me2101 1 design process 2016

8/18/2019 ME2101 1 Design Process 2016

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Application of Design Process

Case Study

Design of a DIYConcrete Mixer


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First step is to identify specific need (ormarket) that is to be satisfied by a solutionbased upon technology.

Engineering design is a purposeful activitydirected toward the goal of fulfilling human

needs.

Driving forces behind design projects maycome from….

Recognition of need

Recognition of Need

Impetus from designer sponsor:Customers, government agencies, etc

Impetus from a changing market

Impetus from a changing customeror stakeholder needs

Impetus from technological breakthrough


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Sony Walkman: Portable and individual music

Examples of design needs:

Aircraft-safe bullets: Counteract hijackersbut save the plane


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Harvesting of water

Need:

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

How to design an innovative,inexpensive, simple but functionalproduct to create potable water?

African Sahara Desert beetle


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Moisture in air condenseson surface. Droplets roll

down and collected at rim.


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Need: To fulfill the craze of buyers for rockets and jet engines in the Post WWII period.

1959 Cadillac Cyclone

1956 Oldsmobile Rocket 1959 Cadillac Biarritz

Need: To fulfill desire of those who missed owning

a classical car; to arouse nostalgic emotion of olderdrivers and attract Y-generation car buyers.

Mazda Miata VW Beetle

Mini Cooper Fiat 500


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Existing product may need to beredesigned 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 business……

All products can be improved through design……


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Run-away alarm clock

Fly-away alarmclock thatmakesmosquito noise


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aXbo Sleep Phase Alarm Clock

During sleep, each person goes through varioussleeping cycles each of 90 to 110 minutes.


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Lance Armstrong’s Tour de France Bicycle

MICHELIN® TWEEL™


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Waterlessurinal


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Morphologyof DesignProcess

Recognition of need

Identification of constraints imposed

Client may impose constraints to fit budget,company manufacturing capabilities or marketniche.

Additional constraints may be: Convention or code (such as building codes)

Compatibility with existing equipment (eg. Standard tire

sizes) Compatibility with mating parts of an assembly

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,humidity)


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Recognition of need

Specifications and requirements


Ferrari Lamborghini

6 Speed Manual Standard Transmission 6 Speed Manual3.6L V8 Standard Engine 6.2L V123586 Displacement (cc) 6192

40 Valves 48400 at 8500 rpm Horsepower 571 at 7500 rpm276 at 4750 rpm Torque (lb/ft) 479 at 5400 rpm35.4/35.4 Steer Diameter (Curb) 41.2/41.2MID/RWD Engine Location/Drive MID/4WD-FTDisc/Disc Brakes (Fr/Rr) Disc/Disc215/45R18 Tires 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

Lamborghini - Murcielago 6.2Ferrari - 360 Modena Spider


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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

Additional Features :

• Automatic focus• Self-timer• Automatic power-saving mode• Video cable included for TV view• 3 Flash modes: Autoflash, Force Flash, and No Flash• JPEG compression

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• Weight 10 oz. (with batteries)

System Requirements :• Windows 95 or 98 only, CD-ROM drive, 32MB RAMmemory, 85MB hard drive space, VGA monitor with 16-bitdisplay card, 24-bit recommended, Sound card(recommended), Available RS-232C serial port

PhotoMAX Fun Flash640 digital camerafrom Polaroid

Example of DesignSpecification:

Portable Winch


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Design Brief

From internal market research, it has been decided that IWC needs to design ageneral purpose winch to sell to the cable and pipe laying market sector. The winchshould be portable but have mounting points for the end user. It is important that thewinch sits within our current range of 'Excel General Purpose winches'.

