DESIGN AND FABRICATION OF MOTORISED VICE

PROJECT REPORT 2009-2010

Submitted by

(Team name)

Guided by:Submitted in partial fulfillment of the requirement for the

Award of Diploma in -----------------------------------------

By the State Board of Technical Education Government of

Tamilnadu, Chennai.

Department:

College name:

Place:

COLLEGE NAME

PLACE

DEPARTMENT

PROJECT REPORT-2008-2009

This Report is certified to be the Bonafide work done by Selvan/Selvi ---------------- Reg.No. ------------ Of VI Semester class of this college.

Guide Head of the Department

Submitted for the Practical Examinations of the board of Examinations, State Board of Technical Education, Chennai, and TamilNadu. On -------------- (date) held at the ------------ (college name),Coimbatore

Internal Examiner External Examiner

DEDICATED TO OUR BELOVED PARENTS

ACKNOWLEDGEMENT

ACKNOWLEDGEMENT

At this pleasing movement of having successfully completed our project, we wish to convey our sincere thanks and gratitude to the management of our college and our beloved chairman------------------------.who provided all the facilities to us.

We would like to express our sincere thanks to our principal ------------------for forwarding us to do our project and offering adequate duration in completing our project.

We are also grateful to the Head of Department professor., for her/him constructive suggestions &encouragement during our project.

With deep sense of gratitude, we extend our earnest &sincere thanks to our guide --------------------, Department of Mechanical for her/him kind guidance and encouragement during this project we also express our indebt thanks to our TEACHING staff of MECHANICAL ENGINEERING DEPARTMENT, ---------- (college Name).

DESIGN AND FABRICATION OF MOTORISED VICE

CONTENTS

CONTENTS

CHAPTER NO TITLE

SYNOPSIS

LIST OF FIGURES

1Introduction

2Literature review

3Description of equipments

3.1Motorised

3.2Lead screw

3.3Frame stand

3.4Lever

3.5Handle

3.6Fixed jaw and moving jaw

4Design and drawing

4.1Machine components

4.2Drawing for design and fabrication of Motorised vice

5Working principle

6Merits & demerits

7Applications

8List of materials

9Cost Estimation

10Conclusion

BIBLIOGRAPHY

PHOTOGRAPHY

LIST OF FIGURES

LIST OF FIGURES

Figurenumber

Title

1Drawing for design and fabrication of Motorised vice

SYNOPSISSYNOPSISIn this project we are fabricate the Motorised vice. It works in the principle or eccentric Motorised mechanism. The main features of the Motorised vice are promotes mass production, can hold irregular jobs, more rigidity, reduce fatigue, etc. Motorised was designed to hold the job at high pressure. The other parts were designed to hold the job in rigid condition. Motorised vice is suitable for mass production. It is possible to hold irregular components also, and similar components can be very quickly.

CHAPTER I

INTRODUCTION

CHAPTER I

INTRODUCTION

Motorised vice is one of the clamping devices used to hold the job in rigid condition. Motorised vice is operated by eccentric Motorised mechanism. There is a Motorised lever. The job can be held tightly in between the jaw. In this, first the job is place in between jaws, and movable jaw is adjusted by adjusting the screw rod to maintain according to the eccentricity of the Motorised with Motorised profile. After that, Motorised lever at the top is operated so that the job is held tightly in the fixture.

This type of fixture is useful for mass production where only similar size of jobs is to be held. It reduces operators fatigue and also reduces stetting time and cost of production.

CHAPTER II

LITERATURE REVIEW

CHAPTER II

LITERATURE REVIEW

TYPES OF VISESWithout qualification, "vise" usually refers to a bench vise with flat, parallel jaws, attached to a workbench.

* A woodworker's bench vise is a more or less integral part of the bench.

* An engineer's bench vise is bolted onto the top of the bench.Other kinds of vise include:

* hand vises (hand-held),

* machine vises - drill vises (lie flat on a drill press bed). Vises of the same general form are used also on milling machines and grinding machines.

* compound slide vises are more complex machine vises. They allow speed and precision in the placement of the work.

* cross vises, which can be adjusted using leadscrews in the X and Y axes; these are useful if many holes need to be drilled in the same workpiece using a drill press. Compare router table.

