DFA of a Stapler (Project)

7/31/2019 DFA of a Stapler (Project)

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DFA of Max Co. Vaimo HD-11FL Stapler

Group Members

Aleem Ullah

Adamu Bashir Gidado

Just because you can make something doesnt mean you can manufacture it

Design for Manufacture& Assembly

Prof: Dr. Ariffin Bin Abdul

Razak

FKM UTM, JB


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Objectives

To study the original product design based on

DFA concept.

To make improvements in the original design

in terms of cost, assembly time, fastening

methods, and number of components.

To determine design efficiency of the product

for original and new design.


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A stapler is a mechanical device that joins sheets of

paper or similar material by driving a thin metal

staple through the sheets and folding the ends.

Staplers are widely used in government, business,

offices, and schools.

Product to be Studied:

In this project DFA will be carried out on Japanese

made Max Co. Vaimo HD-11FL Stapler stapler. It

enables stapling 2 to 35 sheets (80gsm Paper) with

ease using a single hand. Unique twin levermechanism cuts stapling effort by 50%, its

Compact and ergonomic styling provides

comfortable stapling.


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Product Description:

Old Design:

Total No. of Parts = 35Total No. of Different Parts = 33

New Design:

Total No. of Parts = 19Total No. of Different Parts = 19

No. Image Part Name Function Material

1 Metallic Base

Houses the anvil,

metallic base

spring & anvil

plastic support

Steel

2Anvil Plastic

Support

Supports the

anvil on the

metallic base

Plastic


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3 AnvilBends the staples to

the desired shapeSteel

4 Anvil Spring

Provides damping

motion to the

anvil/anvil plastic

support

Steel

5Metallic Base

Spring

Retrieves bottom

staple guide once the

stapling force is

released

Steel

Product Description: Cont.


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6Bottom Staple

Guide

Houses and forwards

the stapes towards

the hammering

position

Steel

7 Pusher RodGuides the pusher

headSteel

8 Pusher Head

Pushes the hammer

towards hammering

location

Plastic



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9Pusher Head

Retriever

Aids in retrieving the

pusher head for

loading/unloading of

staples

Plastic

10 Pusher Spring

Provides the force to

the pusher head to

push the staples

Steel

11Pusher Rod

Cap

Provides the need for

a critical force before

staples are ejected

from the hammering

position

Steel



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12 Lower Pin

Connects the bottom

staple guide to the

metallic base. Also

provides a relative

motion between them.

Steel

13 Upper Arm

Encompasses the

hammer. Presses the

upper staple guide.

Steel

14 Rear Pin

Connects the metallic

base, bottom staple

guide and the upper

arm. Allows a relative

motion between the

three major parts.

Steel



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15Upper Staple

Guide

Prevents the

staples/pusher head

from ejection from

the bottom staple

guide.

Steel

16Upper Arm

Casing

It encloses the upper

arm. Allows the top

plastic casing to snap

fit to it.

Steel

17 Upper Pin

It connects the upper

arm to the upper arm

casing

Steel



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18Top Plastic

Casing

Covers the upper armcasing. Prevents the

upper pin from falling

out. Provides good

comfort & aesthetic

value.

Plastic

19Bottom

Plastic Casing

Supports the anvil.

Covers the metallic

base. Provides good

comfort & aesthetic

value.

Plastic



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Assembly Sequence: (Old Design)


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Main Body

Metallic Base

Rear PinMetallic Base

SpringBottom Plastic

CasingAnvil Upper

Plastic Support

Anvil UpperPlastic Spring

Anvil Lower

Plastic Support

Anvil LowerPlastic Support

Spring

Small Plastic Clip

Anvil SpringAnvil Spring

GuideAnvil

Bottom Staple

Guide Casing

Staple Guide

Joining SpringPlastic Guide Slide Guide

Pusher Head

Pusher Rod

Large Pusher

Spring

Small PusherSpring

Pusher Slides

Pusher Rod Cap

Pusher Head

Retriever

Lower Pin

Upper Arm

Upper StapleGuide

Actuator

Upper LeafSpring

Upper Arm

Casing

Upper Pin

UAC CoverSpring

Upper ArmCasing Cover

Top PlasticCasing

Product Tree Structure: (Old)

Parts Eliminated/Integrated into others


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DFA Worksheet: (Old)

Part#

No.oftimestheoperationis

carriedoutconsequently

Two-Digitmanualhandling

code

Ma

nualHandlingtimeper

part

Two-digitmanualinsertion

code

Ma

nualinsertiontimeper

part

Operationtime(sec)

(2)x[(4)+(6)]

Operationcost

0.0

01499x(7)

