unit-ii-capstan & turret lathe

7/23/2019 Unit-II-Capstan & Turret Lathe

1/101

INTRODUCTION

It is a production lathe used in many industries formass production of identical components

It is a development of engine lathes

It was rst developed in the United States y !rattand "hitney in #$%&

It consists of a ed' all geared headstoc(' and asaddle on which a four station tool post is mounted )

Tailstoc( of an engine is replaced y a he*agonalturret'on the face of which multiple tools may etted and fed into the wor( in proper se+uence)

,dvantage is that several di-erent types ofoperations can e done on a wor( piece without re.setting of wor( or tools)

, numer of identical parts can e produced in the

minimum time)


2/101

Di-erences /w 0ngine lathe

and Capstan/turret lathe Capstan/turret

1athe

2ore tool posts) No tail stoc() 2anual inde*ing) Operational time

is lesser) Semi s(illed laorfor operation)

0ngine 1athe

Only one tool post)

It has tail stoc()

No inde*ing )

Operational time is

more S(illed wor(ers have

to operate)


3/101

No lead screw) 3igh +uality of

accuracy) It is used for mass

production wor() It ta(es lesser time

as changing of

wor( is automatic) 2inimum of #4hp

motor is re+uiredto run the head

stoc() It ta(es more time

in setting up thetool)

as ow accuracy)

It is usedaccording to 5o

order) It ta(es more as

changing of wor( ismanual)

2inimum of 4hpmotor is re+uiredto run the headstoc()

It ta(es less timein setting up tool)


4/101

!RINCI!,1 !,RTS O6

C,!ST,N 7TURR0T 1,T30


5/101

C,!ST,N 1,T30

Capstan lathes are widely used in the precisionauto turned component manufacturer)

8ives a large volume production' high

accuracy' very versatile and maintenance.free) ,ll the machine operations li(e turning'

facing' oring' drilling and tapping can edone oth in ferrous and nonferrous materials)

0ven uns(illed laour can operate this machinevery easily)


6/101

O!0R,TION

It carries the he*agonal turret on a ramor a short slide)

Ram slides longitudinally on a saddlepositioned and clamped on lathe ed

way) This machine is used for machining ar

of smaller diameter) Tools are mounted on the s+uare turret

and si* faces of the he*agonal turret) 6eeding movement is otained whenram moves from left to right)

"hen the ram is moved ac(wards andturret inde*es automatically and thetools mounted on the ne*t face comes


7/101

TURR0T 1,T30

Introduction

It is mounted directly on a saddle and thewhole unit moves ac( 7 forth

Turret lathe is heavier in construction

It is particularly adapted for larger diameterarwor( 7 chuc(ing wor(

2achine can accommodate longer wor(pieces than in a capstan lathe


8/101

O!0R,TION

In a turret lathe' a longitudinally feed ale'he*agon turret replaces the tailstoc()

Turret on which si* tools can e mounted' cane rotated aout a vertical a*is to ring each

tool into operating position) 0ntire unit can e moved longitudinally' eithermanually or y power to provide feed for thetools)

"hen the turret assemly is ac(ed away from

the spindle y means of a capstan wheel' turretinde*es automatically at the end of itsmovement thus ringing each of the si* toolsinto operating position)

S+uare turret on the cross slide can e rotatedmanually aout a vertical a*is to ring each of

the four tools into operating position)


9/101

On most machines' the turret can e movedtransversely' either manually or y power' ymeans of the cross slide' and longitudinally

through power or manual operation of thecarriage) In most cased' a *ed tool holder alsois added to the ac( end of the cross slide9 thisoften carries a parting tool

, numer of tools can e set on the machineand then +uic(ly e rought successively intowor(ing position so that a complete part cane machined without the necessity for furtherad5usting' changing tools' or ma(ingmeasurements)


10/101

,D:,NT,80S O6 TURR0T 1,T30S

#) Tools may e set up in the turret in the properse+uence for the operation);) 0ach section is provided with a feed trip so

that each cut of the tool is the same as theprevious cut)


