me2101 - design process-2012-2x2-landscape-b+w.pdf

7/21/2019 ME2101 - Design Process-2012-2x2-landscape-B+W.pdf

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Associate Professor M O Lai

Room: E2-02-23

E-mail address:[email protected]

Tel: 6516 2577

Some information.

There isThere is NONO final examinationfinal examinationor s mo u eor s mo u e

small group design assignmentsmall group design assignment25% and a uiz 75% .25% and a uiz 75% . (Small(Small

group = minimum 2 maximum 3group = minimum 2 maximum 3students)students)

Tutorial:

Prof Lai None

Prof Seah Yes

Schedule of lecture:

Prof Lai - First 3 weeks (25% mark):

How to design a successful product

Prof Seah Middle 6 weeks (50% mark)

Prof Lai Last 3 weeks (25% mark):

Design against fatigue leading to design of

shafts

Selection of materials


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Prof LaiProf Lai NoneNone

Prof SeahProf Seah Mechanical EngineeringMechanical Engineering,, --

Hill.Hill.

What is engineering design?

ng neer ng es gn s a purpose uactivity directed toward the goal offulfilling human needs, particularlythose which can be met btechnological factors of our civilization.

Design:

Goal (or need) oriented

ar orm

Constrained

Evolutive

Probabilistic

Value comparative omprom s ng

Design philosophy

The relentless pursuit of Perfection


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Product life cycle

eded

NeNe

Mar

Market

ket

Recognition of need

Specifications and requirements

Feasibility study

ea generat on an eve opment

Prototyping/Evaluation

Detailed design

of Design

Production of design

ProcessObsolescence

Application of Design Process

Desi n of a DIYDesi n of a DIY

Concrete MixerConcrete Mixer


4/33

Recognition of need

rs s ep s o en y spec c nee ormarket) that is to be satisfied by a solutionbased u on technolo .

En ineerin desi n is a ur oseful activitdirected toward the goal of fulfilling humanneeds.

Driving forces behind design projects may.

Customers, government agencies, etc

Impetus from a changing market

Recognition of Need

Impetus from technological breakthrough

Impetus from a changing customeror s a e o er nee s

Examples of design needs:

Sony Walkman: Portable and individual music


5/33

Ai rcraft -safe bul lets: Counteract hi jackers

but save the lane The Watercone

50% (2.5 billion) of worlds populationhas no access to clean, drinkable water.

,inexpensive, simple but functional

African Sahara Desert beetle


6/33

Moisture in air condenseson surface. Droplets roll

down and collected at rim.

1959 Cadillac Cyclone

Need: To fulfill the craze of buyers for rockets andet en ines in the Post WWII eriod.

1956 Oldsmobile Rocket 1959 Cadill ac Biarrit z


7/33

Mazda Miata VW Beetle

ee : o u es re o ose w o m sse own nga classical car; to arouse nostalgic emotion of older

- .

Mini Cooper Fiat 500

Existing product may need to be

redesigned to:

eliminate shortcomings by incorporatingnew technology and manufacturingmethods

better serve changing needs of users

to meet competition in the marketplace

reduce cost of the product

Good design is good

Al l products can be

improved through

design


8/33

al

ventio

atches

Co

n

es

Watch

Triax

Nik

Nike sport shoes

Fl -awa alarm

clock that

makes

mosquito noise

Run-awa alarm clock

aXbo Sleep Phase Alarm ClockaXbo Sleep Phase Alarm Clock


9/33

Durin slee each erson oes throu h varioussleeping cycles each of 90 to 110 minutes. Automation of Processes

Lance Armstrongs Tour de France Bicycle


10/33

MICHELIN TWEEL

MICHELIN TWEEL


11/33

urinal

Appl icat ion to Design of a DIY Concrete Mixer

KonKret-miKs Ltd, also known as 3K

Company, designs and produces a widerange o u ng cons ruc on equ pmen .

Market Research Department of 3KCompany has identified a gap in themar e or ow-cos ow-capac y concre e

mixers suitable for practical do-it-yourself.


