10me848qpset Design for Manufacturing and assembly

USN

Time:

1oME848

(09 Marks)

(06 Marks)

different machining(05 Marks)

(08 Marks)(08 Marks)(04 Marks)

3 hrs.

Eighth Semester B.E. Degree Examination, June/July 2014Design for Manufacturing and Assembly

Max. Marks:100

Note: Aruswer any FIVEfull questions, selectingatleast TIYO questions from each parL

PART _ AIllustrate the different types of fits.

4 parts with the following dimensions are to be assembled in randorn What should be thetolerance on the assembled length? Also, what is the dimension of assembled length?

Part 1: 2fi2:o631r:rnIPart2:18.91+0.03 mm

I

Part 3: 62.1?13'3; mm

a.

b.

c.

2a.b.

Part 4: 46.25 + 0.04mm.

Discuss the .relationship between attainable tolerance grades andprocesses.

What is flatness? Explain the procedure for determining flatness.Illustrate the various ter,rns used in connection with surface finish.Explain any 2 terns used to describe surface roughness.

a. Discuss the concept of interchangeability. (12 Marks)b. Explain the term selective assembly. (08 Marks)a. In a pressure measurement experiment, the following values are obtained. Calculate the

mean, mean deviation and standard deviation. (10 Marks)Pressure,lfa Frequency

9.89.910.010.1t0.2

J48J2

b. What is process capabllity? Explain the process capability indices Co and Cpr. (10 Marks)

1 af2

5a.b.

6a.b.

IOME848


Illustrate the various design considerations for thread cutting (external), drilling, milling andtapping operations.eiifaln Uiiefly, how reduction in machinfug area, can be achieved, in turning nro.JlX.*"tut'

(02 Marks)

Iltustrate the use of cored hores to ."I*tk,ilrt* of holes.Illustrate the match-plate patterns used in sand castiig.Briefly explain the design rules for producing good clstings.

Discuss the major phases of design process.List the basic principres that will help the designer in speciffingcomponents for economic production.Discuss the main considerations (any 3) in the design of weldments.Explaiir in detail the materiar selection in product design.Make a comparison of elastic modulus foi different clisses ofmaterials.

7a.b. (10 Marks)the product and its

(04 Marks)(06 Marks)


c.

8a.b.

****d.

ara*

Time: 3 hrs.

1a.b.c.

d.

2a.

3a.'b.

06M8848


(10 Marks)

(08 Marks)

(r0 Marks)

(10 Marks)

Eighth Semester B.E. Degree Examination, Decemb er 2OlODesign for Manufacturing and Assembly

Max. Marks:100Note:1. Answer any FIVEfutl questions, selecting at

least two questionsfrom eoch Part.. IJse of SQL tables ond normal distribution tables is allowed.

PART - A

Explain Indian standard system of limits and fits (IS 919 and2709) (04 Marks)Give the relationship between attainable tolerance grades and different machining processes'(04 Marks)

Give the symbols used in geometric tolerancing, to describe the form of a feature, profileand other related features. (10 Marks)

b. A 25 mm H8-fl/ fit is to be checked. The limits of size for H8 hole are 25.030 mm low limitequal to basic size. The limits of size for the f7 shaft are high limit 24.970 mm andZi.gSO mm. Taking gauge maker's tolerance to be l0% of the work tolerance, design plug

classify fits. Explain different types of fits, with an example each.Differentiate between tolerance and allowance'

gauge (gap gauge) to check the fit.

What are the elements of a surface texture? Explain with a neat sketch'

ofthe surface.

What are the 7QC tools in SPC? Explain them.