* off-center vises,

* angle vises,

* sine vises, which use solving triangles and gauge blocks to set up a highly accurate angle,

* rotary vises,

* diemakers' vises,

* table vises,

* pin vises (for holding thin, long cylindrical objects by one end),

* jewellers' vises and by contrast,

* leg vises, which are attached to a bench but also supported from the ground so as to be stable under the very heavy use imposed by a blacksmith's work.WOODWORKING VISES

For woodworking, the jaws are made of wood, plastic or from metal, in the latter case they are usually faced with wood to avoid marring the work piece. The top edges of the jaws are typically brought flush with the bench top by the extension of the wooden face above the top of the iron moveable jaw. This jaw may include a dog hole to hold a bench dog. In modern metal woodworkers' vises, a split nut is often used. The nut in which the screw turns is in two parts so that, by means of a lever, it can be removed from the screw and the moveable jaw can be quickly slid into a suitable position at which point the nut is again closed onto the screw so that the vise may be closed firmly onto the work.METALWORKERS' VISES

For metalworking, the jaws are made of metal which may be hardened steel with a coarse gripping finish. Quick change removable soft jaws are being used more frequently to accommodate fast change-over on set-ups. They are also kept for use where appropriate, to protect the work from damage.

Metalworking bench vises, known as engineers' or fitters' vises, are bolted onto the top surface of the bench with the face of the fixed jaws just forward of the front edge of the bench. The bench height should be such that the top of the vise jaws is at or just below the elbow height of the user when standing upright. Where several people use the one vise, this is a good guide.

The nut in which the screw turns may be split so that, by means of a lever, it can be removed from the screw and the screw and moveable jaw quickly slid into a suitable position at which point the nut is again closed onto the screw. Many fitters prefer to use the greater precision available from a plain screw vise. The vise may include other features such as a small anvil on the back of its body.

Vise screws are usually either of an Acme thread form or a buttress thread. Those with a quick-release nut use a buttress thread.METALWORKING VISES IN MACHINE SHOPS

In high production machine work, work must be held in the same location with great accuracy, so CNC machines may perform operations on an array of vises. To assist this, there are several machine-shop specific vises and vise accessories.

Hard and soft machine jaws have a very important difference between other metalworking vise jaws. The jaws are precision ground to a very flat and smooth surface for accuracy. These rely on mechanical pressure for gripping, instead of a rough surface. An unskilled operator has the tendency to over-tighten jaws, leading to part deformation and error in the finished workpiece. The jaws themselves come in a variety of hard and soft jaw profiles, for various work needs. One can purchase machinable soft jaws, and mill the profile of the part into them to speed part set-up and eliminate measurement. This is most commonly done in gang operations, discussed below. For rectangular parts being worked at 45 degree angles, prismatic hard jaws exist with V grooves cut into them to hold the part. Some vises have a hydraulic or pneumatic screw, making setup not only faster, but more accurate as human error is reduced.

For large parts, an array of regular machine vises may be set up to hold a part that is too long for one vise to hold. The vises' fixed jaws are aligned by means of a dial indicator so that there is a common reference plane for the CNC machine.

For multiple parts, several options exist, and all machine vise manufacturers have lines of vises available for high production work.

* The first step is a two clamp vise, where the fixed jaw is in the center of the vise and movable jaws ride on the same screw to the outside.

* The next step up is the modular vise. Modular vises can be arranged and bolted together in a grid, with no space between them. This allows the greatest density of vises on a given work surface. This style vise also comes in a two clamp variety.

* Tower vises are vertical vises used in horizontal machining centers. They have one vise per side, and come in single or dual clamping station varieties. A dual clamping tower vise, for example, will hold eight relatively large parts without the need for a tool change.

* Tombstone fixtures follow the same theory as a tower vise. Tombstones allow four surfaces of vises to be worked on one rotary table pallet. A tombstone is a large, accurate, hardened block of metal that is bolted to the CNC pallet. The surface of the tombstone has holes to accommodate modular vises across all four faces on a pallet that can rotate to expose those faces to the machine spindle.

* New work holding fixtures are becoming available for five-axis machining centers. These specialty vises allow the machine to work on surfaces that would normally be obscured when mounted in a traditional or tombstone vise setup.CHAPTER III

DESCRIPTION OF EQUIPMENTS

CHAPTER III

DESCRIPTION OF EQUIPMENTS3.1. MOTORISEDA Motorised is a projecting part of a rotating wheel or shaft that strikes a lever at one or more points on its circular path. The Motorised can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the follower which is a lever making contact with the Motorised.