1.0 Performance 1.1 Lift / lower a load of 2.5 tonnes (+/- 10%). 1.2 Draw in cable in at a rate of 0.2 m/s. 1.3 Winch drive should cut out when the load exceeds 10% of the specified load. 1.4 Drive to stop lowering load when only 1.5 metres of cable remains on drum. 1.5 Winch should operate with forward, reverse, stop and inch facility. 1.6 Any braking system employed, should produce a braking torque of 150% the

full load torque. 1.7 Winch should have a manual device to control the brake release and load

descent in the event of a power failure. 1.8 In the event of the winch 'overrunning', a manual safety relay/braking device

should operate within 1 second or before the load exceeds a speed of 3m/s. 1.9 The product should be portable but with the option for permanent mounting. 1.10 The product must use a portable power source, preferably a diesel engine. 1.11 The weight of the product must be sufficient to aid the stability of the product. 1.12 Efficiency of the unit should be high, preferably in the area of 20 - 30%. 1.13 The drum should hold 50m of cable.

2.0 Environment 2.1 The winch drive and power unit should be power unit. 2.2 The unit will be mainly used in European weather conditions. But we

could expect sales of about 2% unit volume to the Far East. 2.3 Temperature ranges:

-28 degree C - European12 - 44 degree C - Far East

2.4 The product may experience humid conditions. 2.5 Corrosion resistance may be considered by the use of special materials

or surface protection methods. 2.6 Any noise from the equipment should not exceed 95 dB at a distance of

1.0m. 2.7 The winch will be stored in suppliers warehouses before sales.

3.0 Product Life Span 3.1 Product will be on the market for 10 years. 3.2 Spare parts will be available for a further 5 years after that.

4.0 Life in Service 4.1 Should withstand an operating period of 1 hr uninterrupted use per day

for 5 years. 4.2 Life in service should be assessed against the criteria outlined in the

Performance and Environment categories.


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5.0 Shelf Life 5.1 The product will be stored on-site for up to 1 month before dispatched. 5.2 Our Far East distributor may store the product for several months.

6.0 Target Costs 6.1 The product should have an end-user cost of £5500 within Britain. 6.2 The cost of manufacture should be less than £2750. 6.3 The cost of packaging and shipping should be no more than 15% of the

manufacturing cost.

7.0 Quantity 7.1 150 units in the first year, increasing to 800 within four years.

8.0 Maintenance 8.1 To be maintenance free except for light lubrication once a month and a

recommended service every two years. 8.2 Parts requiring lubrication should be accessible within 15 minutes

without the use of special tools or equipment. 8.3 All fasteners used should comply with BS6105. 8.4 Spares should be available for 5 years after the product is replaced with

a new model. 8.5 No special tools should be required for maintenance.

9.0 Marketing 9.1 Initially to be manufactured for European market but Far Eastern

distributors in Singapore, Hong Kong and Australia will find a market. 9.2 The winch should be operating against equivalent models which

include the following companies: Swansom - England Oholom - Sweden Winderhock - Germany

9.3 Applicable markets: Telecom - Cable laying Gas and Electricity operators

Pipe laying services Civil Engineering Operations

9.4 Summary of market requirements: Portable winch which can be attached to vans and low loaders Use portable power source To be used in all weather To allow one man operation To have at least 40m of cable To pull 2000kg

10.0 Packaging 10.1 Packaging / transport cost should be kept to a minimum and

preferably below 5% of the unit cost.


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11.0 Size and Weight Restrictions 11.1 Weight should not exceed 500 kg. 11.2 Length not to exceed 2500 mm.

11.3 Width not to exceed 2000mm. 11.4 Height not to exceed 2000mm.

12.0 Shipping 12.1 Product will be shipped by road within Europe. 12.2 Product will be shipped by sea to Far Eastern markets.

13.0 Manufacturing Processes 13.1 Capacity is available for current market demand within scope to increase production to

200 per year without investment / expansion. 13.2 Motors, transmissions, bearing and ropes are bought in from the following suppliers: Drives:

Electric Motors - Brook Compton Diesel Engines - Gardener Hydraulic Motors - Hydrostatic Transmission Ltd

Bearings: RHP Bearings

Transmissions: Couplings - Wellman Bibby Worm Gears - Reynold Planetary Gears - David Brown (PPG Divisions) In-Line Gears - David Brown Radicon Ltd V-belts - Fenner

Ropes: Bridon

13.3 Castings and injection moulds produced by external suppliers.

14.0 Aesthetics 14.1 The form can follow function. 14.2 If cost dictates, the winch should look attractive to improve our perception

within the market.

