This document provides an overview of various machine tools, including lathes, shapers, milling machines, drilling machines, and broaching machines. It discusses the construction, operations, and classifications of lathes, shapers, slotters, planers, and milling machines. It also covers topics like cutting speed, feed, depth of cut, machining time, indexing, dividing heads, drilling tools, boring, reaming, and broaching. The document aims to give the reader a comprehensive understanding of common machine tools, their workings, applications, and the mathematical relationships involved in machining operations.

1. Machine Tool
Ujjwal Kashyap
A.P., ME, IPEC

2. Syllabus (Machine Tool)
Unit-II --- Machine Tools
(i) Lathe: Principle, construction, types, operations, Turret/capstan,
semi/Automatic, tool layout
(ii) Shaper, slotter, planer: Construction, operations & drives.
(iii) Milling: Construction, Milling cutters, up & down milling. Dividing head &
indexing. Max chip thickness & power required.
(iv) Drilling and boring: Drilling, boring, reaming tools. Geometry of twist drills.

3. 4M principle
Material
Men
Machines
Manufacturing
organization
strive for higher
productivity
and optimum
use of all its
resources
DESIGN
&
MANUFACTURING
Can’t design if cant
manufacture
&
Can’t manufacture if
cant design
Follows
OptimizationMoney

4. Why so many machines
Machine tools essentially need wide ranges of cutting speed and
feed rate to enable
• Machining different jobs (material and size)
• Using different cutting tools (material, geometry)
• Various machining operations like high speed turning, thread cutting
in lathes
• Degree of surface finish desired.

5. Types
• Stepped drive : Conventional machine tools where a discrete
number of speeds and feeds are available and preferably in
G.P. (Geometric Progression) series, using gear boxes or cone
pulley (old method)
• Stepless drive : drives enabling optimum selection and flexibly
automatic control of the speed and feed accomplished usually
by
• Variable speed AC or DC motors
• Stepper or servomotors

6. SELECTION OF MANUFACTURING PROCESSES
• Desirable properties
• Complexity
• Dimensions
• Cost investment for
production.
3Q principle
Quantity--------- Quality ----------Quickness

7. Lathe
Centre lathes
Its major parts are:
o Head stock: it holds the blank and through that
power and rotation are transmitted to the job at
different speeds
o Tailstock: supports longer blanks and often
accommodates tools like drills, reamers etc for hole
making.
o Carriage: accommodates the tool holder which in
turn holds the moving tools
o Bed : headstock is fixed and tailstock is clamped on it.
Tailstock has a provision to slide and facilitate
operations at different locations & carriage travels on
the bed
o Columns: on which the bed is fixed
o Work-tool holding devices: chuck & tool post
Lathe is a machine where workpiece has rotational motion, and cutting is done
with a non‐rotating cutting tool. The shapes cut are generally round, or helical. The
tool is typically moved parallel to the axis of rotation during cutting. Lathe can be
modified with attachments for some more operations.

8. • Uses of center lathes Centre
lathes are quite versatile being
used for various Operations:
External straight
& taper ⎯ turning
Internal stepped
•Facing, drilling, parting, thread
cutting; external and internal ⎯
knurling.
Application
Specification
of lathe

9. Classification
• On the basis of configuration : Horizontal,
Vertical
• Purpose : General centre lathes etc,
Single e.g. facing lathe, roll
turning lathe etc.
Special e.g. gear blank
machining lathe etc
• Size or Capacity : Small
Mini or micro duty lathe
Medium duty
Large (heavy duty)
• Degree of automation:
Non-automatic e.g. centre lathes
Semi-automatic e.g. capstan
lathe, turret lathe
Automatic e.g. swiss type
automatic lathe
• Type of automation: Fixed
Flexible
automation
• Configuration of the jobs being
handled : Bar type,
Chucking (disc type)
• Precision: Ordinary,
Precision (lathes)
• Spindles : Single spindle
Multispindle
• Clamping : 3- Jaw(self centered)
4-Jaw

10. Classification
• Capstan
• Turret
• Automatic
Capstan & Turret are
semi-automatic types of
lathe were developed
from conventional lathes
with multiple tool holder
in order to complete the
maching without the
need of changing tool
further arrangement and
measurement resulting in
time saving.
Turret Capstan
Capstan Turret