The reason the Motorised acts as a lever is because the hole is not directly in the centre, therefore moving the Motorised rather than just spinning. On the other hand, some Motoriseds are made with a hole exactly in the centre and their sides act as Motoriseds to move the levers touching them to move up and down or to go back and forth.

3.2. LEAD SCREWA lead screw also known as a power screw or translation screw, is a screw designed to translate radial motion into linear motion. Common applications are machine slides (such as in machine tools), vises, presses, and jacks.A lead screw nut and screw mate with rubbing surfaces, and consequently they have a relatively high friction and stiction compared to mechanical parts which mate with rolling surfaces and bearings. Their efficiency is typically between 25 and 70%, with higher pitch screws tending to be more efficient. A higher performing, and more expensive, alternative is the ball screw.

The high internal friction means that leadscrew systems are not usually capable of continuous operation at high speed, as they will overheat. Due to inherently high stiction, the typical screw is self-locking (i.e. when stopped, a linear force on the nut will not apply a torque to the screw) and are often used in applications where backdriving is unacceptable, like holding vertical loads or in hand cranked machine tools.

Leadscrews are typically used well greased, but, with an appropriate nut, it may be run dry with somewhat higher friction. There is often a choice of nuts, and manufacturers will specify screw and nut combinations as a set.

The mechanical advantage of a leadscrew is determined by the screw pitch and lead. For multi-start screws the mechanical advantage is lower, but the traveling speed is better.

Backlash can be reduced with the use of a second nut to create a static loading force known as preload; alternately, the nut can be cut along a radius and preloaded by clamping that cut back together.

A lead screw will back drive. A leadscrew's tendency to backdrive depends on its thread helix angle, coefficient of friction of the interface of the components (screw/nut) and the included angle of the thread form. In general, a steel acme thread and bronze nut will back drive when the helix angle of the thread is greater than 20.

ADVANTAGES & DISADVANTAGESThe advantages of a leadscrew are:

Large load carrying capability

Compact

Simple to design

Easy to manufacture; no specialized machinery is required

Large mechanical advantage

Precise and accurate linear motion

Smooth, quiet, and low maintenance

Minimal number of parts

Most are self-locking

The disadvantages are that most are not very efficient. Due to the low efficiency they cannot be used in continuous power transmission applications. They also have a high degree for friction on the threads, which can wear the threads out quickly. For square threads, the nut must be replaced; for trapezoidal threads, a split nut may be used to compensate for the wear.

3.3. FRAME STAND

Frame stand in this device is made up of combination of sheet metal or flat rods welded together. The frame stand is used to hold the fixed jaw, moving jaw, and lever, lead screw, handle and Motorised arrangements in this device.3.4. LEVER

The lever is used to lock and unlock the Motorised arrangements in this device. The liver is an easily operateable device in this equipment.3.5. HANDLE

The handle is used to adjust operate the lead screw in this equipment. The handle is fixed one corner of the lead screw.3.6. FIXED JAW & MOVING JAW

The fixed jaw is stable; the jaw is mounted on the frame stand in this equipment.The moving jaw is easily adjustable by the lead screw arrangement. We can easily move the moving jaw on this equipment by rotating the lead screw by handle and operating the lever in Motorised arrangement.CHAPTER IV

DESIGN AND DRAWING

CHAPTER IV

DESIGN AND DRAWING4.1. MACHINE COMPONENTSThe DESIGN AND FABRICATION OF MOTORISED VICE consists of the following components to full fill the requirements of complete operation of the machine. Motorised arrangements Lead screw Frame stand Lever

Handle

Fixed jaw

Moving jaw

4.2. DRAWING FOR DESIGN AND FABRICATION OF MOTORISED VICE

CHAPTER V

WORKING PRINCIPLE

CHAPTER V

WORKING PRINCIPLE

The Motorised vice consists of fixed jaw, moving jaw, lever, lead screw, handle, Motorised mechanism and frame stand. The fixed jaw is fixed on the frame. The moving jaw is arranged parallel through the fixed jaw. The Motorised arrangement is placed before the moving jaw. The Motorised arrangement consists of lever. The after the Motorised arrangement the lead screw is arranged. The lead screw is used to adjust the Motorised arrangement in the equipment. The main purpose of the Motorised vice is used to clamp and unclamp the same size specimens on it. This vice is used in mass production. The specimen is placed between the fixed jaw and moving jaw, and then the Motorised lever is operated by manually. The specimen is clamped at a perfect stage, and then the lead screw is used to fit the correct area in the Motorised arrangement. Now we can easily clamp and unclamp the same size of specimens in this equipment very easily.CHAPTER VI

