Arun Report Project Edited

HAND INJECTION MOULD FOR GUITAR KEYCHAIN

NETTUR TECHNICAL TRAINING FOUNDATION

AN ISO 9001:2008CERTIFIED TRAINING INSITTUTION

A PROJECTREPORT ON

MULTIPURPOSE ANGULAR GRINDINGFIXTURE

A Dissertation Submitted By, ARUNKUMAR N (1554/DTC/2014)For the award of,

TRAINEE OFFICER IN GRADUATE ENGINEERING TRAININGUnder the valuable guidance of

Mr. A SHANKAR

NETTUR TECHNICAL TRAINING FOUNDATION, KUMBAKONAM TRAINING CENTRE. R.S.No.101/1,Venkatesha Nagar, Chettimandapam,

KUMBAKONAM- 612001

[BEVEL EDGE ANGLE GRINDING FIXTURE FOR TRI SQUARE]

[MULTIPURPOSE ANGULAR GRINDING FIXTURE]

[NETTUR TECHNICAL TRAINING FOUNDATION,BENGALURU]Page 99

[NETTUR TECHNICAL TRAINING FOUNDATION, KUMBAKONAM]Page 8

NETTURTECHNICAL TRAINING FOUNDATION

ANISO9001:2008CERTIFIEDTRAININGINSTITUTION

CERTIFICATE

THIS IS TO CERTIFY THAT PROJECT TITLED MULTIPURPOSE ANGULAR GRINDING FIXTUREIt is a bona fide record of the project work done by, ARUNKUMAR N

This is to Certify that the project work entitled MULTIPURPOSE ANGULAR GRINDING FIXTURE is a bona fide work carried out by N.ARUNKUMAR (1554/DTC/2014), in partial fulfillment for the award of trainee officer in NETTUR TECHNICAL TRAINING FOUNDATION, BENGALURU during the year AUGUST 2014-2015.It is certified that all corrections/suggestions indicated for Internal Assessment have been incorporated in the Report .The project report has been approved as it satisfies the academic requirements in respect of the work prescribed for the GRADUATE ENGINEER TRAINING.

PROJECT GUIDE PRINCIPAL (A SHANKAR) (A SHANKAR)

PREFACE:

I am submitting this project report as a part of fulfillment of the course,GRADUATE ENGINEER TRAINEE at NETTUR TECHNICAL TRAINING FOUNDATION, BENGALURU, KARNATAKA during the year AUGUST 2014-2015.

ABSTRACT:

Fixtures are considered to be one of the most prominent devices designed and used for higher productivity and product quality in batch production. One of the problems faced in machine shops is the cost of fixture.. Fixture setup is used to reduce the work load within the company. These are special work holding and tool guiding device. Quality of the performance of a process is largely influenced by the quality of fixture used for this purpose. What makes a fixture unique is that each one is built to fit a particular part or shape.

The main purpose of a fixture is to locate and in the cases hold a work piece during an operation. . Fixtures reduce operation time and increases productivity and high quality of operation ispossible.

The main aim of this project is to reduce cost of the fixture and used for training purpose.

OBJECTIVES OF PROJECT:

The main objective of project is to design a multipurpose angular grinding fixture with details. The fixture is for training students which are used for NTTF training purposes.NTTF has designed quality objectives to achieve the overall goal and develop eachIndividual undergoing training to expertise the trainees during the training period itself NTTF formulated one of the objectives as TO INCULCATE THE CULTURE, PRODUCE WHILE LEARNING AND LEARN WHILE PRODUCING.The objective of the project that I have complete is to give an insight into theWorking of angular grinding fixture, reduction of manufacturing cost, and inspection of the activities which helps to consistently deliver the components without fail; throughout its life. One method of reducing manufacturing cost per component is to reduce machining cycle time. The manufacturing cycle time can be reduced by reducing nonproductive time like loading, unloading, and the placing of work piece onto the machine. Here jig and fixture design has important role to play. Productive time for a machine is the time required for surface grinding operation by the machine.

SYNOPSIS:

Fixture setup is used to reduce the work load within the company. These are special work holding and tool guiding device. Quality of the performance of a process is largely influenced by the quality of fixture used for this purpose. What makes a fixture unique is that each one is built to fit a particular part or shape.

The main purpose of a fixture is to locate and in the cases hold a work piece during an operation.

The main aim of this project is to reduce cost of the fixture and used for training purpose.

It is decided to manufacture a multipurpose angular grinding fixture for getting different chamfered angles in a work piece.It is planned to reduce the cost of fixture and also to increase the life of fixture, hence it is decided to use mild steel material.Design of the fixture is concentrated more on a comfortable accurate and simple component. It has been carried out with the help of design software Auto CAD.One method of reducing manufacturing cost per component is to reduce machining cycle time. The manufacturing cycle time can be reduced by reducing nonproductive time like loading, unloading, and the placing of work piece onto the machine. Here jig and fixture design has important role to play.

SCOPE OFTHEPROJECT:

To know the basics of fixture practically.Design and Manufacturing of the grinding fixture.Exposure in Auto CAD. SoftwareExposure in functions like planning, routing, scheduling, follow up, inspection of the tool and componentExposure to basic machining.

[NETTUR TECHNICAL TRAINING FOUNDATION, KUMBAKONAM]Page 67

ACKNOWLEDGEMENT:

I would like to express my sincere gratitude to Managing Director Mr. N Reguraj for giving me this lifetime opportunity in carving my career path.

I take the privilege to thank Mr. R Rajagopalan, Mentor Director for his timely support.

I owe my sincere gratitude to Mr. Arul Selvan, Deputy Managing Director Edu tech NTTF and Mr. K Venugopal, Director NTTF for all help and infrastructure provided to complete this project successfully.

