodology has been used to make gear cutting
attachment in lathe. In this chapter, a project flow chart is defined. The
information that included is establishing target specification, Basic drawing
&design , Analysis of design , Selection of components as per suitability
Selection of material, Fabrication of components , Assembly & Testing . It
also allows others to replicate our study and run new and different studies that
are based on our methodology.
3.2 PROCESS FLOW
PHASES TITLE
Phase 1 Establish target
Phase 2 Basic drawing &design
Phase 3 Analysis of design
Phase 4 Selection of components as per suitability
Phase 5 Selection of material
Phase 6 Fabrication of components
Phase 7 Assembly & Testing
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3.3 PHASE 1
ESTABLISH TARGET SPECIFICATION After the investigation of the objective, criteria selection will be developed.
Criteria selection here means the criteria that what people will look on the
product. Our product is not available yet in the market, we can see that usual
machining workshop where lathe machine not use for gear cutting, they still
use conventional milling machine to gear cutting. Our product target is to sell
this product to this kind of workshop and for individual user.
This is the criteria that I had to use to the design product for the gear cutting
in lathe machine.
i. Easy to use ii. Safety iii. Light weight
iv. Nice design v. Low cost vi. Strong
3.4 PHASE 2
BASIC DRAWING & DESIGN CONCEPT The purpose of this project is to design the gear cutting attachment in lathe
machine. The motivation for this project is to make gear without bought extra
machine in workshop and reduce cost to done this process. So the new
product and design should have a mechanism which available to gear cutting
and hold on the carriage of lathe machine so that it move on lathe bad. It will
look more efficient and if people who use it, they could be interested in
product because of the design and function that not available in market yet.
This is the idea concept for new design of gear cutting attachment in lathe.
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Proposed basic drawings
Base plate drawing (3.4.1)
Side frames drawing (fig 3.4.2) slider with screw
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Design of components
Design of base plate (fig 3.4.3)
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Design of left side frame (fig 3.4.4)
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Design of right side frame (fig 3.4.5)
Design of slider with screw (fig 3.4.6)
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Design of shaft with indexing (fig 3.4.7)
Design of locating pin (fig 3.4.8)
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Design of top plate (fig 3.4.9)
Design of assembled attachment (fig 3.4.10)
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3.5 PHASE 3
ANALYSIS OF DESIGN Final parts and final assembly is analyzed by solid works software. We use
parameters of standard lathe machine and milling cutter for force analysis.The
analysis was done on the basis of –
Static force
Maximum principal elastic strain
Maximum shear stress
Von Mises elastic strain
Von Mises stress
Factor of safety
Force Calculations
There are two forces related to the milling cutter. one is cutting force and another is thrust.
According to the machine specifications,
P = Power = 1 kw
N = Speed of rotation of the spindle = 560 rpm
D = Diameter of the cutter = approx. 50 mm
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Therefore,using the formulae for cutting force
V = πDN / 60
P = F. V
Therefore,
F = P / V
Putting the above values in this equation, we get cutting force
F =680 N.
2. Thrust Force
To calculate the thrust force, following formula was used
Thrust force (th) = K * D * f^0.7 N
D =50mm
f = 0.5mm/min
N =560
K = thrust force constant = 42.35
Putting these values in the above equation, we get
Thrust force (th) = 1290 N
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Study Properties
Study name Study 1
Analysis type Static
Mesh Type: Solid Mesh
Solver type FFEPlus
In plane Effect: Off
Soft Spring: Off
Inertial Relief: Off
Thermal Effect: Input Temperature
Zero strain temperature 298.000000
Units Kelvin
Include fluid pressure effects from SolidWorks Flow Simulation
Off
Friction: Off
Ignore clearance for surface contact Off
Use Adaptive Method: Off
Units
Unit system: SI
Length/Displacement mm
Temperature Kelvin
Angular velocity rad/s
Stress/Pressure N/m^2
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Loads and Restraints
Fixture
Restraint name Selection set Description
Fixed-1 <baseplate-1> on 2 Face(s) fixed.