12/33

Board Meeting decisions:

Present: Managing Directora es rec or

Technical Manager

Market Research Manager

Decisions:

a) Draw-up specifications, etc

b) Design mixer

Recognition of need

en ca on o cons ra n s mpose

orp o ogyof Desi n

Process

Client may impose constraints to fit budget,

niche.

Additional constraints may be:

Convention or code (such as building codes) Compatibility with existing equipment (eg. Standard tire

sizes)

Com atibilit with matin arts of an assembl

Available power requirement (eg. 220V, 15amps, etc)

Regulatory requirements (eg. Auto emission rules)

Industry standards (eg. Thread on a light bulb base)

Product environment (eg. Temperature, pressure,humidit


Further market research data:

Suggested price: approximately S$750

Sale forecast: a roximatel 5,000 units eryear (export to neighbouring countries)

Configuration : Compact, light weight, easily

dismantled for transport in a small station-wagon or estate car


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Recognition of need



orp o ogyof Desi n

Process

Lamborghini - Murcielago 6.2Ferrari - 360 Modena Spider

Ferrari Lamborghini

6 Speed Manual Standard Transmission 6 Speed Manual. .

3586 Displacement (cc) 619240 Valves 48400 at 8500 rpm Horsepower 571 at 7500 rpm

a rpm orque a rpm35.4/35.4 Steer Diameter (Curb) 41.2/41.2MID/RWD Engine Location/Drive MID/4WD-FTDisc/Disc Brakes (Fr/Rr) Disc/Disc

215/45R18Tires

245/35R183197/NA Curb Weight 3638/NA102.3 Wheelbase(Fr/Rr) 104.965.7/63.6 Track 64.4/66.7176.3 Length 180.375.7 Width 80.548.6 Height 44.7

Key Features : 1.8in. LCD display Resolution: 640 x 480 pixels, 320 x 240 mode No. of pictures: 15 at 640 x 480, 50 at 320 x 240

Add iti onal Features : Automatic focus

- Automatic power-saving mode Video cable included for TV view

3 Flash modes: Autoflash, Force Flash, and No Flash JPEG com ression

Specifications : Internal memory: 2MB Flash Range: 3 to 6 feet (1 to 1.8 m) Focus Range: 3 feet (1 m) to infinity Batteries: 4 AA (included) or AC adapter (included) Packaged with PhotoMAX SE Software Dimensions 2.63 in.H x 5.38 in. L x 1.88 in. D e g oz. w a er es)

System Requirements :

Windows 95 or 98 only, CD-ROM drive, 32MB RAM-

PhotoMAX Fun Flash, , -

display card, 24-bit recommended, Sound card(recommended), Available RS-232C serial port

from Polaroid

Example of Design

Portable Winch


14/33


15/33


16/33

Design specs may be of several types:

Physical

pace a oca on; mens ona requ remen ;weight limits; energy/power requirements

Environmental

temperature range; noise limits

Funct ional or operationalAcceptable vibrational ranges; operating

times

Economic

Limits on production costs; operating costs;service/maintenance requirements; existence

Government safety requirements;environmental/ ollution control codesproduction standards

Human factors/ergonomics Stren th; intelli ence; anatomical dimensions

of users


Capacity 60 liters mixed batch (equivalent to anaverage wheel barrow load)

Dimensions 420 mm diameter drum opening

1050 mm total hei ht610 mm maximum between wheels

.

Assembly All items easily assembled and

using basic tools

r ve(suitable for domestic

supply)

. p , s ng e p ase, zelectric motor, speed 1450 rpm.

Final specifications cannot be

determined unti l:

A prototype model has been designed,

.

Cost analysis is completed; customerfeedback obtained after a trial batch ofat least two units has been sold and

used.