I express my sincere thanks to Mr. S. Stephen Louis, ASSOCIATE DIRECTOR (HR) NTTF, BANGALORE, for his valuable support during the course of the project

I am highly indebted to Mr. T K Rajiv (GET coordinator) for all his untiring effort in steering us in our Training Arena. I express my thanks to our Principal Mr. A Shankar (Unit head, KTC) for his constant encouragement and valuable suggestions in selecting and completing this Project.

I thank to all to teaching and non-teaching staff of NTTF-DHARWAD, NTTF-BANGALORE and NTTF-KUMBAKONAM and all my COLLEAGUES and well-wishers those who have helped me directly or indirectly to perform the project.

CONTENTS:

SL.NOCONTENTSPAGE NO

1INTRODUCTION TO FIXTURES13-16

2

DESIGN CONSIDERATIONS

16-20

3

TYPES OF FIXTURES

21-26

4 DOWEL PIN AND FULCRUM PIN27

5 ADVANTAGES OF FIXTURES28

6PROJECT SUMMARY & FLOW CHART29-30

7PROJECT SUMMARY DESIGN, MANUFACTURING PROCESS30-42

8COST ESTIMATION43-50

9 INSPECTION51-59

10 3D DESIGN OF FIXTURE 58-65

11PHOTOGRAPHIC IMAGE OF FIXTUREPHOTOGRAPHIC IMAGES OF FIXTURE

66-73

12 CONCLUSION74

13

REFERENCES

76

INTRODUCTION:

Over the past century, manufacturing has made considerable progress. New machine tools, high-performance cutting tools, and modern manufacturing processes enable today's industries to make parts faster and better than ever before. Although work holding methods have also advanced considerably, the basic principles of clamping and locating are still the same.The fixture is a special tool for holding a work piece in proper position during manufacturing operation. For supporting and clamping the work piece, device is provided. Frequent checking, positioning, individual marking and non-uniform quality in manufacturing process is eliminated by fixture. This increase productivity and reduce operation time. Fixture is widely used in theIndustry practical production because of feature and advantages.To locate and immobilize work pieces for machining, inspection, assembly and other operations fixtures are used. A fixture consists of a set of locators and clamps. Locators are used to determine the position and orientation of a work piece, whereas clamps exert clamping forces so that the work piece is pressed firmly against locators. Clamping has to be appropriately planned at the stage of machining fixture design. The design of a fixture is a highly complex and intuitive process, which require knowledge. Fixture design plays an important role at the setup planning phase. Proper fixture design is crucial for developing product quality in different termsof accuracy, surface finish and precision of the machined parts In existing design the fixture set up is done manually, so the aim of this project is to replace with hydraulic fixture to save time for loading and unloading of component. Hydraulic fixture provides the manufacturer for flexibility in holding forces and to optimize design for machine operation as well as process function ability.HISTORYThe first manufactured products were made one at a time. Early artisans started with little more than raw materials and a rough idea of the finished product. They produced each product piece by piece, making each part individually and fitting the parts into the finished product. This process took time. Moreover, the quality and consistency of products varied from one artisan to the next. As they worked, early manufacturing pioneers realized the need for better methods and developed new ideas.Eventually, they found the secret of mass production: standardized parts. Standard parts not only speeded production, they also ensured the interchangeability of parts. The idea may be obvious today, but in its time, it was revolutionary.These standard parts were the key to enabling less-skilled workers to replicate the skill of the craftsman on a repetitive basis. The original method of achieving consistent part configuration was the template. Templates for layout, sawing, and filing permitted each worker to make parts to a standard design. While early templates were crude, they at least gave skilled workers a standard form to follow for the part. Building on the template idea, workers constructed other guides and work holders to make their jobs easier and the results more predictable. These guides and work holders were the ancestors of today's jigs and fixtures.Yesterday's work holders had the same two basic functions as todays: securely holding and accurately locating a work piece. Early jigs and fixtures may have lacked modern refinements, but they followed many of the same principles as todays work holder designs.DEFINITIONSOften the terms "jig" and "fixture" are confused or used interchangeably; however, there are clear distinctions between these two tools. Although many people have their own definitions for a jig or fixture, there is one universal distinction between the two. Both jigs and fixtures hold, support, and locate the work piece. A jig, however, guides the cutting tool. A fixture references the cutting tool. The differentiation between these types of work holders is in their relation to the cutting tool. As shown in Figure 1-1, jigs use drill bushings to support and guide the tool. Fixtures, Figure 1-2, use set blocks and thickness, or feeler, gages to locate the tool relative to the work piece.

A jig guides the cutting tool, in this case with a bushing.

A fixture references the cutting tool, in this case with a set block.

JigsThe most-common jigs are drill and boring jigs. These tools are fundamentally the same. The difference lies in the size, type, and placement of the drill bushings. Boring jigs usually have larger bushings. These bushings may also have internal oil grooves to keep the boring bar lubricated. Often, boring jigs use more than one bushing to support the boring bar throughout the machining cycle.In the shop, drill jigs are the most-widely used form of jig. Drill jigs are used for drilling, tapping, reaming, chamfering, counter boring, countersinking, and similar operations. Occasionally, drill jigs are used to perform assembly work also. In these situations, the bushings guide pins, dowels, or other assembly elements.Jigs are further identified by their basic construction. The two common forms of jigs are open and closed. Open jigs carry out operations on only one, or sometimes two, sides of a work piece. Closed jigs, on the other hand, operate on two or more sides. The most-common open jigs are template jigs, plate jigs, table jigs, sandwich jigs, and angle plate jigs. Typical examples of closed jigs include box jigs, channel jigs, and leaf jigs. Other forms of jigs rely more on the application of the tool than on their construction for their identity. These include indexing jigs, turn-on jigs, and multi-station jigs.Specialized industry applications have led to the development of specialized drill jigs. For example, the need to drill precisely located rivet holes in aircraft fuselages and wings led to the design of large jigs, with bushings and liners installed, contoured to the surface of the aircraft. A portable air-feed drill with a bushing attached to its nose is inserted through the liner in the jig and drilling is accomplished in each location.FixturesFixtures have a much-wider scope of application than jigs. These work holders are designed for applications where the cutting tools cannot be guided as easily as a drill. With fixtures, an edge finder, center finder, or gage blocks position the cutter. Examples of the more-common fixtures include milling fixtures, lathe fixtures, sawing fixtures, and grinding fixtures. Moreover, a fixture can be used in almost any operation that requires a precise relationship in the position of a tool to a work piece.Fixtures are most often identified by the machine tool where they are used. Examples include mill fixtures or lathe fixtures. But the function of the fixture can also identify a fixture type. So can the basic construction of the tool. Thus, although a tool can be called simply a mill fixture, it could also be further defined as a straddle-milling, plate-type mill fixture. Moreover, a lathe fixture could also be defined as a radius-turning, angle-plate lathe fixture. The tool designer usually decides the specific identification of these tools.

