LinköpingUniversity|DepartmentofManagementandEngineeringBachelorthesis,16hp|Mechanicalengineering-Production

Springterm2017|LIU-IEI-TEK-G—17/01306—SE

LinköpingUniversity

SE-58183Linköping,Sweden013-281000,www.liu.se

Automaticdrillingofholesforwing-andfininterface– Atheoreticideaofhowthedrillingcouldbeautomated______________________________________________________________Automatiskborrningavhålförinterfaceavvingeochfena

–Enteoretiskidéförhurborrningenskakunnaautomatiseras

MajaWillLinnKrügerAdvisor:ErikSundinExaminer:MatsBjörkman

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AcknowledgementsThisthesishasbeenconductedduringthespringtermof2017atSaabAeronauticsinLinköping.ThisisthefinalprojectinourBachelordegreeinmechanicalengineering.WewouldliketoexpressourgratitudetoallpeoplewemetworkingatSaabfortheirinvolvementandfortheirinputwithknowledgethesetenweeks.EspeciallywewouldliketothankouradvisorsatSaab,ChristianSamuelssonandMagnusEngström,fortheirsupportandinvaluableknowledge,andMathiasWallinandAndersKristenssonforsupportandpositiveatmosphere.AlsowewouldliketothankBertilFranzén,whohascoordinatedthisthesisforus,hehasbeenverypositiveanddedicatedduringthethesis.WewouldfurtherliketothankouradvisoratLinköping’sUniversity,ErikSundin,whohasguidedandsupported us during the whole process, and also our examiner, Mats Björkman, who has beenaccommodatingwithvaluableinput.Finally,wewouldliketothankouropponentsFilipNaeslundandJohanJonssonfortheirsupportandrewardingdiscussionsduringthewholeworkingprocess.Linköping,June2017LinnKrüger&MajaWill

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AbstractYear2024U.S.AirForcewillreplacetheircurrentNorthropT-38Talonaircrafttrainerforpilots,andthereforetheyhavedesignedtheT-Xprogramwhereseveralaircraftmanufacturescompetesaboutthefirstorderof350aircrafts.BoeingandSaabABhaveincooperationproducedanewaircrafttrainer,BoeingT-X,whereSaabABproducestherearpartofthefuselage.Todaytwoprototypeshavebeenproducedand tested to fly, but if BoeingandSaabwins theorder theproductionhas tobemoreeffectivetomanagetheproductionvolume.Theaircrafthastwowingsandtwofinswhichareassembledviaaninterfacewithseverallargerholeswhichwerepartiallydrilledmanuallyduringtheprototypemanufacturing.Thepurposewiththisthesiswastoexamineifthedrillingoftheinterfacescouldbeautomatedinordertoincreasetheproductionvolume,regardingtoeconomyandhightolerance-andflatnessrequirements.Thepurposewasalsotodeterminehowmuchofthedrillingshouldbedoneinanearlierstageandhowmuchshouldbedonewherethefuselageisassembled.Tomanagethetimelimit,delimitationsweresettoonlymakeapre-studyandexaminewhichpathSaabshouldtakewhenselectingasuitablesolution,thetimelimitwillnotbeenoughforareadysolution.Different drillingmethods and differentmachines and robots suitable for drilling were examined.Conceptselectionmatriceswereusedintheworkprocesstoreacharesult,wheredifferentconceptsweredevelopedandcomparedwitheachotherbasedontherequirements.TheresultwastodeveloptheCNCgantrymachineconcept.

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SammanfattningÅr2024kommerU.S.AirForcebytautsinanuvarandeskolflygplanNorthropT-38Talon,ochhardärförstartatT-Xprogrammetdärolikaföretagärmedochtävlaromförstaordernpå350flygplan.BoeingochSaabABharisamarbetetagitframettnyttskolflygplan,BoeingT-X,därSaabABtillverkarbakredelenavflygkroppen.Idagslägethartvåprototypertillverkatsochprovflugits,menomBoeingochSaabfårordernmåsteproduktioneneffektiviserasförattklaraavproduktionshastigheten.Flygplanethartvåvingarochtvåfenorvilkafästsviaettinterfacemedettfåtalstörrehålvilkaunderprototyptillverkningentillvissdelharborratsmanuellt.Syftetmeddethärexjobbetvarattundersökaomborrningenav interfacengickattautomatisera föratt kunnaökaproduktionshastigheten,medavseendepåekonomisamthögatolerans-ochplanhetskrav.Syftetvarocksåattavgörahurmycketavborrningensomskullegörasietttidigareskedeochhurmycketsomskullegörasdärflygkroppenbyggssamman.FöratthinnaundertioveckorgjordesavgränsningartillattendastgöraenförstudieochettvägvalåtSaab,ochintetaframenfärdiglösning.Olikaborrningsmetodersamtmaskinerochrobotarlämpadeförborrningundersöktes.Förattkommaframtillettresultatanvändesunderarbetetkonceptutvecklingsmatriser,därolikakoncepttogsframochjämfördesmedvarandrautifråndekravsomidentifierats.ResultatetblevattutvecklaCNCgantrymaskinkonceptet.

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NomenclatureADU Automatic drilling unit, a machine that is used for highly demanding

drilling,counterboringandreamingASTM AmericanSocietyforTestingandMaterials,atrustedsourcefortechnical

standardsformaterials,products,systems,andservicesBeam TheouterarticleforthewinginterfaceBoring BoringisusedtoenlargeaholemadebyapreviousprocessCMM ACoordinateMeasuringMachineisabletomeasurecomplexdetailsand

productsCNCmachine ComputerNumericalControlmachineCounterboring EnlargetheentranceofaholeDT The detail manufacturing, DT, is a separate place of the factory and

manufacturessomepartsfortheaircraftFlatness Thesurfacewiththeflatnesstolerancemustbewithinacertaindistance

betweentwoparallelplanesFrame ThepartunderthebeamFuselage ThebodyoftheaircraftGantry AstructurethatbridgesoveranareaInterface ThesurfacewherethewingandfinareassembledLegacyproduct Saab’smainproductthatisfullymanufacturedatSaabPKM ParallelKinematicMachinePlunge A tool that is placed inoneof thedrilledholes to stabilizeduring the

remainingdrillingProbe AhandhelddevicethatreflectsthelaserfromalasertrackerReaming MakinganexistingholedimensionallymoreaccurateSB Thefinalproductionandassemblyaremadeinfuselageassembly,SBShim Athinpieceofmaterialthatisplacedatthedrillingmechanismtomake

suretheholesgetthesamedepthTopskin Theouterarticleforthefininterface

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TableoffiguresFigure1.ApictureofT-XBoeing.Theredhighlightingshowswherethewing-andfininterfaceareplacedontheleftside.©Boeing.........................................................................2Figure2.Schematicfigureoftheworkingprocesstoreacharesultofthethesis...................6Figure3.Processforaneffectiveliteraturereview..................................................................6Figure4.Totheleftanillustrationofhowthespindlerotates.TotherightanorbitaldrillingmachinefromNovator.©Novator..........................................................................................11Figure5.TotheleftaLeicaLasertrackerA960.TotherightaT-probefromLeica................12Figure6.TotheleftanexampleofhowtheADUmachineisclampedtothedrilljig.TotherightanADUmachinefromSeti-Tec.©Desoutter.................................................................13Figure7.ACNCgantryfromZimmermann.............................................................................15Figure8.Thehighlightingshowswherethewing-andfininterfaceisplacedinrelationtothedatumreference.©Boeing.....................................................................................................16Figure9.Aprincipalsketchoftheholepatternforthewinginterfaceinrelationtothedatumreference.Thefigureshowsthedimensionsthatareallowedtobeshowed.............16Figure10.Aprincipalsketchoftheframeandthebeamofthewinginterface.Theupperarticleiscalledbeamandtheloweristheaircraftsframe.....................................................17Figure11.Totheleftapictureofthethreecuttingtoolsusedfortheprototypes,andabovethemtheshaftwherethecuttingtoolandtheshimareassembledbeforedrilling,seetherightpictureofhowitisassembled........................................................................................17Figure12.Thegaugesusedtomeasuretheholes..................................................................18Figure13.Thedrilljigforthewinginterfacemarkedintheordertheholesaredrilled........18Figure14.Totheleftaprincipalsectionalviewofthewingholewiththebushing.Totherightaprincipal3Dviewoftheholewiththebushing...........................................................19Figure15.Aprincipalsketchoftheholepatternforthefininterfaceinrelationtothedatumreference.Thefigureshowsthedimensionsthatareallowedtobeshowed........................19Figure16.Totheleftaprincipalsectionalviewofthefinholewiththebushing.Totherightaprincipal3Dviewofthefinholewiththebushing.................................................................20Figure17.Theleftpictureshowsa3Dprincipalsketchofthewingbushingandtherightpictureshowsa3Dprincipalsketchofthefinbushing...........................................................20Figure18.Ontheleftaprincipalsketchofhowthecutslookslikefromtheside.Ontherightaprincipal3Dsectionalviewofthecutswhencounterbored................................................22Figure19.Totheleftaprincipalsectionalviewwhenbushingplacedincounterboredhole.Totherightaprincipal3Dviewofhowthefinholelookslikewhenabushingisplaced...........22

