Manufacturing Process 1 - Dec 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.

Solve any one question from Q1 and Q2

1 (a) Explain Lost-Wax casting process in detail.(6 marks) 1 (b) A casting of 50cm ×40cm×10cm size solidifies in 20 min. Find the solidification time for 40cm×30cm×5cm casting under similar condition.(6 marks) 2 (a) Explain wire drawing process with neat sketch.(6 marks) 2 (b) Compare Hot working and Cold working process.(6 marks)

Solve any one question from Q3 and Q4

3 (a) Explain blow moulding with suitable sketch.(6 marks) 3 (b) Write a short note on extrusion process in making film and cable.(6 marks) 4 (a) Describe oxyacetylene welding with neat sketch.(6 marks) 4 (b) Why is coating essential on arc welding electrode?(6 marks)

Solve any one question from Q5 and Q6

5 (a) Compare blanking and piercing operation.(6 marks) 5 (b) Determine the material utilisation factor for producing 40 mm dia. circular blank from sheet of 3 mm thickness by considering allowances a=t+0.015*d and b=t. Sequence of blanks show in Fig. 1. Number of blanks = 5. (7 marks) 6 (a) Find the centre of pressure for the following Fig 2: (7 marks) 6 (b) Write a short note on progressive, compound and combination dies.(6 marks)

Solve any one question from Q7 and Q8

7 (a) Draw single point cutting tool, also write down significance of different angles involved in the geometry.(6 marks) 7 (b) A steel shaft of 75 mm diameter and 250 mm long turned on a lathe. Speed of spindle = 2 m/s, feed=0.25 mm/rev. Find time required for 50 jobs by assuming 2 minutes for handling of each job.(7 marks) 8 (a) Explain different operations performed(5 marks) 8 (b) Calculate the machining time required to reduce 60mm diameter shaft to 50 mm diameter for a length of 1500 mm and with depth of cut 2.5 mm for rough cut and 1 for finish cut. Given:
Cutting speed = 30 m/min. Feed = 0.5 mm/rev. Approach length = 5 mm, overall length = 5 mm. Number of passes = 3 (2 rough cut + 1 finish cut).(8 marks)