The hierarchy of work holding options.

DESIGN CONSIDERATIONS The principal considerations when choosing among work holder varieties fall into three general categories: tooling cost, tooling details, and tooling operation. Although each of these categories is separated here, in practice they are interdependent. The following are some design differences and considerations for permanent, general-purpose, and modular work holders.Tooling CostsThe total cost of any jig or fixture is frequently the major area of consideration in many work holder designs. Although initial cost is a major element, it should not be the basis for accepting or rejecting any tooling option.A more-proper economic evaluation of the work holder design takes into consideration many other factors. As discussed previously, permanent fixtures have distinct advantages in the production of high-volume and high-precision parts. They also typically reduce machine setup time, machine cycle time, and the level of operator skill required to produce satisfactory quality output. Over a long production run, or a series of runs in the life of a tool, the average cost of the tool per piece produced can be quite low.General-purpose work holders are more expensive than temporary tools in most cases, but their utility and flexibility often allow these work holders to be regarded as a capital cost to be amortized over a period of time without regard to actual usage. Similarly, modular fixturing is typically a capital investment to be amortized over a set lifespan, with an average cost assigned to usage for each anticipated job.Another cost to be considered is work holder disposition. Permanent fixtures require storage and maintenance to keep them available for their next use. General-purpose tools are reused extensively, but still incur some costs for maintenance and storage. Similarly, modular fixtures will be disassembled, and the components maintained, stored, and reused frequently.Tooling DetailsTooling details are the overall construction characteristics and special features incorporated into the jig or fixture. Permanent work holders are designed and built to last longer than temporary work holders. So, permanent jigs and fixtures usually contain more-elaborate parts and features than temporary work holders.There are several other differences between permanent and temporary work holders in this area. These include the type and complexity of the individual tooling elements, the extent of secondary machining and finishing operations on the tool, the tool-design process, and the amount of detail in the work holder drawings. Since the elements for modular work holders are usually part of a complete set, or system, only rarely will additional custom components need to be made.Permanent work holders contain different commercial tooling components based on expected tool usage. Permanent jigs intended for a high-volume drilling operation, for example, often use a renewable bushing and liner bushing together. A throwaway jig for a smaller production run often uses a simple press-fit bushing.The secondary operations normally associated with tooling include hardening, grinding, and similar operations to finish the work holder. Usually, permanent work holders are hardened and ground to assure their accuracy over a long production run. Since they are intended only for short production runs, throwaway jigs and fixtures do not require these operations. Another secondary operation frequently performed on permanent tools, but not temporary tools, is applying a protective finish, such as black oxide, chrome plating, or enamel paint.In designing a permanent work holder, the designer often makes detailed engineering drawings to show the tool room exactly what must be done to build the work holder. With temporary work holders, the design drawings are often sent to the tool room as simple freehand sketches.Permanent tools are normally designed for long-term use. This being the case, the drawings and engineering data for the permanent jig or fixture then become a permanent record. With modular work holders, the designer may either construct drawings or specify building the work holder directly around the part. Here only a parts list and photographs or video tape are kept as a permanent record.Certain work holding applications require special fixture characteristics. For example, a particularly corrosive environment may require stainless steel components and clamps to deliver a satisfactory life cycle. In other cases, variable work piece dimensions, as in a casting, necessitate clamping devices which can compensate for these variations. Appearance of a finished part might require the use of nylon, plastic, or rubber contact points to protect the part.Similarly, the selection of tooling details can enhance the productivity of some permanent tools. For example, utilizing small hydraulic clamps may allow loading many parts on a work holder due to the compactness of the design. This would enhance productivity by reducing load/unload time as a percentage of total cycle time. Duplicate fixtures are sometimes justified for machining centers because they allow loading of parts on one pallet during the machining cycle on the other pallet.Tooling OperationThe performance of any work holder is critical to the complete usefulness of the tool. If the work holder cannot perform the functions desired in the manner intended, it is completely useless, regardless of the cost or the extent of the detail. As the performance of a permanent, modular, or general-purpose work holder is considered, several factors about the machine tools must be known. These factors include the type, size, and number of machine tools needed for the intended operations.Work holders are sometimes designed to serve multiple functions. For example, it is possible to have a work holder that acts both as a drill jig and a milling fixture. These tools are called combination tools or multiple-function work holders. Figure 1-6 shows a typical temporary work holder for drilling and milling operations on the same part. In this example, since the work holder has provisions for both milling and drilling, it is classified as both a drill jig and milling fixture.

. A combination drill jig/milling fixture used for both types of operations on the same part.

