design and fabrication of cam vice report

8/9/2019 Design and Fabrication of Cam Vice Report

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SYNOPSIS


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SYNOPSIS

In this project we are fabricate the cam vice. It works in the principle

or eccentric cam mechanism. The main features of the cam vice are

promotes mass production, can hold irregular jobs, more rigidity, reduce

fatigue, etc. Cam was designed to hold the job at high pressure. The other

parts were designed to hold the job in rigid condition. Cam vice is suitable

for mass production. It is possible to hold irregular components also, and

similar components can be very quickly.


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CHAPTER I

INTRODUCTION


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CHAPTER I

INTRODUCTION

Cam vice is one of the clamping devices used to hold the job in rigid

condition. Cam vice is operated by eccentric cam mechanism. There is a

cam 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 cam with cam

profile. After that, cam lever at the top is operated so that the job is held

tightly in the fiture.

This type of fiture is useful for mass production where only similar

si!e of jobs is to be held. It reduces operator"s fatigue and also reduces

stetting time and cost of production.


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CHAPTER II

LITERATURE REVIEW


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CHAPTER II

LITERATURE REVIEW

TYPES OF VISES

#ithout 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.

'ther kinds of vise include(

% hand vises )hand*held+,

% machine vises * drill vises )lie flat on a drill press bed+. ises of the

same general form are used also on milling machines and grinding

machines.

% compound slide vises are more comple machine vises. They allow

speed and precision in the placement of the work.


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% cross vises, which can be adjusted using leadscrews in the - and aes/

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


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0or 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 etension 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

0or metalworking, the jaws are made of metal which may be hardened

steel with a coarse gripping finish. 1uick 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.

2etalworking bench vises, known as engineers& or fitters& vises, are

bolted onto the top surface of the bench with the face of the fied jaws just

forward of the front edge of the bench. The bench height should be such that


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the top of the vise jaws is at or just below the elbow height of the user when

standing upright. #here 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. 2any 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.

ise 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 C3C machines may perform operations on

an array of vises. To assist this, there are several machine*shop specific vises

and vise accessories.

4ard and soft machine jaws have a very important difference between

other metalworking vise jaws. The jaws are precision ground to a very flat


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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. 'ne 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. 0or rectangular parts being worked at 56 degree angles, prismatic

hard jaws eist with grooves cut into them to hold the part. 7ome vises

have a hydraulic or pneumatic screw, making setup not only faster, but more

accurate as human error is reduced.

0or 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& fied jaws are

aligned by means of a dial indicator so that there is a common reference

plane for the C3C machine.

0or multiple parts, several options eist, and all machine vise

manufacturers have lines of vises available for high production work.


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% The first step is a two clamp vise, where the fied jaw is in the center of

the vise and movable jaws ride on the same screw to the outside.

% The net step up is the modular vise. 2odular 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 hori!ontal machining centers.

They have one vise per side, and come in single or dual clamping station

varieties. A dual clamping tower vise, for eample, will hold eight relatively

large parts without the need for a tool change.

% Tombstone fitures 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

C3C pallet. The surface of the tombstone has holes to accommodate

modular vises across all four faces on a pallet that can rotate to epose those

faces to the machine spindle.

% 3ew work holding fitures are becoming available for five*ais

machining centers. These specialty vises allow the machine to work on


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surfaces that would normally be obscured when mounted in a traditional or

tombstone vise setup.


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CHAPTER III

DESCRIPTION OF EQUIPMENTS


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CHAPTER III

DESCRIPTION OF EQUIPMENTS

3.1. CAM

A cam is a projecting part of a rotating wheel or shaft that strikes a

lever at one or more points on its circular path. The cam can be a simple

tooth, as is used to deliver pulses of power to a steam hammer, for eample,

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 cam.

The reason the cam acts as a lever is because the hole is not directly in

the centre, therefore moving the cam rather than just spinning. 'n the other

hand, some cams are made with a hole eactly in the centre and their sides

act as cams to move the levers touching them to move up and down or to go

back and forth.

3.2. LEAD SCREW

A lead screw also known as a power screw or translation screw, is a

screw designed to translate radial motion into linear motion. Common


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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 86 and 9:;, with higher pitch screws tending

to be more efficient. A higher performing, and more epensive, 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.


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The mechanical advantage of a leadscrew is determined by the screw pitch

and lead. 0or multi*start screws the mechanical advantage is lower, but the

traveling speed is better.

>acklash 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 heli 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 bron!e nut will back drive when the heli

angle of the thread is greater than 8:@.

ADVANTAGES & DISADVANTAGES

The advantages of a leadscrew are(

=arge load carrying capability

Compact

7imple to design


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asy to manufacture/ no speciali!ed machinery is required

=arge mechanical advantage

Brecise and accurate linear motion

7mooth, quiet, and low maintenance

2inimal number of parts

2ost are self*locking

The disadvantages are that most are not very efficient.