The surface finish on the milled surface is not to exceed 5 pm Ra with a cut off lengthZ mm, machining allowance 0.5 mm and direction of lay parallel. How will you represent iton a drawing? (02 Marks)In the measurement of surface roughness, heights of 20 successive peaks and valleys,measured from a daturn are as follows: 45,25, 40,25, 35, 16,22, 40,25,34,25, 40,20,36,28,18,20,25,30, 38.If these measurements were made over a length of 20 mm, determine CLA and RMS values

4a.b. A control chart has been used to monitor a certain characteristic. The process is sampled in a

subgroup size of 4 at an interval of 2 hours. X -chart has 3o control limits of 121 and t29

with the target value of X =125.i) If the product is sold to a user, who has a specification of 127 + 8, what percentage of

the product will not meet the specification, assuming normally distributed output?ii) If the target value of the process can be shifted, without eflect on the process standard

deviation, what target value would minimize the amount of product being outside thespecifications?

iii) At this new target value, what percentage of the product will not meet the specificationrequirement? (10 Marks)

PART - B5 a. Explain the major design phases (seven phases) in morphology of design. (12 Marks)

b. What are the principles of casting design that must be observed to obtain sound castings?(08 Marks)I of2

7a.b.

06ME848

6 a. What are the design factors, considered in machining and welding? Explain. (t0Marks)b. Explain the following terms, related to a component design:

i) Run out.ii) Reduction of machined areas.iii) Simplification by separation.iv) Simplification by amalgamation.v) Provision for holding the work piece.Explain the composition properties of various materials used in design.A cast iron bearing bracket is shown in the figure Q7 (b). Indicate the preferred parting lineand any necessary sand cores. Offer a design modification that will reduce or eliminate theneed for sand cores. (10 Marks)

8 The hub shown in figure Q8 is made of carbon steel. Discuss the steps of planning the process tomanufacture this part. Draw the operation sheet also. (20 Marks)

Ctmrnl.ar(.t

*[ dfracrr3t cr78 Ln rat

(10 Marks)

(10 Marks)

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Fig. Q7 (b)

Fig. Q8

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USN06ME848

Max. Marks:100

(0E Marls)

(06 Marks)

Eighth Semester B.E. Degree Examination, June/July 20llDesign for Manufacturing and Assembly

Time:3 hrs.

1a.b.c.

3a.b.

4a.b. Write a note on Kurtosis.

Note: Answer FIW full questions selectingat least fWO questionsfrom each part.

PART -

AWith suitable sketcheq explain upper deviation, lower deviation and fundamental deviation.(05 Marks)What is fit? Explain clearance, interference and transition fits. (10 Marks)Write a note on tolerance accumulation. (05 Marks)

a. What is GD and T? Explain any six geometrical characteristics with symbols. (15 Marks)b. Intrepret the following Fig.Q.2(b) : (03 Marks)

Fie:Q.2(b)c. Define true position tolerance. (02 Marks)

Explain the terminology used for surface roughness. (10 Marks)With a neat sketch, explain Tomlinson surface.meter to measure surface roughness.l0

Marts)

Explain how process capability helps to measure whether the process under study meets therequirements or not. (12 Marls)

5 a. Identify the possible parting line for the lever shown in F .s(a).

$+o

Fie.Q.s(a).

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$16izo

PART -

B

6a.b.

06ME848

Indicate the preferred parting line and any necessary sand cores for the C.I. bracket shown inFig.Q.s(b). Offer a design modification that will reduce or eliminate the need for sand cores.

(14 Marks)

Fie.Q.s(b)

With suitable example, explain how amalgarnation helps in reducing machining. (06 Marks)Comment on the undesirable machining feature involved in the shaft design of the sub-assembly shown in Fig.Q.6(b). Also show a suitable design modification to the shaft andshow an alternative method of securing the gear to the shaft when the gears are finishmachined in stores. (14 Marks)

Fig.Q.6(b)

7 a. v/ith the help of a block diagram, explain ttre major design phases.b. Mentionthe factorsto be considered while designing a cast componenl8 a. Explain the factors which affect the design of a component.b. Explain any two material selection processes.


(lOMarks)(10 Marks)

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USN06M8848

Max. Marks:100

(12 Marks)

(20 Marks)

of surface(10 Marks)(10 Marks)

(20 Marks)


machining(06 Marks)(08 Marks)(06 Marks)

(20 Marks)

(15 Marks)behaviour of the

(05 Marks)

Eighth Semester B.E. Degree Examination, I)ecemb er 20llDesign for Manufacturing and Assembly

Time:3 hrs.

la.b.