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IndexoftablesTable1.AdescriptionofSaabGroup’sbusinessareas(SaabGroupAB,2017)........................4Table2.Anexampleofaconceptscreening.(+forbetterthan,0forsameas,-forworse).(AdaptedfromUlrich,K.&Eppinger,S.2008)..........................................................................8Table3.Anexampleofaconceptscoring.(AdaptedfromUlrich,K.&Eppinger,S.2008)......9Table4.Conceptscreeningforwing-andfininterface.Seechapter5.2forconceptdescription..............................................................................................................................26Table5.Anearlierstagematrixtoshowtheimportancescorethatwasusedtocalculatetheweighting.................................................................................................................................28Table6.Conceptscoringforwing-andfininterface..............................................................29

Tableofcontent1 Introduction 2

1.1 Background 21.2 Objective 31.3 Delimitations 31.4 Researchquestions 31.5 CompanyDescription 4

2 Methodologyandimplementation 62.1 Thesisworkprocess 62.2 Literaturereview 62.3 Semi-structuredinterviews 72.4 Benchmarking 72.5 Conceptselectionprocess 8

3 Theoreticalbackground 103.1 Holemaking 103.2 Orbitaldrilling 103.3 Gantry 113.4 Lasertracker 123.5 AutomaticDrillingUnit 133.6 Industrialrobotwithendeffector 133.7 ParallelKinematicMachine 143.8 CNCmachine 14

4 Empirics 164.1 Winginterface 164.2 Fininterface 194.3 Bushings 204.4 BenchmarkingAeronautics 204.5 BenchmarkingAerostructures 214.6 Conclusionbenchmarking 21

5 Concepts 225.1 Conceptforfinholes 225.2 Conceptsfordrilling 23

6 Conceptselectionprocess 266.1 Conceptscreening 266.2 Conceptscoring 28

7 Discussionandconclusion 307.1 Discussionconnectedtoresearchquestions 307.2 Discussionmethodology 317.3 Ethics 327.4 Conclusion 327.5 Futureworkandrecommendations 33

8 References 348.1 Electronicreferences 348.2 Writtenreferences 358.3 Verbalreferences 35

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1 IntroductionThischapterdescribesthebackgroundandtheobjectiveofthethesis,alsotheresearchquestionsand

thedelimitations.ItfollowsbyashortdescriptionofthecompanySaabGroup.

1.1 BackgroundUnitedStatesAirForce,U.S.AirForce,willpurchaseanewadvancedtwo-seatedaircrafttrainerforpilotsthatwillreplacethecurrentNorthropT-38Talon.SeveralaircraftmanufacturesareparticipatinginwhatiscalledtheT-XprogramwhichisdesignedbyU.S.AirForce,tocompeteaboutthefirstorderon350trainingaircraftswhicharecalculatedtakingintooperationandreplaceT-38year2024.BoeingisoneoftheaircraftmanufacturesthatareparticipatingintheT-XprogramandtheyhavepartneredwithSaabwhichmanufacturestherearpartofthebody.InthecurrentsituationtwoT-XprototypeshasbeenbuiltandthefirstflightwithBoeingT-XwasperformedinDecember2016inStLouis,USA(SaabgroupAB,2016).

Figure1.ApictureofT-XBoeing.Theredhighlightingshowswherethewing-andfininterfaceareplacedontheleftside.©Boeing

Theaircrafthas four interfaceswhere the twowingsand two finsareattached.Thewing-and fininterfaceareplacedattherearpartofthefuselage,thebodyoftheaircraft,seeFigure1.Toattachthewingandfinwiththefuselage,sixholesaredrilledatthewinginterfaceandnineholesaredrilledatthefininterface.Thewing-andfininterfacearemadeinaluminum.Whenthetwoprototypesweremanufactured theholes for thewing interfacewerepre-drilled in thedetailmanufacturing,DT, inanother part of the factory. DT has a lot of different manufacturing machines and measuringequipment,forexampleCNCmachinesandCMMmachinesinvariatingsizes.ACoordinateMeasuringMachine(CMM),isabletomeasurecomplexdetailsandproducts.ThearticlesmentionedinthisthesisweremanufacturedinCNCmachinesoutofaluminumblocks.The finalproductionandassemblyweremade in the fuselageassembly,SB,wheretheholeswerereamedandbushingswereplacedintheholes.AlltheholesforthefininterfaceweredrilledinDTandtheflatnesswasmeasuredinaCMM.Thesurfacewiththeflatnesstolerancemustbewithinacertain

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distancebetweentwoparallelplanes.Basedontheresultsfromthemeasuring,bushingswerechosenthatwereadaptedfortheflatness.ThefinaldrillingofthewinginterfaceinSBforthetwoprototypeswasmademanually,howeverifBoeing wins the T-X program the production volume will increase directly and Saab will have todecreasethedrillingtimeconsiderably.Themanufacturingratewillbe48aircraftsperyear,thereforethedrillinghastobemoreeffectiveinordertofulfiltheraterequirement.TheT-Xprojectwillrequireaproductionlinetobeabletohandlethecapacityof48aircraftsayear.Thewing-and fin interfaceareplanned tobedrilledat thesamestation in the future, thedrillingstationwillbeplacedintheendoftheproductionline.Thereasonforthisisthattherearpartofthebodymustbealmostfullyassembledinordertomanagethehightolerance-andflatnessrequirementsoftheholesbecauseofthestressesthatoccur.(Almé,L.2017)1.2 ObjectiveTheobjectivewiththisthesisistodevelopadrillingconceptthatfitsSaab’sgoalsforamoreeffectivedrilling of the wing- and fin interface for Boeing T-X. The conceptmust be robust, effective, andeconomicallyjustifiablebutalsofulfilthehightolerance-andflatnessrequirements.Thepurposeisalsotoexaminehowmuchofthedrillingthatshouldbedoneindetailmanufacturingandhowmuchthatshouldbedoneinfuselageassembly.1.3 DelimitationsTheobjectiveofthethesisisonlytoexaminewhichpathSaabshouldtakewhenselectingasuitabledrillingconcept.Severaldifferentpathswillbeexaminedandsincethisthesiscomprises10weeksthetimewillnotbeenoughforareadysolution.Anotherdelimitationisaccessofinformation.Becauseofthehighsecurityofhandlingoutinformationtoexternalpeople,peoplewithinSaabwithexpertisewill be interviewed in first place to collect information about different concepts instead ofmanufacturesandsuppliers.Thethesisalsoexcludementioningdimensionsbecauseofthesecrecy.1.4 ResearchquestionsTheobjectivewasbrokendowntothefollowingResearchQuestions(RQs):RQ1: Howcanthedrillingofthewing-andfininterfacebeautomatedandmoreeffective?

- Whichconceptismostsuitableregardingtotherequirements?RQ2: Howmuchofthemanufacturingshouldbedoneindetailmanufacturingandhowmuch

shouldbedoneinfuselageassembly?

- HowwillthefininterfaceavoidCMMmeasuring?

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1.5 CompanyDescriptionSaabGroupABwasfoundedin1937tosecureproductionofmilitaryaircrafttomaintainthesecurityof thecountry.FordecadesSaabhavebeenproviding solutions fromtraining-andcommand-andcontrol systems, to military subsystems, weapons and next-generation aircraft. Saab has around14.000employeesandoperatesinallcontinents,theirmainproductionislocatedinLinköpingwithabout5.000employees.Todaytheyoperateinfivebusinessareas,seeTable1,toprovidetheglobalmarketwith products, services and solutions, for bothmilitary and civilianmarkets. Saab’s legacyproduct is themilitary aircraftGripen,which is oneof themost advanced versatile fighters. (SaabGroup,2017)Table1.AdescriptionofSaabGroup’sbusinessareas(SaabGroupAB,2017)

Businessareas Aeronautics AdvanceddevelopmentofmilitaryandcivilaviationtechnologyDynamics Develops ground combat weapons, missile systems, torpedoes,

underwatervehiclesandsignaturemanagementsystemsforthecivilanddefencemarket

Surveillance Providesefficient solutions for safetyandsecurity, for surveillanceanddecisionsupport,andforthreatdetectionandprotection

SupportandServices Offersreliable,costefficientserviceandsupportforallofSaab’smarketsIndustrialProductsandServices

Comprises the business units Combitech, Avionics Systems,AerostructuresandVriconandworkswithindividualgrowthstrategiesforeachbusinessunit,aswellasthedevelopmentofproductideasthatfalloutsideofSaab’scorebusiness

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2 MethodologyandimplementationThischaptercontainsadescriptionofthemethodsusedandimplementationtoreacharesultofthe

thesis.

2.1 ThesisworkprocessAprocessisdefinedassequentialstepsofactivities(Levy,Y&Ellis,T.2006).TheworkingprocesstoreacharesultofthethesishavebeendividedinfourdifferentstepsasshowninFigure2.Thefourstepswillbeexplainedfurtherinthischapter.