11/101

DIS2I1,RITI0S >0T"00NC,!ST,N 7 TURR0T 1,T30

Turret of capstan lathe is mounted on ashort slides on a saddle) The saddle isclamped on ed ways after ad5ustingthe length of the wor( piece)

In case of turret lathe 'the turret ismounted on the saddle which slidesdirectly on the lathe ed ways) Thistype of construction provides utmost

rigidity to the tool post)


12/101

CAPSTAN AND TURRET LATHE

SLIDE ARRANGEMENT


13/101

In case of capstan lathe as the ram feeds intothe wor(' the overhanging of the ram from thestationary saddle presents a non rigidconstruction)

Turret lathe can operate under severe cuttingconditions ' accommodating heavier wor(pieces with higher cutting speeds)

1arger and heavier chuc(ing wor(s are usuallyhandled on a turret lathe)

Capstan lathe is suitale only for ar wor() Capstan lathes are particularly handy for small

articles which re+uire light and fast cuts) In turret lathes the hand feeding is laorious

process which ma(es it unsuitale for smallarticles)


14/101

1arger and heavier chuc(ing wor(s are usuallyhandled on a turret lathe)

Capstan lathe is suitale only for ar wor() Capstan lathes are particularly handy for small

articles which re+uire light and fast cuts)

In turret lathes the hand feeding is laorious

process which ma(es it unsuitale for smallarticles)


15/101

Drilling machine

Drilling: Operation through which holes are produced in asolid metal by revolving tool (drill). Drills are commonly used in woodworking and

metalworking. Drilling doesnt produce perfectly true hole (Basic operation)

ole is generated by rotating edge of a cutting tool knownas drill which e!erts large force on the work.


16/101

Classifcation o Drills "ccording to type of shank:

#arallel $hank %aper $hank

"ccording to type of flute: &lat'$pade drills %wist Drills #arallel %aper*

"ccording to length:

$hort series drills $tub series drills +ong $eries drills

"ccording to applications: ,ore drills Drills for long hole drilling

,entre drills -asonary drills "ccording to tool material:

igh $peed drills ,arbide tipped drills


17/101

Classification of Drilling Machines

#ortable drilling machine $ensitive or bench drilling machine pright drilling machine /adial drilling machine

-ultiple spindle drilling machine Deep hole drilling machine 0ang drilling machine ori1ontal drilling machine"utomatic drilling machine


18/101

Tools or Drilling

&lat'$pade drills:2t carries a flat section at cutting edge-aterial used is carbon steel '$$2t has been obsolete due to many reasons

$till used for small special works %wist drills:-ost widely used for numerous operations-aterial used is $$"vailable in various si1es

$ub types: %aper shank #arallel shank


19/101

"ccording to 2ndian $tandards3 drills are specified:

Diameters $eries -aterial 2.$. number

%ypes: %ype 4 5 4ormal low carbon steel %ype 5 ard materials %ype $ 5 $oft tough materials

6!: 7.89 2$: 89 $:; %wist drill of 7.8 mm 2$:89refers drill made from igh speed steel 2f material is not specified3 type 4 should be taken.

4ormal si1es: In metric sizes, drill dia range from 0.2mm to100mm

Drill size & specification


20/101

Drilling Machines

#ortable drilling machines:$mall3 compact self; contained with small

electric motor.

+ight in weight easily handled."vailable in different si1es capacities

(wider range of holes)

pto ma!imum diameter of


21/101

Sensitive (Bench Drill) Useful for light work Simple construction Consists of iron base(9), ertical column (!),

swiel table("), swiel table clamp(#),electricmotor ($), fee% han%le (),spin%le ('), %rillchuck ()

op of column is proi%e% with %rie consistsof en%less belt running oer *+pulles-

.ne pulle is mounte% on motor shaft & other

on machine spin%le *ertical moement proi%e% b fee% han%lethrough a rack & pinion arrangement-