Other machine considerations may come into play as well. On numerically controlled machines, for example, care must be taken in fixture design to position clamps out of the cutting tool's path. Pallet machines require different fixtures than other machines. Obviously, vertical mills would be tooled differently than horizontal mills. Likewise, the way parts are loaded onto the fixture has implications for fixture design.Despite the work holder design or the size of the production run, every jig or fixture must meet certain criteria to be useful. These criteria include accuracy, durability, and safety. Accuracy, with regard to jigs and fixtures, is the ability of a work holder to produce the desired result, within the required limits and specifications, part after part, throughout the production run.To perform to this minimum level of accuracy, the work holder must also be durable. So, the jig or fixture must be designed and built to maintain the required accuracy throughout the expected part production. If part production is continuous, year after year, the jig or fixture must be more durable than is necessary for only one production run.The final consideration, safety, is actually the most important. No matter how good the design or construction, or how well it produces the desired accuracy, if the work holder is not safe, it is useless. Safety is a primary concern in the design of any work holder.Safety, as well as speed and reliability of part loading, can often be improved by the use of power clamping, either pneumatic or hydraulic. Once set, power clamps will repeatedly clamp with the identical force. This is not always true with manual clamps, which depend on operator diligence for the proper application of clamping force. In addition, power-clamping systems can have interlocks to the machine control which will shut the machine down if the system loses powera clear safety advantage for both operator and machine tool.APPLICATIONS FOR JIGS AND FIXTURESTypically, the jigs and fixtures found in a machine shop are for machining operations. Other operations, however, such as assembly, inspection, testing, and layout, are also areas where work holding devices are well suited. Figure 1-7 shows a list of the more-common classifications and applications of jigs and fixtures used for manufacturing. There are many distinct variations within each general classification, and many work holders are actually combinations of two or more of the classifications shown.EXTERNAL-MACHINING APPLICATIONS:Flat-Surface Machining Milling fixtures Surface-grinding fixtures Planning fixtures Shaping fixtures

Cylindrical-Surface Machining Lathe fixtures Cylindrical-grinding fixtures

Irregular-Surface Machining Band-sawing fixtures External-broaching fixtures

INTERNAL-MACHINING APPLICATIONS:Cylindrical- and Irregular-Hole Machining Drill jigs Boring jigs Electrical-discharge-machining fixtures Punching fixtures Internal-broaching fixturesNON-MACHINING APPLICATIONS:Assembly Welding fixtures Mechanical-assembly fixtures (Riveting, stapling, stitching, pinning, etc.) Soldering fixtures

Inspection Mechanical-inspection fixtures Optical-inspection fixtures Electronic-inspection fixtures

Finishing Painting fixtures Plating fixtures Polishing fixtures Lapping fixtures Honing fixtures

Miscellaneous Layout templates Testing fixtures Heat-treating fixtures

TYPES OF FIXTURES:

The following is a partial list of production operations that use fixtures:Assembling LappingBoring MillingBroaching PlanningDrilling SawingForming ShapingGauging StampingGrinding TappingHeat treating TestingHoning TurningInspecting WeldingTYPES OF FIXTURES:

The names used to describe the various types of fixtures are determined mainly byhow the tool is built. Jigs and fixtures are made basically the same way as far as locatorsand positioners are concerned. The main construction difference is mass. Because of theincreased tool forces, fixtures are built stronger and heavier than a jig would be for thesame part.Plate fixturesPlate fixtures are the simplest form of fixture. The basic fixture is made from a Flat plate that has a variety of clamps and locators to hold and locate the part. The simplicity of this fixture makes it useful for most machining operations. Its adaptability makes it popular. Angle-plate fixtureThe angle-plate fixture is a variation of the plate fixture. With this tool, the part isNormally machined at a right angle to its locator.

Modified angle-plate fixtureWhile most angle-plate fixtures are made at 90 degrees, there are times whenOther angles are needed. In these cases, a modified angle-plate fixture can be used.

Fig. modified angle-plate fixtureVise-jaw fixturesVise-jaw fixtures are used for machining small parts. With this type of tool, theStandard vise jaws are replaced with jaws that are formed to fit the part. Vise-jaw fixturesare the least expensive type of fixture to make. Their use is limited only by the sizes ofthe vises available.

Fig. Vise-jaw fixturesIndexing fixturesIndexing fixtures are very similar to indexing jigs. These fixtures are used forMachining parts that must have machined details evenly spaced. The parts shown inFigures are examples of the uses of an indexing fixture. Indexing fixtures

Parts machined with an indexing fixture.

Multi station fixturesMulti station fixtures are used primarily for high-speed, high-volume productionRuns, where the machining cycle must be continuous.Duplex fixturesDuplex fixtures are the simplest form of multistation fixture, using only twostations. This form allows the loading and unloading operations to be performed whilethe machining operation is in progress. For example, once the machining operation iscomplete at station 1, the tool is revolved and the cycle is repeated at station 2. At thesame time, the part is unloaded at station 1 and a fresh part is loaded.

Duplex fixturesProfiling fixturesProfiling fixtures are used to guide tools for machining contours that the machinecannot normally follow. These contours can be either internal or external. Since thefixture continuously contacts the tool, an incorrectly cut shape is almost impossible. Theoperation in Figure shows how the cam is accurately cut by maintaining contactbetween the fixture and the bearing on the milling cutter. This bearing is an importantpart of the tool and must always be used..

MILLING FIXTURE

Milling Fixtures Milling fixtures are the most common type of fixture in general use today. The simplest type of milling fixture is a milling vise mounted on the machine table. However, as the work piece size, shape, or complexity becomes more sophisticated, so too must the fixture. The design should permit as many surfaces of the part to be machined as possible. Without removing the part. Whenever possible, the tool should be changed to suit the part. Moving the part to accommodate one cutter for several operations is not as accurate or as efficient as changing cutters. Locators must be designed to resist all tool forces and thrusts. Clamps should not be used to resist tool forces. Clearance space or sufficient room must be allotted to provide adequate space to change cutters or to load and unload the part. Milling fixtures should be designed and built with a low profile to prevent unnecessary twisting or springing while in operation. The entire work piece must be located within the area of support of the fixture. In those cases where this is either impossible or impractical, additional supports, or jacks, must be provided. Chip removal and coolant drainage must be considered in the design of the fixture. Sufficient space should be permitted to allow the chips to be easily removed with a brush. Set blocks or cutter setting gages must be provided in the fixture design to aid the operator in properly setting up the tool in production.