Figure2.Schematicfigureoftheworkingprocesstoreacharesultofthethesis

2.2 LiteraturereviewA literature review is a process defined as sequential steps to: collect, know, comprehend, apply,analyze,synthesizeandevaluateliteratureinordertoprovideknowledgeinatopic.Aliteraturereviewcanbedividedinthreesteps:input,processingandoutputshowninFigure3.(Levy,Y&Ellis,T.2006)

Figure3.Processforaneffectiveliteraturereview

Literaturereviewhavebeenincludedduringthewholeworkingprocess,especiallyinthefirstphaseofthethesis.Planningonwhatkeywordstousewhenresearchinghavebeendecidedbeforecollectingliterature. The importance with planning which keywords to use is to not search too wide. Thekeywordswereforexampledifferentdrillingmethods.Thenextstepwastocollectmaterial towriteabout.Literaturewascollectedfrombooks, internetarticles and websites from different manufactures. To find electronic books, internet articles andwebsiteswithdrillingmethodsthedatabasesGoogle,GoogleScholarandUniSearchwereused.AbookaboutproductdesignanddevelopmentwasrecommendedtouseforconceptselectionbyouradvisoratLinköping’sUniversity.Thecollectedliteraturewasfurtheranalyzedtocollectrelevantmaterialandsortoutirrelevantmaterial.Afterplanning,collectingandanalyzingtheliterature,thewritingprocessbegan.Thesestepshavebeendoneforallliteraturereviewduringthethesis.

1.Literaturereview 2.Interviews 3.Benchmarking 4.Concept

selection

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2.3 Semi-structuredinterviewsTherearethreedifferentkindofinterviewtechniques;unstructured,semistructuredandstructured.Asemi-structuredinterviewisaresearchmethodwheretheinterviewerhasanopeninterviewwiththepersonwho is getting interviewed. The interviewerhasprepared several questionsbefore theinterview, and during the interview the interviewer asks questions that are prepared but alsodependingonwhatideasthatisbroughtupduringtheinterview.Theinterviewergenerallyhastopicsthatwillbediscussedandexamined.Astructuredinterviewiswhentheinterviewerhaspreparedallquestionsandthequestionsneverchangeduringtheinterview.(Wilson,C.2013)Theadvantageswithasemi-structuredinterviewisthatnewissuesthatwerepreviouslyunknowncanbediscovered,thiswill leadtonewideasandquestionstoask.Complextopicscanbeclarified,forexampleiftheinterviewerdoesnotknowthatmuchaboutthecomplextopicitisdifficulttothinkofquestionstoaskbeforetheinterview.Butifthepersonwhoisinterviewedexplainsadifficulttopicitwillbeeasiertobringupnewquestions.Anotheradvantagewithsemi-structuredinterviewsisiftheconversationdigressestoofarfromthemaintopictheinterviewercaneasilyredirecttheconversation.Itgivestheintervieweraflexibilitywithsupplementaryquestions,anditalsorequirelesstrainingthanan unstructured interview. The disadvantage with semi-structured interviews is the risk formisunderstandingandmissinginformation.(Wilson,C.2013)Inthisthesissemi-structuredinterviewshavebeenused,thepurposehasbeentogainknowledgeandunderstandingforthethesis.MostlypeoplewithinSaabwithspecialexpertisehavebeeninterviewed,butalsopeopleatLinköping´sUniversityandexternalpeoplewithdrillingcompetence.During theinterviewsnoteshavebeentakenandafterwardsasummaryoftheinterviewshavebeenwrittentoassurethatnofactsareforgotten.2.4 BenchmarkingBenchmarkingisamethodusedtodeveloptheorganizationbycomparingtootherorganizationsorunitswithin the organization. It is considered to be one of themost effectivemethods to collectknowledgeand innovationtoorganizations.Benchmarkingstartswithadeepunderstandingof theinternalprocess,thenextstepistocomparewithcompetitors,variousorganizationsordifferentunitswithinthesameorganization.Itisamethodforlearningandimprovement.Benchmarkingisdescribedas a structuredprocess: plan (plan), collect (do), analyze (check) and adapt (act). (EmeraldGroup,2006)BenchmarkinghavebeenmadewithinSaabGroup’sbusinessareasAeronauticsandAerostructures.ToseedifferentdrillingmethodsavisittoAerostructureswasmadetoseetheaircraftpartproductionforAirbusandBoeing.AeronauticswasvisitedaswelltoseetheproductionofSaab’slegacyproducttocomparedrillingmethodswiththemethodusedonthetwoprototypesforBoeingT-X.ThelegacyproductisSaab’smainproductthatisfullymanufacturedatSaab.

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2.5 ConceptselectionprocessAconceptmatrixisatwo-stageprocess,conceptscreeningandconceptscoring,bothstagesaremadeusingamatrix.Theprocessforbothstagesaredividedinsixsteps:

1. Preparetheselectionmatrix2. Ratetheconcepts3. Ranktheconcepts4. Improveandcombineconcepts5. Selectoneormoreconcept(s)6. Reflectontheresultandtheprocess(Ulrich,K.&Eppinger,S.2008)

Thesolutionselectionprocesswasdoneusingthemethodbelow.Theprocessbeganwithlistingandweightingthecriteriaforthesolution.ThecriteriawerediscussedwithadvisorsandmanagersatSaab.Thecriteriawerealsoweightedtosortoutthemostimportantcriteria.Thepotentialsolutionswerelistedandrankedafterthecriteria,howevernotallsolutionscouldberankedsincealotofinformationaboutthesolutionsareunknown.Finally,thebestsolutionwasselectedandreflectedbasedonthefinalweightedscore.

2.5.1 ConceptscreeningConceptscreening isbasedonamethoddevelopedbyStuartPugh inthe1980sand iscalledPughconceptselection(Pugh,1990).Thismethodisusedtoimproveanddevelopconcepts.Table2.Anexampleofaconceptscreening.(+forbetterthan,0forsameas,-forworse).(AdaptedfromUlrich,K.&Eppinger,S.2008)

Selectioncriteria Concept1 Concept2 Concept3(reference)

Concept4 Concept5

Easytohandle + - 0 0 0

Robust + 0 0 - +

Effective + 0 0 - +

Durability - + 0 0 -

Sum+’s 3 1 0 0 2

Sum0‘s 0 2 4 2 1

Sum–‘s 1 1 0 2 1

Netscore 2 0 0 -2 1

Rank 1 3 3 4 2

Continue? yes combine combine no yes

Asshown inTable2conceptsarecomparedwiththereferenceconceptusingasimplecode(+ for“betterthan”,0for“sameas”,-for“worse”)forthecriteria.Thereferenceconceptisgenerallyanindustrystandardoraconceptwithwhichtheteammembersareveryfamiliar,howeverthematrixdoesnotrequireareference.Conceptscreeningisthefirststepoftheconceptmatrix.Withconceptscreeningtheusercaneasilyseewhichconceptstocontinuewithandwhichtonotcontinuewith.Iftwoconceptsgetthesamenetscoretheteamcanconsidercombiningtheconceptsiftheybelievecombiningthemwillremoveseveral“worsethan”.(Ulrich,K.&Eppinger,S.2008)

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2.5.2 ConceptscoringConceptscoringisthenextstep,howeveritisnotalwaysnecessaryiftheconceptscreeningproducesadominantconcept.Thismethodisusedtoimprovethecomparisonstoeachcriterion.Inthisstageafinerratingscaleisused:Muchworsethanreference 1Worsethanreference 2Sameasreference 3Betterthanreference 4Muchbetterthanreference 5(Ulrich,K.&Eppinger,S.2008)Theconceptscoringcanuseasinglereferenceconcept,asinthescreeningstage,howeverthisisnotalwaysappropriateinscoringstage.Thereasonforthisisifthereferenceconcepthappenstobethebestconcept,alltheotherconceptswillberatedwith1,2,and3.Thereforeitisrecommendedtousedifferentreferencepoints,seeboldnumbersinTable3,inthisstagetoavoidthereferenceconceptreceivinganeutralscore.(Ulrich,K.&Eppinger,S.2008)Table3.Anexampleofaconceptscoring.(AdaptedfromUlrich,K.&Eppinger,S.2008).

Concept1 Concept2,3 Concept5

Selectioncriteria

Weighting Rating Weightedscore

Rating Weightedscore

Rating Weightedscore

Easytohandle 15% 3 0.45 3 0.45 5 0.75

Robust 25% 2 0.5 3 0.75 1 0.25

Effective 45% 3 1.35 4 1.8 2 0.9

Durability 15% 2 0.3 4 0.6 3 0.45

Totscore 2.6 3.6 2.35

Rank 2 1 3

Continue? No Develop No

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3 TheoreticalbackgroundThischaptercontainstheorythatwillbeusedforaresult.

3.1 HolemakingOneofthemostimportantoperationsinmanufacturingisholemaking.Thecommonuseforholesareeitherforassemblywithfastenersortoprovideaccesstotheinsideofapart.Themostaccurateholesareproducedbythefollowingsequenceofoperations:

1. Centering2. Drilling3. Boring4. Reaming

Roundholesofvarioussizesanddepthscanbemadebydrilling,butforahigheraccuracytheholerequiresboringandreamingaswell.Boringisusedtoenlargeaholemadebyapreviousprocess,byproducing circular internal profiles. Reaming is used tomake an existing hole dimensionallymoreaccuratethancanbeobtainedbydrillingalone.Areamerisatoolwithflutededgesthatremovesverylittlematerial.