Drills haing up to /mm %rilling capacit canbe use%-

Drills rotate at er high spee% 0an% fee% enables operator to feel gra%ual

penetration of %rill into work material & eensense obstruction-

1en it can be sense% whether %rill is cuttingproperl

2or these reasons it is known as sensitie%rills


22/101

3a%ial %rilling machine

Useful commonl for its wi%er action

Single spin%le %rilling machines 0as ertical column with ra%ial arm 4rm can swing through $#/%eg Use% for reaming an% tapping Spee% ar from / 5 $"// rpm Consists of iron base, ertical

column, horizontal moing arm, %riespin%le, %rill chuck, interlockingclamping leers etc


23/101

Gang drilling machine

< or more drill heads mounted on same table

6ach spindle has independent set of speed and

depth

-ovement of =obs are fast

#roduction is at faster rate "pplications: -ultiple hole drilling in pipes3 plates


24/101

Multiple spindle drilling machine

Drills several holes simultaneously of differentsi1es

igh production rate "ll spindles have same drive

Drill heads has capacity to drive up to 89spindles simultaneously

$pindles can be placed in different positions toenable drilling of holes at any location


25/101

Upright drilling machine

$everal spindle speed are available

2deally suited for small and big shops

Designed for heavier work

-ounted on a column

$pecified by dist. b'w spindle column


26/101

Deep drilling machines

sed for holes whose length e!ceed >

times the drill si1e

+ike for barrels of guns and tanks

%hey are of vertical and hori1ontal type

igh speed low feed machine tool

?ertical or hori1ontal spindle drive


27/101

Automatic drilling machine

&or high production work Different operations are performed in se@uence at successive

work station "t each workstation3 operation se@uence3 related cutting speeds3

start finish of operation are arranged in synchroni1ed manner.

as inde!ing table and work holding fi!tures as multiple stations as multiple spindles in various orientations $everal operations like drilling3 boring3 tapping3 etc can be

performed


28/101

Drilling operations

Drilling

/eaming

Boring

,ounter boring

,ounter sinking

$pot facing

%apping


29/101

Drilling: 2t is main operation done onthis machine3 producing a hole bymeans of revolving tool (drill)

/eaming: Operation of finishing ahole to bring it to accurate si1e andhave better surface finish (reamer)#roduces straight3 smooth andaccurate hole.

Boring:Operation of enlarging a holeto bring it to re@uired si1e and havebetter finish. "lso used for correctinghole location out of roundness

,ounter boring: Operation ofenlarging only a limited portion ofhole. 2t is performed by means ofcounter boring tool (double toolboring bar)


30/101

,ounter sinking: Operation usedfor enlarging end of hole to give it aconical shape for short distance.

seful in providing a seat forcountersunk heads of screws

$pot facing: Operation used fors@uaring finishing the surfacearound at end of a hole to

provide a smooth true seat tounder seat of bolt heads or collars

%apping: Operation for forminginternal threads by means of tool(tap)


31/101

wistDrills 2t is a cylindrical body carrying two spiral flutes cut on it. 2t consists of two main parts:

$hank (gripped in drill chuck) Body (-ain cutting unit)

$hank carry a tang at end to ensure a firm grip Body consists of flute (removal of chips)3 lips' cutting edges3

point or dead centre3 land (guides drill in hole) relief' body

clearance


32/101

igh eli!: ,arry a heli! angle of >89to A99 a heavy web groove width

is larger than that of usual twist drill (easier @uicker disposal

of chips) +arge employed for deep hole drilling &ast spiral drills*

+ow eli!: ,arry smaller heli! angle are relatively more rigid. ,apable of higher tor@ue heavier feeds slow spiral drills*


33/101

Drilling parameters

,utting $peed: /efers to peripheral speed of a point on the surface of a point on

the surface of drill bit in contact with work. (m'min) ? (>.ACDC4)'999 m'min

&eed (f):

2t is the distance the drill moves into work at each revolution ofdrill spindle (mm'rev)

Depth of cut (t): 2t is e@ual to one half of the diameter. t D'< mm


34/101

Milling

-illing is one of the basic machining processes.-illing is a very versatile process capable of

producing simple two dimensional flat shapes to

comple! three dimensional interlaced surface

configurations. 2ts a machining process in which metal is

removed due to cutting action of a revolving

cutter when work is fed past to it. /evolving cutter is held in spindle'arbor work

is clamped on to machine table.