Lathe FixturesSimilar to the design of milling fixtures. In milling, the work piece is stationary and the cutting tool revolves. In turning operations, the work piece revolves and the cutting tool is stationary. Tool designer must deal with-centrifugal force. The complete fixture must be designed and constructed to resist the effects of the rotational, or centrifugal, forces present in the turning. Since lathe fixtures are designed to rotate, they should be as lightweight as possible. Lathe fixtures must be balanced. While perfect balance is not normally required for slow-speed turning operations, high rotational speeds require the fixture to be well-balanced. Projections and sharp corners should be avoided since these areas will become almost invisible as the tool rotates and they could cause serious Injury Parts to be fixtured should, whenever possible, be gripped by their largest diameter, or cross section. The part should be positioned in the fixture so that most of the machine operation can be performed in the first fixturing. Clamps should be positioned on surfaces, or areas, which are rigid before and after machining. As with other fixtures, some means of cutter setting should also be incorporated into the design. However, since the work holder will be rotating, this setting device should be removed. Whenever possible, standard lathe accessories should be adapted in the design of turning fixtures. Lathe faceplates are an ideal method to mount large fixtures. Likewise, a standard lathe chuck, or collets, can and should be modified for many fixturing applications.Surface Grinding Fixtures Surface grinding fixtures are similar in design to milling fixtures, but made to much closer tolerances. Whenever practical, use magnetic chucks to hold the work piece. Provide adequate room or slots to permit the escape of coolant and to allow easy removal of built-up grinding sludge. Provide coolant containment devices or splash guards to keep the fixture from spilling coolant on the floor around the machine. Fixture elements which are in contact with the magnetic chuck should be made from ferrous materials. Include provisions for rapid wheel dressing and truing in the design of the fixture, if not built into the machine. All locators must be accurately and positively positioned.Boring Fixtures These fixtures differ from boring normally used for large parts with large holes where the boring bar is rigid enough to provide additional support. A pilot bushing is not needed. Boring fixtures, like milling fixtures, should have some provision for setting the position of the cutting tool relative to the part. In cases where a boring fixture is to be used on a very large machine, such as a boring mill or vertical turrets lathe it is also good practice to include areas on the fixture to insure proper alignment with the machine.

DOWEL PINDowel pinsare often used as precise locating devices in machinery. Steel dowel pins aremachinedto tighttolerances, as are the Corresponding holes, Which are typicallyreamed. A dowel pin may have a smaller diameter than its hole so that it freely slips in or a larger diameter so that it must be pressed into its hole (interference fit).

FULCRUM PIN

A Lever is a rigid rod or bar capable of turning about a fixed point called fulcrum. or A shaft or pin on which something turns.

ALLEN SCREW

A screw with a hexagonal hole in the head with a tapered threaded shank and slotted head.It is turned by an axial hexagonal hole in its head.

BEVEL EDGE A beveled edge refers to an edge of a structure that is not perpendicular to the faces of the piece. The words bevel and chamfer overlap in usage; in general usage they are often interchanged, while in technical usage they may sometimes be differentiated as shown in the image at right.

PURPOSE AND ADVANTAGES OF JIGS AND FIXTURES(a) It reduces or sometimes eliminates the efforts of marking, measuring and setting of work piece on a machine and maintains the accuracy of performance.

(b) The work piece and tool are relatively located at their exact positions before the operation automatically within negligible time. So it reduces product cycle time. (c) Variability of dimension in mass production is very low so manufacturing processes supported by use of jigs and fixtures maintain a consistent quality. (d) Due to low variability in dimension assembly operation becomes easy, low rejection due to les defective production is observed. (e) It reduces the production cycle time so increases production capacity. Simultaneously working by more than one tool on the same work piece is possible. (f) The operating conditions like speed, feed rate and depth of cut can be set to higher values due to rigidity of clamping of work piece by jigs and fixtures. (g) Operators working become comfortable as his efforts in setting the work piece can be eliminated. (h) Semi-skilled operators can be assigned the work so it saves the cost of manpower also. (i) There is no need to examine the quality of produce provided that quality of employed jigs and fixtures is ensured.

IMPORTANT CONSIDERATIONS WHILE DESIGNING JIGS AND FIXTURES.

Designing of jigs and fixtures depends upon so many factors. These factors are analyzed to get design inputs for jigs and fixtures. The list of such factors is mentioned below:1) Study of work piece and finished component size and geometry.2) Type and capacity of the machine, its extent of automation.3) Provision of locating devices in the machine.4) Available clamping arrangements in the machine.5) Available indexing devices, their accuracy.6) Evaluation of variability in the performance results of the machine.7) Rigidity and of the machine tool under consideration.8) Study of ejecting devices, safety devices, etc.9) Required level of the accuracy in the work and quality to be produced.

PROJECTSUMMARY:

STEPS INVOLVING IN MANUFACTURING PROCESS:

FLOW CHART:

AUTO CAD drawingCADD drawing

Process planning

Purchasing

Machining

MillingTurning

Bench workSurface grinding

Drilling

Bench work

RejectInspectionRework

OK

ApprovalTrialAssemblyBench work

PROJECT BOUNDARYDESCRIPTIONTARGET DATE

Selection Of fixture24-06-2015

Component Design in CADD Softwares24-07-2015

Purchase of raw materials26-07-2015

Work Schedule And Process Planning26-07-2015

Machining Work and Assembly18-08-2015

Work piece Trial-1 And Corrections22-08-2015

Work piece Trial-224-08-2015

Project Report10-09-2015

Approval

JOB DETAILS: NAME : TRI SQUARE MATERIAL : MILD STEEL THICKENESS : 5mmSCALE : 1:1

All dimensions are in mm

Machining time calculations:

The major aim and objectives in machining industries generally are:

Reduction of total manufacturing time,

Increase in MRR, i.e., productivity

Reduction in machining cost without sacrificing product quality

Increase in profit or profit rate, i.e., profitability.