Anothermethodforholemakingishigh-speedmachining.Inhigh-speedmachiningtheapproximaterangeofthecuttingspeedis600-1800m/min.Highcuttingspeedsarerecommendedwhendrillinginaluminumbecauseofitshighthermalcoefficientofexpansionandrelativelylowelasticmoduluswhichotherwisecancauseaproblemwiththedimensionaltolerancecontrol.Withhigh-speedmachining,thetoolandtheworkpieceremainclosetoambienttemperaturebecausemostoftheheatgeneratedincuttingisremovedbythechip.Thisisbeneficialbecausethereisnothermalexpansionorwarpingoftheworkpiecethatcanaffectthetolerancesduringmachining.(Kalpakjian,S&Schmid,S.2001)

3.2 OrbitaldrillingOrbitaldrillingisanotherdrillingmethod.Inorbitaldrillingthreemotionsarecombined-feed,spindlerotationsandorbitalrotation.Thecuttingtoolisalwayssmallerthanthediameterofthehole.Thedrillingmovementsareeccentricalongwiththeouteredgeofthehole.Thecuttingtoolhasahighspeedarounditsownaxisandthespindlerotationhasalowspeedaroundthecentralaxisofthehole,seeFigure4.(Manufacturingguide,2017)Byuseofatraditionaldrillingmachine,chipsandcrackscanemergeby theedgeof thehole,andahighpressure isneeded todrill through thematerial.Withorbitaldrillingitispossibletodrillthroughcarbonfiberandothercomposites,alsothroughstacksofseveralhardmaterials,withoutpressingwithhighforcethroughthematerial.Inorbitaldrillingcoolantis notneeded since the cutting forces are relatively low. (Ståhl, F. 2014)Witha traditionaldrillingmachinetheholeisoftendrilledinseveraloperations,withapredrilledholethatlaterisreamedandcounterbored.Howeverorbitaldrillingdoesnotrequireapredrilledhole.Withorbitaldrillingtheholecanbemadeinonestep,withthesametoolandhigherqualityofthehole.(Mellgren,E.2002)

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Figure4.Totheleftanillustrationofhowthespindlerotates.TotherightanorbitaldrillingmachinefromNovator.©Novator

NovatorAB isaSwedishcompanythathaspatentedorbitaldrillingsince itwasthefounderofthecompany,Dr. Ingvar Eriksson,who invented thedrillingmethod.NovatorABmanufactures orbitaldrilling machines, see Figure 4, which are used by for example Boeing, Airbus and BombardierAerospace.SaabAerospaceandtheRoyal InstituteofTechnologywere involved inaprojectwhichpurposewastofindoutwhateffectthequalityofdrilledholeshadonthestrengthanddurabilityoffiber composites. For this project, a reference holewithout delamination and burrswas required,whichresultedinthefirstpatentrelatedtoorbitaldrilling.(NovatorAB,2017)Thedisadvantagewithorbitaldrillingisthatitdoesnotoccurtensionsinthematerialwhichitdoeswithtraditionaldrilling,becauseofthelowerforcethatisusedtodrillthroughthematerial.Totestthestrengthofaholeso-calledopen-holetestsaremade.Ifafastenerisinsertedintotheholeitiscalledfilled-holetests.Thetestmethodsweredevelopedtocomparetoughness innewcompositematerials.(Adams,D.2016)Fortheopen-holetestthereareASTM-standards,AmericanSocietyforTestingandMaterials,ofhowthetestwillbeperformed,whichisrelativelycheapandeasytofollow.Themethodmeansthataholeisdrilled inacouponmadeofaspecificmaterial, inthiscasealuminum.Thecoupon isplaced inamachinethatpullsthecouponuntilfailure.Therearenostandardsforthefilled-holetestwhichmakesitmoredifficulttoperform.NovatorABisinvolvedinaprojectwheretheyperformfilled-holetests,toinvestigatehowthestrengthinthematerialisaffectedwhenthereisafastenerplacedinthehole.Theprojecthasbeengoingonfortwoyearsandisexpectedtobedoneintheendof2017.(Andersson,H-P.2017)3.3 GantryAgantryisastructurethatbridgesoveranarea.Itiseitherplacedonthegroundoronparallelrailsthatmakesthestructuremovable.Therailsworksasoneaxisandthegantrybridgeformstheotheraxis.Therailsarestrongenoughtocarrytheweightofthemachineandtheequipmentthatismountedonit.Theyarealsodesignedtoprovideaccuratemotionforthemachine.Bycoordinatingthemotionofthetwoaxessimultaneously,itcanmoveinanypatternnecessaryforexamplecutshapesoutofsteelplate.ThatiswhyagantrydesignlendsitselftoCNCshapecutting.Gantriesareavailableinawidevarietyofsizesthatcanhandlealotofdifferentareasandweights.(ESAB,2013)

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GüdelisaSwisscompanywhichmanufacturesforinstancegantriesandGantryrobots.Thegantriesconsistofseveralcomponentsthatcanbecombinedforlinearmovements.Theyareverypreciselyand can handle weights from a few kilos up to several tons. Güdels Gantry robots can handlecomponentsweighing up to several tons aswell, with extreme accuracy, speed and repeatability.(Güdel,2017)3.4 LasertrackerAlasertrackerisaportablemeasurementsystemthatconsistsofalaserbeamandsomethingthatcanreflectthelaser,whichiseitherheldormountedontheobjecttobemeasured.Areflector,whichisasmallmirroredsphere,isanexampleofathingthatismountedontheobject.Whenusingabushing,thereflectorcanbeplacedinahole,orifthematerialismagneticitcanbeplacedrightonasurface.Ahandhelddevicethatcanreflectthe laser iscalledprobe,seeFigure5.Theoperatorcanmovetheprobetothedesiredlocationasthelasertrackerfollowswiththelaserbeam.Whenthereflectorortheprobeareplacedthelaserbeamreentersthetrackeratthesamepositionfromwhichitleftandthedistanceisrecorded.(Meagher,H.2014)Alasertrackerissensitiveforairflows,temperaturechangesandvibrations.Themeasuringshouldbedoneinatemperaturecontrolledroomandnotclosetomachinesthatcancausevibrations.Toreachpoints that is difficult for an operator to reach, a laser tracker can be combinedwith a robot, forexampleanURrobotthatcanworkbesideahuman.ThelasertrackercanalsobeusedformeasuringtheT-Xaircraft inSM.Anadvantagewitha lasertracker isthat it ismoveable/portableandcanbeusedbothinSBandSM.(Cristalli,G.2017)LeicaGeosystemsisacompanythatmanufacturesmeasuringsystemsforseveralindustriessuchasaerospace,defence,security,constructionandmanufacturing.Theirlasertrackersystemscanhandlehighaccuracyprobing,scanningandreflectormeasurementforlargepartsinindustrialapplications.LeicaAT960,seeFigure5,isaportablemodelthatisusedforlargevolumemeasurementbyprobing,scanning, reflector measurements and automated inspection. (Hexagon, 2017) The accuracy, themeasuringtimeandthepurchasecostofLeicaAT960areapproximatelyequaltoaCMMmachine,thedifferenceisthatLeicaAT960isportable.(Cristalli,G.2017)

Figure5.TotheleftaLeicaLasertrackerA960.TotherightaT-probefromLeica.

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3.5 AutomaticDrillingUnitAnAutomaticDrillingUnit, ADU, is a device that can perform various types of drilling operations,including counterboring and reaming. Themotor is generally electric and the feed system can bepneumatic,hydraulic,electricormechanical.(Directindustry,2017)ADUmachinesarededicatedtotheaerospace industryandusedbymajoraircraftmanufactures likeBoeingandAirbus. Inaircraftindustryitisoftennecessarytodrillthroughdiversematerialcomponents,thecomponentsareofteninlightweightmaterialssuchasaluminumandtitanium.Itisoftencomplextodrillthroughthesekindof materials with the most precise drilling results, this claim technically highest requirements.(Lübbering,2017)AnADUissemi-automatedandcandrillholesinvariatingdiameters.AnADUmachinerequiresadrilljig fixed to theworkpiece, see Figure 5, in order to stabilize itself before drilling. Themachine isclampedtoadrilljigbyexpandingitsconcentriccolletwhichisco-axialwiththecuttingtool.(ApexToolGroup,2016)HoweverLübberinghasanotherlockingsystemaswell,calledtwistlockwhichisdesignedlikeabayonetthatcanbelockedbyaquarterturninginthelockingbushing.This lockingsystemallowslargerdrillingholes.(Lübbering,2017)

Figure6.TotheleftanexampleofhowtheADUmachineisclampedtothedrilljig.TotherightanADUmachinefromSeti-Tec.©Desoutter

Lübbering and Seti-Tec are two manufactures of ADU machines to aerospace industry. BothLübbering’sandSeti-Tec’sADU,seeFigure5,buildsonmodularsolutionswherethemachinesarebuiltafter thecustomers’ requirements.Seti-Tec’sADUmachinesareusedwithinSaabandSaab isveryfamiliarwiththisproduct.HoweverthereisnoADUmachineatSaabthatdrillstheseholedimensions.Lübberingintheotherhandaremorefamiliarwithdrillinglargerholedimensions.BothLübberingandSeti-Teccanhandlespecificrequirements.(Wikström,T.2017)3.6 IndustrialrobotwithendeffectorAs defined by ISO 8373, an industrial robot is “an automatically controlled, reprogrammable,multipurposemanipulatorprogrammableinthreeormoreaxes,whichmaybeeitherfixedinplaceormobile foruse in industrialautomationapplications”. Industrial robotsareusedformanydifferentapplications,forexamplewelding,painting,assemblingandpackaging.Theyareoftenusedtoperformtasksthataredangerousorunsuitableforhumans.Theindustrialrobotimprovestheproductivityandquality,withitshighspeed,accuracyandrepeatability.(Ribeiro,L.2015)Aroboticendeffectorisanobjectthatisattachedtotheendofaroboticarm,forexamplegrippers,toolsforscrewfastening,materialremovaltoolsandforce-torquesensors.(Bouchard,S.2014)