35/101

or!ing principle

ork is rigidly clamped onto table' held b'w centers -ulti;teeth cutter mounted onto spindle. ,utter revolves at fairly high speed work is fed slowly

past the cutter. "s work advances3 cutter;teeth remove the metal from

work surface.


36/101

The Process

%he milling process:%ypically uses a multi;tooth

cutter

ork is fed into the rotatingcutter

,apable of high -//

ell suited for mass

production applications,utting tools for this process

are called milling cutters


37/101

Classifcation o milling process

#eripheral millingp milling

Down -illing

&ace -illing

6nd -illing


38/101

Classifcation o milling process

#eripheral millingp milling

Down -illing

&ace -illing

6nd -illing


39/101

Up"milling (Conventional milling)

#rocess of removing metal by a cutter which is

rotated against the direction of travel of work piece.

,hip thickness is min at beginning of the cut and itreaches to ma! when cut terminates.

,utting force increases from 1ero to ma! per tooth

movement of cutter.

,utting force is directed upwards and tends to liftwork from table.

$urface milled appears to be wavy.


40/101

Up+milling

Down+milling


41/101


42/101

Down+milling (Climb milling)E #rocess of removing metal by a cutter which is rotated

in same direction of travel of work piece.

E ,hip thickness is ma! at beginning of the cut and it

reduces to min when cut terminates.

E

,utting force decreases from ma! to min per toothmovement of cutter.

E ,utting force is directed downwards and tends to seat

the work firmly onto the table.

E$urface finish is improved.

E 2t is to be performed only on rigid machines provided

with backlash eliminator.


43/101

2ace MillingE Operation performed by milling

cutter to produce flat surface

perpendicular to a!is of rotation of

cutter.

E #eripheral cutting edge does actual

cutting face cutting edges does

finishing operation.E During one half cutter rotation3

direction of movement of cutter tooth

is opposite to direction of feed

during rest half3 direction reverses.

E ,hip thickness is min in beginning and ma! when work passes

through centre;line of cutter.

E -illed surface contains tooth circular marks.


44/101

1n% MillingE ,ombination of peripheral face milling operation.

E ,utter has teeth both on end face periphery.

E Direction of rotation direction of heli! of cutter should be

same 5 end cutting edges.

E Direction of rotation direction of heli! of cutter should be

opposite 5 peripheral cutting edges.

Milling Machines


45/101

Milling MachinesE ,olumn knee type milling machine.

hand

?ertical ori1ontal'plain

niversal

Omniversal

E &i!ed bed type milling machine. $imple!'plain(having single hori1ontal spindle)

Duple! head(having two hori1ontal spindles)

%riple! head(having < hori1ontal and vertical

spindle)

E #laner type milling machine.E $pecial type milling machine.

/otary table

Drum

#lanetary


46/101

0orizontal67lain Milling Machine

E ?ertical column houses

electrical3 main drive3 spindlesetc mounted onto heavy base.

E Fnee acts as support for

saddle3 worktable other

accessories 5inde!ing head

etc.

E Over arm supports yoke and

free end of arbor.

E"rbor carries cutter which

rotates about hori1ontal a!is.

E %able can move in

longitudinal3 cross vertical

directions.


47/101


48/101

*ertical Milling MachineE ?ertical column houses electrical3 main drive

mounted onto heavy base.

E Fnee acts as support for saddle3 worktable other

accessories 5inde!ing head etc.

E Over arm is integral part with column and carries a

housing at its front.

E ousing (ead) can be of fi!ed'swiveling type .

E &i!ed type 5 ead containing spindle is always vertical

and can be ad=usted up down.E $wiveling type 5ead can be swiveled to any desired

angle.

E ,utter is held into spindle which rotates about its a!is.


49/101


50/101

Fig. 2 Schematic illustration of milling machines


51/101


52/101

Uniersal Milling MachineE $imilar to plain milling machine.

