DMT Int Journal July 2008 8

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Abstract

In this era of stiff competition the economic success of manufacturing firms depends on their ability to identify theneeds of customers and to quickly create products that meet these needs and can be produced at low cost.

Achieving these goals is not solely a design problem or a manufacturing problem; it is a product developmentproblem involving all of these functions. The present work is carried out in a manufacturing unit, developingindustrial products. In itsproduct range thecompany involves themanufactureof keyduplicatingmachine on smallbasis and this machine required improvement to survive in competitive market (key making). The paper highlightshow the product development techniques are applied in improving the key duplicating machine effectively andefficiently. The present paperdiscusesabout the re-designing and improvements in the product performance. Thework was further extended for developing a revised product with better features. The scope of work involves

extensive survey of users and design options available. The significant aspect of the present work is that, thetheoretical concepts involved in product development have been realized with a practical perspective. The workhasbeen realized by incorporating these improvementsin theproduct.Thework is supportedby digital prototypingofthemodelusingCADmodeler.

Keywords: ProductDevelopment,Performance, re-designing.

PRODUCT RE-DESIGNING AND DEVELOPMENT OFKEY DUPLICATING MACHINE A CASE STUDY

1 2 3Deshpande A.S. , Chate U.N. , Vinayak Malik

1Fr.C.Rodrigues College of Engineering, Mumbai, India

2,3Department of Industrial and Production Engineering, Gogte Institute of Technology, Belgaum, India

1

E-mail: [email protected]

I. INTRODUCTION AND GENERAL BACKGROUND

There is a great demand for key duplication inmarket. Theconventionalmethodof makingduplicateof akey is by using files and bench vice. The original key andthenewkeyblankofitsshapeareheldinvice,setproperly

and the required profile is generated using files. Thisprocess requiresa lotof efforts, time andpersonnel skill.

In the recent time the key duplicating work is madeeasier, quicker and without much efforts by the use of keyduplicating machines. One of such machines ismanufactured by ToolHolders Pvt. Ltd at Belgaum.As perthe needs of customers and to meet the new changes inmarket of key making the machine required improvement.To solve this problem, the machine was developed, byfollowing a structured product development process.Fig. 1 shows the picture of existing model of keyduplicating machine,whichhas tobe improved.

Fig. 1. Existing model of key duplicating machine

52 International Journal on Design and Manufacturing Technologies, Vol.2, No.1, July 2008

P RO DU CT D EV EL OP ME NT M ET HO DO LO GYAPPLIED FOR KEY DUPLICATING MACHINEIMPROVEMENT

A product is something sold by an enterprise to itscustomers. Product development is the set of activities

beginning with the perception of a market opportunity andendingintheproduction,saleanddeliveryofaproduct.

Few products are developed by a single individualand the current case of key duplicating machine is a goodexample of this. To improve the key duplicating machine astructured product development methodology is used,whichcontainsthefollowingsteps

l Product planning

l Concept development

a) Identifying customer needs

b) Establishing target specification

c) Concept generation

d) Concept selection

e) Concept testing

f) Establishing final specification

l Re-design of key duplicating machine


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Automobilekeys

Table 3. Kind of problem and Percentage ofdifferent types of keys (Automobile)

Table 3 shows which type of automobile keys cannotbe duplicated on theexistingmachine,andthereasons forthe same. It also shows the percentage for different typesof keys that come for duplication purpose at key makershop. From the Table 3 it can be observed that in case ofduplicating variety of automobile keys, the existingmachineissatisfyingtoagoodextent.

CONCEPT DEVELOPMENT 1) IDENTIFYING

CUSTOMER NEEDSThis phase presents a method for comprehensively

identifying a set of customer needs. The goals of themethodareto:

l Ensure that the key duplicating machine is focusedon customer needs

l Provide a fact base for justifying the key duplicatingmachine specifications

l Create an archival record of the needs activity ofthe development process

l Ensure that no critical customer need is missed orforgotten

General steps that come under identifying customerneed activity are

l Gathering the raw data from customers

l Interpreting the raw data in terms of customerneeds

l Establishing the relative importance of the needs

Templates were prepared during identifying the

customer needs phase for key duplicating machine. Thetemplate was filled in soon after the interaction with thecustomer and edited. Many customers were interviewedandtemplateswereprepared.