The total time required to perform a machining operation consists of following elements:Set-up time,Handling time,Machining time,Allowances.

(a) Set-up time:

This is the time taken to prepare the machine for operation. The set-up time includes the time taken to: (i) Study the component drawing. (ii) Draw tools from tool crib, and (iii) Install and adjust the tools, jigs and fixtures on the machine.

(b) Handling Time:It is the time taken by the operator in preparing a part for machining and for disposing the partAfter operation has been completed. The handling time includes the time for loading and unloadingThe component on the machine, making measurements on parts during machining, etc.(c) Machining Time:It is the time for which the machine works on the component, i.e. from the time when the tool touches the work piece to when the tool leaves the component after completion of operation. The machining time depends on the type and extent of machining required, material being machined, speed, feed, depth of cut and numberOf cuts required.(d) Allowances:

In additions to the elements of time described above, the total time to perform an operation includes a number of allowances like time for personal needs of the operator, time for checking, time for tool sharpening etc.Lathe:

The factors that govern machining time will be understood from a simple case of machining. A steel rod has to be reduced in diameter from D1to D2 overall length L by straight turning in a centre lathe.TC= (Lc ( Ns0))xnpWhereL=required length of cutTC= cutting timeLC= actual length of cut

=L+A+O

A, O= approach and over run

Estimation of machining time in turning. A, O= approach and over run as shownN =spindle speed, rpm so = feed (tool), mm/revnp=number of passes required

Speed N, is determined from cutting velocity, VC

VC=D N(1000)

Where, D =diameter of the job before cut

The number of passes, npis mathematically determined from, np=( D1-D2) 2 tWhere,t is the depth of cut in one pass in mm.

Milling:

Milling time TC= (l+a) / F Wherel is the length of work piece in the direction of feed

a is the approach length a=d (D -d)

d depth of cut in mm

D Diameter of milling cutter in mm (18mm carbide insert cutter) F Table feed in mm/min (~100 mm/min)Surface grinding:

Machining time t m = 2xLxBxi

V x1000xS L=l+ (2 x over travel)Where,

L=grinding length in mm l = length of work piecei = number of cuts

V=Speed of table in m/min

S=lateral feed in mm/stroke

B=Width of work piece

Drilling:

Ex: For 18mm,

V= d n/1000m/min

N=1000X25/18

=442.09 rpm. Feed=0.5mm/rev Machining time: Tm=L/Sr XNTm=machining time

L =Length of the tool travel

Sr =feed

N =speed in rpm.

MILLING TIME CALCULATIONS FOR TOP PLATE:

SPEED:

Dia of cutter=20mm; v=20m/min

N=VX1000/D

=20X1000/20

=318.31rpm

FEED:

Fm=Ft X Z X N [N=No. of tooth sin cutter]

=0.1X6X318.31 [Ft=feed/tooth]

=190.98mm/min

DEPTH OF CUT:

0.5mm/pass

Machining time:Tm =L+a/fa=d (D-d)=0.5(15-10)=3.535mm

Tm =115+10.94/160=0.7783min =46.68secper pass =46.68x2.5 = 10.12minOther side,

=46.68X2=93.36sec/side

Breadth wise, Tm=46.68x2=93.36 sec/sideTm=46.68x1.5=70.02sec/sideDRILLING TIME CALCULATIONS FOR FIXED & SLIDING PLATE:

V=DN/1000m/min. Feed=0.5mm/revFor =18mm

N=1000XV/D Machining time,=1000X20/ X18 Tm=18/0.5x2000 =353.677rpm =1.08min

For =6mmN=1000x20/ X6 Tm=18/0.5X550 =1061.0rpm =3.5min.

For =8.5mmN=1000x20/ X8.5 Tm=20/0.5X994.71

=748.96rpm =2.5minDRILLING TIME CALCULATIONS FOR BOTTOM PLATE:

V=DN/1000m/min. Feed=0.5mm/rev

For =4mm

N=1000XV/D Machining time,

=1000X20/ X4 Tm=20/0.5x2122.00

=1591.54rpm =1.18min

For =8.5mmN=1000x20/ X8.5 Tm=20/0.5X994.71

=748.96rpm =2.5min.

For =13mmN=20000/ X13 =489.70rpm Tm=20/0.5X544

=3min.

Tm=8/0.5X578

=1.6min.

DRILLING TIME CALCULATIONS FOR TOP PLATE:

V=DN/1000m/min. Feed=0.5mm/rev

For =6mmN=1000x15/ X6 Tm =8/0.5X1224.2

=795.77rpm =0.78min.

For =6.8mmN=15000/X6.8 =702.15rpm Tm=8/0.5X1500

For =10mmN=15000/X10 =477.46rpm =0.64min. Tm=4/0.5X578

=0.87min.

