1. MACHINE TOOLS
Dept. of Mech & Mfg. Engg.

2. A Machine tool
A machine tool may be defined as a power driven machine which accomplishes the cutting or machining operations in it.
Examples: Lathe,
Drilling machine,
Milling machine,
Grinding machine.
Shaping machine
Dept. of Mech & Mfg. Engg.

3. Functions of Machine Tools
To hold and support job/work to be machined
To hold and support the cutting tool in position
To move the cutting tool, work or both in a desired direction
To regulate cutting speed and provide feeding movement.

4. Working principle of lathe
Chuck
Direction of rotation of work piece
Work piece
Cutting tool
Direction of cutting tool
Dept. of Mech & Mfg. Engg.

5. Working principle of a lathe
Cutting tool can remove material in the form of chips from rotating work pieces to produce circular objects
Work piece is held rigidly by one of the work holding devices known as chuck
Uses V – shaped cutting tool
Chuck
Direction of cutting tool
Cutting tool
Direction of rotation of work piece
Dept. of Mech & Mfg. Engg.

6. Dept. of Mech & Mfg. Engg.

7. Lathe Basics Spindle Nose Tailstock Spindle Clamp Tool Post HEADSTOCK
Compound Rest
TAILSTOCK
Saddle
Feed Change Lever
Feed Reverse Lever
BED WAYS
Lead Screw
APRON
Bed
Gear Box
Carriage Hand Wheel
Friction-clutch Control
Half Nut Lever
Motor Drive
Cross Slide
Dept. of Mech & Mfg. Engg.

8. Explain with neat diagram the principal parts of an engine lathe.
Dept. of Mech & Mfg. Engg.

9. LATHE
Dept. of Mech & Mfg. Engg.

10. MAJOR PARTS 1] Bed 2] Head stock 3] Tail stock 4] Main drive
5] Carriage assembly consisting of
a) Saddle
b) Cross-slide
c) Compound rest
d) Tool post
e) Apron
6] Lead screw
7] Feed rod
Dept. of Mech & Mfg. Engg.

11. BED Foundation part of the machine Supports all other parts
The top of the bed is formed by
two Precession guide ways
i) Outer guide way--- Carriage assembly mounted
and align it with centre line of lathe
ii) Inner guide way--- Head stock and Tailstock
are mounted
Dept. of Mech & Mfg. Engg.

12. Headstock: Housing comprising of
feed gear box
stepped cone pulley
Rigidly mounted on the inner guide ways of lathe bed at its left end.
Dept. of Mech & Mfg. Engg.

13. MAIN DRIVE Cone pulley Cone pulley which drives the main spindle is
driven by the motor.
Various spindle speeds can be obtained by shifting the belt on different steps of the cone pulley.
Dept. of Mech & Mfg. Engg.

14. Dept. of Mech & Mfg. Engg.

15. Tailstock:
Movable part of the lathe that carries the dead centre in it.
Used to clamp tools like: Twist drills
Reamers
For making holes.
Mounted loosely on the inner guide ways of a lathe bed
Moved and locked in any position.
Dept. of Mech & Mfg. Engg.

16. Dept. of Mech & Mfg. Engg.

17. Carriage assembly: To support the tool
Moves over the outer guide ways longitudinally between headstock
and tailstock.
It is composed of 5 main parts:
Saddle
Cross slide
Compound Rest
Apron
Tool post
Dept. of Mech & Mfg. Engg.

18. Lathe Carriage and Apron
Tool Post
Compound Rest
Carriage Lock Screw
Cross Feed Knob
Cross Slide
Apron Hand Wheel
Half Nut Lever
Compound Rest Knob
Dept. of Mech & Mfg. Engg.

19. H shaped casting that slides over set of guide ways
Saddle
H shaped casting that slides over set of guide ways
Serves as the base for the cross slide.
Cross slide
Mounted on the saddle
Enables the movement
of the cutting tool laterally
across the lathe bed by
means of cross feed hand wheel.
Dept. of Mech & Mfg. Engg.

20. Cross Feed Knob
Used to move cutting tool across the end of the stock - Facing (Cross Feed)
Dept. of Mech & Mfg. Engg.

21. Compound Rest Mounted on the top of the cross slide
Supports the tool post.
Swiveled to any angle in the horizontal plane
To facilitate following
operations:
Taper turning
Threading operations
Dept. of Mech & Mfg. Engg.

22. Apron Hand Wheel
Used to move tool along the work - for Turning (Longitudinal Feed)
Apron Hand Wheel
Dept. of Mech & Mfg. Engg.

23. Tool post Apron Mounted on the front of the saddle Consists of,
- Carriage
- Cross slide mechanisms
Tool Post
Compound Rest
Tool post
Clamps the tool holder in the proper position for machining
operations.
Dept. of Mech & Mfg. Engg.

24. Chuck Three Jaw Chuck - For holding cylindrical stock centered.
Dept. of Mech & Mfg. Engg.

25. Lead Screw:
A screw rod which moves longitudinally in front of the lathe bed.
Rotation of the lead screw moves the carriage to and fro longitudinally during thread cutting operation.
Dept. of Mech & Mfg. Engg.

26. A stationary rod mounted in front of the lathe bed
Feed rod:
A stationary rod mounted in front of the lathe bed
Facilitates longitudinal movement of carriage during turning and facing operations.
Dept. of Mech & Mfg. Engg.

27. Center Drilling
Dept. of Mech & Mfg. Engg.

28. Turning Between Centers
Dept. of Mech & Mfg. Engg.