MANUFACTURING PROCESS-II UNIT-1 THEORY OF METAL CUTTING
PPT ON LATHE MACHINE BY MD G.QUADIR
1. Presentation
of
Vocational Training on
“Lathe Machine”
HEAVY ENGINEERING
CORPORATION
RANCHI
UNDER THE GUIDENCE OF:
Mr. SUNDER SUBRAMANIAM
(Sr. ENGINEER)
HEC, RANCHI
BY:
MD GULAM QUADIR
B. Tech. (MECH) Final Year
A.H.C.E.T. CHEVELLA
13H11A0331
5. TYPES OF LATHES
•Speed Lathe :
It is the simplest type lathe. It is mainly used for metal
spinning, polishing etc.
•Bench Lathe :
It is small sized engine lathe mounted on bench. It is used
for turning small and light weight workpiece.
•Tool Room Lathe :
It is used for production of small tools, gauges, fixtures and
accurate parts in tool room.
6. •Turret Lathe :
These lathes are used in mass production and for
heavy duty work pieces.
•Capstan Lathe :
These lathes are used in mass production used for
light duty work pieces
•Special Purpose Lathe :
These lathes are modification of engine lathes
developed for machining special types of workspaces.
8. COMPUTER NUMERICALLY CONTROLLED LATHE
Computer Numerical Controls (CNC)
Equipped with one or more turrets
Each turret is equipped with a variety of tools
Performs several operations on different surfaces of the workpiece
9. TURRET LATHE
Capable of performing multiple
cutting operations on the
same work piece
Turning
Boring
Drilling
Thread cutting
Facing
Turret lathes are very versatile
Types of turret lathes
Ram-type: ram slides in a
separate base on the
saddle
Saddle type:
more heavily
constructed
Used to machine large
workppieces
12. PARTS OF LATHE
•Bed : Supports all major components
•Carriage: Slides along the ways and consists of the cross-slide,
tool post, apron
•Headstock : Holds the jaws for the work piece, supplies power to
the jaws and has various drive speeds
•Tailstock : Supports the other end of the work piece
•Feed Rod and Lead Screw : Feed rod is powered by a set of
gears from the headstock
14. HEADSTOCK
Clamped on left-hand end
of bed
Headstock spindle
Hollow cylindrical shaft
supported by bearings
Provides drive through
gears to work-holding
devices
15. CARRIAGE
Used to move cutting
tool along lathe bed
Consists of three
main parts
Saddle
Cross-slide
Apron
18. ACCESSORIES
Chucks :
Three jaw chuck
Four jaw chuck
Collet chuck
Centres:
Live centre
Dead centre
Tipped centre
Ball centre
Mandrels :
Plain mandrel
Stepped mandrel
Collared mandrel
Screwed mandrel
19. Chucks :
• Three Jaw Chuck (Self Centering Chuck) :
This chuck is used to hold circular
work piece and is available in sizes from
100mm to 600 mm.
Four Jaw Chuck (Independent Chuck) :
It is used to hold rectangular,
square and irregular shaped work pieces .
ACCESSORIES
20. Collet Chuck :
Pull operating rod
Push operating rod
It is ideal for holding tube and thin
walled work pieces.
21. Centres:
Live Centre
Dead Centre
Ball Centre
Pipe Centre
Half Centre
Tipped Centre
25. BORING
Boring produces circular internal profiles in hollow work pieces
Boring mills are used for large work pieces
Holes can be bored up to 20M if needed
See fig. 22.20
Machines are available with a variety of features
Horizontal boring machines
Jig borers
26. TURNING
Forces in turning
Cutting force: acts downward on the tool tip
Thrust force: acts in the longitudinal direction
Radial force: acts in the radial direction
Roughing and Finishing Cuts
Rough cut: high speed cut with little regard for dimensional
tolerance
Finishing cut: lower feed rate and depth of cut
Tool Materials, Feeds, and Cutting Speeds
Cutting Fluids
27. CONCEPT OF SPEED, FEED AND DEPTH OF CUT
•Cutting speed=Πdn mm/min
1000
•Feed :
•It is expressed in mm/rev
•Depth of cut :
t=D-d mm
2
28. SINGLE POINT CUTTING TOOL GEOMETRY
•Clearance
•Rake
•End cutting
edge angle
•Side cutting
edge angle