The document discusses various types of lathe machines and their components and operations. It begins with an introduction to lathes, describing them as important metalworking tools that rotate the workpiece while a cutting tool shapes it. It then explains different lathe types like engine lathes, speed lathes, and CNC lathes. The main lathe components discussed are the bed, headstock, tailstock, carriage, and lead screw. Common lathe operations like turning, threading, boring, drilling and tapering are also summarized.

1. Department of Mechanical engineering
Atria institute of technology
By :-)
Adarsh maiya
Akash B S
Darshan Kumar
Raghu K H

2. Introduction
Lathe is one of the most important
machine tool in the metal working
industry. A lathe operates on the
principle of a rotating work piece and a
fixed cutting tool
The cutting tool is feed into the work
piece which rotates about its own axis
causing the work piece to be formed
to the desired shape
Lathe machine is also known as
the mother or father of the entire
Tool Family

3. Lathe machine is one of the oldest
and the most important Machine
tool.
The lathe was very important to
the industrial revolution.It is
known as the mother of machine
tools, as it was the first machine
tool that led to the invention of
other machine tools.
Lathe machine also ENGINE
LATHE become the first type of
lathe driven by a steam engine.

4. Lathe accessories are tools and equipments used for holding the workpiece and also for holding
the tool rigidly during machining.The common lathe accessories used in lathe are illustrated and
briefiedbelow :-)
LATHE CENTERS :-) Lathe center are required to support the long workpiece
between them. There are two types of centers Live center
and dead center. The center filled the head stock spindle
and rotating with the spindle and the work is called filled in
the revolving center while the center filled in the tailstock are
remains stationary, supporting the workpiece is called the
dead center.
LATHE CHUCK :-) Lathe Chuck is a tool which by means of It’s adjustable jaws
hards the works as well as rotates the workpiece so that the
stationary cutting can perform machining operation. The
Chuck is used for workpiece of shart length and large
diameter or of irrugular Shape that supported between
centers. Chicks in manual lathe can be a 3-jaw or self
ceentering Chuck independent Chuck collect Chuck etc ..

5. LATHE DOG :-) Lathe dog is a tool which transmits motion to the workpiece from the spindle
which when the work is held between two centers
DRIVE PLATE :-) The drive plate is a circular plate having a central boss projecting from it. The boss
has a inner threaded hole that helps it to attached to be attachedused the
headstock spindle. A hole is provided on the plate to accommodate which
engages with the tail of a dog plate. When a bent dog is used , the pin is taken out
and the bent portion of the tail inserted into the hole.
FACE PLATE :-) A face plate is larger than the drive plate and is screwed
o the spindle nose. It is used for holding the workpiece
and cannot be supported by chucks. The plate has four
T-slots and a number of plain radial slots for clamping the
workpiece by bolts or clamps.

6. MANDREL :-) The lathe mandrel Is a cylindrical bar with central hole at each end. It is
used to hold workpiece like gear block pulleyes, etc., to machine the
external surface. The workpiece revolves with mandrel which is mounted
between the centers.
STEADY REST :-) When long workpieces are long Slender
workpieces of low rigidity are machined
between centers, steady rests are used to
additionally support the workpiece and
prevent it from bending due to the pressure of
the cut. The steady rest is bolted the lathe bed
in a suitable position.
FOLLOWER REST :-) A follower rest unlike steady rest not fixed
in one position, rather is fitted on the lathe
saddle to travel along with the cutting tool
thereby providing constant support to the
workpiece during every cut taken by the
tool.

7. SPEED LATHE :-) Speed Latheia is used primarily for woodturning, metal
spinning and polishing, a speed lathe is a high-speed spindle
used to make everything from bowls and baseball bats to
furniture parts. Speed lathes are simpler than other lathes and
consist of a headstock, tailstock, and tool turret.
ENGINELATHE :-) The name “engine lathe” comes from early iterations of the
machine, back in the 19th and 20th century, which used a
steam engine, though modern engine lathes are powered
by individual motor drives. Engine lathes are ideal for
manufacturers operating with a range of metals.
Engine lathe includes boring, drilling and reaming then an
engine lathe.
CNC LATHES :-)
CNC lathes, short for Computer Numeric Control lathes,
use CNC programs to achieve the desired results. This
enables high levels of accuracy achievedin a fraction of
the time it takes to produce the same result with a manual
lathe.

8. Engine lathe is one of the most widely used lathe
and so calledin view of the fact that earlier lathe
where driven by steam engines. It is general
purpose turning machine used to perform a variety
of operations. Engine lathe is also called outer lathe
, since the workpiece is held and rotated between
two centers one being the live center rotating at
the head stock side and the other, dealcenter,
supporting the workpiece at the tailstock side.
It is a regid structure which forms the base or
function to support all the othe parts such as head
stock, tailstock,carriage,etc.. It is usually made
from gray cast iron. At the top of the bed are the
guide ways which guides for accurate movement
of carriage and tailstock.
BED :
CROSS-
SLIDE :
The cross slide is mounted on the saddle it can be made to move in a direction
perpendicular to the saddle movement, or perpendicular to the lathe axis thereby
providing the necessary depthof cut to the workpiece.

