A view of different parts of a lathe machine,their classification,different operations can be performed on it and machining time,MRR calculations.

1. LATHE

2. Introduction
Working principle of lathe:
• The lathe is a machine tool which holds the work piece between two rigid
and strong supports called centres or in a chuck or face plate which
revolves. The cutting tool is rigidly held and supported in a tool post which
is fed against the revolving work.

3. Specification of lathe:

4. Classification of Lathe
• Speed Lathe
a)wood cutting lathe b)centering lathe
c)polishing lathe d)spinning lathe
• Engine Lathe
a)belt driven lathe b)individual motor drive lathe
c)gear head drive lathe
• Bench Lathe
• Tool room Lathe
• Capsten & Turret Lathe
• Automatic Lathe
• Special purpose Lathe
a)wheel lathe b)gap-bed lathe
c)t-lathe d)duplicating lathe

5. Speed lathe
Bench lathe
Tool room lathe

6. Work Holding Devices
Lathe centers
Three jaws chuck Four jaws chuck
Collet chucks

7. Magnetic chuck
Lathe dog
Angle plates
Face plate
Mandrel

8. Tool Holding Devices
Single tool holder
Four tool holder
Turret

9. The engine lathe is an accurate and versatile machine on which many
operations can be performed. These operations are:

10. Capstan and Turret lathes
• A capstan lathe or a turret lathe is a production lathe used to
manufacture any number of identical pieces in the minimum time.
These lathes are development of engine lathes. The capstan lathe
was first developed in the United States of America by Pratt and
Whitney sometimes in 1860.
• Special characteristics of a capstan or turret lathe enable it to
perform a series of operations such as drilling, turning, boring,
thread cutting, reaming, chamfering, cutting- off and many other
operations in a regular sequence to produce a large number of
identical pieces in a minimum time.
• Capstan and Turret lathes are the examples of semi automatic lathes.

11. Turret
Turret lathe

12. S.N
o
Capstan lathe Turret lathe
1 It is a light duty machine It is a heavy duty machine
2
The turret head is mounted on the ram and the ram is
mounted on the saddle.
The turret head is directly mounted on the saddle and
the saddle slides over the bed ways
3 The saddle will not be moved during machining
The saddle is moved along with the turret head
during machining
4
The lengthwise movement of turret is less
The lengthwise movement of turret is more
5
Short work pieces only can be machined.
Long work pieces can be machined
6
It is easy to move the turret head as it slides over the
ram
It is difficult to move the turret head along with
saddle
7 The turret head cannot be moved crosswise
The turret head can be moved crosswise in some
turret lathes
8
As the construction of lathe is not rigid, heavy cut
cannot be given
As the construction of lathe is rigid, heavy cut can be
given
9
It is used for machining work pieces up to 60mm
diameter
It is used for machining work pieces up to 200mm
diameter
10 Collet is used to hold the work piece Jaw chuck is used to hold the work piece

13. Automatic Lathe
• A lathe in which the work piece is automatically fed and removed without
use of an operator. Cutting operations are automatically controlled by a
sequencer of some form.
Automatic lathes are mainly
classified into two types
a)single spindle automatic
lathes
b) multi spindle automatic
lathes

14. Single spindle Automatic Lathe:
The general purpose single spindle automatic lathes are widely used for
quantity or mass production (by machining) of high quality fasteners; bolts,
screws, studs etc., bushings, pins, shafts, rollers, handles and similar small
metallic parts from long bars or tubes of regular section and also often from
separate small blanks. Unlike the semiautomatic lathes, single spindle automats
are :
• Preferably and essentially used for larger volume of production i.e., large lot
production and mass production used always for producing jobs of rod, tubular or
ring type and of relatively smaller size.
•Provided with up to five radial tool slides which are moved by cams mounted on
a cam shaft of relatively smaller size and power but have higher spindle speeds.

15. Multi spindle automatic lathe:
• These lathes are modified from the single spindle automatic
lathes. They have 2 to 8 spindles. Operations are done
simultaneously in all the spindles. Hence the rate of production
is increased.

16. Some calculations: