1. PRESENTATION ON LATHE MACHINE

2. PRINCIPLE OF LATHE
Lathe is a machine, which is used to remove metal from the workpiece to required shape and size.

3. COMPONENTS OF LATHE

4. 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.

5. Turret Lathe :
These lathes are used in mass production and for heavy duty workpieces.
Capsten Lathe :
These lathes are used in mass production used for light duty workpieces.
Special Purpose Lathe :
These lathes are modification of engine lathes developed for machining special types of workpices.

6. Automatic Lathe
Engine Lathe
Tracer Lathe
Computer Controlled lathe
Swiss Type Automatic Lathe
Duplicating Lathe

7. 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

8. TURRET LATHE
Capable of performing multiple cutting operations on the same workpiece
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 workpeiceces

9. ENGINE LATHE

10. BENCH LATHE
AUTOMATIC LATHE

11. 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 workpiece
Feed Rod and Lead Screw : Feed rod is powered by a set of gears from the headstock

12. LATHE BED Heavy, rugged casting Made to support working parts of lathe
On top section are machined ways
Guide and align major parts of lathe

13. HEADSTOCK Clamped on left-hand end of bed Headstock spindle
Hollow cylindrical shaft supported by bearings
Provides drive through gears to work-holding devices

14. CARRIAGE Used to move cutting tool along lathe bed
Consists of three main parts
Saddle
Cross-slide
Apron

15. APRON

16. TAILSTOCK

17. 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

18. ACCESSORIES Chucks : Three Jaw Chuck (Self Centering Chuck) :
This chuck is used to hold circular
workpiece and is available in sizes from
100mm to 600 mm.
Four Jaw Chuck (Independent Chuck) :
It is used to hold rectangular,
sqare and irregular shaped workpieces .

19. Collet Chuck :
Pull poerating rod
Push poerating rod
It is ideal for holding tube and thin walled workpieces.

20. Centres: Live Centre Dead Centre Ball Centre Pipe Centre Half Centre
Tipped Centre

21. Mandrels : Plain Mandrel Collared Mandrel Screwed Mnadrel
Stepped Mandrel

22. LATHE OPERATIONS

23. LATHE OPERATIONS Grooving Forming Reaming Undercutting Thread cutting
Knurling
Turing
Facing
Boring
Drilling
Taper
Camfering

24. BORING Boring produces circular internal profiles in hollow workpieces
Boring mills are used for large workpieces
Holes can be bored up to 20M if needed
See fig
Machines are available with a variety of features
Horizontal boring machines
Jig borers

25. 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

26. 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

27. SINGLE POINT CUTTING TOOL GEOMETRY
Clearance
Rake
End cutting edge angle
Side cutting edge angle