15.0 Ergonomics 15.1 Controls to be mounted in an accessible position, relative to the operator i.e.

waist height - around 1m, to accommodate 95% of the working population. 15.2 All controls should be hand operated, requiring one-hand operation with a

maximum force of 1.5 N/m2 15.3 One man should be able to operate the product.

16.0 Customer Requirements

See Marketing

17.0 Competition 17.1 The winch will be operating against equivalent models which include the

following companies: Swansom - England Oholom - Sweden Winderhock - Germany

18.0 Quality and Reliability 18.1 Quality should be such that winches should not generally fail within a period

of three years and only 1 in 50 should fail within the first year. 18.2 No winch should fail in the area of the safety overload device.


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19.0 Standards and Specifications 19.1 Standards to be adhered to:

BS 5000 part 99 Motor Performance BS 6105 and BSEN 20898(1) Bolts BS 6322(2) & BS 4320 Nuts and washers BS 7676 and BS 4517 Gears BS 3019 Welding BS 5989 Bearings BS 2754 Electrical Insulation BS 5646 pt4 Bearing Housing BS 4235 Keys and Keyways BS 7664 Painting BS 1399 Seals

20.0 Company Constraints 20.1 None - except those outlines in Manufacturing and Processes.

21.0 Processes 21.1 All components to be of metric form and comply with ISO 4900 for

limits and fits.

22.0 Safety 22.1 No winch should fail in the area of the safety overload device. 22.2 Winch should not operate when maintenance is being carried out.

23.0 Testing 23.1 Testing is to be carried out on 5% of units. 23.2 All cables should be tested to BS3621.

24.0 Legal 24.0 Possible litigation lies in the user injuring themselves by having

access to moving parts during winch operation.

25.0 Installation N/A

26.0 Documentation 26.1 Product should be supplied with a user manual covering winch

operation and maintenance. 26.2 Suppliers require maintenance and repair manual.

27.0 Disposal 27.1 Plastic parts should be separable and marked to aid disposal.


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Design specs may be of several types:

Physical Space allocation; dimensional requirement;

weight limits; energy/power requirements…

Environmental Moisture limits; dust levels; intensity of light;

temperature range; noise limits……

Functional or operational Acceptable vibrational ranges; operating

times…

Economic

Limits on production costs; operating costs;service/maintenance requirements; existenceof competitors; equipment depreciation…

Legal

Government safety requirements;environmental/pollution control codes;production standards…

Human factors/ergonomics

Strength; intelligence; anatomical dimensionsof users…


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Recognition of need


Feasibility study


Aim: to verify possible success or failure of adesign proposal from technical and economicstandpoint.

Some factors to consider:

Any natural law defied?Any specs beyond technically available

currently?

Any dependency on scarce materials?

Product cost being too high?

Any public objection to use of product?


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Recognition of need


Feasibility study

Idea generation and development


This is most challenging part of design whereinnovative ideas are generated (throughbrainstorming)

All possible ideas are examined carefully andunbiasedly

Best solution is chosen for preliminary design

Overall configuration is made to establishfunctional relations between various parts andsystems to validate the functional and overall sizerequirements of design specifications


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Recognition of need


Feasibility study



Prototyping/Evaluation

Built and test prototype to evaluateperformance and to decide uponmodifications required.

At least three construction techniquesavailable:

1. Mock-up :–

Generally constructed to scale fromplastics, wood, cardboard, etc to givedesigner a feel of the design


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Purpose – to check clearance, assembly

techniques, manufacturing considerations,and appearance

Least expensive

May be replaced by solid model in CADsystem

Often referred to as Proof of Conceptprototype

Mock-up


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Mock-up

2. Model :-

This is a detailed visual, mathematical, 2-D or 3-D representation of the design,often used to test ideas and/or makechanges to a design

Purpose – test some of the functions orfeatures of the final design

Often referred to as Proof of Productprototype


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Computer Models

3. Prototype :-

This is a full-scale working model of adesign intended to have complete form, fitand function of the intended design

Purpose – test a design concept bymaking actual observations and makingnecessary adjustments

Most expensive technique but producesthe greatest amount useful information


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Prototypes

Prototype of J-20 Stealth fighter, China - 2011


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Other departments involved at this stage of

design include:

Manufacturing

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?

