REPORT

Design And Analysis Of Machine Fixtures
Dept. Of Mechanical Engg, TOCE Page 1
CHAPTER 1

Dept. Of Mechanical Engg, TOCE. Page 2
1. COMPANY PROFILE
Toyota Kirloskar Auto Parts Pvt Ltd. (TKAP) is an automobile parts manufacturing
company for Toyota in India. TKAP is a joint venture among Toyota motor corporation,
Japan, Toyota industries corporation, Japan and Kirloskar systems limited, Bangalore.
TKAP is having two plants, viz, 100% export oriented unit (EOU) transmission plant and
a domestic axle’s plant. In the EOU plant, TKAP manufactures front axle, rear axle and
propeller shaft for INNOVA and supplies to Toyota Kirloskar Motor Pvt Ltd.
The 3 units part plant focuses primarily on domestic consumption of parts viz, front axle
rear and propeller shaft, this plant was set up in 1999 and has an installed capacity of 75000
units per year, its consumer being Toyota Kirloskar Motor Limited.
The transmission plant is 100% export oriented unit plant which was set up in 2004 and has
an installed capacity of 180,000 units/year. It manufactures the R type and C type
transmission which is supplied to Toyota companies all over the world.
8.1 Location
TKAP is located at Bidadi industrial estate, Bidadi, 32 km from Bangalore in the state of
Karnataka, India. TKAP has about 200,000 sq. mts of land area and a human capacity of
1000+ members.
8.2 Manufacturing
The actual production and machining of any part is the responsibility of manufacturing.
The members of manufacturing actually machine the part from start to finish. They solve
the day to day problems arising the in co-ordination with other departments. They ensure
that the daily targets are met and the product satisfies the strict quality standards.

8.3 Maintenance
Since Toyota follows the lean manufacturing technique, maintenance is of prime
importance to them, thus machining dept. has a more subjective role here compared to other
companies, rather than repairing NG machines they ensure nothing breaks down and thus
assume a proactive role.
8.4 Organizational structure
The company functioning is divided into various for better operating efficiency. The 6
departments we interacted as follows;
Safety department:
Toyota has always given the highest priority to safety. They believe that safety is the pre-
requisite for quality and productivity. A reflection of this philosophy is the existence of a
department dedicated to the task of maintaining a safe working environment ensuring the
safety of the employees, company and company assets is their main responsibility
Quality control:
Good quality is the core of the Toyota way. Toyota believes that quality must be built in
during the manufacturing process and hence quality control department is not just a filter
to weed out defectives but a preventive and corrective entity involved at all stages right
from conception to design to manufacturing of a product.
Production control (P.C) department:
TKAP follows a lean manufacturing system to minimize inventory and WIP time. The P.C
department decides the target production for the day depending on the customer pull. A
working schedule of when and what is to be produced is drawn up by them and conveyed
to mfg. Department. PC also handles raw material and finished goods logistics.

Production engineering department (P.E): The production engineering department deals
with the planning and setup of process layouts, machine setups and plant layout. Production
engineering encompasses the application of castings, joining processes, metal cutting and
tool design, metrology, machine tools, machining systems, automation, jigs and fixtures,
and dies and mould design.
Once the design is realized, production engineering concerts such as ergonomics, operation
research, work study, manufacturing management, materials management , production
planning, etc., lays important roles in efficient production processes. These deal with
integrated design and efficient planning of the entire manufacturing systems.

PRODUCTS OF TKAP

CHAPTER 2

2. INTRODUCTION
8.5 FIXTURES
Fixtures are the tools used to locate and hold the work piece in position during the
manufacturing process. Fixtures are used to hold the parts firmly which are to be machined,
it is used to produce the duplicate parts accurately. In order to produce parts with required
accuracy and dimensions the parts must be firmly and accurately fixed to the fixtures. To
do this, a fixture is designed and built to hold, support and locate the work piece to ensure
that each work piece is machined within the specified limits. Set blocks, feeler or thickness
gauges are used in the fixture to refer the work piece with the cutter tool. A fixture should
be securely fastened to the table of the machine upon which the work is to be done. Though
largely used on shaping machines, fixtures are also designed to hold the work for various
operations on most of the standard machine tools. Fixtures vary in design based on the use
of relatively simple tools to expensive or complicated devices. Fixture helps to simplify
metalworking operations performed on special equipment’s.
Basic fixture design for manufacturing applications envelopes two main aspects:
Location and clamping. Between these two functions, the 6 (3 translation and 3 rotation)
degrees of freedom are constrained, while effectively positioning and orienting the part
during processing. The location of box-type parts is usually achieved using the 3-2-1
principle. This principle locates the primary plane by three non-collinear points, typically
widely spaced; the second plane is located by two points and the third plane by one point.
Cylindrical part axes are usually located using V-blocks while concentric locators are used
to locate priorly drilled holes. The cutting wrenches (forces) are supported by effectively
holding the work piece, to minimize distortion or deformation of the object.
Chip clearance, ease of part loading and removal, use in multiple applications (versatility)
is often additional considerations in designing fixtures. Jigs also provide tool guidance in
addition to the location and clamping provided by fixtures. Usually sheet metal fabrication
and assembly often requires other types of fixtures than machining fixtures.
In any case, fixture design is most cost-justified for batch or mass production runs.
Considering this, the fixture designs for single-piece parts are better accomplished by
modular fixtures. Fixture design is typically a setup cost function, making it very
Valuable in flow time and indirect cost calculations. Due to the rapid response required in
many applications, the fixture design principles must be integrated and properly detailed
so as to facilitate the fast design development of a fixture. Flexible, palletized and modular
fixtures are quite common in today’s industry to maintain rapid tooling in the agile
environment.
The types of fixtures currently developed and employed for each application will again be
recorded. The principles and limitations of each fixture will then be analyzed. Design
manual, a procedural for fixture design principles for manufacturing of different part
geometries will be developed. The links with conventional CAD and CAE systems will be
explored to automatically integrate part design concepts and engineering (stress, deflection,
etc.) analysis. In summary, a roadmap to fixture design and/or existing fixture modification
will be developed.

Fixture is a work piece-locating and holding device used with machine tools. Fixture does
not guide the cutting tool, but is always fixed to machine or bench. By using fixture,
responsibility for accuracy shifts from the operator to the construction of machine tool.
When a few parts are to be machined, work piece clamp to the machine table without using
fixture in many machining operations. However, when the numbers of parts are large
enough to justify its cost, a fixture is generally used for holding and locating the work.
In the existing clamping system, the collet is fixed in the wedge with suitable length. This
length does not change at any time. Suppose we require the different length of collet, to
dismantle the system and to fix the various length of the collet. It has more time consuming
and production rate cannot be enhanced. In the existing model wedge is not used in any
design models. Only bolt is used to tighten the collet. It has more time consuming so that
the production rate cannot be improved. The demands made on the quality of the gear teeth
required and the output of the gear-cutting machine is constantly increasing a large problem
in the design of gear cutting machines. Providing the proper work holding platform is an
important issue in any kind of operations performed on the work component. In this way
automation has played a vital role in providing a reliable and fast clamping system which
will reduce the cycle time of clamping with the increase in accuracy thus decreasing the
possible damages to the work piece

