1. The Lathe machine

2. What is lathe??
The lathe can be defined as a machine tool which holds the work between two rigid and strong supports, called centers, or in a chuck or face plate and revolves it.
The chuck or the face plate is mounted on the projected end of the machine spindle(head stock spindle).

3. Types of lathes
According to different designs, different construction.
1. Centre lathe –
(a) Bench lathe
2. Tool room lathe
3. Capstan and Turret lathe
4. Special purpose:
(a) hollow spindle lathe
(b) Gap bed lathe
(d) Duplicating lathe
5. Automatic lathe

4. Component Description

5. DIFFERENT PARTS OF CENTRE LATHE :
Main six parts of Lathe Machine.
Bed
Headstock
Tailstock
Carriage
feed mechanism
Legs

6. Bed
part of lathe machine which is the base of the machine.
The all other parts are located on it.
It carries all the weight of the machine.
lathe bed being the main guiding member of the tool for accurate machining work.

7. Condition
sufficiently rigid to prevent deflection under tremendous cutting pressure transmitted through the tool-post and carriage to the lathe bed.
It must be massive with sufficient depth and width to absorb vibration.
It must resist the twisting stress.
The bed should be seasoned naturally to avoid distortion or warp.

8. Material
high compressive strength, wear resistant and absorb vibration.
Cast iron alloyed with nickel and chromium forms a good material suitable for lathe bed.
The uses:-
It resists all the weight of machine’s parts.
It can resist the vibration of working machine.

9. 2. Carriage
Used to move cutting tool along lathe bed.
Saddle
The cross-slide
3. compound rest
4. Tool post
5. Apron

10. Saddle
The saddle is an H-shaped casting that fits over the bed and slides along the ways.
It carries the cross slide and tool post.

11. The cross-slide
Mounted on top of saddle
Provides manual or automatic cross movement for cutting tool.
The cross piece of the saddle is made at right angles to the centre axis of the lathe.
The compound slide or compound rest
Mounted on the top of the cross-slide and has a circular base graduated in degrees.
It is used for obtaining angular cuts and short tapers as well as convenient positioning of the tool to the work.

12. The tool post
This is located on the top of the compound rest to hold the tool and to enable it to be adjusted to a convening working position.
Types of tool post
1 Single screw tool post
2 Four bolt tool post
3 Open side tool post
4 Four way tool post
The apron:-
The apron is fasted to the saddle and hangs over the front of the bed, so the working of machine is vary fast.
It contains gears, clutches and levers.
It carriage by hand and power feeds.

14. 3. TAIL STOCK Parts -Dead center -Tail stock spindle -tail stock spindle clamp -tail stock handle wheel -tail stock clamp lever - Offsetting screw

15. Tail stock
It is also known as loose head stock.
It is located on the inner ways at right hand end of the bed.
To accommodate different lengths of work, the body of the tail stock can be adjusted along the ways chiefly by sliding it to the desired position where it can be clamped by bolts and plates.
The main uses
It supports the other end of the work piece when it is being machined between centers.
It holds a tool for performing operations such as drilling, reaming, tapping etc.

16. 4. Headstock

17. Clamped on left-hand end of bed Headstock spindle
Hollow cylindrical shaft supported by bearings
Provides drive through gears to work-holding devices
-faceplate, or chuck fitted to spindle nose to hold and drive work
Driven by stepped pulley or transmission gears
Feed reverse lever
Reverses rotation of feed rod and lead screw

18. Work Holding Devices

19. Three jaw chuck - For holding cylindrical stock centered.
- For facing/center drilling the end of your job.
Four-Jaw Chuck
- This is independent chuck generally has four jaws , which are adjusted individually on the chuck face by means of adjusting screws

20. Collet Chuck
Collet chuck is used to hold small workpieces
Thin jobs can be held by means of magnetic chucks.
Magnetic Chuck
Thin jobs can be held by means of magnetic chucks.

21. Lathe Operations