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0rame 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 fied jaw,

moving jaw, and lever, lead screw, handle and cam arrangements in this

device.

3.4. LEVER

The lever is used to lock and unlock the cam 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 fied one corner of the lead screw.

3.. FI!ED "AW & MOVING "AW

The fied jaw is stable/ the jaw is mounted on the frame stand in this

equipment.


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The moving jaw is easily adjustable by the lead screw arrangement.

#e can easily move the moving jaw on this equipment by rotating the lead

screw by handle and operating the lever in cam arrangement.

CHAPTER IV

DESIGN AND DRAWING


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CHAPTER IV

DESIGN AND DRAWING

4.1. MACHINE COMPONENTS

The EICATI'3 '0 CA2 ICF consists of the

following components to full fill the requirements of complete operation of

the machine.

Cam arrangements

=ead screw

0rame stand

=ever

4andle

0ied jaw

2oving jaw


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4.2. DRAWING FOR DESIGN AND FA#RICATION OF CAM

VICE


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CHAPTER V

WORKING PRINCIPLE


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CHAPTER V

WORKING PRINCIPLE

The cam vice consists of fied jaw, moving jaw, lever, lead screw,

handle, cam mechanism and frame stand. The fied jaw is fied on the

frame. The moving jaw is arranged parallel through the fied jaw. The cam

arrangement is placed before the moving jaw. The cam arrangement consists

of lever. The after the cam arrangement the lead screw is arranged. The lead

screw is used to adjust the cam arrangement in the equipment. The main

purpose of the cam vice is used to clamp and unclamp the same si!e

specimens on it. This vice is used in mass production. The specimen is

placed between the fied jaw and moving jaw, and then the cam 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 cam arrangement. 3ow we

can easily clamp and unclamp the same si!e of specimens in this equipment

very easily.


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CHAPTER VI

MERITS & DEMERITS


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CHAPTER VI

MERITS & DEMERITS

MERITS

Idle time of the machine is reduced

#hen compared with the mechanical vices, it continues less time for

clamping and unclamping the job

It reduces the clamping time

4ence, production rate is higher

DEMERITS

=imited si!e of specimens only clamped in this vice


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CHAPTER VII

APPLICATIONS


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CHAPTER VII

APPLICATIONS

Applicable in workshops

Applicable in small and medium scale industries


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CHAPTER VIII

LIST OF MATERIALS


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CHAPTER VIII

LIST OF MATERIALS

FACTORS DETERMINING THE CHOICE OF MATERIALS

The various factors which determine the choice of material are

discussed below.

1. PROPERTIES

The material selected must posses the necessary properties for the

proposed application. The various requirements to be satisfied

Can 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

Bhysical

2echanical

0rom manufacturing point of view

Chemical


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The various physical properties concerned are melting point, thermal

Conductivity, specific heat, coefficient of thermal epansion, specific

gravity, electrical conductivity, magnetic purposes etc.

The various 2echanical 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

#eld ability

7urface properties

7hrinkage


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3. QUALITY REQUIRED

This generally affects the manufacturing process and ultimately the

material. 0or eample, 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. AVAILA#ILITY OF MATERIAL

7ome 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 CONSIDERATION

7ometimes high strength materials have to be selected because the

forces involved are high and space limitations are there.

. COST

As in any other problem, in selection of material the cost of material

plays an important part and should not be ignored.


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7ome times factors like scrap utili!ation, appearance, and non*

maintenance of the designed part are involved in the selection of proper

materials.


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CHAPTER I!

COST ESTIMATION


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CHAPTER I!

COST ESTIMATION

1. MATERIAL COST

2. LA#OUR COST

=athe, drilling, welding, drilling, power hacksaw, gas cutting cost

3. OVERGHEAD CHARGES

The overhead charges are arrived byF manufacturing costF

2anufacturing Cost G 2aterial Cost H =abor Cost

G

G

'verhead Charges G 8:;of the manufacturing cost

G

4. TOTAL COST

Total cost G 2aterial Cost H=abor Cost H'verhead Charges


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G

G

Total cost for this project G


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CHAPTER !

CONCLUSION


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CHAPTER !

CONCLUSION

This project is made with pre planning, that it provides fleibility in

operation.

This innovation has made the more desirable and economical. This

project EICATI'3 '0 CA2 ICF 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.


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#I#LIOGRAPHY


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#I#LIOGRAPHY

. angalore.

K. 7trength of 2aterials * E.7.Lurmi

5. 2anufacturing Technology * 2.4aslehurst.

6.


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PHOTOGRAPHY

design and fabrication of cam vice report

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