CHAPTER 3

3. LITERATURE SURVEY
To begin with, imperfections in manufacturing processes induce machining errors in
components. Machining errors are introduced, transformed and accumulated when the
work piece is being machined. Djurdjanovic and Ni (2001) proposed an analytical
engineering tool for machining error analysis and root cause identification. Static form
errors in the peripheral milling of complex thin-walled work pieces have been predicted by
Wan et al (2005) using the finite element formulation.
Also they investigated cutter modeling, finite element discretization of cutting forces, tool-
work piece coupling and variation of the work piece’s rigidity in milling. An error
compensation model by considering the geometric and cutting force induced errors in a 3-
axis CNC milling machine has been proposed (Raksiri and Parnichkun 2004) and the
combination of geometric and cutting force induced errors are modelled by the combined
back propagation neural network. The influence of the wear of the cutting tool on
machining errors has been demonstrated by an experimental study (Rahou et al 2010) and
the circularity error has been evaluated from the measured profiles using computational
geometric techniques (Venkaiah and Shunmugam 2007). Abdullah et al (2011) quantified
geometric and dimensional error of an Autonomous Underwater Vehicle (AUV) propeller
blade by comparing the profiles obtained from 9 optical method. They reported that the
thickness error depends on deformation ratio of the blade. Wang et al (2005) addressed the
special features of the deformation analysis between complex shaped components and
fixture elements and reported that the deformation error of the fixture depends on the fixture
layout. Cioata and Kiss (2009) presented analytic models of calculus of the errors due to
contact deformation between locators and work piece using the finite element method in
order to determine the contact deformation. Literature related to machining errors
concludes that the part errors are mainly because of machining errors and 20% to 60% of
the overall machining errors are caused due to fixture errors (Cioata and Kiss 2009).

8.1 STUDIES RELATED TO FIXTURE DESIGN
Fixture is an important element in most of the manufacturing processes and related to
machining errors the role of fixture is very crucial. Studies pertaining to the design of
machining fixture are generally of two categories i. e. fixture analysis and fixture synthesis.
While fixture analysis deals with forces and deformations, the fixture synthesis is
concerned with the design of fixture configuration to completely immobilize the work part
when subjected to external forces. In the fixture analysis and synthesis, a concern on the
conditions for constraining a work piece is critical. The essential requirement of fixturing
is the century-old concept and the same has been extensively studied by Mishra et al (1987)
and Markenscoff et al (1990) in the field of robotics with efficient algorithms to synthesize
positive grips for bounded polyhedral objects. Chou et al (1989) developed a mathematical
theory for automatic configuration of machining Fixtures for prismatic parts. The
performance of fixture has been analyzed 10 based on the popular screw theory and
engineering mechanics. The determination of locating and clamping points on work piece
surface and the determination of clamping forces have also been synthesized.
Trappey and Liu (1990) carried out a literature survey of fixture design automation and
emphasized computer aided fixture design. In the frictionless case, Lakshmi Narayana
(1978) investigated the minimum requirements for the form closure of a rigid body and
proved that at least four and seven contacts are necessary to achieve force closure for 2D
and 3D parts respectively. For the same frictionless case, Salisbury and Roth (1982)
demonstrated that a necessary and sufficient condition for force closure is that a strictly
positive linear combination of the primitive wrenches at contacts is zero and the primitive
wrenches span the whole wrench space. Mishra and Silver (1989) later proved that when
friction is taken into account, three contacts are sufficient in the planar case while four are
adequate in the spatial case. A Projective Spatial Occupancy Enumeration (PSOE)
approach has been applied as a representational and manipulating scheme for developing
algorithms in automatic fixture configuration by Trappey and Liu (1993). King and Lazaro
(1994) optimized fixture for a particular datum specification and sequence of operations.
Then the fixture system has been analyzed and presented via the CAD system.

Deiab and Elbestawi (2005) stated that the tangential friction force plays an important role
in fixture configuration design and presented the results of an experimental investigation
of the work piece-fixture contact characteristics. Roy and Liao (2002) reported that stability
analysis plays a critical role in determining the applicability of a fixture design and
developed a computational methodology for quantitatively analyzing the stability of the
work piece in the automated fixture design environment. 11 Liu et al (2004) proposed an
algorithm for searching form-closure grasps of hard fingers on the surface of a three-
dimensional object represented by discrete points with the consideration of both frictional
and frictionless cases. This algorithm starts to search a form-closure grasp from a randomly
selected grasp using an efficient local search procedure until encountering a local
minimum. Work piece location error is examined by considering the fixture geometric error
and elastic deformation of the fixture and work piece due to fixturing forces (Raghu and
Melkote 2005). The deformations at the contact points are obtained by solving a
constrained optimization model and the experimental validation is also provided for several
fixture work piece variable levels using a 3-2-1 machining fixture.
Kang and Peng (2009) reported designing and fabricating fixtures can take up to 10-20%
of the total cost of a manufacturing system and reviewed various approaches used in
Computer-Aided Fixture Planning (CAFP). Wang et al (2010) presented a literature survey
of computer aided fixture design and automation, including their approaches, requirements
and working principles. Related to computer aided fixture design approaches, an interactive
Computer Aided Fixture Design (CAFD) system using the Gauss Elimination Method for
the design of a fixture to hold prismatic components during machining on a CNC machining
centre is described by Krishnamachary and Reddy (2005). Cecil (1995), Pehlivan et al
(2009) and Nee et al (1987) have reported the other feature-based methodologies in CAFD.
Boyle et al (2011) reviewed over seventy-five CAFD tools and approaches in terms of the
fixture design phases and technology and reported two research issues that require further
effort. The first is that current CAFD research is segmented in nature and there remains a
need to provide more cohesive fixture design support. Secondly, a greater focus is 12
required on supporting the detailed design of a fixture’s physical structure.

The general situation of research on agile fixture design is summarized and pointed out the
achievements and deficiencies in the field of case-based agile fixture design (Li et al 2002).
The automation of fixture design and integration of setup and fixture planning is discussed
by Stampfer (2009). Boonsuk and Frank (2009) presented a methodology for the automated
design of a fixturing system for a rapid machining process. An adaptive fixture design
system with an evolutionary search algorithm has been developed by Fathianathan et al
(2007) to deal with the automatic design changes to meet the requirements of different
domains. Armillotta et al (2010) described the procedure for kinematic and tolerance
analysis and demonstrated its significance on a sample case of fixture design. Kinematic
analysis verifies that any relative motion between the part and the worktable is constrained
and the tolerance analysis tests the robustness of part orientation with respect to
manufacturing errors on datum surfaces. Luo et al (2011) developed a novel model for work
piece positioning analysis by using surface-to-surface signed distance function and a two-
sided quadratic model for fixture locating analysis. This model has potential applications
in fixture design, tolerance analysis and fault diagnosis. Studies related to fixture design
show that fixture design has received considerable attention in recent years. However, little
attention has been focused on the optimum fixture layout and clamping forces.

8.2 Fixture
A fixture is a work-holding or support device used in the manufacturing and
industry. Fixtures are used to securely locate (position in a specific location or orientation)
and support the work, ensuring that all parts produced using the fixture will maintain
conformity and interchangeability. Using a fixture improves the economy of production
by allowing smooth operation and quick transition from part to part, reducing the
requirement for skilled labor by simplifying how work pieces are mounted, and increasing
conformity across a production run.
A fixture's primary purpose is to create a secure mounting point for a work piece, allowing
for support during operation and increased accuracy, precision, reliability, and
interchangeability in the finished parts. It also serves to reduce working time by allowing
quick set-up, and by smoothing the transition from part to part, it frequently reduces the
complexity of a process, allowing for unskilled workers to perform it and effectively
transferring the skill of the tool maker to the unskilled worker.[2]
Fixtures also allow for a
higher degree of operator safety by reducing the concentration and effort required to hold
a piece steady.
Fixtures are work holding devices designed to hold, locate and support work pieces during
manufacturing operations. Fixtures provide a means to reference and align the cutting tool
to the work piece but they do not guide the tool. Fixtures that have the added function of
guiding the tool during manufacturing are called jigs.
8.3 Fixture Type and Design
The fixture must be designed to withstand the forces generated by the machining process.
Allowances in fixture design, as well as part design, must be made with respect to firm
clamping of the work and in the robustness of the fixture itself. Additionally, the forces
generated by the tool should be directed toward the clamping whenever possible.