MERITS & DEMERITS

CHAPTER VI

MERITS & DEMERITS

MERITS

Idle time of the machine is reduced

When compared with the mechanical vices, it continues less time for clamping and unclamping the job

It reduces the clamping time Hence, production rate is higher

DEMERITS

Limited size of specimens only clamped in this viceCHAPTER VII

APPLICATIONS

CHAPTER VII

APPLICATIONS

Applicable in workshops

Applicable in small and medium scale industriesCHAPTER VIII

LIST OF MATERIALS

CHAPTER VIII

LIST OF MATERIALS

FACTORS DETERMINING THE CHOICE OF MATERIALS

The various factors which determine the choice of material are discussed below.

1. PROPERTIESThe material selected must posses the necessary properties for the proposed application. The various requirements to be satisfiedCan be weight, surface finish, rigidity, ability to withstand environmental attack from chemicals, service life, reliability etc.

The following four types of principle properties of materials decisively affect their selection

Physical

Mechanical

From manufacturing point of view

Chemical

The various physical properties concerned are melting point, thermal Conductivity, specific heat, coefficient of thermal expansion, specific gravity, electrical conductivity, magnetic purposes etc.

The various Mechanical properties Concerned are strength in tensile,

Compressive shear, bending, torsion and buckling load, fatigue resistance, impact resistance, elastic limit, endurance limit, and modulus of elasticity, hardness, wear resistance and sliding properties.

The various properties concerned from the manufacturing point of view are,

Cast ability

Weld ability

Surface properties

Shrinkage

Deep drawing etc.

2. MANUFACTURING CASE

Sometimes the demand for lowest possible manufacturing cost or surface qualities obtainable by the application of suitable coating substances may demand the use of special materials.

3. QUALITY REQUIRED

This generally affects the manufacturing process and ultimately the material. For example, it would never be desirable to go casting of a less number of components which can be fabricated much more economically by welding or hand forging the steel.

4. AVAILABILITY OF MATERIAL

Some materials may be scarce or in short supply, it then becomes obligatory for the designer to use some other material which though may not be a perfect substitute for the material designed. The delivery of materials and the delivery date of product should also be kept in mind.

5. SPACE CONSIDERATIONSometimes high strength materials have to be selected because the forces involved are high and space limitations are there.

6. COSTAs in any other problem, in selection of material the cost of material plays an important part and should not be ignored.

Some times factors like scrap utilization, appearance, and non-maintenance of the designed part are involved in the selection of proper materials.CHAPTER IX

COST ESTIMATION

CHAPTER IX

COST ESTIMATION

1. MATERIAL COST2. LABOUR COST

Lathe, drilling, welding, drilling, power hacksaw, gas cutting cost

3. OVERGHEAD CHARGES

The overhead charges are arrived by manufacturing costManufacturing Cost = Material Cost + Labor Cost

=

=

Overhead Charges = 20%of the manufacturing cost

=

4. TOTAL COSTTotal cost = Material Cost +Labor Cost +Overhead Charges

=

=Total cost for this project =CHAPTER X

CONCLUSION

CHAPTER X

CONCLUSION

This project is made with pre planning, that it provides flexibility in operation.

This innovation has made the more desirable and economical. This project DESIGN AND FABRICATION OF MOTORISED VICE is designed with the hope that it is very much economical and help full to workshops, small and medium scale industries.

This project helped us to know the periodic steps in completing a project work. Thus we have completed the project successfully.BIBLIOGRAPHY

BIBLIOGRAPHY

1. Design data book

-P.S.G.Tech.

2. Machine tool design handbook Central machine tool Institute,

Bangalore.

3. Strength of Materials- R.S.Kurmi

4. Manufacturing Technology - M.Haslehurst.

5. Design of machine elements - R.S.Kurmi

PHOTOGRAPHY

COLLEGE LOGO

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