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Requirements to be considered:

(1) Condit ions of use:

Mixer must be able to mix quantities of cement,water, sand aggregates or plaster in varying,

spillage

It should be light, portable, manoeuvrablearound garden or work area; transportable in

sma s a on wagon or es a e car

er ormance an re a y o m xer no a ec eby climate condition

(2) Characteristics of components:

x ng rum: p ast c n ect on

molded or welded steel cone;

suppor ted by bearings; 2 heavy-

Mouth: easily loaded with

shovel, and enable fast

duty mixing blades;

Drive: speed

reductionTilt-handle:

from motor

by gears or

belt drive

main frame for

transport, circular

Guard:

welded steel

s ee u es, ong

enough for easy

tipping, ergonomic

platesas per e man

Frame: welded steel angles or

,

200 mm, plastic injection

molded or welded steel plates

stiffness but minimum

materials to reduce weight

filling and tipping

Ease of manoeuvrability Ease of tipping

Comfortable grip of tilt-handle

Ease of assembly, dismantling and maintenance

Weight of dismantled parts

Availability of tools (for assembling and

dismantling)

(4) Aesthetics (appearance) considerations:

Should look symmetrical and stable; giveim ression of recision and efficienc offunction; quality of manufacturing; pleasingcontinuity of profile; refreshing up-dated sense

Flat surfaces and smooth lines to enable easycleaning

(prime and finishing) against rust, weather and

rough treatment; pleasing colour choice on drum,


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(5 Performance:

Protot e to be tested for erformance under

similar conditions as in actual service

Should allow some overloading; to cope withsevere cases, motor to be fitted with thermal

6 Life and reliabilit :

=

for stated number of hours per day and days peryear operation

Prototype to be tested under stated conditionsw n erm en s op s ar

during prototype testing should be quoted infinal specification

packed in cardboard carton with assembly

instruction booklet and warranty card (for motoronly)

Instruction manual to consist of mixer inexploded view with parts numbered; parts to be

(8) After-sales service:

Servicing to be done by owner with aid of instructionbooklet and standard workshop tools.

General spare parts available are:

Pulleys and belts Shafts (for gears and drum) Motor

Special parts (in small quantity) available are:

rum Wheels Guard Tilt-handle


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Mixer be scraped at end of useful life

Metal parts to be reused or recycled

Plastic (if used) parts be made of recyclable orbio-degradable materials

Recognition of need



Feasibility study

orp o ogyof Desi n

Process

Feasibility study

Aim: to verify possible success or failure of adesi n ro osal from technical and economicstandpoint.

Some factors to consider:

Any natural law defied?

Any specs beyond technically availablecurrently?

Any dependency on scarce materials?

Product cost being too high?Any public objection to use of product?

Appl ication to Design of a DIY Concrete Mixer

eas ty eva uat on:

Mixer is technologically and economicallyfeasible to be designed, fabricated and marketed

Guard: fo rmedand welded in-

house

,

internal parts and

structures:

o or ear

box: to be

purchased as

orme an

welded in-house;

if plastic drum, be

stan ar

parts;

available

su -con rac e

out; quality to be

ensured

Wheels and rims: purchased

as standard parts; available

Frame and tilt -handle:

formed and welded in-house


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1 Order of drive motor 0.5 week

2 Delivery of motor 4 weeks

3 S n thesis and evaluation of drive s stem 0.5 week

4 Order of pulleys and belts (if chosen in design) 0.5 week

5 Delivery of pulleys and belts 2 weeks

6 Cost analysis of drum 0.5 week

Planning

schedule -

Network7 rder o Drum 0.5 week

8 Delivery of drum 6 weeks9 Cost analysis of wheel and rim 0.5 week

10 Order of wheels and rims 0.5 week

analysischart:

11 Delivery of wheels and rims 5 weeks

12 Selection and order of bearings 0.5 week

13 Delivery of bearings 3 weeks

to determine

design time

to produce a- .