Fixture types fall generally into five groups:
4.7.1 Plate Fixtures
Plate fixtures are constructed from a plate with a variety of locators, supports and clamps.
They are the most common type of fixture because their versatility makes them adaptable
to a wide range of machine tools. They are made from many different kinds of materials,
which are governed only by the part being machined and the process being performed.
4.7.2 Angle-Plate Fixtures
Angle-plate fixtures are a modification of plate fixtures in that rather than a reference
surface parallel to the mounting surface, it is set perpendicular to the mounting surface.
4.7.3 Vise-Jaw Fixtures
Vise-jaw fixtures are modified inserts for vises designed to accommodate a particular work
piece. These fixtures are the least expensive and simplest to modify. The only limitations
to these types of fixtures are size of the part and capacities of available vises.
4.7.4 Indexing Fixtures
Indexing fixtures are used to reference work pieces that need machining details set at
prescribed spacing’s. Indexing fixtures must have a positive means to accurately locate and
maintain the indexed position of the part.
4.7.5 Multi-Part or Multi-Station Fixtures
Multi-part or multi-station fixtures are normally used for either machining multiple parts
in a single setup, or machining individual parts in sequence, performing different operations
at each station. In addition to their basic construction, fixtures may be classified in respect
to the process or machine tool to be used in the machining process. The primary types
include:

4.7.6 Milling Fixtures
Milling fixtures are the most common type of fixture and include standard vises and clamps.
However, as the work piece size, shape and complexity becomes more sophisticated so
does the fixture. Tombstones, which are commonly used on horizontal machining centers,
come in a wide variety of configurations to hold multiple parts on up to four sides of the
fixture. The t-slots of the machine table are standardized in size and spacing and are the
primary means of holding work and fixturing devices for machining. Fixtures are typically
mounted to the table using a variety of accessories such as clamps, straps, t-slot bolts, nuts
and jacks.
4.7.7 Lathe Fixtures
The same basic design principles that apply to milling fixtures also apply to lathe, or
turning, fixtures, with one major difference. In most milling operations, the cutting tool
rotates during machining, while with turning the part rotates. This situation creates another
condition the tool designer must deal with - centrifugal, or rotational, force. Work holding
devices include two to six jaw chucks and collets of varying shapes and diameters. Work
may also be held between the head and tail stock of the lathe or “between centers.”
4.7.8 Grinding Fixtures
Grinding fixtures are a family of fixtures rather than a single classification. The two major
types of grinding fixtures are those used for surface grinding and cylindrical grinding. The
magnetic table is the preferred work holding device on surface grinders. Cylindrical
grinding is usually a secondary operation after turning. Often the same center holes used
for between-centers turning may be used for grinding the part. As friction is more of a
factor in grinding than in other processes, fixture design must allow for coolant flow and
smooth removal. If not built into the grinding machine itself, the fixture design should
include wheel dressing capability as well.

4.7.9 Broaching Fixtures
Broaching fixtures hold and locate the part in relation to the broaching tool. Internal and
external broaching requires different approaches to their respective designs. Internal
broaching requires less clamping because the process tends to keep the part firmly seated
on the fixture. External broaching requires resistance to both pull and push forces that are
exerted on the part, requiring more sophisticated fixturing.
4.7.10 Vise Fixture
It is easy to clamp work piece with regular shape and parallel sides in a vise. However,
work pieces with round or irregular shapes are very difficult to clamp properly. Hence,
special jaws are created to hold work pieces with irregular shape properly and at the same
time, it also avoid damage to the important surfaces
4.7.11 Boring Fixture
According to the type of boring operation, boring fixture are used. Boring Fixture may have
characteristics of a drill jig or a mill fixture. The work piece always has an existing hole
which is enlarged by the boring operation. It may be final or may be preliminary to grinding
and other sizing operation.
8.4 Essential features of Jigs and Fixtures
 Reduction of idle time – Should enable easy clamping and unloading such that idle
time is minimum.
 Cleanliness of machining process – Design must be such that not much time is
wasted in cleaning of scarf’s, burrs, chips etc.
 Replaceable part or standardization – The locating and supporting surfaces as
far as possible should be replaceable, should be standardized so that their
interchangeable manufacture is possible.
 Provision for coolant – Provision should be there so that the tool is cooled and the
swarfs and chips are washed away.

 Hardened surfaces – All locating and supporting surfaces should be hardened
materials as far as conditions permit so that they are not quickly worn out and
accuracy is retained for a long time.
 Inserts and pads – Should always be riveted to those faces of the clamps which
will come in contact with finished surfaces of the work piece so that they are not
spoilt.
 Fool-proofing – Pins and other devices of simple nature incorporated in such a
position that they will always spoil the placement of the component or hinder the
fitting of the cutting tool until the latter are in correct position.
 Economic soundness – Equipment should be economically sound, cost of design
and manufacture should be in proportion to the quantity and price of producer.
 Easy manipulation – It should be as light in weight as possible and easy to handle
so that workman is not subjected to fatigue, should be provided with adequate lift
aids.
 Initial location – Should be ensured that work piece is not located on more than
points in anyone plane test to avoid rocking, spring loading should be done.
 Position of clamps – Clamping should occur directly above the points supporting
the work piece to avoid distortion and springing.

 Clearance – Sufficient amount of clearance should be provided around the work so
that operator’s hands can easily enter the body for placing the work piece and any
variations of work can be accommodated.
 Ejecting devices – Proper ejecting devices should be incorporated in the body to
push the work piece out after operation.
 Rigidity and stability – It should remain perfectly rigid and stable during
operation. Provision should be made for proper positioning and rigidly holding the
jigs and fixtures.
 Safety – The design should assure perfect safety of the operator.
8.5 MATERIALS USED
Fixtures are made of variety of materials, some of which can be hardened to resist
wear.
 High speed Steel: Cutting tools like drills, reamers and milling cutters.
 Die steels: Used for press tools, contain 1% carbon, 0.5 to 1% tungsten and less
quantities of silicon and manganese.
 Carbon steels: Used for standard cutting tools.
 Collet steels: Spring steels containing 1% carbon, 0.5% manganese and less of
silicon.

 Non shrinking tool steels: High carbon or high chromium Very little distortion
during heat treatment. Used widely for fine, intricate press tools.
 Nickel chrome steels: Used for gears.
 High tensile steels: Used for fasteners like high tensile screws.
 Mild steel: Used in most part of Fixtures Cheapest material contains less than 0.3%
carbon.
 Cast Iron: Used for odd shapes to some machining and laborious fabrication CI
usage requires a pattern for casting Contains more than 2% carbon Has self-
lubricating properties Can withstand vibrations and suitable for base.
 Nylon and Fiber: Used for soft lining for clamps to damage to work piece due to
clamping pressure.
 Phosphor bronze: Used for nuts as have high tensile strength Used for nuts of the
lead screw.