Load
Load name Selection set Loading type Description
Force-1 <nut-2> on 1 Edge(s) apply force 1290 N normal to reference plane with respect to selected reference Face< 1 > using uniform distribution
Sequential Loading
Force-2 <shaft-3> on 1 Face(s) apply normal force -680 N using uniform distribution
Sequential Loading
Contact
Contact state: Touching faces - Free
Global Contact Contact component: Bonded on gear cutting atachments
Description:
Component Contact-1 Contact component: Bonded on nut-1
Description:
Component Contact-2 Contact component: on baseplate-1
Description:
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Mesh Information
Mesh Type: Solid Mesh
Mesher Used: Standard mesh
Automatic Transition: Off
Smooth Surface: On
Jacobian Check: 4 Points
Element Size: 11.88 mm
Tolerance: 0.59399 mm
Quality: High
Number of elements: 9423
Number of nodes: 16542
Time to complete mesh(hh;mm;ss): 00:00:04
Computer name: Dushyant
Reaction Forces
Selection set Units Sum X Sum Y Sum Z Resultant
Entire Body N 674.682 -513.388 -1183.44 1455.78
Free-Body Forces
Selection set Units Sum X Sum Y Sum Z Resultant
Entire Body N -0.000866733 0.000642514 0.0014296 0.00179104
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Free-body Moments
Selection set Units Sum X Sum Y Sum Z Resultant
Entire Body N-m 0 0 0 1e-033
Study Results
Name Type Min Location Max Location
Stress1 VON: von Mises Stress
0.185681 N/m^2
Node: 11046
(79.976 mm,
27.6158 mm,
-147.677 mm)
5.36901e+007 N/m^2
Node: 11882
(-66.3766 mm,
-0.896929 mm,
-147.045 mm)
Displacement1 URES: Resultant Displacement
0 mm
Node: 32
(30.459 mm,
-13.8979 mm,
-9.63401 mm)
0.0936979 mm
Node: 11001
(-140.034 mm,
3.95554 mm,
-145.318 mm)
Strain1 ESTRN: Equivalent Strain
7.73579e-013
Element: 6289
(81.6661 mm,
18.116 mm,
-106.54 mm)
0.000176823
Element: 6243
(-65.899 mm,
1.46701 mm,
-145.064 mm)
Stress2 VON: von Mises Stress
0.185681 N/m^2
Node: 11046
(79.976 mm,
27.6158 mm,
-147.677 mm)
5.36901e+007 N/m^2
Node: 11882
(-66.3766 mm,
-0.896929 mm,
-147.045 mm)
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gear cutting attachment-static stress analysis (fig 3.5.1)
gear cutting attachment-displacement analysis (fig 3.5.2)
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gear cutting attachment-strain analysis (fig 3.5.3)
gear cutting attachment-Study factor of safety (fig 3.5.4)
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Conclusion
It is evident from the above simulation images that all the values of stresses and strain were in the permissible limits.The factor of safety of wholegear cutting attachmentis very high.
3.6 PHASE 4
SELECTION OF COMPONANTS AS PER SUITABILITY After the design and analysis, the best design is studied to relate it with
criteria selection. Then make decision which components are suitable. For
this project, As per the suitability of dimensions according to the lathe
machine designed the various parts which are the best after considering the
criteria selection.
3.7 PHASE 5
SELECTION OF MATERIAL After the analysis we specified the material of various components which use
in this project. For this project, I plan to use mild steel and galvanized iron.
Mild steel is used as body for main part in this project to hold the slider as
well as indexing plate support. Besides that, galvanize iron is use as a screw
with thread and in shaft which use for holding work piece with the help of nut
and collar. A spring of mild steel is also use which support locating pin.
Table below is the list of material that needed to fabricate this project. I chose
to use all this material because of the safety factor and all this material are
easily available.
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Material Properties No. Body Name Material Mass Volume
1 Slider with screw 1023 Carbon Steel Sheet (SS)
2.44255 kg 0.000310837 m^3
2 Shaft with indexing plate
1023 Carbon Steel Sheet (SS)
0.996566 kg 0.000126822 m^3
3 Base plate 1023 Carbon Steel Sheet (SS)
4.11032 kg 0.000523074 m^3
4 Side frame 1023 Carbon Steel Sheet (SS)
2.16095 kg 0.000275 m^3
5 Side frame 1023 Carbon Steel Sheet (SS)
2.16095 kg 0.000275 m^3
Material name: 1023 Carbon Steel Sheet (SS)
Material Source: Market
Material Model Type: Linear Elastic Isotropic
Default Failure Criterion: Max von Mises Stress
Application Data:
Property Name Value Units Value Type
Elastic modulus 2.05e+011 N/m^2 Constant
Poisson's ratio 0.29 NA Constant
Shear modulus 8e+010 N/m^2 Constant
Mass density 7858 kg/m^3 Constant
Tensile strength 4.25e+008 N/m^2 Constant
Yield strength 2.8269e+008 N/m^2 Constant
Thermal expansion coefficient
1.2e-005 /Kelvin Constant
Thermal conductivity 52 W/(m.K) Constant
Specific heat 486 J/(kg.K) Constant
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Hardening factor (0.0-1.0; 0.0=isotropic; 1.0=kinematic)
0.85 NA Constant
Part such as Screw, Nut, washer, and spring is available in the market.
3.8 PHASE 6
FABRICATION OF COMPONANTS
Base plate
Base plate cut by gas cutting of dimension 200x165x16 and than finishing is
done on grinding machine .Two hole of diameter 14 mm done by the vertical
drilling machine as shown in fig.
Side frames
First we cut the galvanized plate by gas cutting of dimension 200x140x16
then cut it into trapezoidal shape which have sides140mm ,200mm &
80mm.after this a groove of depth 7 mm is cut by the face milling machine of
width 55 mm. Side frame is shown in fig.