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3.7 ParallelKinematicMachineThe first Parallel Kinematic Machine, PKM, was developed by Karl-Erik Neumann and was calledTricept, thismachinewasused in industry already in 1994. Then in 2004Exechon technologywasinventedandthePKMwasfurtherdeveloped.WithaPKMtheflexibilityismaintainedandtheaccuracyandstiffnessisoutstanding,inthistechnologythemotionsinX,Y,Zareperformedbythreeormoreparallelaxes.(ExechonWorld,2008)Thelinksofthemachineareactinginparallelandincooperationwitheachotherandhavealargeloadcarryingcapability.Theaxescanbepushedinandoutfromtheirattachmentwhichmeans it does not need any ball joints. Thismakes it as stiff as a conventionalmachinetool.(Mellgren,E.2011)APKMcaneasilycarryaprobe,whichisahandhelddevicethatreflectsthelaserfromalasertracker.Incombinationwitha5-axismachineitcanmeasureandadjustrelevantprogrammingdatabeforemachining.Forexample,a frameforacaroraplanecanbemeasured inproductionandadjustedbefore the finalmachining ifneeded.Boeing isusing this technology in theirproduction. (ExechonWorld,2008) Exechon Enterprises L.L.C. is a joint venture in the United Arab Emirates focused on advancedmachining technology,ownedbyLockheedMartin, TecgrantAB (formerlyExechonAB),aSweden-based technology company and Abu Dhabi-based Injaz National. Exechon will establish amanufacturingandengineeringcenterofexcellenceforPKMintheaerospaceareaandotherindustrialareas.(Exechon,2016)Oneof theirproducts is calledXMini,madeof carbon fiber, ithas thecapability tomakea50mmdiameterholeintitaniumwitha5-axismachinetool.TheXMiniisproducedincooperationwithBoeingandAirbus.Theproduct isas flexibleasa robotandcaneasilybemovedaround in the factory todifferentworkingstations.Thepositioningaccuracyis+/-10micronanditcanbeappliedwithatoolforceof7kN.Ittakesonly72hourstointegratetheXMiniintoproductionanditcanbeadaptedtoanyexistingjigorfixturesinceithasaflexibleframesystemcalledXFrame.(Exechon,2016).GüdelisacompanymanufacturinggantryrobotsandtheyhavealicenseforproducingtheXMini.(Engström,M.2017)AgantryTaurobotisanotherPKM,butincontrastwithotherPKMaTau-robothasalargerworkingrange.Therobothasthreelinearactuatorswitharmlinks,workinginparallel,connectedtotheendoftherobotarmusingaTau-structure.Todaythereisadesiretofindanefficientwaytoassisthumanworkers. Thiswould require amuch stiffer robot in the sense ofmotion compliance compared totraditional industrial robots, itwouldalso requireamuchmore flexible robot touse.AgantryTaurobotcanofferhighstiffness,accuracyandspeed.ABBhasthepatentofthisrobot,howeveritissofaronlymanufacturedasprototypesandisstillinresearchstage.AtLund’sUniversitytherearefourprototypesofgantryTaurobots,thesearecombinedwithGüdel’sgantries.(Nilsson,K.2017)3.8 CNCmachineThemulti-axiscomputernumericalcontrolled(CNC)isaprogrammablemachinewithacuttingtoolthat is movable relative to a workpiece. Modern CNC machines are used in almost all industryproductiontodaywithvariatingsizes.Themachinetoolsareversatileandcapableofmilling,drillingandboring.CNCmachinescanalsodo3Dprinting,plasmacuttingandlaserweldinganditcanprocessalotofdifferentmaterialsdependingonrequirements,forexampleitcanprocesssteel,aluminum,plasticetc.TheaccuracyofaCNCmachineisofaveryhighlevel,thepositioningandtherepeatabilityare measured with an incremental coder to manage the accuracy. The CNC machine could beprogrammedwithmodernCAD/CAMsystems,thisisthemostefficientandcommonsystemtouse.(IselGermanyAG,2017)

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A CNC machine can be combined with a gantry, see Figure 7, to be able to handle large parts.ZimmermannisacompanywhichmanufacturesconventionallyCNCmachinesand5-and6axisCNCgantrymachines. They cover all possiblemachining capabilitieswith top-qualityworkpieces, shortthroughputtimesandoptimizedsurfacequality.Thegantryconstructionhasastableclampingtableandsidewallsfilledwithspecialconcretewhichleadstoareliablestructure.(Zimmermann,2017)

Figure7.ACNCgantryfromZimmermann.

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4 EmpiricsThis chapter contains a description of how the drilling at the wing- and fin interface of the two

prototypesweremanufacturedatSaab,andalsoadescriptionofthebenchmarkingvisitswithinSaab.

Figure8.Thehighlightingshowswherethewing-andfininterfaceisplacedinrelationtothedatumreference.©Boeing

Thewing-andfininterfaceisrelatedtoadatumreferencewhichisplacedwheretherearpartandthefrontpartofthefuselageareattached.ThepositionofthedatumreferenceisshowninFigure8.Itishighpositioningtolerancesbetweentheholesandthedatumreference,andbetweentheholes ineachinterface.4.1 WinginterfaceThewinginterfacehassixcounterboredholesthatisusedtoattachthewingwiththefuselage,seeFigure9.Counterboringisamethodusedtoenlargetheentranceofahole.ThepositioningtolerancebetweentheholesinFigure9isveryhigh.

Figure9.Aprincipalsketchoftheholepatternforthewinginterfaceinrelationtothedatumreference.Thefigureshowsthedimensions

thatareallowedtobeshowed.

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Theholesaredrilledthroughthebeamandtheframeandbotharticlesaremadeinaluminum.Thebeamistheskinonthewinginterfaceandtheframeisthepartunderthebeam,seeFigure10.Thefuselageandthewingareattachedwithboltsandnutsviatheholesatthewinginterface.AllholeswerepredrilledinDT,bothfortheframeandthebeam,anddrilled(reamedandfinemachined)inSBwhentheframeandbeamwereassembled.Thedrilling inSBwasperformedmanually,withthreedifferentcuttingtools,withadrillingmechanism,seeFigure11.Afixtureheldthefuselageintherightplaceandadrilljigwasclampedatbothsidesfortheinterfaces,seeFigure13.Thedrilljigandthefuselagewereattachedviaasmallholeandthreescrewsthatheldthejigintherightplace.

Figure10.Aprincipalsketchoftheframeandthebeamofthewinginterface.Theupperarticleiscalledbeamandtheloweristheaircrafts

frame.

! = 4 − %&' + %)*2 (1)

Figure11.Totheleftapictureofthethreecuttingtoolsusedfortheprototypes,andabovethemtheshaftwherethecuttingtoolandthe

shimareassembledbeforedrilling,seetherightpictureofhowitisassembled.

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Figure12.Thegaugesusedtomeasuretheholes.

Thefirststepwastomeasurewherethedrilljigisinrelationtothefuselage.Thiswasmadeinalltheholeswithagauge,seeFigure12.Amax-andminimumvaluewerereadandwiththeequation(1)avaluewascalculatedthatdecidedwhichshimthatshouldbeusedforthedrillingofallholesatoneinterface, the shims could vary on the two interfaces. The shim is a thin piece ofmetal thatwasassembledonthedrillingshaft,seeFigure11,tomakesuretheholesgotthesamedepth.Maxisthelargestnotedvalueandmin is thesmallest.T is the thicknessof theshims thatshallbeused.Thedrillingshaftwasclampedinthefirstholeandthenitwasdrilledwiththreedifferentcuttingtools,seeFigure11.Thefirstcuttingtoolwasforboringwhichisamethodtoenlargeahole.Thesecondcuttingtoolwasusedforplanningthebottomofthehole,andthelastwasforreamingthediameter.Whenthefirstholewasdrilleditwasmeasuredwithago/nogogaugetocheckthediameter.Thenaplungewasplacedintheholetoaddstabilizationduringthedrillingoftheremainingholes.Theprocedurewasrepeatedinholenumber6,3,4,andthenalsoinholenumber2and5,seeFigure13,butwithoutplacingtheplunge.Whenallholesweredrilledtheyweremeasuredwithagaugetocheckthattheygottherighttolerances.

Figure13.Thedrilljigforthewinginterfacemarkedintheordertheholesaredrilled.

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52

6

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AsshowninFigure14therearetwodifferentdiameters,D1andD3,ofthewinghole,tisthethicknessandD2istheinnerdiameterofthebushing.ThelowerholewasdrilledinDTandupperholewasonlypredrilled inDT, thiswasmade inaCNCmachine.Thearrow indicates thesurface thathasahighrequirement on the flatness for all the holes after drilling, the hole pattern has to be in a certaindistance between two parallel planes. However the flatness of the bushings surface is the finalrequirement.AllthedimensionsshowninFigure14havehightolerances.

