This document summarizes the design and analysis of a lathe machine. It describes the materials selected for different parts of the lathe based on their properties like strength, rigidity, and economy. It then outlines the specifications of the lathe model created in Pro-E, including dimensions and maximum workpiece size. Cutting forces acting on the tool for a given depth of cut and feed rate are calculated. A static structural analysis of the lathe assembly is performed in ANSYS to determine stress distributions in parts like the tool, base, tail stock, and at interfaces. The analysis shows stresses and deformations are within allowable limits.

1. Machine tool(LATHE)
TALIYA HEMANTH
2012ABPS451H
MRUDUL NEKKANTI
2012ABPS525H
KONREDDY VARUN KUMAR REDDY
2012ABPS828H
SURYA TEJ BODDU
2012ABPS953H

2. MATERIAL SELECTION:
Any machine tool must be designed in such a way that it bears all the three important loads i.e,
Tension
Bending stress
Torsion
The weight of the bar is inversely proportional to the quantity E / ɤ , is known as unit stiffness of
the material in tension. The larger the unit stiffness of a material, the smaller is the weight of
the structure required to ensure the deflection of the structure due to a particular given load
does not exceed a specified value

3. Material E. kgf/cm2
ɤ.kgf/cm3 E / ɤ
LOW carbon steel 2.0*106 7.8*10-3 2.56*108
Medium carbon steel 2.1*106 7.8*10-3 2.69*108
Alloyed steel 2.1*106 7.8*10-3 2.69*108
Grey cast iron 1.2*106 7.2*10-3 1.66*108
Duraluminium 0.75*106 7.8*10-3 2.68*108

4. Property Steel Relation Cast iron
Strength steel > cast iron
Rigidity steel > cast iron
Wall thickness needed steel < cast iron
Casting steel < cast iron
Economy steel < cast iron

5. Part Material
Bed Grey cast iron
Head stock Steel
Tail stock Steel
Cross slide Steel
Carriage Grey cast iron
Tool post Steel

6. Pro-E model

7. Machine specifications
Length =1.542m
Width=0.43m
Maximum work piece dimensions= 50mm*550mm(cylindrical)
Factor of safety =2.5
Materials used =grey cast iron and steel , aluminum alloy .

8. Cutting forces
We basically look at turning operation on lathe machine and we tried to calculate the forces for
appropriate depth of cut and feed of the cutting tool.
Depth of cut=3mm
Feed =2mm/rev
Forces acting on the tool are
◦ Axial(Fa)
◦ Tangential(Ft)
◦ Radial(Fr)

9. Cutting forces calculation
Axial force= 2mm*3.14*50mm*1500
=805N
Calculated from the merchant circle diagram with a side rake angle of 8 and back rake angle of 6
degrees.
Radial force=315N
Tangential force=620N

10. Analysis
Static analysis of the structure is made on the ANSYS “static structural” module.
The governing constraint conditions are
The base is fixed i.e no degrees of freedom for it.
 The work piece is fixed onto the head stock and tail stocks rigidly.
 There is no sliding between the parts .

11. Meshed Assembly

12. Stress distribution at tool-workpiece interface

13. Stress distribution at base

14. Stress distribution at Tail Stock

15. Stress distribution (cross section of tool)

16. Conclusion
The lathe machine parts are assembled and are analysed for a real time machining operation
like turning and is tested for stress distribution , deformation, and torsion are calculated for each
part and the machine structure is allowable within the specified limits.