11. Automatic Lathe  Next stage NC/CNC
The automatic refers to those machine tools capab le of producing identical pieces without
the attention of an operator, after each piece is completed. Thus, after setting up and
providing an initial supply of material, further attention beyond replenishing the material
supply is not required until the dimensions of the work pieces.
A number of types of automatic lathes are developed that can be used for large volume
manufacture application, such as single spindle automatics, Swiss type automatics, and
multi‐spindle automatic.
Different attachments can also be
introduced to perform other cutting
operations , restricted on a normal
Lathe. E.g. milling attachment,
automatic screw lathe.. etc

12. Mathematical relations
• Cutting velocity, Vc mm/min
• Feed, f mm/revolution
• Depth of cut, d mm
D= initial dia. d= final dia
• Maching time, MT
N rotational speed
D diameter of workpiece
T cutting time

13. Shaper
Operations: Producing flat surfaces,
Grooving
Splitting.
Shaping machines are generally used for
producing flat surfaces, grooving, splitting
etc. Because of poor productivity and
process capability these machine tools
are not widely used now-a-days for
production.
Construction
Ram: it holds and imparts cutting motion
to the tool through reciprocation
Bed: it holds and imparts feed motions to
the job (blank)
Housing with base: the basic structure and
also accommodate the drive
mechanisms
Power drive with speed and feed change
mechanisms.

14. • The vertical slide holding the cutting tool is
reciprocated by a crank and slotted lever
mechanism, quick return effect is present.
Operation’s

15. Slotter
Shaping machines and slotting machines, for their low productivity, are
generally used for job production required for repair and maintenance.
• Slotting machines can simply be
considered as vertical shaping
machine where the single point
cutting tool reciprocates vertically
(but without quick return effect)
and the workpiece, being mounted
on the table, is given slow
longitudinal and / or rotary feed.
Only light cuts are taken due to
lack of rigidity of the tool holding
ram for cantilever mode of action.
• Slotting machines are generally
used to machine internal surfaces
(flat, formed grooves and
cylindrical).
workpiece
Cutting
tool
Cutting motion:
vertical

16. • Slotting machines are very
similar to shaping machines in
respect of machining principle,
tool-work motions and general
applications. However, relative
to shaping machine, slotting
machines are characterised by
:
• Vertical tool reciprocation with
down stroke acting
• Longer stroke length
• Less strong and rigid
• An additional rotary feed
motion of the work table
• Used mostly for machining
internal surfaces.
Operations
The usual and possible machining applications of
slotting machines are :
• Internal flat surfaces
• Enlargement and / or finishing non-circular
holes
• Blind geometrical holes like hexagonal
• Internal grooves and slots of rectangular
and curved sections.
• Internal keyways and splines

17. Some products of
slotter

18. Planer
Like shaper machines, planing machines
are also basically used for producing flat
surfaces in different planes. However, the
major differences between planing
machines from shaping machines
• In planing machine, instead of the tool,
the workpiece reciprocates giving the
fast cutting motion and instead of the
job, the tool is given the slow feed
motion
• Planing machines have more
productivity (than shaping machines)
for longer and faster stroke, heavy cuts
(high feed and depth of cut) possible
and simultaneous can use of a number
of tools.
• Compared to shaping machines,
planing machines are much larger and
more rugged and generally used for
large jobs with longer stroke length
and heavy cuts.

19. Features
• The length and position of stroke
can be adjusted.
• Only single point tools are used.
• Form tools are often used for
machining grooves of curved
section.
• Can also produce large curved
surfaces by using suitable
attachments.
Usage
All the operations done in shaping
machine can be done in planing
machine. But large size and stroke
length and higher rigidity enable the
planing machines do more heavy duty
work on large jobs and their long
surfaces The long parallel T-slots, Vee
and inverted Vee type guideways are
also machined in planing machines.

20. Milling
A multipoint cutter based machine, Milling machine is often
used to produce surfaces of various configurations, grooving,
slitting & parting with a higher rate w.r.t. other machine which
uses single point cutting tool for the same.
General configuration of knee type conventional
milling machine with horizontal arbour:
• Milling arbour: to hold and rotate the cutter
• Ram: to support the arbour
• Machine table: on which job and job holding
devices are mounted to provide the feed motions
to the job.
• Power drive with Speed and gear boxes: to
provide power and motions to the tool-work
• Bed: which moves vertically upward and
downward and accommodates the various drive
mechanisms
• Column with base: main structural body to
support other parts. ram Cutter job
arbour
Machine
table
Arbour
bracket
column

21. Classification
Broadly machining has been classified on
basis of relative motion between cutting tool
and workpiece (i.e. feed).
Up Milling : for opposite motion
Down Milling : for motion in same direction
According to nature of
purposes of use :
• General
• Single
• Special purpose
According to configuration &
motion of work holding
bed.
• Knee type
• Bed type
• Planer type
• Rotary table type

