IPE- 304Product Design-IΙ Sessional

Multipurpose Grass Cutting Machine

Presented By:Lab Group- 031. Jahangir Kabir Anik (1008002)2. Md. Sabbir Hossain(1008003)3. Jannatul Bushra (1008005)4. Sohel Rana (1008022)5. Imran Hasan Tusar (1008024)

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Contents

IntroductionCustomer SurveyQuality Function DeploymentBlack box & Functional DecompositionMaterial & Manufacturing Process SelectionStress-Strain AnalysisCost AnalysisConclusion

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Our Selected Product is

Multipurpose Grass Cutting Machine

Causes for selection:• A common daily

used equipment• No local

manufacturer• Encouraging

gardening

Introduction

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Customer Survey

Number of Persons Surveyed: 25

Survey location: Lawns of

residential areas & halls

Focus Group: Middle aged gardeners

One of the vital Survey

Questions was

Dis-satisfied Indifferent Satisfied Highly Satisfied0

10

20

30

40

50

60

70

80

Satisfaction Level

Perc

enta

ge o

f peo

ple 68 percent dis-

satisfied !!

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Yes

No

Not now

64%

Will you buy a manually operated grass cutter?

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Operating facility with pedal

Aerating facility

Adjustable cutter height

Brushing facilityNo fuel needed

Simultaneous operation

Two alternative driving

force

Unique Features

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Quality Function

Deployment

QFD

BLACK BOX METHOD

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Product presente

d as a function

al system

Energy

Mechanical energy

Information

Function

Smooth uniform cutting of grass

Information

1.Cutting speed(rpm)2.Running speed(m/s)

3.Safety Precaution

1. Grass of desired height after cutting

2. Aerated healthy green grass3. Collected grass in two

containers

Component Hierarchy

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Multipurpose Grass Cutting

Machine

1. Adjustable sitting & pedaling unit

3. Brushing unitCollecting the grass

2.Cutting unit & Aerating unitGrass cutting & Aerating

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Cutting & Aerating Unit

CutterFrame & Container

Flat blade (1)

Spiral blade(6)

Blade holders(5)

Shaft(1)

Aerator

Shaft(1)

Fin(8)

Half Cylindrical portion

Handle Gripper

Long Handle

Nob (2)

Nut & Bolt (2 pair)

Sheet metal

Roller strard with multiple holes

Roller

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Design Analysis of Multiple Grass

Cutting Machine

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Some Important Components of Our Product

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Arrangement for Pedaling & Pushing Drive

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Material and Manufacturing

Process Selection (Weighted Average

Method)

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Purchasing MaterialHere are the materials we are going to purchase1. Nut-bolts2. Bearing3. Plastic Seat4. Wheel5. Chain6. Handle Gripper7. Sprockets

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Comparison of Mechanical Properties of Some Materials

Property Cast iron Mild steel Wrought iron

Density (kg/m^3) 7200 7858 7600

Shear Modulus (N/m^2) 5.00E+10 8E+10 2.5E+8

Coefficient of Thermal Expansion(/k)

1.21E-05 1.20E-5 1.22E-5

Elastic Modulus (N/m^2) 6.62E+10 2.05E+11 2E+8

Compressive Strength(N/m^2) 5.72E+8 4.077E+8 3.03E+8

Material Selection

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Goals Number of positive decisions, N=n(n-1)/2=6(6-1)/2=15 Positivedecisions

RelativeemphasisCoefficient,α

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Cost 1 0 1 0 0 2 0.13

Dimensionalaccuracy

0 0 1 1 0 2 0.13

Availability 1 1 1 0 1 4 0.27

Powerrequirement

0 0 0 1 0 1 0.07

SurfaceFinish

1 0 1 0 0 2 0.13

Metallurgicalchange

1 0 1 0 1 1 4 0.27

Total Number of Positive Decisions 15 ∑α =1.00

Determination of Relative Importance by Digital Logic Method

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Manufacturing Process Selection for Cutting Tubes and Rods

Goals WeightingFactor,α

Saw Cutting Gas cutting Laser cuttingScaledProperty, β

WeightedScore, αβ

ScaledProperty, β

WeightedScore, αβ

ScaledProperty, β

WeightedScore, αβ

Cost 0.13 100 13.00 80 10.40 60 7.80Dimensionalaccuracy

0.13 75 9.75 50 6.50 100 13.00

Availability 0.27 100 27.00 80 21.60 40 10.80Powerrequirement

0.07 100 7.00 80 5.60 60 4.20

SurfaceFinish

0.13 80 10.40 60 7.80 100 13.00

Metallurgicalchange

0.27 100 27.00 75 20.25 100 27.00

Material PerformanceIndex, γ

94.15 72.15 75.8

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GoalsWeightingFactor,α

Turning in Lathe Machine ExtrusionScaledProperty,β

WeightedScore, αβ

ScaledProperty,β

WeightedScore, αβ

Cost 0.27 80 21.60 100 27.00Dimensionalaccuracy

0.27 80 21.60 100 27.00

Forcerequirement

0.12 100 12.00 60 7.20

Powerrequirement

0.07 80 5.60 100 7.00

SurfaceFinish

0.07 80 5.60 100 7.00

Metallurgicalchange

0.20 80 16.00 100 20.00

Material PerformanceIndex, γ

82.40 95.20

Manufacturing Process for Shaft Cutter, Aerator , Brush & Wheel

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Stress-Strain Analysis

25 Static Nodal Stress Distribution Spectrum

26 Static Displacement (Strain) Distribution Spectrum

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Cost Analysis

Units of Production per year: 750 Tk.

Total machine cost: 5,27,000 Tk.

Interest paid per year: 7,50,000 Tk. (13% interest ,10 years)

Total raw material cost per year : 21,15,000 Tk.

Total labor cost per year : 7,02,000 TK

Total purchasing cost : 60,37,500 TK

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• 81,52,500 Tk.Raw material Used in production per

year:

• 6,60,600 Tk.Total manufacturing

overhead per year:

• 95,14,500 Tk.Total manufacturing Cost per year:

• 3,09,400 Tk.Total administrative cost

per year:

• 60,000 Tk.Total marketing cost per year:

• 71,56,800 Tk.Total non-manufacturing

overhead per year:

Total Fixed Cost =

84,08,000TK

Total Variable Cost =

106,14,500 TK

Variable Cost per Unit =

14150 Tk.

Selling Price Per

Unit = 30000 Tk.

At Break Even Point,• QBEQ = 531

Units

Break-Even Analysis

0 100 200 300 400 500 600 700 800 9000

5000000

10000000

15000000

20000000

25000000

30000000

8408000 982300011238000

1265300014068000

15483000

16898000 1831300019728000

Fixed Cost Total Cost Linear (Total Cost) Total Revenue

Units Sold

Cos

t & R

even

ue

Break Even Quantity=531 units

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Conclusion

Main focus was the following customer requirements

•Adjustable cutter height•Grass collection facility•Aerating option•Lightweight•Cheap

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Any Query

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