A scale from 1 to 5 was used as shown below toindicate importance of the feature, to give the importanceweightingto theneedscollected from thekey makers.

Scalefrom1to5indicatinghowimportantthefeatureis

1. Feature is undesirable, I would not consider aproduct withthisfeature.

2. Feature is not important, but I would not mind havingit.

3. Feature would benice tohave, but isnot necessary.

4. Feature is highly desirable, but I would consider a

productwithoutit.5. Feature is critical, I would not consider a product

withoutthisfeature

Table 4. Customer needs for the key duplicatingmachine and their relative importance

Table 4 showscustomerneeds forthe keyduplicatingmachine and their relative importance shown in a

convenientspreadsheet format.

II. ESTABLISHING TARGET SPECIFICATIONS

Customer needs are generally expressed in thelanguage of the customer. However, while suchexpressions are helpful in developing a clear sense of theissues of interest to customers, they provide little specificguidance about how to design and engineer the keyduplicating machine. They simply leave too much marginfor subject ive interpretation. For this reason,specificationswereestablished, which spellout in precise,measurable detailwhat thekey duplicatingmachine hasto

do, what is to be attempted to achieve in order to satisfythecustomerneeds.

The target specifications are established after thecustomer needs have been identified but before productconcepts have been generated and the most promisingone selected. The process of establishing the targetspecificationscontainsfollowingsteps,

l Preparation of listof metrics,usingthe needs-metricsmatrix, if necessary



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III. CONCEPT GENERATION

A product concept is an approximate description ofthe technology, working principles, and form of theproduct. The degree to which a product satisfiescustomers and can be successfully commercialized

depends to a large measure on the quality of theunderlying concept. A concept is expressed as a sketchand is accompanied by a brief textual description. In thepresent case of key duplicating machine improvement 10concepts were generated. To develop concepts for keyduplicating machine external and internal search wereconducted.

Charts containing description regarding eachconcept, and the salient features of each concept werealso prepared, which guides in selecting the particularconcept for key duplicating machine development project.Since it is an incremental improvement kind of projectdifferent concepts in the form of different kinds ofmechanismtogivefeedareproposed.

IV. CONCEPT SELECTION

Concept selection is the process of evaluatingconcepts with respect to customer needs and othercriteria, comparing the relative strengths and weakness ofthe concepts, and selecting one or more concepts forfurther investigation or development. Decision techniquesemployed for selecting concepts range form intuitiveapproaches to structured methods. One of suchstructured approach is concept scoring method which is

used inpresent case ofkeyduplicatingmachine.

Concept scoring uses a reference concept toevaluate concept variants against selection criteria.Concept scoring uses weighted selection criteria and afiner ratingscale.The selectioncriteria are listedalong thelefthandsideofthescreeningmatrixasshowninTable14.These criteria were chosen based on the customer needsthat have been identified, as well as on the needs of theenterprise. In the current case of key duplicating machineimprovement theexisting modelof themachineis taken asthe reference itself. In key duplicating machine project, 10concepts were proposed, after discussions 3 concepts

wereselectedforevaluation.

Table 9 illustrates the scoring matrix used in thisstage. The concepts which have been identified foranalysis are entered on the top of the matrix. After thecriteria areentered, importance weights were added to thematrix. To distinguish among competing concepts, a finerscalewasusedasshowninTable8.

Table 8. A finer scale

After entering the ratings, weighted scores werecalculated by multiplying the raw scores by the criteriaweights. The total score for each concept is the sum of theweighted scores. Finally, each concept was given a rankcorresponding to its total score, as shown in Table 14.Based on the selection matrix, it was decided whichconcept orconcepts toselect. Table 14 shows theconceptscoring method applied to key duplicating machine. Fromthe table it can be observed that the Nut and ScrewMechanism withSpringArrangement is finally selected forfurtherdevelopment.Fig. 2 shows the line sketch of Nutand Screw Mechanism with Spring Arrangement, which

was finalizedin conceptselectionstage.