Example: Airbus A380has been designed with

25% of plane’s overallstructure made from

lightweight carbon-fiberreinforced plastic to

reduce weight.

Materials used in Boeing 787 - Dreamliner


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Use of Composites in Aircraft

L a r g e r w i n d o w s a v a i l a b l e

o n c o m m e r c i a l a i r c r a f t

Single sectionfuselage and

nose cone


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More questions to ask:

Can amount of material required bereduced?

Can assembly time be reduced? Or madeeasier?

Can number of drawings be reduced?

Is there a simpler way to design it?

Can it be made from standard parts?

Is it more economical to buy part thandesigning and manufacturing it?

How do others do it? Copy it? Modify it?Improve it? Buy it for your own use?

NUMBER OF PARTS REDUCED Swatch used novelmaterials, manufacturing techniques and visual design tobeat foreign competition. The number of componentsinside is reduced drastically. The plastic casing quartzanalog watch requires only 51 parts compared to typical90 to 150 parts found in conventional watches. Flexiblemanufacturing system is used to allow easy changes ofdesign. More than 30 million such watches have beensold, saving the Swiss watch industry in the nick of time.


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Recognition of need


Feasibility study


Detailed design




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Finalise and fully design all componentsand systems with dimensions/tolerances,materials selection, quantity, andassembly details

Prepare all working drawings

Verification/Approval of drawings


Recognition of need


Feasibility study


Detailed design

Production of design




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Approve detailed design and produceproduct

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 12.5

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


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Recognition of need


Feasibility study


Detailed design


Sale/Usage



Ensure supply of raw materials/services

Distribution of

Advertising and marketing

Pricing to ensure optimum sales andprofits

Feedback of public opinion

Availability of spare parts and services


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Recognition of need


Feasibility study


Detailed design


Sale/Usage

Obsolescence



At end of useful life, product should notbe capable of prolonged operation

Product to be succeeded by new

improved version or scrap?

Disposed? What about environment?Recycleable?


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Example: Sony Walkman Before the Walkman is obsolete, new

technologies and features have been introducedto prop up the sale of the product.

History of innovation of Walkman 1979-1988:

Feature Company Date Imitated

Walkman Sony 1979 yes

Mini headphones Sony 1979 Yes

AM/FM stereo radio Sony 1980 yes

Stereo recording Sony/Aiwa 1980/1 yes


FM tuner cassette Toshiba 1980/1 no

Auto-reverse KLH SOLO 1981/2 yes

FM headphone radio Sony 1981/2 yes

Downsized unit Sony 1982 yes

Dolby 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

Graphic equalizer Sony 1985 yes

Rechargeable Sony 1985 yes


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Solar-powered Sony 1986 noRadio presets Panasonic 1986 yes

Dual cassette Sony 1986 no

TV audio band Sony 1986/7 no

Digital tuning Panasonic 1986/7 yes

Child’s model Sony 1987 yes

Enhanced bass Sony 1987/8 yes

Voice activated Toshiba 1988 no

As worldwide sales grew rapidly, competitionbecame intense. To maintain market share andleading position, Sony had to continually developand launch improved products, even beforeexisting ones became obsolete.

Recognition of need


Feasibility study


Detailed design


Sale/Usage

Obsolescence




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Application ofDesign Process

Case Study

Design of a DIY

Concrete Mixer


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KonKret-miKs Ltd, also known as 3KCompany, designs and produces a widerange of building construction equipment.

Market Research Department of 3K

Company has identified a gap in themarket for low-cost low-capacity concretemixers suitable for practical do-it-yourselfenthusiasts.