E %able can be swiveled about saddle in hori1ontal

plane.

E ,ircular guide ways are provided on saddle along

which it can be swiveled.

E Over;arm can be pushed back or removed vertical

milling head can replace arbor (?ertical milling

machine).

E

-ost used machine after lathe 3as most of operationscan be performed.


53/101

2i8e% be% tpe plain milling Machine

Simple8

&i!ed bed replaces saddle and knee

and table has only longitudinal

travel only.

pwards3 downwards3 crosswise

movement is restricted. ?ertical column carries parallel

vertical ways on which ad=ustable

spindle head'spindle carrier is

mounted.

$pindle head carries spindle to which arbor is fitted to carry

cutter.

,arrier can be moved up down along the column ways to

ad=ust the tool to work.

3 t t bl Milli M hi


54/101

3otar table Milling MachineE "lso known as continuous milling

machine.

E 2t is used in mass production.

E ,onsists of heavy sturdy

column.

E $pindle carrier mounted on column

carries two vertical spindles each spindle carries a cutter at its

bottom.E $pindle carrier can be moved up down.

E ,onsists of heavy rotating circular table mounted on base.

E &i!tures mounted onto table carries no. of components to be

machined.

E #rocess is continuous.

D t Milli M hi


55/101

Drum tpe Milling MachineE 2t is heavy duty production where two

end faces are machined

simultaneously.

E ,onsists of two vertical columns

mounted on sturdy base.

E eavy drum mounted centrally.

E -illing heads mounted onto columns.E eads carry spindles can be ad=usted

in vertical direction (A;spindles)

E pper < spindles are roughening

cuttersE +ower < spindles are finishing cutters

E &i!tures mounted on periphery of drum

carry =ob.E Drum rotates continuously brining =ob in contact with upper

cutter first finishing cutter latter


56/101

7lain (Slab) Milling

E %o produce flat3 plain3 hori1ontal surface parallel to a!is ofrotation of cutter.

E Operation is carried out on plain machine.

E Depth of cut is ad=usted by rotation of vertical feed screw of

table


57/101

2ace Milling

E %o produce flat3 plain surface parallel to a!is of rotation of cutter.E Operation is carried out in plain machine.

E Depth of cut is ad=usted by rotation of cross feed screw of table


58/101

Si%e6Stra%%le Milling

E %o produce flat vertical surface on the side of work piece using aside milling cutter.

E Depth of cut is ad=usted by rotating vertical feed screw of table.

E hen the machining is re@uired on both sides of work piece3 two

side milling cutter is used mounted on same arbor ($traddle 5

milling)


59/101

4ngular Milling

E%o produce flat surface at an angle3 other than right angle to a!isof revolution of cutter.

E ,utter can be single'double angle cutter depending upon whether

a single surface to be machined or two mutually inclined surfaces

simultaneously.


60/101

:ang MillingE Operation of machining several surfaces of a work piece

simultaneously by feeding table against no. of cutters havingsame'different diameters mounted on a common arbor of

machine.


61/101

1n% MillingE $urfaces produced may be hori1ontal3 vertical or inclined with

respect to top of machine table.E &or hori1ontal surface3 a!is of rotation should be hori1ontal

same for vertical for inclined.

Milli ; 6 6 l t


62/101

Milling ;ewas6grooes6slot

E ses plain milling cutter of

various shapes si1es.E Open slot can be cut by #lain

milling cutter3 side milling

cutter.

E ,losed slot by using end mill.E %;slot'dove tail by using

re@uired shape.

E Fey slot by using end mill or

side mill cutter


63/101

Milling Cutter Characteristics

,utter ,haracteristicsarder than metal being machined

$trong enough to withstand cutting pressures

%ough to resist shock resulting from contact/esist heat and abrasion of cutting

"vailable in various si1es and shapes

Milling cutter


64/101

Milling cuttermaterials.igh carbon steel.$tellite

A.,emented carbides8.,eramics.