15 Comparison and evaluation of frame 1 week

16 Design calculations 1 week

17 Design drawings/sketching 1 week

fully-tested

prototype

mixer. Table18 Overall cost analysis of product 1 week

19 Re-design for cost (if necessary) 0.5 week

20 Detail drawings and instruction manual 1 week

showsallotted

tasks , , , , ,

22 Assembly of whole mixer 0.5 week

23 Testing of mixer 3 weeks

24 Re-design for function (if necessary) 1 week

Network analysis chart: indicates a prototype design time of 12.5

weeks is required (crit ical path along tasks 14, 15, 16, 17, 18, 19,20, 21, 22, 23 and 24)

Recognition of need



Feasibility study

Idea generation and development

orp o ogy

of DesignProcess

Idea generation and development

This is most challenging part of design whereinnovative ideas are enerated throu h brainstormin

All possible ideas are examined carefully andun ase y

functional relations between various parts and

systems to validate the functional and overall sizerequirements of design specifications


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Some

possible

solutions

1.25m

Some1.0m

solutions

After some brainstorming sessions and evaluation:

Idea generation/development of tilt-handle

Idea generation/development of drive


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Idea generation/development of supporting frame

Idea (a) Idea (b) Idea (c)

Idea generation/development of drive(reduce motor speed = 1450rpm to drum speed = 30 rpm; speed reduction = 48.3 : 1)

Idea (a) Idea (b) Idea (c)

Worm ear box Worm ear box Sim le, neat and

expensive; and

unnecessary

bulky, heavy, and

expensive

low cost; no gear

box needed

Recognition of need


Feasibility study



of DesignProcess


Built and test prototype to evaluate

required.

At least three construction techniques available:

1. Mock-up :

Generally constructed to scale from

plastics, wood, cardboard, etc to givees gner a ee o e es gn


23/33

Purpose to check clearance, assemblyec n ques, manu ac ur ng cons era ons,

and appearance

Least expensive

May be replaced by solid model in CAD

en re erre o as roo o oncepprototype

Mock-up

2. Model :-

This is a detailed visual, mathematical, 2- - ,

often used to test ideas and/or make

features of the final design

Often referred to as Proof of Product

rotot e


24/33

3. Prototype :-

This is a full-scale working model of a,

and function of the intended design

Purpose test a design concept by

necessary adjustments

Most expensive technique but producesthe reatest amount useful information

Prototypes

Prototype of J-20 Stealth f ighter, China - 2011

Other departments involved at this stage of

Manufacturin

Maintenance

Materials etc

Some questions to ask:

Can material be changed to improve product?

Can parts be fabricated?

What is the best process to fabricate them? Fabricate in-house or sub-contract out?


25/33

More questions to ask:

Can amount of material required be

Can assembly time be reduced? Or madeeasier?

Can number of drawings be reduced?

Is there a sim ler wa to desi n it?

Can it be made from standard parts?

Is it more economical to buy part than

designing and manufacturing it? How do others do it? Copy it? Modify it?

mprove uy or your own use


Human

factors :

To estimate framedimensions,

estimated full

weight of concrete

mixer, comfortable

lifting force of a 5th

percentile adult

man (from

anthropometricdata charts) at

315mm handle

height, are

considered

Details of support st ructure: Size of rectangular hollow steel

sections as supporting frame calculated for bending and torsionwith critical area at base of upright pedestal to support drumshaft assembly and handle

Details of

wheel axle:

rcu ar steetube used and

for bending

Examples of detail


26/33

Examples of detail

calculations:

Handle tube sized to be33.7mm outside diameter

.

max bending moment

Drum shaftdoes not

transmittorque; sized

usin

maximum

bending stress

suppor t assembly.Note fabrication

tension adjusting

method

Pinion-shaft

calculated for

bending andtorsion under

.Stressconcentrationfactor at weakestpoint considered

e ec on o s an ar componen s:

Bought-out components like belt drive,

from manufacturers catalogues

Sizes of bolts and screws determinedor ens e an s ear oa ng

C t A l i

R d i f t


27/33

Cost Analysis:

Unit cost of mixer = $500

Fixed cost per batch (5,000 units) =,

For 5,000 units, total cost = $350,000 +x , = , ,

For $750 sellin rice, total income =

5,000 x $750 = $3,750,000 , .

Re-design for cost:

Unit cost of mixer of $750 appears reasonable

To be competitive, comparison is made withcompetitors products:

List price Remarks

ompe or

Competitor B $1092 Selling at 15% below list price

ompet tor scoun or mu p e or ers

Competitor D $1560 Selling at 15% below list price

Competitor E $840 Selling at 10 % below list price

Actual cost comparison:

Competitor A $1104 $773

Competitor C $950 $713

ompe or

Competitor E $840 $756

To be competitive with competitor C, proposeinitial price be discounted by at least 5%.