8.6 Parts of Fixture
1) Collet
2) Drawbar
3) Body
4) Stopper
5) Washer
6) Nut
7) Holder
8) Clamp rod
9) Datum plate
Collet
A collet is a subtype of chuck that forms a collar around an object to be held and exerts a
strong clamping force on the object when it is tightened, usually by means of a tapered
outer collar. It may be used to hold a work piece or a tool.
An external collet is a sleeve with a (normally) cylindrical inner surface and a conical outer
surface. The collet can be squeezed against a matching taper such that its inner surface
contracts to a slightly smaller diameter, squeezing the tool or work piece whose secure
holding is desired. Most often this is achieved with a spring collet, made of spring steel,
with one or more kerf cuts along its length to allow it to expand and contract. An alternative
collet design is one that has several tapered steel blocks (essentially tapered gauge blocks)
held in circular position (like the points of a star, or indeed the jaws of a jawed chuck) by
a flexible binding medium (typically synthetic or natural rubber). The Jacobs Rubber-Flex
brand is a name that most machinists would recognize for this type of collet chuck system.
Regardless of the collet design, the operating principle is the same: squeeze the collet
against the tool or work piece to be held, resulting in high static friction. Under correct
conditions, it holds quite securely.
An internal collet can be used to lock two telescoping tubes together. In this case the collet
is in the form of a truncated cone drilled and threaded down the centerline. The collet

diameter matches the bore of the inner tube, having the larger end slightly greater than the
bore while the smaller diameter is slightly less than the bore. A threaded stud, anchored at
its other end to the tube, is then used to pull the collet into the tube. The increasing diameter
of the collet forces the inner tube to expand and be pushed against the inner wall of the
outer tube thus locking the two tubes together. The inner tube is often slotted to facilitate
this expansion.
8.7 Nomenclature
Generally, a collet chuck, considered as a unit, consists of a tapered receiving sleeve
(sometimes integral with the machine spindle), the collet proper (usually made of spring
steel) which is inserted into the receiving sleeve, and (often) a cap that screws over the
collet, clamping it via another taper.
Usually in shop-floor terminology, the terms collet and chuck are used in contradistinction;
users speak of holding a work piece or tool with either a collet or a chuck. In this context
"chuck" means any type of chuck other than a collet chuck (scroll chuck, independent-jaw
chuck, etc.).
8.8 General features
Each collet has a narrow clamping range, which means that a large number of collets are
required to hold a given range of materials in the chuck, unlike other types that have a wider
range. This gives collets the disadvantage of higher capital cost.
The collet's advantages over other chucks is that it combines all of the following traits into
one chuck, a valuable combination for repetitive work.
Particulars Collet Scroll chuck Independent-jaw
chuck
1. Fast chucking (unclamp
one part, switch to a new
part, reclamp)
Reliably Reliably Generally not
2. Self-centering Reliably Reliably Never
3. Strong clamping Reliably Usually Reliably
4. Resistance against being
jarred loose (untightened)
Reliably To varying
extents
Usually

8.9 DATA TABLE FOR CARBON STEEL (SUP6)
4.7.1 MECHANICAL PROPERTIES
4.7.2 PHYSICAL PROPERTIES
4.7.3 HEAT TREATMENT
Quantity Value Unit
Thermal expansion 10-10 e-6/K
Thermal conductivity 25-25 W/m.K
Specific heat 460-460 J/kg.K
Melting temperature 1450-1510 ˚C
Density 7700-7700 Kg/m²
Resistivity 0.55-0.55 Ohm.mm²/m
Quantity Value Unit
Young’s Modulus 200000-200000 MPa
Tensile strength 650-880 MPa
Elongation 8-25 %
Fatigue 275-275 MPa
Yield strength 350-550 kMPa
Annealing Quenching Tempering Normalizing Q & T
    

8.10 ADVANTAGES OF FIXTURES
 Productivity:
Fixtures increases the productivity by eliminating the individual marking,
positioning and frequent checking. The operation time is also reduced due to
increase in speed, feed and depth of cut because of high clamping rigidity.
 Interchangeability and quality:
Fixtures facilitate the production of articles in large quantities with high degree of
accuracy, uniform quality and interchangeability at a competitive cost.
 Skill reduction:
There is no need for skillful setting of work on tool. Fixtures makes possible to
employ unskilled or semi-skilled machine operator to make savings in labour cost.
 Cost reduction:
Higher production, reduction in scrap, easy assembly and savings in labour cost
results in ultimate reduction in unit cost.
8.11 DISADVANTAGES OF FIXTURES
 Can wear away over time.
 Can have complicated design.
 High initial setup cost.
 Due to more no of parts, assembly of fixture is complicated.

8.12 Modular Fixturing
Modular systems allow the rapid construction of fixtures from kits of various components
such as base plates, supports, and locator’s devices.
Modular systems start from a pattern of locating dowel holes and tapped holes, or from
conventional t-slots.
A t-slot-based system starts with a t-slotted baseplate. Fixture elements like clamps are
attached to the baseplate, angle-plate, and so on, to create the fixture. Like t-slotted machine
tables, the t-slot system has one major disadvantage -- it lacks exact fixed references in the
X and Y axes. Time is wasted when locating and reconstructing previous setups.
Precision dowel-pin-based modular fixturing systems do assure the exact position of each
fixture element. Its disadvantage is that the dowel pin layout may restrict the location of
clamping devices.
8.13 Fixture Economics
Major concern in fixture design is the cost-to-benefit ratio. Fixture costs are amortized by
production quantities, part quality requirements and tooling accuracy. Also to be considered
are:
a) Tool life
b) Work piece location
c) Support and tool referencing
d) Clamp requirements
To justify fixture cost and the lowest cost per part, the fixture must exhibit:
1. Fast operational characteristics
2. Ease of part loading and unloading
3. Foolproof part locating during the production run

8.14 Fixture Function
Machining is basically a method of material or stock removal to a specified limit or
tolerance. To control this removal, the machining tool is fitted with stops, gages or
computer controls. Also, spatial relationships between the surface or edge being machined
and any part of the fixture must be identified and controlled.
Tool positioning in relation to the work piece, or vice versa, is commonly referenced from
designated alignment or gauging surfaces that are part of, or secured to, the worktable or
fixture. Gages and setup blocks are the standard means of setting these relationships.
Optical methods may also be used effectively.

8.15 TRANSMISSION
4.7.1 What is transmission?
Transmission is generally defined as an assembly of parts including the speed
changing gears and the propeller shaft by which the power is transmitted from an engine to
axle. Often transmission refers simply to the gearbox that uses gears and gear trains to
provide speed and torque conversions from a rotating power source to another device.
A gearbox is any device which converts speed and torque, whereas a transmission
is a type of gearbox that can be shifted to dynamically change the speed and torque. The
most common use is in motor vehicles. In motor vehicle applications, the transmission will
generally be connected to the crankshaft of the engine. The output of the transmission is
transmitted via driveshaft to one or more differentials, which in turn drive the wheels. Often
a transmission will have multiple gear ratios, with the ability to switch between them as
speed varies. This switching may be done manually or automatically. Directional (forward
and reverse) control may also be provided.
4.7.2 Purpose of Transmission
1. To transmit power generated by the engine to the axle.
2. To change the torque and speed characteristics.
3. To change the direction of rotation.

4.7.3 TYPES OF TRANSMISSIONS
Engine
Clutch
T/M
Propeller Shaft
Diff
Rear AxleFront Axle
Chassis
Front Axle
Chassis
Clutch
T/M
Engine
Rear Axle
Engine
Clutch
T/M
Propeller Shaft Diff
Rear AxleFront Axle
Chassis
Diff
Transfer Box

8.16 GEARS USED IN TRANSMISSION
Gears are toothed members which transmit power and motion between two shafts by
meshing without any slip.
4.7.1 SPUR GEARS
fig.4.1
Spur gears have their teeth parallel to the axis and are used for transmitting power
and motion between two parallel shafts. They are simple in construction, easy to
manufacture and cost less. They have high power transmission efficiency. They make lot
of noise while operating at high speeds and exerts large amount stress on gear teeths. For
his reason, spur gears are known as slow speed gears.
Applications:
 Automobile gear boxes.
4.7.2 HELICAL GEARS
fig.4.2
Helical gears have their teeth inclined to the axis and are used for transmitting
power and motion between two parallel shafts. The hand of helix is designated as either left
or right. Right hand and left hand helical gears mate as a set. But they have same helix
angle.

