Department of Mechanical Engineering

Presentation on Lathe Machine

PREPARED BY:MD. Habib Ullah Khan

Dept. of Mechanical EngineeringKhulna University of Engineering & Technology

Khulna-9203, BANGLADESH

Size & Specification of Lathe:

The size of a Lathe is usually specified by:

1. Height of the centres measured from the lathe bed2. The swing of the work piece diameter over bed, this is the maximum diameter of work that can be rotated on a lathe3. The maximum distance between the centres; this is the maximum length of a work piece that can be mounted between the lathe centres 4. The length of the bed; this indicates the approximate floor space occupied by a lathe

A lathe size is indicated by 356mm* 762mm * 1800mm means

Maximum diameter 356mm Length between the lathe centres 762 mm Length of the lathe bed 1800mm

Difference between Turret Lathe & Centre Lathe:

Sl No. Centre Lathe Turret Lathe

1 It is a manually operated lathe It is a semi automatic lathe

2 It has only one tool post tool changing time is more

Front and rear tool posts are available. Tool changing time is less

3 It has tail stock It has turret head instead of tail stock

4 Only one tool can be fitted in the tail stock

Six different tools can be fitted in the turret head.

5 Number of speeds is less Number of speeds is more

6 Tool changing time is more Tool changing time is less

7 The machine should be stopped for changing tool

Tool can be changed without stopping the machine

8 It is not suitable for mass production It is suitable for mass production

Sl No. Centre Lathe Turret Lathe

9 No feed stops to control the tool The tools are controlled by feed stops

10 The tool is centered manually after changing the tool

The tool is centered automatically

11 Only one operation is done at a time More than one operation can be done at a time

Difference between Turret Lathe & Capstan Lathe:

Sl No. Turret Lathe Capstan Lathe

1 Turret mounted directly on the saddle Turret is mounted on an auxiliary slide

2 For feeding the tools entire saddle is moved

Saddle is fixed at a convenient distance from the work

3 Very high rigidity Tool support unit is subjected to bending & deflection

4 Can handle heavier jobs Confined to lighter & smaller loads

5 Maximum bar size is upto 200mm Maximum bar size is upto 60mm

6 Tool travels almost full length of the bed Limited tool travel

7 Rate of tool feeding relatively slower Rate of tool feeding relatively faster

8 Reach over type or side hung type Carriage

Usually equipped with the reach over type carriage