JNTU III B.Tech Supplimentary Examinations, Aug/Sep 2008

JNTU III B.Tech Supplimentary Examinations, Aug/Sep 2008

METROLOGY AND SURFACE ENGINEERING

(Mechanical Engineering)

SET-I

1. Sketch the fit for each of the following three pairs. For each of shaft and hole pair,

calculate shaft tolerance and hole tolerance and analyze whether the pair is

(a) Clearance fit

(b) Transition fit

(c) Interference fit.

Pair 1: Hole: 18+0.50+0.00 mm Shaft: 18?0.02+0.005 mm

Pair 2: Hole: 20+0.25+0.00 mm Shaft: 20+0.05+0.005 mm

 

2. Explain the classification of plain limit gauges? Sketch and explain any four types

of plug gauges?

 

3. (a) What are the measuring techniques employed in optical projector?

(b) Explain the application of chart gauges in optical projectors?

 

4. With the help of neat sketches describe how a dial gauge may be used as:

(a) Comparator

(b) Part of limit gauge

(c) A fiducial indicator

(d) Test indicator.

 

5. What is meant by Best Size Wire? Derive the expression for the same in terms of the pitch and angle of the thread. Explain the terms involved in the expression.

 

6. How are the following alignment tests carried out on a lathe machine? with figure.

(a) Parallelism of the main spindle to saddle movement

(b) Parallelism of quill movement of lathe tailstock with machine bed guides.

 

7. What is Gear Pitch? Describe any two methods of measuring Gear Pitch.

 

8. Describe different degreasing methods in detail with the help of neat sketches.