Figure14.Totheleftaprincipalsectionalviewofthewingholewiththebushing.Totherightaprincipal3Dviewoftheholewiththe

bushing

4.2 FininterfaceBoeingT-Xhastwofinsonthefuselage.Theholesofthefininterfacesaredrilledthroughthetopskin.As shown in Figure15, one fin interfacehas threepinholesplaced in themiddle rowof theholepattern,whichtakesuptheloadandhelpstosteerinwhenassemblingthefin.Thentherearesixholesfortheboltsandnutsplacedinthefirstandthirdrowoftheholepattern.TheseholesweremadeinDT in aCNCmachineandafterwards the flatnesswasmeasured in aCMMmachinewithnominalbushingsplacedintheholes.ThearrowinFigure16indicatesthesurfacethathasveryhighflatnesstolerancesonthefinalrequirement.Afterwardsbushingsfortheholeswereselecteddependingontheresultfromthemeasurementoftheflatness.SincetheCMMmachineisveryexpensiveandnotalwaysavailableitwouldbeanadvantageifthiscouldbedoneintheSB-line.ForthetwoprototypesalltheholesgotthesameresultintheCMMmachineandthesamebushingswereusedforallholes,butsinceonlytwoaircraftshavebeenmanufactureditistooearlytosayifthiswasjustacoincidenceornot.

Figure15.Aprincipalsketchoftheholepatternforthefininterfaceinrelationtothedatumreference.Thefigureshowsthedimensions

thatareallowedtobeshowed.

t

02

03

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Figure16.Totheleftaprincipalsectionalviewofthefinholewiththebushing.Totherightaprincipal3Dviewofthefinholewiththe

bushing

4.3 BushingsThebushings,seeFigure17,thatarepressedusingatoolintheholesafterreamingaremadeofsteel.Thereasonforusingbushingsisthatsteeltakesuploadbetterthanaluminum.Theprocessforplacingthebushingsisdifficultbecauseofthetimelimit.Itisinterferencefitbetweenthebushingsandtheholes,thereforethebushingsarecooleddowntoshrinkinliquidnitrogentoatemperatureof-200°C.Afterpickingupthebushingsfromtheliquidnitrogen,thebushingsmustbeplacedintheholeinthetimelimitof20seconds.Thecauseforthetimelimitisthataluminumshrinkfasterthansteel,andsincemetal conducts cold the aluminum holewill shrink in contactwith the steel bushings. Afterreamingtheholesandaftermachiningthesurfacebytheholesthebushingsmustbeplacedin30-60minutestoavoidsurfacetreatment.(Almé,L.2017)

Figure17.Theleftpictureshowsa3Dprincipalsketchofthewingbushingandtherightpictureshowsa3Dprincipalsketchofthefin

bushing

4.4 BenchmarkingAeronauticsAvisittoAeronauticswasmadetoseetheproductionofGripen.Thewholeproductionlinewasvisited,fromdetailmanufacturingtofuselageassembly.Infuselageassemblytherewasafuselagewherethewingwasnotattachedyet.TheinterfacewasstudiedwhichledtoincreasedunderstandingfortheattachmentofthewingatBoeingT-X,sincetheinterfaceofGripenissimilartoBoeingT-X.FurtherasecondvisitwasmadetoAeronauticstolearnmoreabouthowthedrillingareperformedatGripen.Thedrillingmethodatthewing-andfininterfaceattheprototypesofBoeingT-Xaresimilartothedrillingmethodatthewing-andfininterfaceatGripen.Thefuselagewasclampedinafixtureandtheholesforthewinginterfaceweredrilledwithatraditionaldrillingmechanism.Theholesweremeasuredwithseveralgauges.KarolinaGustafsson,anoperatoratGripen,wasinterviewedaboutthedrillingstationforthewinginterface.

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4.5 BenchmarkingAerostructuresTwovisitsweremadetoAerostructures toseedifferentdrillingmethods.The firstvisitwasat theproductionof flapsupportstructuresforAirbusA350-1000.Holes indifferentsizesaredrilledwithveryhighprecisioninalargeCNCmachinefromDMGMori.Thereasonforthisvisitwasespeciallytoseeamethodfordrillingoflargeholeswithhighaccuracy.Afterthedrilling,thepartsaremeasuredinaCMMmachinethatisplacedinthesamepartofthefactory.TheCNCmachineisplacedataconcretefoundationtoavoidvibrationsthatcanaffecttheaccuracy.ThesecondvisittoAerostructureswasmadewherethepurposewastolookatadrillingmachinecalled“thephonebox”,whichisusedfordrillingattheleadingedgeforAirbusA380.Thedrillingmachineismovedalongthe32meterlongpartwhichisclampedinafixture.Theoperatorfixesthemachineatdifferentplaceswhereitperformsthedrillingwithveryhighprecision.AlotofholesatthisstructurearealsodrilledwithADUmachineswhichcanbemadeatthesametimeasthe“thephonebox”drills.4.6 ConclusionbenchmarkingThe benchmarking studies were especially very helpful for increased understanding for how theproductionofanaircraftcanbedesignedandhowthedrillingwasperformedatbothGripenandtheprototypesofBoeingT-X.Alsohelpfultogainknowledgeindifferentmachinesthatcanbeusedfordrilling. This knowledge have been used during the working process to develop the differentconcepts.

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A B

5 ConceptsThis chapter contains information about the different concepts for the fin hole and for the drilling

conceptsthatwillbecomparedintheconceptselectionprocess.

5.1 ConceptforfinholesThefinholeshaveaveryhighflatnesstolerance,andasmentionedearlierthefinholesforthetwoprototypes havebeenmeasured in CMM-equipment after detailmanufacturing to select the rightbushingfortheholes.Sincethismethodtakestoomuchtime,becausethepartneedstobemovedtoanotherlocationandtheCMMisnotalwaysavailable,anothermoreeffectivesolutionforthefinholesisnecessaryifBoeingandSaabwinstheorder.Differentideashavebeendiscussedonhowtosolvethisproblem.5.1.1 CounterboredholesThisideabuildsonthemethodusedforthewinginterface,itissimplydescribedasacounterboredholewiththesamediameterasthebushing’souterdiameter.TheinnerholewouldbedrilledinDT,andthecounterboredholewouldbepredrilledinDTlikethewinginterface.TheninSBtheholewouldbereamedandplaned.Theadvantagewiththisisthatbothwing-andfininterfacecouldbedrilledwiththesamemethod.However,withthisideaitremovesmaterialfromthefuselageandthatisnotanoptionsinceitcouldhaveanimpactonthestrengthsoftheaircrafteventhoughitisjustaremovalofacoupleofmillimeters.Itisnotcertainitwouldhaveanimpactontheaircraft,butevenifitwouldnot,alotofstrengthscalculationswouldhavetoberemade.Anotherdisadvantagewiththismethodisthatotherbushingsmustbeusedsincetheflangeofthebushingneedstobethicker.5.1.2 A“cuts”A“cuts”iswhenleavingmaterialabovethesurfaceinDTwheretheholewillbedrilled,seeFigure18.TheideaofacutsistogetcontrolofthesurfaceafterDTbymakingacounterboredholeinthecuts,whenthetopskinisassembledtothefuselageinSB.ThecounterboredholewillbedrilledtothesameheightofthesurfacewherearrowBpointsatinFigure19.Therefore,thesamebushingsusedfortheprototypescanbeused,seearrowAinFigure19onhowthebushingisplaced.Withacutsthesurfaceiscontrolledandthesamemethodcouldbeusedforboththewing-andfininterface.Theadvantageisthatthismethoddoesnotdifferfromtheprototypes,sinceitonlyremovesmaterialfromthecuts.

Figure18.Ontheleftaprincipalsketchofhowthecutslookslikefromtheside.Ontherightaprincipal3Dsectionalviewofthecutswhen

counterbored.

Figure19.Totheleftaprincipalsectionalviewwhenbushingplacedincounterboredhole.Totherightaprincipal3Dviewofhowthefin

holelookslikewhenabushingisplaced.