Recognition of need

Board Meeting decisions:

Present: Managing DirectorSales DirectorTechnical ManagerWorks Director

Market Research Manager

Decisions:

a) Draw-up specifications, etc

b) Design mixer


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Further market research data:

Suggested price: approximately S$750

Sale forecast: approximately 5,000 units peryear (export to neighbouring countries)

Configuration: Compact, light weight, easilydismantled for transport in a small station-wagon or estate car


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

Dimensions 420 mm diameter drum opening

1050 mm total height

610 mm maximum between wheelsDrum speed Approximately 30 rpm.

Assembly All items easily assembled anddismantled by average DIY personusing basic tools

Drive(suitable for domesticsupply)

0.25 kW (1/3 hp), single phase, 50 Hzelectric motor, speed 1450 rpm.



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Final specifications cannot bedetermined until:

A prototype model has been designed,fabricated and tested.

Cost analysis is completed; customer

feedback obtained after a trial batch ofat least two units has been sold andused.

(1) Conditions of use:

Mixer must be able to mix quantities of cement,water, sand aggregates or plaster in varyingproportions under its own power, without

spillage

It should be light, portable, manoeuvrablearound garden or work area; transportable insmall station wagon or estate car

Performance and reliability of mixer not affectedby climate condition

Requirements to be considered:


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(2) Characteristics of components:

Mixing drum: plastic injectionmolded or welded steel cone;

supported by bearings; 2 heavy-duty mixing blades;

Drive: speedreductionfrom motorby gears orbelt drive

Guard:

welded steelplates

Wheels: two wheels, diameter200 mm, plastic injectionmolded or welded steel plates

Tilt-handle:detachable from

main frame fortransport, circular

steel tubes, longenough for easy

tipping, ergonomicas per 5th %tile man

Frame: welded steel angles orplates or tubes; ensurestiffness but minimum

materials to reduce weight

Mouth: easily loaded withshovel, and enable fastemptying

(3) Ergonomic considerations:

Size and height of drum (and whole mixer) forfilling 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 anddismantling)


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(4) Aesthetics (appearance) considerations:

Should look symmetrical and stable; giveimpression of precision and efficiency offunction; quality of manufacturing; pleasingcontinuity of profile; refreshing up-dated senseof styling suitable for display in catalogue

Flat surfaces and smooth lines to enable easycleaning

Steel surfaces be given double coats of paint(prime and finishing) against rust, weather andrough treatment; pleasing colour choice on drumand guard, contrast with black frame and wheels

(5) Performance:

Prototype to be tested for performance undersimilar conditions as in actual service

Should allow some overloading; to cope withsevere cases, motor to be fitted with thermaloverload and reset button


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(6) Life and reliability:

Useful life = 7 years under full loading capacityfor stated number of hours per day and days peryear operation

Prototype to be tested under stated conditionswith intermittent stop/start

Periods between lubrication and change of partsduring prototype testing should be quoted infinal specification

(7) Packaging:

Mixer to be supplied in totally dismantled formpacked in cardboard carton with assemblyinstruction booklet and warranty card (for motoronly)

Instruction manual to consist of mixer inexploded view with parts numbered; parts to belisted with corresponding numbers


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(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 Bearings

Special parts (in small quantity) available are: Drum Wheels Guard Tilt-handle

(9) Obsolescence:

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


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Feasibility evaluation:

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

Motor/Gearbox: to be

purchased asstandardparts;available

Guard: formedand welded in-house

Wheels and rims: purchasedas standard parts; available

Mixing drum,internal parts and

structures:formed and

welded in-house;

if plastic drum, besub-contractedout; quality to be

ensured

Frame and tilt-handle:formed and welded in-house

Feasibility study

1 Order of drive motor 0.5 week

2 Delivery of motor 4 weeks

3 Synthesis and evaluation of drive system 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

7 Order of Drum 0.5 week

8 Delivery of drum 6 weeks

9 Cost analysis of wheel and rim 0.5 week

10 Order of wheels and rims 0.5 week

11 Delivery of wheels and rims 5 weeks

12 Selection and order of bearings 0.5 week

13 Delivery of bearings 3 weeks

14 Analysis of frame and tilt-handle 0.5 week

15 Comparison and evaluation of frame 1 week

16 Design calculations 1 week

17 Design drawings/sketching 1 week

18 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

21 Fabrication of frame, handle, gears, shafts, guards, etc 2 weeks

22 Assembly of whole mixer 0.5 week

23 Testing of mixer 3 weeks

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

Planningschedule -

Networkanalysis

chart:

to determine

design timeto produce a

fully-testedprototype

mixer. Tableshows

allottedtasks


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

Some possiblesolutions



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Somepossible

solutions

1.25m

1.0m

After some brainstorming sessions and evaluation:design below is deemed best for simplicity and cost