F

iguresfortheoretical

min

imum

partsestimation

Name Of Assembly

1 1 30 1.95 00 1.5 3.45 0.0052 1 Metallic Base

2 1 30 1.95 30 2 3.95 0.0059 0 Anvil Lower Plastic Support

3 1 40 3.6 30 2 5.6 0.0084 0 Anvil Lower Plastic Support Spring

4 1 01 1.43 00 1.5 2.93 0.0044 0 Anvil Upper Plastic Support Spring

5 1 30 1.95 30 2 3.95 0.0059 1 Anvil Upper Plastic Support

6 1 20 1.8 06 5.5 7.3 0.0109 1 Anvil

7 1 03 1.69 06 5.5 7.19 0.0108 0 Anvil Spring

Unchanged Modified Eliminated


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8 1 31 2.25 00 1.5 3.75 0.0056 0 Anvil Spring Guide

9 1 31 2.25 30 2 4.25 0.0064 0 Small Plastic Clip

10 1 00 1.13 00 1.5 2.63 0.0039 1 Metallic Base Spring

11 1 30 1.95 00 1.5 3.45 0.0052 1 Bottom Staple Guide Casing

12 1 30 1.95 00 1.5 3.45 0.0052 0 Bottom Staple Slide Guide

13 1 40 3.6 30 2 5.6 0.0084 0 Staple Guide/Casing Joining Spring

14 1 30 1.95 30 2 3.95 0.0059 0 Plastic Support For Metallic Base Spring

15 1 03 1.69 00 1.5 3.19 0.0048 1 Pusher Rod

16 1 30 1.95 00 1.5 2.925 0.0044 1 Pusher Head

17 1 13 2.06 30 2 4.06 0.0061 1 Pusher Head Retriever

18 1 00 1.13 00 1.5 2.63 0.0039 0 Small Pusher Spring

19 1 00 1.13 00 1.5 2.63 0.0039 0 Large Pusher Spring

20 2 72 5.85 08 6.5 24.7 0.037 0 Pusher Head Slides

21 2 30 1.95 31 5 13.9 0.0208 0 Pusher Rod Caps

22 1 03 1.69 31 5 6.69 0.0100 0 Lower Pin

DFA Worksheet: (Old) Cont.


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23 1 30 1.95 06 5.5 7.45 0.0112 1 Upper Arm

24 1 30 1.95 35 5 6.95 0.0104 0 Upper leaf spring

25 1 00 1.13 30 2 3.13 0.0047 1 Rear Pin

26 1 30 1.95 00 1.5 3.45 0.0052 0 Actuator

27 1 30 1.95 30 2 3.95 0.0059 1 Upper staple Guide

28 1 30 1.95 30 2 3.95 0.0059 1 Upper arm casing

29 1 00 1.13 30 2 3.13 0.0046 0 Upper pin

30 1 33 2.51 30 2 4.51 0.0068 0 UAC Cover Spring

31 1 30 1.95 00 1.5 3.45 0.0052 0 Upper Arm Casing Cover

32 1 30 1.95 30 2 3.95 0.0142 0 Top plastic casing

33 1 30 1.95 30 2 3.95 0.0142 0 Bottom plastic casing

170.045 0.2571 12 Design efficiency=21.17%

Design Efficiency = 3 x NM/TM

DFA Worksheet: (Old) Cont.

Labor Rate = 950/(22x8x60x60) = 0.001499 RM Per Second

Our Assembly Time: (387 + 411+ 398)/3 = 398.6 Sec


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1. Combination of the 4 parts of bottom staple guide to one

Difficult to assemble the spring

Assembly time for the 4 parts:

3.45+3.45+3.95+5.6= 16.45 sec

Combine the 4 parts to make 1 part

Assembly time for the new bottom

staple guide: 3.45sec

(Time reduced = 13 sec)

(Cost Cut=0.0195 RM)

Design Improvements:

Weakness: Solution:


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2. Modifying the anvil upper plastic support while eliminating the anvil lower plastic supportWeakness:Long handling/assembly time

Assembly time for the 5 components:3.95 + 3.95+5.6+2.93+4.25 = 20.68 sec

Solution:Combine the upper plastic with the lowerplastic support

Assembly time for the new anvil plasticsupport: 3.95 sec

(Time reduced = 16.72 sec)




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3. Combining the upper arm with the upper leaf spring and hammer head

Requires riveting which is time

consuming

Assembly time for the three parts:

7.45+6.95+3.45= 17.85 sec

Combine to form a single component

Assembly time for the new upper arm:

7.45sec



Weakness: Solution:



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4. Eliminating 1 pusher spring

1. One spring must be inserted in the

other spring

2. Time consuming

Assembly time for the two springs:

2.63+2.63= 5.26 sec

Use only one spring

Assembly time: 2.63 sec



Weakness: Solution:



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1. One of the pusher rod caps is

inserted in the other

2. Time consuming

Assembly time for the two pusher rod

caps: 13.9 sec

Use only one pusher rod cap

Assembly time for the pusher rod cap:

6.95 sec

(Cost Cut=6.95 RM)

Weakness: Solution:

5. Eliminating 1 pusher rod cap.



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6. Combining the pusher head with the pusher slides

Inserting the pusher slides is time

consuming and difficult.