Table 9. The Concept Scoring Matrix

Fig. 2. Nut and Screw Mechanism with Spring Arrangement



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V. CONCEPT TESTING

In concept testing basically the concepts werecommunicated to the end users so that the responsesfrom the users, guide in further development for theproduct. Concepts were tested to verify that the customer

needs have been met, and identifying any shortcomings,whichcanberemediedduringfurtherdevelopment.

The concept, which was selected in conceptselection stage, that is nut and screw mechanism withspring arrangement, was communicated to customers(key makers) by means of verbal descriptions and linesketches and their responses were fairly positive. Butsince it is an iterative process 3D computer model of keyduplicating machine and its color pictures based on theselected concept were shown after modeling procedurewasover.

VI. RESULTS AND DISCUSSIONWhen the new product is an incremental

improvement on an existing product concept, then theproduct architecture is defined within theproduct concept.This is because, the basic technologies and workingprinciples of the product are predefined, and soconceptual design efforts are generally focused on betterways to embody the given concept. That's why thesystem-level design and detailed design stages geteliminated in the current case of key duplicating machineimprovement project. Since key duplicating machinedevelopment is an incremental improvement kind of

project, most of the parts remain the same, which areused, in existing model of key duplicating machine.To geta basic idea about the dimensions of the parts that aremodified, revised, changed in the new model of keyduplicating machine brief design calculations were done.The design data cannot be displayed due to theconfidential reasons. The components were analyzed on3DCADmodeler.

The variable cutting speed is achieved by using avariable speed DC motor. The motor is a normal singlespeed permanent magnet motor, but variable speed is gotby attaching an electric drive unit to it. The speed is varied

by controlling the voltage to motor with the help of electricdrive unit. Though other options were available to get avariable speed for example, stepped pulley and speedchange gearbox used as in lathe, the electrical step lessregulation of speed was chosen. Thedecision wasguidedbythefollowingreasons

m Safety and convenience for control while speedchanging

m Fatigueless speedchangingactivity

m Possibility of carrying out key cutting operations atoptimum cutting speed. This not only increasesproductivity, butalsoincreasestool life.

m Noiseless and more smooth rotation and absence ofjerks whichare characteristicof geared drive

Two parallel springs are used in the mechanism, toguide the cutting action, while cutting automobile keys, sothat automobile keys can be cut at a single pass ofcarriage, making automobile key cutting operation moresimple than earlier. This logic of spring force applicationwas captured during competitive benchmarking of theproduct (silica key duplicating machine). The springs aredisengaged or locked using locking pins while cuttingdomestickeys.

To enhance the key cutting capacity in terms ofvariety, the concept of cutter position interchange thereby

changing the layout of keys was introduced, along withlinear dimensional changes between the two vices andbetween the cutters and the respective copy dogs, so thatlongkeyscanbeaccommodated.

Fig. 3 shows the picture of new model of keyduplicating machine modeled in SolidWorks CADpackage.Itgivesanidea,aviewthathowakeyduplicatingmachinelookslikewithnewlyappliedconcept.

Fig. 4 shows the picture of improved version ofexisting model of key duplicating machine (model 2),modeled in SolidWorks CAD package. It shows how the

machine looks like after making some incrementalchanges.

Fig. 3. Re-designed and developed new model [Model 1]

Fig. 4. Improved version of existing keyduplicating machine [Model 2]

57Deshpande et al: Product Re-designing and Development of Key Duplicating...


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m More business to the key makers, as on theimproved version of the existing model of keyduplicating machine 90% of the keys can be cut,compared to the existing model of keyduplicating machine on which 80% of keys can

becut.ACKNOWLEDGEMENT

Authors express their sincere thanks to Mr.DeelipBhagwat, an expert entrepreneur from Belgaum forsuggestingtheproblemandhelpingallthrough.

