Manufacturing Process 1 - Jun 2015

Mechanical Engg (Semester 3)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.

Answer any one question from Q1 and Q2

1 (a) Explain commonly used materials for pattern making with advantages and limitations.(6 marks) 1 (b) A slab of size 300×300×50 mm³ is requires to cast from a molten steel using a top riser of 170 mm diameter. If (d/h) = 2 for riser, calculate the freezing ratio.(6 marks) 2 (a) Explain friction and lubrication in metal forming.(6 marks) 2 (b) Explain types of rolling mills.(6 marks)

Answer any one question from Q3 and Q4

3 (a) Explain submerged arc welding process. State the advantages and limitations of the process.(6 marks) 3 (b) Explain extrusion of film.(6 marks) 4 (a) Write short note on edge preparation in welding.(6 marks) 4 (b) Compare between TIG and MIG welding process.(6 marks)

Answer any one question from Q5 and Q6

5 (a) Calculate the amount of shear on the punch to cut a hole of 60 mm diameter in 2 mm thickness plate. The ultimate shearing strength of plate material is 400 MPa. If the punching force is to be reduced to half of the force using a punch without shear. Assume percentage penetration 68%.(7 marks) 5 (b) Write a note on strip layout.(6 marks) 6 (a) Explain with sketch type of pilots used in sheet metal working(6 marks) 6 (b) Find centre of pressure for a MS part as shown in Fig. 6(b) with 1 mm thickness. Take ultimate shear strength of MS as 200 N/mm². (7 marks)

Answer any one question from Q7 and Q8

7 (a) With neat sketch explain back gear cone pulley type Headstock.(7 marks) 7 (b) Explain Half nut mechanism.(6 marks) 8 (a) Why lathe centres and mandrels are required while machining on lathe? Also draw neat sketch of any two types of lathe centres and mandrels.(7 marks) 8 (b) Calculate the angle by which compound rest will be swiveled when cutting a taper on a job with diameters 90 mm and 40mm. Length of the job is 1.2m.(6 marks)