22. According to the orientation of the spindle
• Plain horizontal knee type
• Horizontal axis (spindle) and swivelling bed type
• Vertical spindle type
• Universal head milling machine
According to mechanisation/ automation &
production rate
• Hand mill
• Planer and rotary table type vertical axis milling,
• Tracer controlled copy milling
• Milling machines for short thread milling
• Computer Numerical Controlled (CNC)

23. Milling cutters &
Classifications
Milling machines are mostly general
purpose and have wide range of
applications requiring various types and
size of milling cutters. Intermittent cutting
nature and usually complex geometry
necessitate making the milling cutters
mostly by HSS. Tougher grade cemented
carbides are also used without or with
coating, where feasible, for high
productivity and product quality.
• Profile sharpened cutters – where
the geometry of the machined
surfaces are not related with the
tool shape
• Form relieved cutters – where the
job profile becomes the replica of
the tool-form.
Classification of cutters

24. Profile sharpened cutters
• Slab or plain milling cutter : ⎯ straight or
helical fluted
• Side milling cutters – single side or both sided
type
• Slotting cutter
• Slitting or parting tools
• End milling cutters – with straight or taper
shank
• Face milling cutters

25. Form relieved cutters
• Gear (teeth) milling cutters
• Spline shaft cutters
• Tool form cutters
• T-slot cutters
• Thread milling cutter

26. Slab or Plain milling
cutters
Side and slot milling cutters

27. Slitting saw or parting tool
End milling cutters

28. Face milling cutters
Form cutters

29. Gear milling cutters
Spline shaft cutters

30. Tool form cutters Thread milling cutters

31. Straddle milling
Gang milling

32. Turning by rotary tools (Milling)
Besides above application, the
milling machine have several other
types of milling cutters are employed
for many other machining work like
cam milling, keyway cutting, making
hob cutter and so on. For enhancing
capability range of milling work a
number of attachments are fitted in
the milling machines. Such milling
attachments include
•Universal milling and spiral milling
attachmen
•Indexing head – simple, compound
and differential
•Universal milling and spiral milling
attachment
•Slotting attachment

33. Dividing headDividing head
One of the most important
attachments for milling
machine.
Used to divide circumference
of workpiece into equally
spaced divisions when milling
gear teeth, squares,
hexagons, and octagons.
• They can be right or left handed
depending on which end you have it
assembled.
• Also used to rotate workpiece at
predetermined ratio to table feed rate

34. Indexing
Indexing mechanism is a system of rigid elements arranged and connected
to transmit motion in a predetermined fashion. Indexing mechanisms
generally converts a rotating or oscillatory motion to a series of step
movements of the output link or shaft.
Methods of indexing :
1.Direct
2.Simple
3.Angular
4.Differential

35. Simplest form of indexing & Performed
by disengaging worm shaft from worm
wheel by means of disengaging the
drive gear
Often used for quick indexing of
workpiece when cutting flutes,
hexagons.
Direct Indexing

36. Workpositioned by means of
crank, index plate, and sector
arms
Worm attached to crank must
be engaged with worm wheel
on dividing head spindle 1: 40
teeth on worm wheel
Simple Indexing

37. When you divide work
into degrees or
fractions of degrees by
plain indexing.
one turn of
the index crank will
rotate a point on the
circumference of the
work 1/40 of a
revolution.
Angular Indexing

38. A method used on a dividing
engine for dividing a circle into
subdivisions otherwise
unobtainable by utilizing the
difference between
simultaneous movements of
index plate and index crank.
Instead of relying on worm
wheel assembly here we use
bevel gears to drive the
indexing plate
Differential Indexing

39. Drilling, Boring & Reaming
Drilling machines are used to machine through or blind straight
symmetrical cylindrical holes in solid rigid bodies.
Boring is the process of enlarging a hole that has already been
drilled (or cast).
Reaming is a finishing operation of high-precision holes
performed with a multi-edge tool.
Counter boring : An operation done to enlarge a hole
concentric to drilled hole for accommodating the heads of bolt
or nut.
Classification on basis of : Material, Size, helix Angle of flute,
Number of flute, shank type.. Etc.

40. A twist drill is made up of three
components: A twist drill is made up
of three components:
Shank
Body
Drill point
Point angle

42. Crank slotted quick
return mechanism

43. Broaching is a machining process for removal of a layer
of material of desired width and depth usually in one stroke by
a slender rod or bar type cutter having a series of cutting
edges with gradually increased protrusion

44. End of unit II