Weight of MS flat

WEIGHT = VOLUME (m3) X DENSITY OF A PARTICULAR MATERIAL (Kg/m3)

Density of mild steel =7861.093 Kg/m3

Weight = 200/1000 X 16/1000X200X7861.093

Weight = 5.0310Kg =5.0310+5.0310+5.0310+5.0310 =20.124Kg

Weight of ms rod

Weight = area x length x density

= x d2 /4 x 25x7.85g/cm3 =3.14 x 0.252/4 x 25x 7.85 =9.6285Kg =0.096Kg

Estimated time for different machining operations:

SL.NOPart nameMilling

(hr)SurfaceGrinding(hr)Lathe

(hr)Drilling

(hr)Bench

(hr)Total

(hr)

1Fixed Plate2:002:001:002:007:00

2Sliding Plate2:002:001.002:007:00

3Top Plate2:502:001:002:007:50

4Base Plate3:503:001:002:009:50

5Fulcrum Pin 2:000.52:50

6Clamp plate 1:00-0.252:003:25

Total (hr)10:0010:002:004:2510:5036:75

COST ESTIMATION:

Estimation is the art of determining the cost which is likely to be incurred on the manufacturer of article, before it is actually manufactured.

Actually estimation is necessary to complete in the market and be sure if the manufactured article is profitable or not .Here we have considered the approximate value of the following

1. Machine hour rate2. Machining time3. Cost of material

Machining cost estimation:

SLNOMachine

DescriptionMachine

UtilizationMachiningrate/hourTotalamount

(Rs)

1Milling10:0080/hr800.0

2Surface grinding10:0090/hr900.0

3Lathe2:0050/hr100.0

4Drilling4:00120/hr360.0

5Bench work10:5070/hr735.0

Total cost (Rs)2895/-

Material cost estimation:

SL.NOMaterial descriptionQuantityRate

(Rs)Total Amount(Rs)

1MS Flat 20.224Kg601214

2MS Round rod 1105 562.0

3Allen screw2010196

4Dowel pin 2 Nos 1020

Total Cost(Rs)1992.0/-

Total cost estimated =2895.50 +1992.0 Rs =4887

Selection of Raw Materials:

SL.NODescriptionMaterialQuantityRemarks

1Fixed PlateM.S2

2Sliding PlateM.S2

3Top Plate M.S2

4Base PlateM.S1

5Fulcrum PinM.S1

6Dowel pinSTD2

7Clamp plateM.S1

\

PROCESS PLAN FOR FIXED PLATE:

Sl.NoProcessTools usedMachine

1Interpretation of diagram

2Check the raw material size,Parallelism and thickness.Vernier caliper,Micrometers, vernierheight gauge.

3Clamp the work piece in milling vice remove the excess stock and machined the references in SG.Vernier Caliper, 20 end mill cutter, fly mill cutter.Milling machine,Surface Grinding Machine.

4Marking and Punching.Vernier height gauge, dot punch, ball peen hammer.Surface table and Anvil.

5Use 9.7, 10, 17.5 mm drills.Drill chucks, drill bits.Sensitive and Radial drilling machine.

6Do the machine reaming forgetting18H7 and 10H7 finished hole.18H7 and 10H7 machine reamer.Radial Drilling Machine.

7Do the countersinking for all the holes.Countersink tool.Drilling machine.

8Do the chamfering on the plate as per the drawing.6 flat file.Bench vice.

PROCESS PLAN FOR SLIDING PLATE:



2Check the raw material size,parallelism and thickness.Vernier caliper,micrometres,vernierheight gauge.


4Marking and Punching.vernier height gauge, dot punch, ball peen hammer.Surface table and Anvil.

5Use 9.7, 10, 17.5 mm drills.Drill chucks, drill bits.Sensitive and Radial drilling machine.

6Do the machine reaming forgetting18H7 and 10H7 finished hole.18H7 and 10H7 machine reamer.Radial Drilling Machine.

7Do the countersinking for all theholes.Countersink tool.Drilling machine.

8Do the chamfering on the plate asper the drawing.6 flat file.Bench vice.

PROCESS PLAN FOR TOP PLATE:



2

Check the raw material size,Parallelism and thickness.Vernier calliper,micrometres,vernierheight gauge.


4Marking and Punching.Vernier height gauge, dot punch, ball peen hammer.Surface table and Anvil.

5Use 6, 7, 9, 12mm drills.Drill chucks, drill bits.Sensitive and Radial drilling machine.

6Do the profile cutting of insert by boring tool in lathe.Boring tool, R5 radius tool.Lathe machine.

7Do the hand reaming forgetting6H7 hole and do the tapping of M8.Tap wrench, hand reamer and M8 tap.Bench vice.

8Do the countersinking for all theHoles.Countersink tool.Drilling machine.

9Do the chamfering on the plate asper the drawing.6 flat file.Bench vice.

PROCESS PLAN FOR BASE PLATE:



2Check the raw material size,parallelism and thickness.Vernier caliper,Micro meters, vernier height gauge.


4Marking and Punching.Vernier height gauge, dot punch, ball peen hammer..Surface table and Anvil.

5Use 6, 7, 9, 12mm drills.Drill chucks, drill bits.Drilling machine.

6Do the countersinking for all theHoles.Countersink tool.Drilling machine.

7Do the chamfering on the plate as per the drawing.6flat file.Bench vice.

PROCESS PLAN FOR FULCRUM PIN:



2

Check the raw material size,Parallelism and thickness.Vernier caliper,micrometres, vernierheight gauge.

3Clamp the work piece in lathe remove the excess stock Knife edge tool, parting toolDie and die stock chuck key Lathe

4MarkingOutside calipers ,inside calipers engineers protractorLathe

5Step turning as per the drawing Parting tool, cutting tool.Lathe

6Threading as per the drawing Cutting tool.Lathe

7Do the chamfering on the rod as per the drawing.Cutting toolLathe.

Planning the sequence of operations for all the positions. The operations, which can be done at our tool room.

Placing Order for Materials:

Indent was placed in the purchasing department for the material required for the production.

Tool manufacturing:

Manufacturing of tool was started after receiving the material as per the operation sequence.

Bench work and Assembly:

Once all the components were finished I started with final assembly of the tool. Before doing assembly bench work like tapping, chamfering etc were done.