Stan%ar% Milling c tters


65/101

Stan%ar% Milling cuttersE 7lain Milling cutter

E uilt+up face

E


66/101

#lain Milling Cutters

Once widely used ,ylinder of high;speed steel with teeth cut

on periphery

sed to produce flat surface $everal types

+ight;duty+ight;duty helical

eavy;dutyigh;heli!


67/101

$ight"Dut% #lain Milling Cutter

+ess than H in. wide3 straight teeth

sed for light milling operations

%hose over H in have heli! angle of


68/101

&eav%"Dut% #lain Milling Cutters

ave fewer teeth than light;duty type#rovide for better chip clearance

eli! angle varies up to A8I

#roduces smoother surface because ofshearing action and reduced chatter

+ess power re@uired

i h li l i illi


69/101

&igh"&eli' #lain MillingCutters

ave heli! angles from A8I to over J9I

$uited to milling of wide and intermittent

surfaces on contour and profile milling$ometimes shank;mounted

with pilot on end and used

for milling elongated slots

St d d Sh ! T & li l


70/101

Standard Shan!"T%pe &elicalMilling Cutters

,alled arbor;type cutters sed for

-illing forms from solid metal/emoving inner sections from solids

2nserted through previously drilled holeand supported at outer end with type "

arbor support

id illi


71/101

Side Milling Cutters

,omparatively narrow cylindrical millingcutters with teeth on each side and onperiphery

sed for cutting slots andfor face and straddle millingoperations

&ree cutting action at high

speeds and feeds $uited for milling deep3

narrow slots

&al"Side Milling


72/101

&al Side MillingCutters sed when only one side of cutter

re@uired

"lso make with interlocking faces so two

cutter may be placed side by side for slotmilling

ave considerable

rake "ble to take heavy

cuts

Milli C


73/101

ace Milling Cutters

0enerally over J in. in diameterave inserted teeth made of high;speed

steel held in place by wedging device

-ost cutting action occursat beveled corners and

periphery of cutter

-akes roughing and

finishing cuts in one pass

A l C


74/101

Angular Cutters

%eeth neither parallel nor perpendicular to

cutting a!is

sed for milling angular surfaces

0rooves3 serrations3 chamfers and reamer teeth Divided into two groups

$ingle;angle milling cutters

Double;angle milling cutters

A l C tt


75/101

Angular Cutters

$ingle;angle%eeth on angular surface-ay or may not have teeth on flat

A8I or J9I Double;angle

%wo intersecting angular surfaceswith cutting teeth on both

6@ual angles on both side of lineat right angle to a!is

d C tt


76/101

ormed Cutters

2ncorporate e!act shape of part to be produced seful for production of small parts 6ach tooth identical in shape

$harpened by grinding tooth face (may havepositive3 1ero or negative rake)2mportant to maintain original rakeDifficult to sharpen

T%pes o ormed


77/101

T%pes o ormedCutters

Concae Cone8 :ear ooth

M t l Slitti S


78/101

Metal"Slitting Sas

Basically thin plain milling cutters with sidesrelieved or KdishedK to prevent rubbing orbinding when used

idths from '>< to >'J in. Operated at appro!imately 'A to 'L of feed

per tooth used for other cutters 4ot advisable to key saw to milling arbor

Backlash eliminator should be engaged

M t l Slitti S


79/101

Metal"Slitting Sas


80/101

Sh ll * d Mill


81/101

Shell *nd Mills

&ace milling cuttersunder J inch

$olid3 multiple;tooth

cutters with teeth onface and periphery

eld on stub arbor

-ay be threaded or usekey in shank to drive

cutter

T Sl t C tt


82/101

T"Slot Cutter

sed to cut wide hori1ontal groove atbottom of %;slot"fter narrow vertical groove machined with

end mill or side milling cutter

,onsists of small side milling cutter withteeth on both sides and integral shank formounting

D t il C tt


83/101

Dovetail Cutter

$imilar to single;angle milling cutter withintegral shank

sed to form sides of dovetail after tongue

or groove machined Obtained with A8I3 89I3 88I3 or J9I angles


84/101


85/101


86/101

I d i /Di idi H d


87/101

Indexing/Dividing Head

#lain dividing head niversal dividing head

Optical dividing head


88/101

Plain dividing head simple indexing


89/101

2t carries a cast body3 carrying spindle.