For the same width, their teeth are longer than spur gears and have higher load
carrying capacity. Their contact ratio is higher than spur gears and they operate smoother
and quieter than spur gears.
Applications:
 Automobile gear boxes.
4.7.3 BEVEL GEARS
Bevel gears are used for transmitting power between intersecting shafts. Bevel gears
may be Straight bevel gears or Spiral bevel gears.
fig.4.3
Straight bevel gears are used for transmitting power and motion between
intersecting shafts. They can operate under high loads. They are suitable for 1:1 velocity
ratios and higher velocity ratios and for right-angle meshes to any other angles. Their good
choice is for right angle drive of particularly low ratios.
Applications:
 Differential of an Automobile.
fig.4.4

Spiral bevel gears are also used for transmitting power and motion between
intersecting shafts. Because of the spiral tooth, the contact length is more and contact ratio
is more. They operate smoother than straight bevel gears and have higher load capacity.
Applications:
 Differential of an Automobile.
8.17 GEAR TERMINOLOGY
fig.4.5
Various terms used in study of gears are as follows:
Pitch circle: It is an imaginary circle along which the gear rolls without slipping on the
corresponding pitch curve of other gear for transmitting equivalent motion.
Pitch circle diameter: It is the diameter of the pitch circle. The size of the gear is usually
specified by the pitch circle diameter. It is also known as pitch diameter.
Pitch point: It is a common point of contact between two pitch circles of two meshing gear
wheels.
Pitch: It is defined as follows
 Circular pitch: It is the distance measured on the circumference of the pitch circle
from a point on one tooth to the corresponding point on the adjacent tooth. It is
usually denoted by pc. If d is diameter of the pitch circle and T be number of teeth,
circular pitch is given by

The angle subtended by the circular pitch at the centre of the pitch circle is known
as the pitch angle.
 Diametral Pitch: It is defined as the number of teeth per unit pitch circle diameter.
It is usually denoted by pd. Diametral pitch can be expressed as
Also from above equations
 Module: It is the ratio of the pitch circle diameter in millimeters to the number of
teeth.
Also from above equation
Addendum: It is the radial distance of a tooth from the pitch circle to the tip of the tooth.
Addendum circle: It is the circle passing through the tips of gear teeth and and is
concentric with the pitch circle.
Dedendum: It is the radial distance from the pitch circle to the root of the tooth.
Dedendum circle: It is the circle passing through the root of gear teeth. It is also called
root circle.
Clearance: It is the radial distance between the addendum and the dedendum of a tooth.
Base circle: It is the circle from which gear teeth profiles are generated.

Total depth of teeth: It is the radial distance between the addendum and the dedendum
circles of a gear. It is equal to the sum of the addendum and dedendum.
Working depth of teeth: It is the radial distance from the addendum circle to the clearance
circle. It is equal to the sum of the addendum of the two meshing gears.
Tooth thickness: It is the thickness of the tooth measured along the pitch circle.
Tooth space: It is the width of space between the two adjacent teeth measured along the
pitch circle.
Backlash: It is the difference between the tooth space and the tooth thickness as measured
along the pitch circle.
Face width: It is the width of the gear tooth measured parallel to its axis.
Top Land: It is the top surface of the tooth
Bottom Land: It is the bottom surface between the adjacent fillets.
Face: It is the part of the tooth surface which is above the pitch surface.
Flank: It is the part of the tooth surface which is below the pitch surface.
fig.4.6

Pressure angle: It is the angle between the common normal to two gwar teeth at the point
of contact an the common tangent at the oitch point.
Pressure line: The force, which the driving tooth exerts on the driven tooth is along a line
from the pitch point to the point to the point of contact of the two teeth. This line is also the
common normal at the poin of contact of the mating gears an is known as the line of action
or the pressure line.
Path of contact: The locus of the point of contact of two mating teeth from the beginning
of the engagement to the end of engagement is known as the path of contact or the contact
length. It is represente by line CD in the above figure. The pitch point P is always one point
on the path of contact.
Arc of contact: The locus of the point on the pitch circle from the biginning of engagement
to the en of the engagement of two mating gears is known ar arc of contact. In figure APB
or EPF is the arc of contact.
8.18 GEAR MANUFACTURING PROCESSES
The most commonly practiced method is preforming the blank by casting, forging
etc. followed by pre-machining to prepare the gear blank to desired dimensions and then
production of the teeth by machining and further finishing by grinding if necessary.
Gear teeth are produced by machining based on
4.7.1 Forming
Where the profile of the teeth are obtained as the replica of the form of the cutting tool. The
cutting tool must have complicated contour and it is difficult to maintain an accurate tooth
shape. It is also difficult to maintain accuracy of indexing by tooth. Therefore this method
is not suitable for forming a gear requiring high accuracy, and good efficiency is not
expected. Eg: Milling.
4.7.2 Generation
Where the cutting tool with cutting edges arranged in a straight line is used to generate a
tooth that has an involute curve. The cutting edges on a cutting tool used in the generating
method can be formed by a rack (excluding pinion shaped cutter). For the reason the cutting
edges are easily shaped, and productivity and machining accuracy are high.

Eg: Hobbing, Gear shaping etc.
8.19 Methods of Production of Gear Teeth by Machining on
Forming Principle
4.7.1 Forming Gear Teeth by Shaper
fig.4.7
A Shaper is a type of machine tool that uses linear relative motion between the work
pieces an cutting tool. The shape of cutting tool conforms to the gear tooth space. Each
tooth is cut at a time and then indexed for next tooth space for cutting. It is suited for a
small volume production of low precision gears. Figure shows how teeth of straight toothed
spur gear can be produced in shaping machine.
4.7.2 Forming Gear Teeth by Milling
Form Forming is sub-divided into milling by disc cutters and milling by end mill cutter
which are having the shape of tooth space.
4.7.3 Form Milling by Disc Cutter
fig.4.8
The disc cutter shape conforms to the gear tooth space. Each tooth is cut at a time
and then indexed for next tooth space for cutting. It is suited for a small volume production
of low precision gears. The form milling by end mill cutter is as shown in figure above.

4.7.4 Form Milling by End Mill Cutter
fig.4.9
The end mill cutter shape conforms to tooth spacing. Each tooth is cut at a time and
then indexed for next tooth space for cutting. It is suited for a small volume production of
low precision gears. The form milling by end mill cutter is as shown in figure above.
Production of gear teeth by form milling are characterized by:
 Low production rate as the process needs indexing after machining each tooth gap
an slow speed and feed.
 Low accuracy and surface finish.
8.20 Methods of Production of Gear Teeth by Machining
on Generation Principle
Generation method is characterized by automatic indexing and ability of a single
cutter to cover the entire range of number of teeth for a given combination of module and
pressure angle and hence provides high productivity and economy.
4.7.1 Gear Teeth Generation by Rack Type Cutter
fig.4.10