REFERENCES

[1] Karl T. Ulrich And Steven D. Eppinger 'ProductDesign And Development', Published ByMcgraw-HillCompanies,1995

[2] A.K.Chitale. R.C.Gupta 'Product Design AndManufacturing' Published By Prentice-Hall OfIndiaPvt. Ltd.,SecondEdition,2002

[3] P.L.Ballaney 'Theory Of Machines' KhanaPublishers,SixteenthEdition,1988

[4] Cmti 'Machine Tool Design Handbook' TataMcgraw-Hill PublishingCompanyLimited,1982

[5] N.K.Mehta 'Machine Tool Design' Tata McgrawHillPublishing Company Limited,1995

[6] S.K.Hajra Choudhury, S.K.Bose,A.K.HajraChoudhury And Nirjhar Roy, 'Elements OfWorkshop Technology Vol Ii Machine Tools',Media Promoters And Publishers Pvt. Ltd., FirstEdition, 1964

[7] R.S.Khurmi And J.K.Gupta 'Machine Design'Eurasia Publishing House Pvt. Ltd., SecondEdition,1980

[8] R.K.Jain 'Machine Design' Khanna Publishers,SixthEdition,1991

[9] S.S.Bhavikatti 'Strength Of Materials', VikasPublishing House Pvt. Ltd., Second Edition,1999

[10] ermann JutzAndEduard Scharkus'WestermannTables For The Metal Trade' Published By WileyEasternLimited,ThirdEdition,1984

[11] http://www.lvsales.com/lvskymch.htm

A suitable cutter cover of size 80 x 95mm is made toavoid chips of metal from entering into eyes while keycutting.

All the above solutions are applied to the existingmodelof keyduplicatingmachine

except the spring force application solution to get the newimproved version of the machine (model 2). Also otherchanges like suitable color combination that is goldenyellowand white, and cover of drive are done for improvedmodelofkeyduplicatingmachine(model2).

VII. CONCLUSION

Few of the challenging aspects covered in thepresentworkwereasfollows,

l Understanding and applying a structured productdevelopment technique to key duplicating machine

which is helpful in developing any type of complex orsimple productseffectivelyandefficiently.

l Conducting the market survey and intervening thecustomers (key makers) at the key duplicatingmachine use site in a systematic step by stepprocess to create a high quality information channelthat runsdirectlybetween customersin target marketand thedevelopers of thekeyduplicating machine tobest experience theuseenvironment of theproduct,thedata recorded is helpful for futuredevelopment ofthekeyduplicatingmachine.

l The solutions got from the structured productdevelopment process, were applied to the existingmodel of keyduplicating machine to get an improvedversion of key duplicating machine (model 2) andconstructing its pre-production version and also anewmodel (model1) of keyduplicatingmachine wasdeveloped.

l An improved version of existing model of keyduplicating machine, which provided the followingadvantagestokeymakers

m Steel keys (steel with tensile strength of 82 kg/sqmm)canbecut

m Longkeys(upto18cms)canbeduplicated

m Long steel keys (steel with tensile strength of 82kg/sqmm) canbe duplicated inmuch lessertimethat is in 5 minutes compared to earlier whichwould require 30 minutes using files, and whichwasnotpossible to duplicate in existingmodel ofkeyduplicating machine

m Improvedlifeof'U'cutter(improvedby60%)



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[12] http://www.keymart.com/key_machines.htm

[13] http://www.engineeringtalk.com/news/tce/tce107.html

[14] h t t p : / / w w w . j t sm a c h . c o m / j t s w e b s h o p /asp/saws_index.asp

[15] http://www.thurstonmfg.com/pg_2.htm#plainmet

[16] h t t p : / / w w w. s o l i d w o r k s . c o m / p a g e s /products/edu/solidworksforstudents.html

[17] http://www.ulrich-eppinger.net

[18] http:/ /web.mit .edu/2.744/www/courseinformation/ classnotes.shtml

Dr. A. S. Deshpande is thePrincipalof Fr. C. Rodrigues College ofEngineering, Bandra, Mumbai. Apost-graduate from IIT Kanpur, heobtained his doctorate from NIT,

Suratkal in the area of CAD / CAM.He has published 22 papers inJournals and Conferences and his

experience in the field of academics and industry extendsoveraperiodof23years.

59Deshpande et al: Product Re-designing and Development of Key Duplicating...

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DMT Int Journal July 2008 8