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Fabricatedbase plate with side frames
Slider with screw-
A block of dimension of 105x55x55 is cut by power saw and hole is done by
drill machine throughout 55 mm from center point .A screw of length 120
mm which consist Mx20x3 thread is weld on block at center.
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Fabricated slider with screw
Shaft with indexing plate
A shaft is of dia 25 mm is found after turning operation on lathe machine,
length of shaft is 225 mm which is found after cutting by power saw . A
counter turning is done on lathe of dia 20 mm and length 40 mm for
workpiece mounting .For Indexing plate ,we cut a circular plate of dia 70 mm
and 8 mm thick with the help of divider then finish it by surface grinder .Hole
on plate is done by drilling machine in circular way as shown in fig.
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Locating pin arrangement
Locating pin arrangement is done by a mild steel strip of length 230 mm and
3 mm thick.we gave the shape as shown in fig. by the hammer and anvil. Pin
and spring is available in the market.
Fabricated locating arrangement with slider and shaft
3.9 PHASE 7
ASSEMBLY & TESTING Assembly of gear cutting arrangement is done by welding mainly. Side
frames are welded on base plate .The lead screw is fixed on slider by welding
it and a cover plate on the top of the side frames is welded for providing
proper alignment and stability to lead screw. locating pin arrangement is
welded on slider in the side of indexing plate . a compression spring is used
on the pin for getting the pin tightened in desired hole of indexing plate at the
time of operation .Washer and nut are used for the arrangement of this spring
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A tapping pin is provided for preventing the movement of the shaft in the
slider hole while cutting gear
The tool post on lathe machine is replaced by this whole assembly and a work
piece is mounted on shaft by nut and at moderate speed and low feed rate gear
is cut successfully.
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ATTACHMENT ASSEMBLY (fig7.1)
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Atachment mounted on lathe (fig 7.2)
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CHAPTER 4
RESULT AND DISCUSSION
4.1 HOW TO USE THIS Firstly, remove the tool post from lathe carriage and mount this attachment in
place of tool post. Adjust the cutter tool arbor between chuck and tail stock.
Get the workpiece tightened on the mount shaft with the help of nut. Start the
lathe machine. Feed is given by cross slide and depth is given by screw on
slider.
4.2 HOW THIS PROJECT ACHIVES THE OBJECTIVES
The foremost and primary purpose to cut the gear is satisfactorily achieved with good accuracy. The attachment has build and cutting is to be tested.
By providing gear cutting attachment on the lathe machine ,lathe becomes more versatile.
4.3 BENEFITS AFTER MOUNTING THE ATTACHMET
i. The attachment is to be used on lathe for gear cutting.
ii. It is a simple and low cost device.
iii. With some improvement, it can be used for precision cut and finish.
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CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION We know that Country’s GDP is largely affected by many small scale
industries. Also, we saw that in this fast moving world a micro industries are
facing very tough competition from large scale industries and it’s almost very
difficult for them to survive and earn their share of bread and butter as they
have an only choice of selecting one or two machine at a time due which there
is a rise of a serious problem called as either sub contraction or renting of
machines which further decreases the overall efficiency of whole machine
and industry. By selecting and incorporating such small but useful ideas a
small scale industrialist can save huge amount of time, energy, and money
hence forth increasing the overall productivity of a firm and hence
contributing more efficiently in countries GDP.
5.2 RECOMMENDATION If direct indexing is replaced by compound indexing then the limitation of
cutting specific number of teeth can be eliminated and we can cut any no of
teeth on gear.
If use of bush come into picture in slider’s hole then wear and tear of shaft
can be minimized upto a commendable level and so life of shaft as well as
slider will increase.
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REFERENCES: 1.Designing and Fabrication of Multipurpose Tool Post for Lathe Machine
(IJSRD/Vol. 2/Issue 03/2014/033).
2.IMPROVEMENT IN GEAR-CUTTING ATTACHMENTS FOR
LATHES.(Specification forming part of Letters Patent No. 208,491, dated
October 1, 1878 ;application filed March 1l, 1878).
3.MILLING ATTACHMENT FonLÀfrHEsJoseph C. Harbison, Eldorado,
Ill., assignor of forty-three and onefthird per cent to .Obe Roberts, Eldorado.
(Application January 17, 1946, Serial No. 641,783)
4.THOMAS O. MILLS, OF ROGKFOItI), ASSIGNOR OF ONE-HALF ÍHIS
RIGHT TOWILLIAM H. MILLS, OF FREEPORT, ILLINOIS.
(IMPROVEMENT IN GEAR-CUTTING ATTACHMENTS )
(Patent No. 144,214, dated November 4, 1873)
5.Richard A. Maker (1993) “Milling machine lathe attachment” Application
number : US 08/002,967.
6.Production technology by R.K.Jain & Workshop technology by Hajariya
Chaudhry.
7. Wikipedia and GOOGLE SCHOLAR.