This process is used for shaping of spur and helical gear teeth with the help of a
rack type cutter. In this process the gear blank is mounted on a horizontal aims and rotated
impertinently. At the same time the gear blank is kept in mesh with a reciprocating rack
type cutter. The teeth cutter gradually removes material to cut the teeth and to make the
required profile. The whole operation includes some important operations. These are
feeding cutter into the blank, rolling the blank intermittently and keeping cutter in mesh
with the rolling gear blank. After each mesh the gear blank is rolled by an amount equal to
one pitch of gear tooth. After each cutting, the rack is withdrawn and re-meshed after the
rotation of gear blank.
A few of the initial teeth of rack type cutter perform the cutting action and remaining
teeth to very small removal of workpiece material, these are used to maintain dimensional
accuracy of the already cut teeth and to provide them a good finishing.
4.7.2 Gear Shaping
This process uses a pinion shaped cutter mounted on a spindle of the machine with its
axis in vertical position. It is also made reciprocating along the vertical axis up and down
with adjustable and predefine amplitude. The cutter and the gear blank both are set to
rotate at very low rpm about their respective axis. The relative rpm of both (cutter and
blank) can be fixed to any of the available value with the help of a gear train. This way all
the cutting teeth of cutter come is action one-by-one giving sufficient time for their
cooling and incorporating a longer tool life. The specific advantages of the process over
other processes,

fig.4.11
. The principle of gear cutting by this process as explained above is depicted in the
above figure.
The main parameters to be controlled in the process are described below.
Cutting Speed: Shaper cutter can move vertically upward and downward during the
operation. The downward movement of the cutter is the cutting stroke and its speed (linear)
with which it comes down is the cutting speed. After the completion of cutting stroke, cutter
comes back to its top position which is called return stroke. There is no cutting in the return
stroke. Length of cutting stroke can be adjusted to any value out of available values on the
machine.
Indexing Motion: Indexing motion is equivalent to feed motion in the gear shaping
operation. Slow rotations of the gear cutter and workpiece provide the circular feed to the
operation. These two rpms are adjusted with the help of a gear mechanism. The rpm are
relatively adjusted such that each rotation of the cutter the gear blank revolves through n/N
revolution.
Where n = Number of teeth of cutter.
N = Number of teeth to be cut on the blank.
Depth of Cut: Indexing movement or circular feed and reciprocating motions continue until
the required numbers of teeth to the required depth are made all along the periphery of the
gear blank. The required depth is maintained gradually by cutting the teeth into two or three
pass. In each successive pass, the depth of cut is increased as compared to its previous path.

This gradual increase in depth of cut takes place by increasing the value of linear feed in
return stroke.
fig.4.12
The whole of this process is carried out an a gear shaping machine which is of the
shape of a column and knee type milling machine. All the motions given to gear blank and
gear cutter are set controlled very precisely. A setup of gear shaping machine is shown in
above figure.
Advantages:
Main advantages of gear shaping process are described below
 Shorter product cycle time and suitable for making medium and large sized gears in
mass production.
 Different types of gears can be made except worm and worm wheels.
 Close tolerance in gear cutting can be maintained.
 Accuracy and repeatability of gear tooth profile can be maintained comfortably.
Limitations:
Main limitations of gear shaping process are described below
 It cannot be used to make worm and worm wheel.
 In case of cutting of helical gears, a specially designed guide containing a particular
helix and helix angle, corresponding to the teeth to be made.

8.21 Gear Grinding
Various gear grinding methods may be employed depending on productivity and quality
desired, Fig. 4.81. Generally, form or generation grinding by a single formed wheel (or two
single formed wheels) is time consuming. With the advent of continuous generation
grinding method using a single start or multiple-start grinding worm, the process has
become very fast. Continuous shifting permits high material removal rate. The profile of
the grinding worm corresponds to the desired tooth profile of the gear. The point contact
between grinding worm and tooth flank is maintained throughout the grinding. The rotating
worm meshes continuously with the teeth of the gear and produces the involute tooth profile
by means of innumerable trace cuts. The gear moves axially in several passes past the
grinding worm. For high production setup, one roughing and one or two finishing passes
are necessary. Axial shifting of the grinding worm to an unused portion of its profile before
making the finishing passes ensures consistent quality. Cutting occurs in both directions of
the stroke of the gear. Coolant is used to cool the point of contact of the grinding worm and
the gear. The grinding worm is regularly and automatically reprofiled with a diamond
coated gear with an approximate life of 3000 dressing operations. Setup change hardly
takes about 30 minutes. Gear grinding eliminates soft finishing by shaving. With the
continuous generation grinding, even protuberance hobs/shaper cutters may not be required
for gear cutting. Up to module 3, a 2-start profiled grinding worm may be used increasing
thus the output by 100%. Necessary modifications in profile and lead can be easily done.
Presently with CNC control grinding machines are highly productive.
Fig. 4.13 Various Gear Grinding Methods

CHAPTER 4

4. EXPERIMENTALPART
4.1 DESIGN OF FIXTURES
4.7.1 METHODOLOGY
Methodology is a systematic approach for realization of total task. It consists of following
details:
Study of component: The study of component is the most important and the first step for
the designer.
Geometric model of component: Geometric modeling of component is done using Co-
Create considering all the critical dimensions.
Step by step design calculations: It is carried out to determine the various design
parameters that determine cutting force induced on the component during shaping
operation.
Selection of tooling materials: The material used in the manufacturing of fixture varies
depending on the applications.
Solid modeling of tool: 3-D modeling of entire Component is done using Co-Create
software. For the better understanding of 2D drawings and visualization, modeling has been
done
Analysis: Structural analysis is carried using ANSYS software to determine the total
deformation and the stresses induced in the fixture during operation.

4.2 DESIGN OF FIXTURES
4.7.1 Design Consideration in Fixtures
(a) The main frame of fixture must be strong enough so that deflection of the fixture
is as minimum as possible. This deflection of fixture is caused because of forces
of cutting, clamping of the workpiece or clamping to the machine table. The
main frame of the fixture should have the mass to prevent vibration and chatter.
(b) Frames may be built from simple sections so that frames may be fastened with
screws or welded whenever necessary. Those parts of the frame that remain
permanently with the fixture may be welded. Those parts that need frequent
changing may be held with the screws. In the situation, where the body of
fixture has complex shape, it may be cast from good grade of cast iron.
(c) Clamping should be fast enough and require least amount of effort.
(d) Clamps should be arranged so that they are readily available and may be easily
removed.
(e) Clamps should be supported with springs so that clamps are held against the bolt
head wherever possible.
(f) If the clamp is to swing off the work, it should be permitted to swing as far as it is
necessary for removal of the workpiece.
(g) All locator’s clamps should be easily visible to the operator and easily accessible
for cleaning, positioning or tightening.
(h) Provision should be made for easy disposal of chip so that storage of chips doesn’t
interfere with the operation and that their removal during the operation doesn’t
interfere with the cutting process.
(i) All clamps and support points that need to be adjusted with a wrench should be of
same size. All clamps and adjustable support points should be capable of being
operated from the fronts of the fixture.

(j) Workpiece should be stable when it is placed in fixture. If the Workpiece is rough,
three fixed support points should be used. If Workpiece is smooth, more than
three fixed support points may be used. Support point should be placed as
farthest as possible from each other.
(k) The three support points should circumscribe the center of gravity of the
Workpiece.
(l) The surface area of contact of support should be as small as possible without
causing damage to the Workpiece. This damage is due to the clamping or work
forces.
(m) Support points and other parts are designed in such a way that they may be easily
replaced if they break.
4.3 Fixture locating principle
One of the principal purposes of a fixture is to locate the work piece surfaces for performing
a different operation. This is usually done with respect to a number of factors to be
considered such as the reference datum, supporting Surfaces, features those are likely to
obstruct the tool movement or access direction, etc. In general, the following Surfaces
should be distinguished:
a) Active surfaces: These are surfaces to be machined, i.e. surfaces which are
subjected to the action of cutting tools.
b) Supporting and locating surfaces: These are surfaces by means of which the work
piece is to be located with respect to set-to-size cutting tools.
c) Clamping surfaces: Clamping surfaces are subjected to the clamping forces for
obtaining invariant location. Clamping surfaces are usually not finish-machined
surfaces as clamping marks could damage the finish.
d) Datum surfaces: Datum surfaces are reference surfaces where the dimensions are
to be maintained and measured.
e) Free surfaces: Free surfaces are surfaces not involved in the set-up for the
particular operation. (An advance treatise on fixture design).