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5.1.3 MeasuringwithotherequipmentThefinalideaissimplyexplainedbyfinishingtheholesofthefininterfaceinDTandwhenassembledinSBusealasertracker,model960fromLeica,toassesswhichbushingstouse.AlasertrackerwillmostlikelybepurchasedforotherusesifBoeingandSaabwinstheorder,andthereforeitcouldbeeconomically justifiabletousethismethodforthefin interface.A lasertrackercanmeasure inthesametimelimitasaCMMmachine,theadvantageisthatthearticlethatneedstobemeasureddoesnothavetobemovedtoanotherpartofthefactory.Theonlydisadvantageisthatthelasertrackerrequiresregulatedenvironment,forexampleregulatedtemperature.(Cristalli,G.2017)5.2 ConceptsfordrillingSixdifferentconceptshavebeencompared,byusingconceptscreeningandconceptscoringmatrices,onhowtoautomateandmakethedrillingstationforthewing-andfininterfacemoreeffective.Theconceptsbelowaredescribedbyaddingacutsforeachfinhole.5.2.1 ConceptA–ADUmachineThe first concept is touseADUmachines fromforexampleLübberingorSeti-Tec.Thesemachinesrequiredrilljigsforallfourinterfacestoachievestabilityandmanagethehightolerances.Afixtureholds the fuselage in therightplaceandthedrill jigsareclamped in the fixture.Themachinesareclampedinthedrilljigandplacedbyanoperator.ADUmachinesrequirepredrilledholesfromDTatbothwing-andfininterface,foramoreeffectiveandeconomicproduction.Otherwisemoremachineswouldneedtobepurchasedforpredrillingoperations.However,ADUmachinesarerelativelylowinpurchasecost,andsincetheyarerelativelydifficulttoadjust,differentADUmachineswillbeusedforthedifferentdrillingoperationsandholediameters.Forexamplethedrillingforthewinginterfaceismadeinthreesteps,andthefininterface’sholeswouldbepredrilledinDT,andinSBuseoneortwoADUmachinesforreamingandfinemachiningthecounterboredholesintheaddedmaterial.MostlikelytwoormoresetsofADUmachineswillbepurchasedtoincreasethereliabilityforthemachine,toavoidstopinproductionifthemachinebreakorwhenitneedsrepairability.Thisconceptissimilartothemethodusedforwinginterfaceoftheprototypes,onlythisconceptissemi-automatedapartfromtheoldmethodthatismanual.5.2.2 ConceptB–GantrywithXminiThisconceptbuildsoncombiningagantryfromGüdelwithanXminifromExechon.Thegantrycanmoveinthreeaxes(X,Y,Z)andcombinedwiththeXminiitcanreachboththewing-andfininterface.Thefuselagewillbeplacedinafixture.Thisconceptrequiresanautomaticchangeoftoolsinordertomanagedrillingatbothwing-and fin interface.Theadvantageswith this is thatanXminihashighaccuracyandiseasytointegrateintoproduction.Howeverthisconceptdoesnotfulfilthebudgetorthedimensions.5.2.3 ConceptC–GantrywithTaurobotConceptCbuildsonthesameideaasconceptB,butwithaTaurobotinsteadoftheXmini.However,theTaurobotisstillunderresearchprogressandfornowonlymanufacturedasprototypes.5.2.4 ConceptD–CNCgantrymachineThisconceptistouseaCNCgantrymachine,forexamplefromZimmermann.Thespindlecanreachalltheinterfaces,themachinehasanautomaticchangeoftoolsandaveryhighaccuracy.Thefuselagewill be placed in a fixture. An advantagewith a CNC gantrymachine is that it is fully automated,howeveritrequiresaCNC-operatorwithspecialeducation.Thepurchasecostforthemachinedoesnotfulfilthebudget,howeveritmightbeprofitableiftheproductionvolumewillincreaseandifmoreoperationscouldbedoneintheCNCmachine.

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5.2.5 ConceptE–OrbitaldrillingmachineConceptEistouseanOrbitaldrillingmachine.Todaythereisnomachinethatfulfilthedimensionsforthewinginterface,butaccordingtotheCEOofNovatorABitshouldbepossible.Thedisadvantagewithorbitaldrilling is that itdoesnotoccur tensions in thematerialwhich itdoeswith traditionaldrilling,becauseofthelowerforcethatisusedtodrillthroughthematerial.NovatorABisinvolvedina project where they perform filled-hole tests, to investigate how the strength in thematerial isaffectedwhenthereisafastenerplacedinthehole.Theprojecthasbeengoingonfortwoyearsandisexpectedtobedoneintheendof2017.AnorbitalmachinewouldbeusedinsimilarwayasconceptA, theadvantagewithorbitaldrillingcomparedto traditionaldrilling is that itdoesnothavetobedrilledinseveraloperationstomanagethehightolerances,itcouldbemadeinonestep.5.2.6 ConceptF–IndustrialrobotwithendeffectorThisconceptistocombineanindustrialrobotfromforexampleKUKAwithanendeffectorfordrilling.Thefuselagewillbeplacedinafixture,andtherobotwouldbeplacedonforexamplerailsorunderthefuselage.Thiswouldrequirethefuselagetobeabletorotateinordertoreachalltheinterfaces.Thedisadvantagewiththismethodisthatturningthefuselagemayaffecttheaccuracybecauseitisdifficulttostabilizethefuselagecompletely.Anotherdisadvantagewiththisconceptisthatitdoesnotfulfilthebudget.

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6 ConceptselectionprocessThischaptercontainstheconceptselectionprocess.

6.1 ConceptscreeningFortheconceptscreeningmatrix,seeTable4,noreferencewasusedbecausenoneoftheconceptsare an industry standard. Therefore all the concepts were compared to each other for everyrequirement. Thematrixwas discussedwith peoplewithin Saabwith special expertise for amoreaccurateresult.TheconceptscreeningmatrixresultedincontinuingwithconceptAandconceptDinaconceptscoringmatrix.Thematrixisfurtherexplainedinthesubheadings,6.1.1–6.1.6.Belowthedifferentconceptsarelisted:ConceptA ADUmachineConceptB GantrywithXminiConceptC GantrywithTAUrobotConceptD CNCgantrymachineConceptE OrbitaldrillingmachineConceptF Industrialrobotwithendeffector

Table4.Conceptscreeningforwing-andfininterface.Seechapter5.2forconceptdescription.

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6.1.1 FunctionalityThefunctionalitydescribestherequirementswithfunctionsthattheconceptsneedsforoperating.Withstrengthrequirementstheconceptneedstofulfilthestrengthinthefin-andwingholes,orbitaldrillingdoesnotfulfilthisrequirementsinceintraditionaldrillingtensionsoccurintheholeswhichdoesnotoccurinthesamewayinorbitaldrilledholes.AlltheconceptswillavoidCMMmeasuring.Theconceptmustfulfilthedimensions,theholediameterandthetolerances,conceptsB,C,EandFtechnologydoesnotfulfilthedimensionrequirements.AnADUmachinecanmanagethedimensionsandaCNCgantrymachinecanmanagetherequirementswithhighertolerances.Whendrillinginmetalitisimportantthatthemetalchipsthatoccurdoesnotaffectthequalityoftheholewithscratches.ADUmachinescanaffectthequalityoftheholewithmetalchipswhenthecuttingtoolisretractedfrom the hole, the other concepts does not have the same problem. Another requirement is thecapacity/productionvolume,theconceptmustmanagethecycletimeof48aircraftsperyear.Alltheconceptsmanagethecapacity,howeverconceptsB,C,DandFcouldhandlelargercapacity.6.1.2 ConvenienceConvenienceisthestateofbeingabletoproceedwithlittleeffortordifficulty.Itisaconvenienceiftheconceptiseasytouseinformofeducation,forexampleaCNCmachinerequireaspecialeducatedCNCoperator. ADUmachines andorbital drillingmachines are relatively easy to use compared toConceptsB,C,DandF.Howevertheseconceptsarebetteriftheproductionvolumewillincreaseto,forexample60aircraftsperyear.IftheproductionvolumewouldincreasemoreADUmachinesandorbitaldrillingmachineswouldhavetobepurchased.Anotherconvenienceistheabilitytoplacebushingswithin30-60minutestoavoidsurfacetreatment,thisisaproblemforalltheconcepts.HoweverconceptsB,C,DandFmightbeabletodrilloneholepattern in lessthananhourandthereforebeabletoplacethebushingswithinthetime limit.ThedifficultywithADUandOrbitaldrillingisthetimefordrillingaholepatternandalsothedrilljigsthatareinthewayofplacingbushings.Anautomaticconceptwouldeasetheproduction,conceptsAandEaresemi-automatedandtherestarefullyautomated.Thelastconvenienceisifthedrillingofthefin-andwinginterfacecouldbedoneatthesamestation,alltheconceptsfulfilthis.6.1.3 ErgonomicsEnvironmental requirements compares if the concepts fulfils laws concerning theenvironment.Allmachinesneedstofulfilthistobeapprovedtobeused.Safetyforoperatorcompareshowsafeitisforanoperatortolaborintheworkingenvironment.Someconceptsmayneedlightbeamsandsafetyfences.Howeverallthemachinesneedstofulfilthesafetylawstobeapprovedtobeused.6.1.4 DurabilityThedurabilitydescribeshowreliable themachineand thecutting tool is, forhow long time it canoperatebeforeitbreaks.Italsodescribeshoweasyitistorepairandserve,andhowlongtimeittakes.Therepairability/reliabilityfortheADUmachineisbetterincomparisontotheotherconceptssinceitispossibletohaveseveralsetsbecausetheADUmachinehasalowpurchasecost.ThismeansthattheproductiondoesnotneedtostopwhileanADUmachineisonreparation.6.1.5 OtherFinishedsolution/Deliveryisacomparisonofthedeliverytimeandifthereexistsafinishedsolutionoftheconceptorifitneedstobedeveloped.ADUmachinesandCNCgantrymachinesareconceptsthatalreadyexistsandcouldbepurchasedanddelivereddirectlyforthistask.AgantryXmini,anOrbitaldrillingmachineoranindustrialrobotcouldbeused,buttodaytheydonotfulfiltherequirements,thereforetheyhavetobedevelopedfirst.ThegantryTAUisstillinresearchstage.Machinesizeshowshowmuch space eachmachine needs. An ADUmachine and anOrbital drillingmachine does notrequiremuchspaceincomparisontoaCNCgantrymachinethatisverylarge.