9. HEAD STOCK : The head stock mounted at the left end
of the lathe bed serves as ahousing for
the spindle driving gears or pulleys by
means of which the workpiece can be
rotated at different speeds the head
stock spindle is provided with a live
center to support one end of the
workpiece while it is being rotated.
TAIL STOCK : The tailstock at the right end of the bed
perform two functions:
• Provides support to the other end of
the rotating work pieces.
• Hold a tool performing operations like
drilling,raming, tapping etc..
CARRIAGE : The cutting tool Is supported movedand
controlledwith the help of carriage. The
carriage consists of following parts.
SADDLE : The saddle is a part of carriage that can be made slide along the bed ways. It supports
the cros-slide compoundrest and tool past.

10. COMPOUND REST :
TOOL-POST :
APRON :
FEED ROD :
LEAD SCREW :
This mountedon the cross slide and supports the tool post. The compoundrest
has a circular guided in degrees. This helps the cutting tool to be swivelledat
any angle to obtain taper surfaces.
It is mounted on the compoundrest, and is used to hold/support the cutting tool
firmly in position during machining.
It is fitted beneath the saddle facing the operator. It houses the
gears,levers,handwheels and clutches operate the carriage by hand or by
automatic power feed.
The feed rod is a long shaft that gives automatic feed to the carriage for
various operations namely, boring, turning etc., Except thread cutting.
It is a long shaft Which square thread cut on it. The rotation of the lead screw
facilities the movement of carriage during thread cutting operations.

11. The operations which are performed on the lathe machine are
called lathe operations and are as follows.
* Turning
* Thread Cutting
* Boring
* Countersinking
* Taper turning
* Drilling Operation
* Facing
* Counterboring
* Reaming
* Knurling operation

12. TURNING :-)
Turning, also Called plain turning or straight turning is a
Machining process for producing a cylindrical surface on
the workpiece. One end of the workpiece is held regidly
in a Chuck, while the other end is supported by the dead
center of the machine.The cutting tool is fed against the
revolving workpiece, in a direction parallel to the lathe
axis so as to produce a cylindrical surface.
THREAD
CUTTING :-) In oparation a suitable tool which gave the requride thread
profile, say V- thread,square thread etc... ,is mountedon
the tool post of the lathe.The workpiece is made to revolve
at a very slow speed. The depth of cut is selectedand tool
is made to move parallel to lathe axies by means of
automatic arrangement. The thread cutting is carried out in
number of passes .
In oparation a suitable tool which gave the requride thread
profile is mounted on the tool post of the lathe.The
workpiece is made to revolve at a very slow speed. The
depth of cut is selected and tool is made to move parallel
to lathe axies by means of automatic arrangement. The
thread cutting is carried out in number of passes . The final
cut is a finishing cut with a very small depth of cut in order
to obtain a good surface finish.

13. BORING :-) Boring is the process of enlarging a hole that has already
been drilled(or cast) by means of a single-point cutting
tool (or of a boring head containing several such tools),
such as in boring a gun barrel or an engine cylinder. Boring
is used to achieve greater accuracy of the diameter of a
hole, and can be used to cut a tapered hole. Boring can
be viewedas the internal-diameter counterpart to turning,
which cuts external diameters.
Boring and turning have abrasive counterparts in internal
and external cylindrical grinding. Each process is chosen
based on the requirements and parameter values of a
particular application.
COUNTER
SINKING :-)
Conical enlargement of an end of the hole is called a
countersinking Operation.

14. TAPER TURNING :-) Taper turning is a machining process for producing
conical surface on a cylindrical workpiece as
shown in figure . The work peice is rigidly between
two support of machine and the cutting tool is fed
aganist the revolving workpiece at an angle to the
lathe axis.
This angle referred as half-taper is calculatedusing
as equation:
Half-taper angle= α=tan’
=[D-d / Lt]
Where D= larger diameter of taper
d= smaller diameter of taper
Lt= length of taper
The compoundrest supporting the tool is swived at
the half taper angle causing the tool to be fed at
the angle,there by producing the corresponding
taper on the workpiece.