4.4 CNC MACHINES
A CNC Machine is abbreviated as Computer Numerical Control Machine. It is generally
operated by precisely programmed commands encoded on a storage medium. A CNC
Machine uses computer controls to cut different materials. CNC Computer Numerical
Control machines are widely used in manufacturing industry. The CNC machine comprises
of the computer in which the program is fed for cutting of the metal of the job as per the
requirements. The main function of CNC machines is to remove some of the metal so as to
give it proper shape such as round, rectangular, etc.
A CNC system consists of three basic components-
1. Part program.
2. Machine control unit (MCU).
3. Machine tool.
4.7.1 CNC LATHE MACHINES (TURNING).
fig.6.1
Specs: Details:
Max. work piece diameter mm Φ500
Spindle bore mm 82
Chuck type - 3 Jaw chuck system
Spindle speed rpm 150 to 2500
Tailstock sleeve travel mm 150
Tailstock taper - MT5
Machine weight kg 3500

4.7.2 CNC SHAPING MACHINE.
fig.6.2
Specs: Details:
Max. work piece diameter mm φ250
Max. module mm 6
Max. gear width mm 60
Cutter stroke * min-1
120 to 1,000
Rotary federate mm 0.1 to 10
Radial cutting feed mm 0.001 to 0.1
Radial rapid traverse mm/min 10.000
Number of cuts 1 to 4
Cutter spindle diameter mm φ100
Controlled axes 6
Main motor kw 10
Machine weight kg 6,500

4.7.3 CNC GRINDING MACHINE.
fig.6.3
Specs: Details:
Max. work piece diameter Mm φ240
Max. module Mm M6
Grinding wheel diameter × length Mm φ300 × 125 (φ160)
Grinding wheel shift Mm 200
Helix angle Deg ±45
Max. grinding wheel speed min-1
6,000
Max. table speed min-1
600
Radial feed distance Mm 270
Radial rapid traverse speed mm/min 10.000
Axial rapid traverse speed mm/min 10.000
Main motor Kw 25
Machine weight Kg 11,00

4.5 GEAR 4TH
PART SPECIFICATIONS
SL
NO
SPECIFICATIONS GEAR 4TH
EC-50
(DIESEL)
GEAR 4TH
C-550
(PETROL)
1 NO OF TEETH 42 38
2 MODULE 1.25 1.25
3 PRESSURE ANGLE 300
300
4 PITCH CIRCLE DIA 52.5 mm 47.50 mm
5 BASE CIRCLE DIA 45.46 mm 41.14 mm
6 MAJOR DIA 53.95 mm 48.58 mm
7 FORM DIA 51.59 mm 46.40 mm
8 WHOLE DEPTH 1.40 mm 1.16 mm
9 BALL DIA 2.25 mm 2.25 mm
10 O.B.D
MEASUREMENT
VALUE
50.935±0.03
55.83±0.035

4.6 GEAR 3RD
PART SPECIFICATIONS
SL
NO
SPECIFICATIONS GEAR 3rd
EC-50
(DIESEL)
GEAR 3rd
C-550
(PETROL)
1 NO OF TEETH 38 38
2 MODULE 1.8 1.630
3 PRESSURE ANGLE 16.50
150
4 PITCH CIRCLE DIA 84.55 mm 73.85 mm
5 HELIX ANGLE 360
330
6 BASE CIRCLE DIA 78.39 mm 70.35 mm
7 MAJOR DIA 89 mm 77.75 mm
8 FORM DIA 80 mm 70.87 mm
9 WHOLE DEPTH 5.676 mm 5.10 mm
10 BALL DIA 3.5 mm 3.5 mm
11 O.B.D
MEASUREMENT
VALUE
90.097±0.05
79.965±0.05

4.7 ANALYSIS OF PARTS OF FIXTURE
4.7.1 Analysis of datum plate
fig.7.1
4.7.2 Units
Unit System (mm, kg, N, s, mV, mA) Degrees rad/s
Celsius
Angle Degrees
Rotational Velocity rad/s
Temperature Celsius

4.7.3 Material
4.7.4 Ansys input
Assignment Structural Steel
Nonlinear Effects Yes
Thermal Strain Effects Yes
Moment of Inertia Ip1 274.63 kg·mm²
Statistics
Nodes 18094
Elements 91322
Mesh Metric None
Object Name Datum plate
State Fully Defined
Type Design Modeler
Length Unit Meters
Element Control Program Controlled
Display Style Body Color
Type Cartesian
Length X 79.941 mm
Length Y 49 mm
Length Z 80 mm

4.7.5 Properties
4.7.6 Structural Steel Constants
4.7.7 Strain-Life Parameters
Volume 81577 mm3
Mass 0.64038 kg
Definition
Suppressed No
Stiffness Behavior Flexible
Coordinate System Default Coordinate System
Reference Temperature By Environment
Density 7.85e-006 kg mm^-3
Coefficient of Thermal Expansion 1.2e-005 C^-1
Specific Heat 4.34e+005 mJ kg^-1 C^-
Thermal Conductivity 6.05e-002 W mm^-1 C^-1
Resistivity 1.7e-004 ohm mm
Strength
Coefficient
MPa
Strength
Exponent
Ductility
Coefficient
Ductility
Exponent
Cyclic
Strength
Coefficient
MPa
Cyclic
Strain
Hardening
Exponent
920 -0.106 0.213 -0.47 1000 0.2

4.7.8 Alternating Stress Mean Stress
4.7.9 Isotropic Elasticity
Alternating Stress MPa Cycles Mean Stress MPa
3999 10 0
2827 20 0
1896 50 0
1413 100 0
1069 200 0
441 2000 0
262 10000 0
214 20000 0
138 1.e+005 0
114 2.e+005 0
86.2 1.e+006 0
Temperature C Young's
Modulus MPa
Poisson's Ratio Bulk Modulus
MPa
Shear Modulus
MPa
32 2.e+005 0.3 0.376923 76923

4.7.10 Analysis of collet
fig.7.2
4.7.11 Units
Unit System (mm, kg, N, s, mV, mA) Degrees rad/s
Celsius
Angle Degrees
Rotational Velocity rad/s
Temperature Celsius

4.7.12 Material
4.7.13 Ansys input
Assignment Structural Steel
Nonlinear Effects Yes
Thermal Strain Effects Yes
Statistics
Nodes 22554
Elements 11210
Mesh Metric None
Object Name Collet
State Fully Defined
Type Design Modeler
Length Unit Meters
Element Control Program Controlled
Display Style Body Color
Type Cartesian
Length X 25.993 mm
Length Y 34. mm
Length Z 25.993 mm

4.7.14 Properties
4.7.15 Structural Steel > Constants
4.7.16 Strain-Life Parameters
Volume 9056. mm³
Mass 7.109e-002 kg
Definition
Suppressed No
Stiffness Behavior Flexible
Coordinate System Default Coordinate System
Reference Temperature By Environment
Density 7.85e-006 kg mm^-3
Coefficient of Thermal Expansion 1.2e-005 C^-1
Specific Heat 4.34e+005 mJ kg^-1 C^-
Thermal Conductivity 6.05e-002 W mm^-1 C^-1
Resistivity 1.7e-004 ohm mm
Strength
Coefficient
MPa
Strength
Exponent
Ductility
Coefficient
Ductility
Exponent
Cyclic
Strength
Coefficient
MPa
Cyclic
Strain
Hardening
Exponent
920 -0.106 0.213 -0.47 1000 0.2

4.7.17 Alternating Stress Mean Stress
4.7.18 Isotropic Elasticity
Alternating Stress MPa Cycles Mean Stress MPa
2999 10 0
1827 20 0
1715 50 0
1413 100 0
1052 200 0
752 2000 0
212 10000 0
150 20000 0
88 1.e+005 0
62 2.e+005 0
48 1.e+006 0
Temperature C Young's
Modulus MPa
Poisson's Ratio Bulk Modulus
MPa
Shear Modulus
MPa
32 2.e+005 0.3 0.376923 76923