Better to re-design to reduce cost: Use lessro us rum; re uce qua y o e ec r c mo or,use thinner steel structures, etc

Re-design for function:

Protot e mixer fabricated tested andanalyzed

Torsional deflection of motor-mountinglate caused excessive vibration under

dynamic loading

Motor-mounting re-designed with flange

rather than stiffening plate

Rigidity of motor mounting plate improved with flangesRecognition of need


28/33

Rigidity of motor-mounting plate improved with flangesg


Feasibility study

ea genera on an eve opmen


Detailed design

of Design

Process

Detailed design

Finalise and full desi n all com onents andsystems with dimensions/tolerances, materialsselection, quantity, and assembly details

Prepare all working drawings

Verification/Approval of drawings

Workingdrawings are

drawn

Final product:


29/33

Final product: Mixer stand(optional extra):

Stand may beneeded for tippingconcrete directlyinto wheel barrow

Designed usingRubberstopper

stee tu es we etogether; feet with

ensure stability

Optional stand fortipping concrete directlyinto wheel barrow

Instruct ion booklet:

Information in instruction bookletinclude:

Part list of mixer

Assembly instruction of mixer


30/33

1 Ex loded1A

2

34

5

view of

mixer

6

7

88A9

assemblyprocedure1011

1213

14

16

17

1819

20

2122

2324

2526

2728

Dismantled parts of mixer

Opening of

cardboard carton in

which complete

mixer is packageds

r

uctio

ingins

Operati

Dismantled for transport in a small Recognition of need


31/33

station wagon at end of use


Feasibility study



Detailed design

of Design Production of design

Process


A rove detailed desi n and roduceproduct

Consider capital investment to pay forfor materials, labour, subcontractors,fabrication, and loan etc.

Time schedule for production and

delivery dates Network analysis chart: indicates a prototype design time of 12.5weeks is required (crit ical path along tasks 14, 15, 16, 17, 18, 19,20, 21, 22, 23 and 24)

Recognition of need


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Feasibility study



Detailed design

of Design Production of design

Process

Distribution, sale, usage

Distribution of product ver s ng an mar e ng

Pricing to ensure optimum sales andprofits

Feedback of ublic o inion

Availability of spare parts and services

Recognition of need


Feasibility study



Detailed design

of Design


ProcessObsolescence

Obsolescence

,be capable of prolonged operation

Product to be succeeded by new

spose a a ou env ronmenRecycleable?

E l S W lkFeature Company Date Imitated


33/33

Exam le: Son Walkman

Before the Walkman is obsolete, newtechnologies and features have been introduced

to prop up the sale of the product.

History of innovation of Walkman 1979-1988:

Feature Company Date Imitated

Mini headphones Sony 1979 Yes

Stereo recording Sony/Aiwa 1980/1 yes

Auto-reverse KLH SOLO 1981/2 yes

FM headphone radio Sony 1981/2 yes

Downsized unit Sony 1982 yesDolby Sony/Aiwa 1982 yes

Direct drive Sony 1982 no

Cassette-sized unit Sony 1983 yes

Short-wave tuner Sony 1983 no

Remote control Aiwa 1983 yes

Detachable speakers Aiwa 1983 yes

Water resistance Sony 1983/4 no

rap c equa zer ony yes

Rechargeable Sony 1985 yes

Feature Company Date Imitated

-

Radio presets Panasonic 1986 yes

Dual cassette Sony 1986 no

TV audio band Sony 1986/7 no

Digital tuning Panasonic 1986/7 yesChilds model Sony 1987 yes

Enhanced bass Sony 1987/8 yes

Voice activated Toshiba 1988 no

As worldwide sales rew ra idl com etitionbecame intense. To maintain market share and

leading position, Sony had to continually developan aunc mprove pro uc s, even e oreexisting ones became obsolete.

Recognition of need


Feasibility study



Detailed design


Obsolescence

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