Assembly time of the three parts

above: 12.35+12.35+2.925= 27.625 sec

Combine the pusher head with the

pusher slides

Assembly time of the new pusher head:

2.925 sec


(Cost Cut=0.037 RM)

Weakness: Solution:



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7. Modification of the metallic base

The anvil spring passes through a

hole in the metallic base. So, it

requires holding during subsequent

operation

Assembly time for the 3 parts above:

3.45+7.19+3.75= 14.39 sec

Provide a support for the anvil spring

and eliminate the anvil spring guide

Change the anvil spring with a bigger

diameter spring

Assembly time for the new anvil spring

and metallic base: 3.45+2.63= 6.08 sec



Weakness: Solution:



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8. Combining the top plastic casing with the UAC cover

Assembly of UAC cover is time

consuming and sensitive.

Assembly time for the 3 components

above: 3.95+3.45+4.15= 11.55 sec

Combine the top plastic casing with theUAC cover and eliminate the UAC coverspring

Assembly time for the new top plasticcasing: 3.95 sec



Weakness: Solution:



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Main Body

Metallic Base

Bottom PlasticCasing

Rear Pin

Metallic Base Spring

Anvil PlasticSupport

Anvil

Anvil Spring

Bottom StapleGuide

Pusher Head

Pusher Rod

Pusher Spring

Pusher Rod Cap

Pusher HeadRetriever

Lower Pin

Upper Arm

Upper Staple Guide

Upper ArmCasing

Upper Pin

Top Plastic Casing

Product Tree Structure: (New)


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DFA Worksheet: (New)

Part#

No.

oftimestheoperationis

carriedoutconsequent

ly

Two-Digitmanualhandling

code

ManualHandlingtimeper

part

Two-digitmanualinsertion

code

Manualinsertiontimeper

part

Operationtime(sec)

(2)x[(4)+(6)]

Operationcost

0.0

01499x(7)

Figuresfortheoreticalminimum

partsestimation

Name Of Assembly

1 1 30 1.95 00 1.5 3.45 0.0052 1 Metallic Base

2 1 30 1.95 30 2 3.95 0.0059 1 Anvil Plastic Support

3 1 20 1.8 00 1.5 3.30 0.0049 1 Anvil

4 1 00 1.13 00 1.5 2.63 0.0039 0 Anvil Spring

5 1 00 1.13 00 1.5 2.63 0.0039 1 Metallic Base Spring

6 1 30 1.95 00 1.5 3.45 0.0052 1 Bottom Staple Guide

7 1 03 1.69 00 1.5 3.19 0.0048 1 Pusher Rod


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8 1 30 1.95 00 1.5 2.925 0.0044 1 Pusher Head

9 1 13 2.06 30 2 4.06 0.0061 1 Pusher Head Retriever

10 1 00 1.13 00 1.5 2.63 0.0039 0 Large Pusher Spring

11 1 30 1.95 31 5 6.95 0.0104 0 Pusher Rod Caps

12 1 03 1.69 31 5 6.69 0.0100 0 Lower Pin

13 1 30 1.95 06 5.5 7.45 0.0112 1 Upper Arm

14 1 00 1.13 30 2 3.13 0.0047 1 Rear Pin

15 1 30 1.95 30 2 3.95 0.0059 1 Upper staple Guide

16 1 30 1.95 30 2 3.95 0.0059 1 Upper arm casing

17 1 00 1.13 30 2 3.13 0.0046 0 Upper pin

18 1 30 1.95 30 2 3.95 0.0059 0 Top plastic casing

19 1 30 1.95 30 2 3.95 0.0059 0 Bottom plastic casing

75.365 0.1068 12 Design efficiency=47.8%

Design Efficiency = 3 x NM/TM

DFA Worksheet: (New) Cont.

Labor Rate = 950/(22x8x60x60) = 0.001499 RM Per Second


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Comparison Between Old & New Design:

Old Design New Design Improvement

No. of Different

Components33 19 42.4% Reduction

Assembly Time 170.045 Sec 75.365 55.7% Reduction

Assembly Cost 0.2571 0.1068 58.5% Reduction

Design Efficiency 21.17% 47.8%Increased By

26.6%(125.8% Improvement)

Assembly Levels 3 2 33% Improvement

Labor Rate = 950 RM Per Month OR 0.001499 RM Per Second


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Conclusion:

From DFA method, we reduced the number of

parts, assembly time and cost by Boothroyd-

Dewhurst method.

We eliminated certain springs, while keeping

their functionality. Parts were redesigned to

integrate other parts hence reducing the total

number of parts, and improve ease of assemblyand its cost. 4 major and 4 minor improvements

were made.


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Thank You !

DFA of a Stapler (Project)

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