Note: Answer any FIW full questions, selectingot least TWO questionsftom eoch part'

PART -

AMention the importance of tolerance. fxplain the unilateral tolerance and bilateral tolerance.(0E Marks)Determine the type of fit for 60mm shaft and hole pair designated H8lf7 '

Diameter stePs = (50 - 80)is:-5.5DoarIT8 :25 iIT7:16i

Z Explain the following geometrical characteristics, with symbol and its interpretation:i) circularity ii) cylindricity iii) Flatness iv) Runout

3 a. Explain how the Tomilson surface meter can be used for direct measurement.

qualitY.b. Exptain the terminologies used for surface rougness'

4 Write short notes on:i) Process caPabilitY ii) Kurtosis.

PART -

BDefine pattern. With the help of a sketch, explain the various pattern allowances.With skeJches, differentiate between cast and cored holes.Identify the possible parting line for ahollow bush.

6 a. Explain with an example, how length of the twist drill is an importantconsideration.

b. Write a note onthe reduction of machined areas.c. Explain how the amalgalnation helps in the reduction of machining areas.

7 Explain the major design phases with the help of a block diagram.

8 a. Exptain the following material selection processes:1) Cost Per unit ProPertY methodii) Weighted ProPerties methodiii) Limits on ProPerties method.

b. With a suitable example, explain how component geometry affects thecomponent.

5a.b.c.

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USN

2a.b.

c.

3a.

b.

4a.

b.

c.

06ME848

(0E Marks)

Eighth Semester B.E. Degree Examination, June 2012Design for Manufacturing and Assembly

Time: 3 hrs.Note: l. Answer FrvEfult questions, selecting

Max' Marks:100

at least TWO questionsfrom each parL2. Missing data if any, ffie be suitably assumed

PART -

AI a. Define the following :

D Fits ii) Basic size iii) Fundamental deviation. (06 Marks)(06 Marks)b. State the Taylor's principle for the design of limit guage.

c. Determine the dimension and tolerances on flange thickness 'T' as in Fig. Ql (c). (08 Marks)

+ o'ogrt8'3-

o.o1

Fig. Ql (c)

Describe a method to find out the flatness of a surface plate. (06 Marks)Describe how a lobed surface is defured mathematically and show the dimensions of thegeometric form ofthe cross section. (06 Marks)A cylindrical piece ground on centreless grinding machine when measured by micrometerscrew guage shows the readings to be 20.000 mm. It is found that it only just fits into a trulycircular ring guage of 2A.040 mm diameter and it is uniformly three lobed. Determine thedimensions of the geometric form of the cross section.

Explain the following terms in connection with surface finish measurement:i) waviness ii) Lay iii) Envelope method iv) crest line method.

(08 Marks)Name and describe any two methods used for measuring surface roughness. (12 Marks)The mean value and standard deviation of set of observations have been found to be I00 andI0 respectively. Determine what percentage of observations will lie between 84 and I 16,i) above 82 and ii) below 79. (0E Marks)What do you understand by frequency distribution? What are the common probabilitydistributions? What are their forms and applications in statistical quality control? (06 Marks)What is the task of statistical quality control (SQC) and what are the statistical quality toolsavailable?

I of2(06 Marks)

5a.

b.

06M8848

PART -

B

Explain with sketches the different possible parting line for casting a hollow bush. What ismost suitable parting line for bush? (08 Marks)A cast iron bearing bracket is shown in Fig. Q5 (b). Indicate prefened parting line and anynecessary sand cores. Suggest the design modification that will reduce or eliminate sandcores. (12 Marks)

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Fig. Qs (b)

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6 a. Explain Dowels and Dwelling procedure.b. Suggest suitable sequence of machining operations to given cast iron plate

Fig. Q6 (b) and suggest a design modification which will reduce machining cost.

(05 Marks)shown in(15 Marks)

7 a. write a note on major phases ofdesign. (08 Marks)b. Explain the influence of fabrication properties on design in the below mentioned processes: 'i) Machinabilitv ii) castabitity iii) weldabitityiv) Polymer processing (12 Marks)

8a.

b.

Explain:i) Cost per unit property method.ii) Weighted properties method.Write a note on limits on properties method.


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10me848qpset Design for Manufacturing and assembly