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Idea generation/development of tilt-handle

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

Idea generation/development of supporting frame

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


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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 gear boxexpensive; and

unnecessary

Worm gear boxbulky, heavy, and

expensive

Simple, neat andlow cost; no gearbox needed

Humanfactors:

To estimate framedimensions,estimated full

weight of concretemixer, comfortablelifting force of a 5th

percentile adultman (fromanthropometricdata charts) at315mm handleheight, areconsidered



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Details of support structure: Size of rectangular hollow steelsections as supporting frame calculated for bending and torsionwith critical area at base of upright pedestal to support drumshaft assembly and handle

Details ofwheel axle:Circular steeltube used andsize calculatedfor bending


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Handle tube sized to be33.7mm outside diameterwith 2.6mm thickness usingmax bending moment

Drum shaft

does nottransmittorque; sizedusingmaximumbending stress

Examples of detail

calculations:

Details of drumsupport assembly.

Note fabricationmethod and belt

tension adjustingmethod


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Pinion-shaftcalculated forcombinedbending andtorsion underfatigue loading.Stressconcentrationfactor at weakestpoint considered

Selection of standard components:

Bought-out components like belt drive,pulleys and rolling bearings selected

from manufacturers’ catalogues

Sizes of bolts and screws determinedfor tensile and shear loading


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Cost Analysis:

Unit cost of mixer = $500

Fixed cost per batch (5,000 units) =$350,000

For 5,000 units, total cost = $350,000 +($500 x 5,000) = $2,850,000

For $750 selling price, total income =5,000 x $750 = $3,750,000

Profit expected = $900,000.

Re-design for cost:

Unit cost of mixer of $750 appears reasonable

To be competitive, comparison is made withcompetitors’ products:

List price Remarks

Competitor A $1104 30% discount for multiple orders

Competitor B $1092 Selling at 15% below list price

Competitor C $950 25% discount for multiple orders

Competitor D $1560 Selling at 15% below list price

Competitor E $840 Selling at 10 % below list price


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Actual cost comparison:

List price Actual costCompetitor A $1104 $773

Competitor B $1092 $928

Competitor C $950 $713

Competitor D $1560 $1326

Competitor E $840 $756

To be competitive with competitor C, propose

initial price be discounted by at least 5%.

Better to re-design to reduce cost: Use lessrobust drum; reduce quality of electric motor,use thinner steel structures, etc

Re-design for function:

Prototype mixer fabricated, tested andanalyzed

Torsional deflection of motor-mountingplate caused excessive vibration underdynamic loading

Motor-mounting re-designed with flangerather than stiffening plate


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Rigidity of motor-mounting plate improved with flanges

Workingdrawings are

drawn

Detailed design


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Final product:

Mixer stand(optional extra):

Stand may beneeded for tippingconcrete directlyinto wheel barrow

Designed usingsteel tubes weldedtogether; feet withrubber stoppers toensure stability

Rubberstopper


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Optional stand for

tipping concrete directlyinto wheel barrow

Instruction booklet:

Information in instruction bookletinclude:

Part list of mixer

Assembly instruction of mixer

Maintenance and care


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1

1A

2

34

56

78

8A9

1011

1213

1415

16

17

18

1919A20

2122

2324

2526

2728

Explodedview ofmixer

showingassembly

procedure

Dismantled parts of mixer


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Opening of

cardboard carton inwhich completemixer is packaged

for assembly

O p e r a t i n g i n s t r u c t i o n s


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Dismantled for transport in a small

station wagon at end of use

me2101 1 design process 2016

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