&ront end is mounted with carrier center.

/ear end has inde! plate (diff. hole circles on its face teeth on periphery. #late is rotated through worm by handle.

,rank mounted on bolt can be swung to any desired position to bring pin

in front of desired hole.

#lates with > circles of J3A< J9 or 9 >J holes are provided on

heads.


90/101


91/101

Dividing head -working


92/101

Dividing head working

$upports the =ob hold it in

position rotates it through adesired angle after each cut is

over.

2nde! crank rotates the =ob

and inde! plate enables this

rotation through desiredangle.

4ormally inde!ing plates

are provided with no. of

circles on each face.

>rown an% Sharpe tpe7late = + $!, $", $?, $#, $9, / holes

7late + $, ', ?, 9, '$, '' holes

7late ' + '?, '9, $, ', ?, 9 holes

Indexing methods


93/101

Indexing methods

Direct;inde!ing #lain or simple inde!ing

,ompound inde!ing

Differential inde!ing "ngular inde!ing

Direct Indexing


94/101

Direct Indexing

2t is simplest case of inde!ing using plain dividing head.

2nde! plate is mounted on spindle rotated by hand. #referably used when no. of divisions to be obtained is a

multiple of no. of slots on periphery of inde! plate.

2nde!ing ratio 4'n

4 4o. of slots on periphery of inde! plate.

n 4o. of divisions re@uired to be obtained.

6!: ,ircumference of =ob is to be divided into J divisions

inde! plate has


95/101

2t is simplest case of inde!ing using plain dividing head'universal

dividing head.

sed when direct method of inde!ing cant be used for obtainingre@uired no. of divisions on work.

%his method involves use of crank3 worm3 wheel and inde! plate.

orm is single start worm wheel has A9 teeth.

$tandard inde!ing plates like Brown $harpe are used.

/ules for inde!ing: 2nde! crank movement A9'4 (4 no. of divisions re@uired)

2f whole no. is obtained3 inde! crank should rotate through a complete no. of

turns obtained.

2f fraction no. is obtained3 numerator denominator of fraction is simplified by

multiplying by a common no. 4ew 4umerator no. of holes to be moved by inde! crank.

4ew Denominator no. of holes in inde! plate circle.

6!: >9 teeth on spur gear 5 2nde! crank movement A9'>9 .'>.'>CP'P.P'


96/101

p gE sed when no. of divisions re@uired is outside the range that cant be

obtained by simple inde!ing.

E


97/101

E 6!: 2nde! J7 divisions

. J7 C>

>

>. >>; 9

A. 9

9


98/101

E #rinciple is similar to that of compound inde!ing.

E ,arried out in < stages:

!" trning the crank a de#ne amont in certain direction$

!" trning index plate and crank %oth& either in same direction or reversedirection$

E -ovement of inde! plate is accomplished by moving plate by means of a train of

gears3 connecting dividing head spindle to worm spindle.

E Differential gears are furnished with change of gears as shown below.

E 4o. of possible teeth:


99/101

' ( no$ o) divisions re*ired

1 ( selected no$ which can %e indexed

E 2n gear ratio obtained3 numerator of fractiondriving gears on

inde! spindle head denominator driven gears on inde! plate.

E 2nde! crank movement A9'"

E 2nde! crank inde! plate should move in same direction or

opposite to each other depending upon gear ratio.

E 2f ";4 is Q3 inde! plate crank rotate in same directionE 2f ";4 is ; 3 inde! plate crank rotate in opposite direction

E $imple gear train ";4 is Q3 : idle gear used

E ,ompound gear train ";4 is Q3 no idle gear used

E $imple gear train ";4 is ; 3


100/101

. 2nde! crank movement A9'L> (#lain inde!ing 5 not possible)

. sing formula: 0./ (L9;L>)CA9'L9 ;>'

unit-ii-capstan & turret lathe

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