Centre Lathe Machine

cnc tuning machine

the turning operation is applied on the metal to get the required shape dimension and surface roughness with the given accuracy. In this process the material is removed in the form of chip.
 The main purpose of turning process is to get parts in circular , tapered from either internally or externally . Also can be used fro drilling , reaming and threading processes.
the machine tool used in turning is called a lathe . lathes are the most important and oldest machine tools . they are used for machining cylindrical , conical or other profiled surfaces , for thread cutting and for cutting off materials. further it is possible to drill to bore , to mill or to grind on lathes . 
Lathes are divided according to the arrangement of the machine and its equipment.. 

Centre Lathe

it is the most important member of the lathe family and is the most widely used , moreover, it is the simplest of all types of lathes. 

it consists of a bed , a head-stock , a tail-stock and a tool post mounted on an adjustable slide.

the tool is fed in both longitudinal and cross direction with reference to the lathe axis with the help of a carriage , feed rod and lead screw .

the main parts of the centre lathe are :

1-Main drive (gear box or head stock )

gearbox

the gearbox is mainly used for producing different numbers of R P M to be suitable for cutting condition i.e. main motion .

2-Secondary Drive

the secondary drive feed gear box is a part of the feed mechanism .

the following are the different types of gear box which are widely used in a lathe 

A-Norton gear box

Norton gearbox

In this gearbox different speeds of driven shaft are obtained by engaging the tumbler gear with each gear or gear cone fitted on the driving shaft.

the sliding gear is keyed to the driven shaft and matches with the tumbler gear which is held in a bracket pivoted on the driven shaft 

B-sliding key mechanism 

the mechanism consists of a hollow shaft into which a slotted rod carrying the key is located, and by end wise movement the rod pulls the key into the key ways or various gears in turn so that any one of a nest gears is driven by the sliding key.

C-Changeable gears

this is a set of gears consists of three or four gears for transmitting the motion from the main gearbox to the secondary drive.

      Changeable gears

3- Carriage

Lathe machine carriage 

the cutting tools are held and controlled by carriage across slide and a compound rest. 

the combination of the three is known as saddle . the carriage is movable on the bed on which is mounted across slide and a compound rest . the compound rest can be swiveled in any desired angle in a horizontal plane . there is a hand wheel for cross slide a lever for engage automatic feed , a lever for engaging cross slide and another lever for engaging screw cutting half nut.

4- Tailstock 

tailstock

the tailstock is movable on the bed ways and can be clamped to the bed at any desired position .

the main important parts of a tailstock are :

Tailstock base                            Handle
Allen bolt for taper                     Pin
Barrel                                         Dead center
Square Thread screw                Clamping bolts

5- clamping tools

a tool post is used to clamp the tool , it must be rigid enough. 

the common types of tool posts are:

• Open side tool post
• four way tool post  

four way tool post

open side tool post

6- Workpiece Clamping

clamping of workpiece may be carried out by one of the following methods:

• universal chucks
• chuck Collet 
• face plate
• mandrels
• rests
• magnetic chuck
• air chuck 

  

  Magnetic Chuck

  
  

  

  Chuck Collet

  
  

  

  Winder Mandrels

  
  

  

  air chucks