CHAPTER 5

5. RESULTSAND DISCUSSIONS
8.1 SHAPING FIXTURE RESULTS
fig.8.1
8.2 MACHINE FLEXIBILITY:
BEFORE IMPLIMENTATION:
 The shaping fixture was limited only for one variant (Gear 4th
C550 (petrol)).
 Life of the collet was not good to operate for minimum working cycles.
 Collet was breaking due to more stroke (8.5mm) of the draw bar.
 Because of collet breakage cutting tool used to get damaged and part loaded will
be affected (gear teeth’s breakdown).
 Production time, maintenance & cost of production, cost of tooling was more.
AFTER IMPLIMENTATION:
 Along with the Gear 4th
C550 (petrol) Gear 4th
EC50 (diesel) is added.
 Setup change time is also reduced.
 Collet life increased by redesigning the stroke of the drawbar using spacers by
trial and error method.
 New stroke of the drawbar set to 2.5mm with consideration of part clamping for
the same clamping force.
800 865 925 950
1458
1822
2100
2700 2700 2700
2 5 5 4 5 5 3 1 1 1
0
500
1000
1500
2000
2500
3000
LIFEOFCOLLET
(NOOFPARTS)
NO OF COLLETS
COLLET LIFE
FUTURE
PRESENT

8.3 CHANGE POINTS
1. Redesigning the stroke of the drawbar.
a) Assembly drawing confirmation.
b) Spacer added.
c) Part clamp confirmation.
2. Quick setup for new variant Gear 4th
EC50 (diesel).
a) Design change of datum.
b) Design change of collet.
c) Design change of drawbar.
d) Double collet locking along with previous variant.
8.4 SCOPE OF INHOUSE COLLET MANUFACTURING
Current Scenario: Procure Collet from Supplier [Local & Japan supplier]
Localization under progress
fig.8.2
2,388,264
4,080,264
0
1000000
2000000
3000000
4000000
5000000
2014 2015 [Till Feb]
Amount [in
rs.]
Collet Cost

fig.8.3
fig.8
127
54
0
20
40
60
80
100
120
140
2014 2015 [Till Feb]
Nos.
Collet Consumption
0
20000
40000
60000
1 2 3 4 5 6 7 8 9 10
Rs.
No. of Years/Collets
Break Even Point
Fixed Cost Variable Cost Procurement Cost

8.5 GRINDING FIXTURE RESULTS
8.6 MACHINE FLEXIBILTY
BEFORE IMPLEMENTATION:
 Only gear 4th
C550 (petrol) variant can produced.
 It’s rigid for specific variant only.
AFTER IMPLEMENTATION:
 Flexible to produce many variants that are ,
 Current production variants (2016).
1. Gear 4th
C550(petrol)
 Future production variants (2019).
1. Gear 5th EC50 (diesel).
2. Gear 6th EC60 (diesel).
3. Gear 5th
variant for EC65 (petrol).
4. Gear 6th
variant for EC65 (petrol).
458
76
230
76
230
0
100
200
300
400
500
G4 C550 G5 EC50 G5 EC60 G6 EC50 G6 EC60
Quantity
(noofparts)
Variants
GRINDING FIXUTRE FLEXIBILITY
PRESENT
FUTURE

8.7 CHANGE POINTS
1. Clamping mechanism
a) Draw bar design changed (Pitch of the draw bar).
b) Collet design changed (OD & ID changed according to new
variant dimensions).
c) Arbor plate design changed (pitch increased)
2. Work holding devices in quick change
a) For different variants collet and datum can be changed in one
touch (change time 3 minutes).

CHAPTER 6

CONCLUSION
1. The design of the fixture is simple, the loading and unloading of component is very
easy.
2. At a time all the operations such as turning, shaping, grinding, can be done in a
single set up which in turn decreases the handling and machining time.
3. This fixture is designed in such a way that any operations are supposed to be done
at certain angle can be easily performed on this fixture as we can perform the
machining action on both the sides.
4. Fixture is designed with minimum number of parts. Considering the static forces
over the component which is in contact with the fixture is analyzed, it shows the
total deformations and the stresses acting on the fixture during the machining
process done on the fixture. Hence these results indicate that the design is well
within the safe limits. Hence the design is safe.
5. By increasing the length of the collet and the wedge for suitable bore diameters
more no of work pieces can be machined at the same time, thus further increasing
the productivity of the machine.
6. By increasing the number of slots in the collet, the expansion limit can also be
increased. Hence hydraulically operated fixture is a good option to increase the
production.

CHAPTER 7

8.1 Scope for Future Work
In this project many things were redesigned to improve the machine capability, were in
grinding machine fixture is designed for quick set up change, which reduces the set time
and increases the product quality. The other concern in the shaping machine was about the
collet breakage in less cycles, were the stroke (movement) of the draw bar was redesigned
by introducing the spacers which controls the expansion of collet and with the same
clamping condition.
• Only the limited aspects of fixture issues were considered here. However, Multi-
spindle machine tools are widely used in mass production. They can execute
multiple processes at the same time, which can greatly increase productivity and
reduce cycle time. The machine tool capability model can be extended to multiple
spindle machine tools in future studies.
• In this project, knowledge in the setup planning and fixture design area is restricted
with more focus being given on process and design. This can be further elaborated
with details of fixtures design and setup planning depending upon the type of
machine tools that are being used, which can be linked with the framework
developed.
 Implementation of a real optimization process is suggested to determine the optimal
surface contact areas between the workpiece and fixture components such as
locators and clamps. The current FE model can be modified to perform an
optimization process
 The frictional force between workpiece and fixture components such as locators
and clamps should be studied for the effects such as the true magnitudes of clamping
force required.
 Future research work can be planned for the improvement of the proposed
framework, for creation of a model for evaluation of productivity improvements, in
order to quantify time and more variants in production, cost reduction.

CHAPTER 8

8.1 References
i. Rong Y, Bai Y (1996) Machining accuracy analysis for computer aided fixture design
verification. Journal of Manufacturing Science Engineering, 118, 289–300.
ii. Rong Y, Bai Y, J Manufacturing Science Engineering, “Automated generation of
fixture configuration design” vol 5, 1997.
iii. Ratchev, K. Phuah , G. Lammel, W. Huang, “An experimental investigation of
fixture–work piece contact behavior for the dynamic
iv. simulation of complex fixture–work piece systems” vol 2, 2013
v. K.V.S. Seshendra kumar, “Design of gear cutting fixture for CNC gear cutting
machine.” , International Journal of Scientific and Research Publications, Volume
2, Issue 9, September 2012.
vi. M. Lukacs, “State of process development and trends in hard gear finishing,”
Hungarian Journal of Industrial Chemistry Veszprem, vol.38(2). Pp.107-111, 2010.
vii. P.C.Sharma, “A Textbook of Production Engineering”, S.Chand & Company
Limited, 2011.
viii. DeMeter, E.C. (1995), “Min-Max load model for optimization machining fixture
performance”, J. of Eng for Industry, Vol.117 pp186-193
ix. Chen, W., Ni, L, and Xue, J, “Deformation control through fixture layout design
and clamping force optimization”, Int J. Adv Manuf Technol Vol. 38 pp860-867
x. Walcyzk, D.F, and Longtin, R,S (2000), “Fixturing of compliant parts using a
matrix of reconfigurable pins”, Journal of Mfg Science and Engineering, Vol. 122
pp766-772

Appendix-A

Appendix-B

Appendix-C

Appendix-D

Appendix-E

REPORT

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (7)

Similar to REPORT

Similar to REPORT (20)

REPORT