Inspection and trial:

Inspection means measurement of quality of a product other prescribed standard. For the approval of fixture, the job is inspected .All the elements of the tool were inspected as and when it was machined using vernier caliper and micrometer etc .Finally after try-out, the job was centrally inspected after visual inspection near the machine itself.

MACHINES UTILISED:

LATHEMILLING MACHINEDRILLINGSURFACE GRINDING

LATHE

The main function of lathe is to remove metal from a piece of work to give it the requires shape and size. This is accomplished by holding the work securely and rigidly on the machine and then turning it against cutting tool which will remove metal in the form of chips.

Operations involved:

Turning Facing Chamfering Threading.

MILLING:Milling machine is used for removing excess material from a work piece with aRotating cutting tool. The rotating cutting tool is called the milling cutter. The cutter rotates at a high speed and because of the multipoint cutting edge it removes metal at a very fast rate. The machine can also hold number of cutters at a time.Milling process is used for producing flat, contoured or helical surfaces, for cutting thread and tooth edges and for making helical grooves.Operations involved

Face milling End milling

DRILLING:

Drilling machine is used to originate or cut a hole where none previously existed. This is an extensively used machine for through or blind holes. The hole is produced by axially feedingtherotatingdrillintotheworkpiecewhichisheldonthetableofthedrilling machine.

Operation involved

DrillingChamfering

GRINDING:Grinding operation is a method of machining work pieces by use of rotary abrasiveTool, called grinding wheel. The grinding operation can be roughGrinding or finishing grinding (precision grinding).Rough grinding is a commonly used method for removing excess material from castings, forgings etc.Precision grinding is the principal production method of cutting materials that are too hard to be machined by other conventional tools and a finer surface finish as compared to other manufacturing method.

Surface grinding machine:

It is used for producing accurately machined surface by removing material in small quantity. The material is removed by the rotating wheel which is made of abrasive particles. It is used in my project for machining of all the plates.

Inspection report:


INSPECTION REPORT

DESCRIPTION: FIXED PLATE DRG NO:1 QTY:2

S.NODRG.SIZEACTUALSIZEREMARKS

1149.0

297.0

348.5

480.6

550.6

680.6

716.4

818H7

99H7

105X45

112X45

1218

139

1416.0

15Surface finish

16Flatness

17Parallelism

18Perpendicularity

ACCEPTED:YES INSPECTION:

REJECTED: SECTION HEAD: REWORK:

F/COM/7526

Inspection report:


INSPECTIONREPORT

DESCRIPTION: SLIDING PLATE DRG NO:2 QTY:2


1190

2109

327.0

4 49.0

555.3

653.7

731.5

819.5

977.5

1079.0

1116.0

1218H7

139H7

142X45

155X45

169

1718

18Surface finish

19Flatness

20Parallelism

21Perpendicularity



F/COM/7526

Inspection report:


INSPECTION REPORT

DESCRIPTION: TOP PLATE DRGNO:3 QTY:1


1197.0

2148.0

316.5

447.2

582.2

698.0

7114.5

8145.2

9180.2

1010

117

128

1334.5

1460.5

1598.0

162X45

175X45

18133

197.0

2010.0

218.0

22Surface finish

22Flatness

23Parallelism

24Perpendicularity



F/COM/7526

Inspection report:


INSPECTION REPORT

DESCRIPTION: BASE PLATE DRGNO:4 QTY:1


1200

2181.0

372.5

4107.0

5143.5

6179.5

78.5

813

92X45

105X45

11Surface finish

12Flatness

13Parallelism

14Perpendicularity



F/COM/7526

Inspection report:


INSPECTION REPORT

DESCRIPTION:FULCRUM PIN DRGNO:5 QTY:1


122.4

2182.0

3204.4

4216.4

512.0

6 24.3

7 18.4

8M8

9Filing finish

10Surface finish

11flatness

12parallelism

13perpendicularity



F/COM/7526

3D DESIGN OF FIXTURE

BOTTOM PLATE

FIXED PLATE

SLIDING PLATE

TOP PLATE

CLAMP PLATE

DOWEL PIN

TRI SQUARE

FULCRUM PIN

NUT

PHOTOGRAPHIC IMAGES OF FIXTURE:FRONT VIEW

SIDE VIEW

REAR VIEW

TOP VIEW

ANGLE 450

ANGLE 600

FIXTURE MOUNTED TO SURFACE GRINDING MACHINE

WORK PIECE

OUTCOME OF THE PROJECT

Learned about design software such as AUTOCAD.

Known about PROCESS PLAN FOR SEQUENCE OF OPERATION Involving in PRODUCTION.

Got hands on experience operating in basic Machines.

Assembly of fixtures, trail and trouble shooting.

Learnt about INSPECTION process.

CONCLUSION:

The grinding fixture was successfully completed and assembled on. It took three months for completion of the tool. All that was involved in the project is good design, systematic work and the co-operation and coordination from all staff members to me, which fetched outstanding result at the end.

Though we have taken all care to complete the project to the best of our ability, some errors may have crept in due to over sight or ignorance or trial and error methods .There is definitely scope for improvement in the different aspects of this project.

It really persuades me to do more & more, perhaps in better ways in my future. I take this opportunity to thank everyone, who contributed directly or Indirectly to the success of my project.

REFERENCES:

Production Technology - NTTF Master File

Fixture Design PPTs - PG School

JIGS AND FIXTURES - NTTF Master File

WESTERMANN TABLES - Hermann Jutz

ALL ABOUT MACHINE TOOLS - Heinrich Gerling

[MULTIPURPOSE ANGLE GRINDING FIXTURE]

[ANGULAR GRINDING FIXTURE FOR TRAINING MODEL]









NETTUR TECHNICALTRAINING FOUNDATION,BENGALURU. Page 73



[BEVEL EDGE ANGLE GRINDING FIXTURE FOR TRI SQUARE]

Arun Report Project Edited

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