15. DRILLING
OPERATION :-)
Drilling is the operation of producing a cylindrical hole by
means of a revolving tool called twist drill or drill bit
In, operation, one of the work piece is held in a chuck, while the
other end is left free (not fitted to the tailstock end). Refer figure
. The tool is held in the tapered hole of the tailstock sleeve and is
fed into the rotating work piece with the help of the rotating
hand wheel of the tailstock.
Drilling on lathe is limitedto holes through the axis of rotation of
the work piece and from any of the ends only. Although drilling
operation can be done on lathes, it is best performed on drilling
machines, which will be discussedin the succeeding sections.
FACING :-) Facing us a Machining process a flat surface at the
workpiece. One end of the workpiece is held rigidly in the
Chuck , while the other end is left free and un-supported. The
tool is fed in a direction perpendicular to the lathe axis to
produce a flat surface at the end of the workpiece. Facing is
also carried out to reduce or the workpiece to the required
length.

16. Counter boring :-) The Boring operation used for enlarging the end of
the hole is called as counterboring.
Reaming :-) Reaming is similar to drilling operation used for
removing a small amount of material for sizing
and finishing of the hole to get exact
dimensions.
The maximum size of the hole produced by
using in stages method of drilling operation is up
to 50 mm only.

17. Knurling is a machine process carried out on a lathe, whereby a
visually attractive criss-cross pattern is cut or rolled on the surface of
metallic parts as shown in figure . The work piece is made to revolve
at a slow speed, and the knurling tool is pressed against the rotating
work piece and pressure is slowly increaseduntill the tool produces a
pattern on the work surface. Sometimes more one pass may be
required to get a deep cut.
Depending on the knurling tool selected, a variety of patterns can be
produced, the pattern thus produced on the work surface allows the
human hands or fingers to get better grip on the knurled part than
would be provided by the originally smoothsurface.
Knurling operation :-)

18. :-》 The lathe is a useful machine tool. As a maintaince
machinist you will often use a lathe to carry out repairs
or machine new components. To do these tasks you
must be able to operate the lathe safely and correctly.
These training unit covers the skills and knowledge you
will need to operate the centre lathe correctly.
:-》 A lathe is a machine tool that carries out many
machine shop tasks. It can cut and smooth the face of
a work piece. It can make holes to an exact size and
position . It can also make external or internal threaded
parts on a work piece. This ability to do different tasks
makes it an important tool. In most tasks a lathe’s use is
only limited by the size of the work piece. As a
maintenance machinist,it is important that you know
how a lathe functions and how to operate it correctly.
:-》 To identify a lathe, look for its headstock and
tailstock . The lathe holds and rotates the work piece
about the center line of these two parts .It can also
machine a part between its headstock and tailstock
centers .This is why we call it a center lathe.

19. ADVANTAGES OF LATHE MACHINE
* The accuracy is very high in the case of CNC
lathes compared to Normal Machining lathes.
* The flow of production is more.
* It requires few operators in a manual lathe.
* The machining in the lathe and CNC lathe
was very fast.
* Due to the CNC lathes, the time tocarry out
the experiment was very less than
conventional machines.
* The lead time will be very less.

20. * If the maintenance was not good then it results in
the damage of machine parts by not using
lubrication.
* The tool also wears out fastly, if the operator is
not good to handle the experiment.
* Due to the cutting speeds, the odor in the
environment will be very high which impacts the
health also.
* These machines were more expensive than other
conventional machines because you can do almost
all operations on the lathe.

21. Which machinetool is known as the mother machine tool?
a) drill
b) milling
c) lathe
d) none of mentioned
Lathe is primarily used for producing ____surfaces.
A) flat
b) curve
c) taper
d) none of the mentioned
Which type of surface is produced by turning operation in lathe
machine?
A) flat
b) cylindrical
c) taper
d) none of the mentioned

22. What is the necessary conditionfor turning?
A) material of work piece shouldbe harder than the cutting tool
b) cutting tool shouldbe harder than the material of work piece
c) hardness of the cutting tool and material of of piece shouldbe same
d) none of the mentioned
Traversing of tool parallel to the axis of job is termed as_____
a) cross feed
b) longitudinal feed
c) both cross feed and traversing feed
d) none of the mentioned
The swing diameter over the bed is the largest diameter.
A) true
b) false
Lathe cannot produce internal features like holes.
A) true
b) false

23. Which type of feed is needed in facing operation?
A) longitudinal
b) cross
c) both cross and longitudinal
d) none of the mentioned
Which type of surface is produced in facing operation?
A) cylindrical
b) taper
c) flat
d) none of the mentioned
Traversing of tool at any angle to the job axis produces curve surfaces.
A) true
b) false

24. 1. C
2. D
3. B
4. B
5. B
6. A
7. B
8. B
9. C
10. B

25. Lathes are normally robust in construction and they will, with
good care, last for many years. It is not unusual for instance
to see good lathes still in uses that are 50 years old. To ensure
good, accurate, trouble free use it is necessary that the
correct maintenance routines are regularly carried out and
that important surfaces such as slide - ways are kept well
protected so as to reduce wear and thus maintain good
accuracy, and the lubrications used, are all factors that
require your attention.

26. Thank you