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6.1.6 CostsPurchasemachine,installationandfixturesarefixedcostsfortheconcepts.GantryXmini,gantryTAU,CNCgantrymachineandindustrialrobotarequiteexpensivecomparedtotheOrbitaldrillingmachineandtheADUmachine.TheADUmachineisthecheapestalternative.Variablecostschangesdependingtotheoperatingvolume,forexampleoperating-andservicecosts.TheADUmachineandtheOrbitaldrillingmachinehaslowvariablecostsandtheCNCgantrymachinehashighercosts.6.2 ConceptscoringFortheconceptscoringmatrix,seeTable6,conceptAwasusedasreferencebecauseitiseasiertohaveareferencewhenjustcomparingtwoconcepts,inthiscaseconceptAandDwerecompared.Thesame criteria were used in the concept scoring matrix as in the concept screening matrix, thedifference isthatthismatrix ismoreaccurate,partlybecause ithasamoreaccuratescalebutalsobecauseallthecriteriaareweighted.Theweightingsarebasedonanimportancescorefrom1to5,where 5 is themost important, that all the criteria got before weighting them, see Table 5. Theimportance scores were discussed with advisors at Saab and afterwards the weighting for eachcriterionwascalculatedfromequation(2)and(3).

4567ℎ96:7;<=<:56>?<=9@:A5BA<=5 = 100∑6>?<=9@:A5BA<=5 (2)

4567ℎ96:7 = 6>?<=9@:A5BA<=5×4567ℎ96:7;<=<:56>?<=9@:A5BA<=5(3)

Table5.Anearlierstagematrixtoshowtheimportancescorethatwasusedtocalculatetheweighting.

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The concept scoringmatrix resulted in a very even result between concept A andD. The conceptscoringmatrixisfurtherexplainedinthesubheadings.Theconceptscomparedinthismatrixarelistedbelow:ConceptA ADUmachineConceptD CNCgantrymachineTable6.Conceptscoringforwing-andfininterface

6.2.1 WeightingthecriteriaAllthecriteriaunderfunctionalityareweightedhighbecausethesearerequirementsthathavetobefulfilled,therearerequirementsunderergonomicsandunderotherthatalsohavetobefulfilled.Thecriteriaunderconveniencedoesnothavetobefulfilled,howeversamedrillingforthewing-andfininterface is weighted higher because this would ease the production. Some criteria are not thatimportant,forexamplemachinesizesincethedrillingstationwillbebuiltaftertheconceptifBoeingandSaabwinstheorder.ThebiggestdifferencebetweenADUandCNCgantryisthepurchasecost.

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7 DiscussionandconclusionThischaptercontainsdiscussions,ethics,conclusionsandfuturerecommendationsforSaab.

7.1 DiscussionconnectedtoresearchquestionsTofindapossibleconceptforthedrillingofthewing-andfininterfacethatisautomatedandthatismore effective regarding to the requirements, different concepts have been compared by usingconcept selection matrices. Six concepts were developed and compared with each other in thematrices.OveragroupmeetingwithpeoplewithinSaabwithspecialexpertisetheconceptscreeningmatrixwasdiscussed,itresultedincontinuingwithtwoconceptsfortheconceptscoringmatrix.IntheconceptscoringmatrixthetotalscoreprovedtobeveryevenbetweenADUmachinesandaCNCgantrymachine.However,conceptD,CNCgantrymachine,gotahighertotalscore.WithaCNCgantrymachinethewing-andfininterfacecanbeautomatedandmoreeffectivebutalsomanagethehigh tolerances and dimensions. Concept D manages most of the requirements with margin, thedifficultyisthepurchasecostfortheCNCgantrymachinecomparedtoseveralADUmachines,andthisisacriterionthatneedstobeconsidered.AnotherdifficultywithconceptDisthecriterioneasytouse,aCNCgantrymachinerequiresaneducatedCNCoperator.ToexaminehowmuchofthedrillingthatshouldbedoneinDTandhowmuchthatshouldbedoneinSBthreedifferentideaswerediscussedonhowtosolveavoidingCMMmeasuringforthefinholes.Itresultedintwoideasthatcouldwork.OneincludedleavingmaterialinDTonthefinhole,calledcuts,andthendrillacounterboredholeinSB.ThesecondideawastousealasertrackerinSBtomeasurewhich bushings to use. The concepts were described by using the cuts idea for the fin interface,becausewhenpurchasingoneoftheconceptsyouwanttoassumeitcanbeusedforallinterfaces.Ifthereisacutsonthefininterface,alltheholesatallinterfacescouldbecounterbored.Thisprobablysavestimecomparedtousingalasertracker.Alsowhencomparingtheconceptstheyneedtobeequalforthepurposeofuse.ThereforetheresultforhowtosolveavoidingCMMmeasuringforthefinholes,canbechangedaftertheresultofdrillingconcept.Forexample,iftheresultwouldbeADUmachines,thenitcouldbeconsideredtopurchaseADUmachinesonlyforthewinginterfaceandthendrillthefinholesinDTandusealasertrackerinsteadofpurchasingmoreADUmachinesforthefininterface.Thedrilling for the interfacesare todaypredrilledanddrilled inDTbeforeSB,oneof the researchquestionswastoexaminehowmuchofthedrillingshouldbedoneinDTandhowmuchshouldbedoneISB.SincetheinterfacesinDTaremadeinCNCmachinesitisworthlookingintoifthedrillingoftheinterfacesmadeinDTcouldbedoneintheCNCgantrymachineinSB.TheadvantagewithaCNCgantrymachineisthatthefininterfacedoesnothavetobemeasuredinaCMMmachinesinceconceptDcan implementdifferentmachiningoperationsandthereforemanagethehightolerances,by forexamplemillingtofinemachinethesurfaceofthefininterfacetomanagetheflatnessrequirement.

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7.2 DiscussionmethodologyAproblemwithliteraturereviewistoknowhowreliablethesourceis,especiallyiftheliteratureisfromaninternetarticle.Thearticlesmaybewrittenbyunprofessionalpeoplewhoarenotcompletelyfamiliarwiththetopic,whichcanbedifficulttodecide.Howevertherearearticlesthathavebeenpeerreviewed,whicharemorereliablesourcessinceseveralknowledgeablepersonshavepreviewedthearticles before publishing. Another issue with electronic references is to use information from amanufacturer’swebsite.Itisareliablesourcebuttheinformationarewrittentotheadvantageofthecompanysoitcanbedifficulttofinddisadvantageswiththeproduct.Thedisadvantagewithcollectinginformationfrombooksisthatbookscanbemanyyearsoldwithouttheabilitytobeupdatedwithnewinformation.ThebookManufacturingengineeringandtechnology(Kalpakjian,Serope&Schmid,StevenR.)whichisusedinthisthesiswaswritten2001whichmaybeconsideredtooold.Howeveronestepinliteraturereviewistoanalyzethecollectedmaterialwhichisawaytodecideiftheinformationisstillvalid,whichhasbeenmadeinthiscase.Alotofinterviewshavebeenmadeduringthesetenweeks.Interviewsareagoodmethodtocollectinformationthatcanbedifficulttofindinbooks,forexamplehowthedrillingoperationsweremade.Adisadvantageisthatitcanbedifficulttoremembertheconversationjustbywritingkeywordsfromthe interview,which can lead tomisunderstandings.Abetterwaywouldhavebeen to record theinterviews,howeverthiscouldnotbedonebecauseofthesecrecy.Oneofthedelimitationsisaccessofinformation.AlotofinformationinthisthesisiscollectedfrompeoplewithinSaab, insteadofmanufactures,becauseofthesecrecy.Thedisadvantagewiththis isthatsomeoftheinformationusedinthethesismightnotbefacts.Forexample,thegroupmeetingwhendiscussingtheconceptscreeningmatrix,notalltheinvitedcouldshowup.Thiscouldhaveledtoaninaccurateresultsincethepeoplewhodidnotshowupcouldnotcontributeinthediscussionsand“defend”themachinetheyhaveknowledgeabout.Anotherdisadvantagewithnotbeingabletocontactmanufactures is that the information is used in Saab’s perspective and not from an angleoutsideSaab.However,theadvantagewithnotcontactingmanufacturesisthattheycannottrytosellintheirproductbyonlytellingtheadvantageswiththeirproducts.ThebenchmarkingwasonlymadeinternalatSaab.ItwasausefulwaytogetaclearerpictureofSaabandhowdrillingoperationsweremadeinotherplacesofthecompany.Therewereveryrewardingdiscussionswithalotofpeopleduringthebenchmarkingwhichledtonewideas.Itwouldhavebeenveryinterestingtovisitothercompaniestoseetheirsolutionsbuttenweekswasnotenoughforthat.Intheconceptselectionprocesstwomatriceswereusedtoreacharesult.Theadvantagewithmatricesisthatitisaneasywaytopresenttheprocedureandtheresult.Apersonthatisnotfamiliarwiththethesis can still understand which alternatives to proceed with from the first matrix and whichalternativetodevelopinthesecondmatrix.Anotheradvantageisthattheconceptselectionprocessoccursintwosteps.Intheconceptscreeningmatrixthealternativesarecomparedinrelationtoeachother and the alternatives that does not fulfil enough requirements are excluded. In the conceptscoringmatrixthealternativesgettheirscorefromhowimportanttherequirementsare.Inthiswaythemostsuitableconceptcanbeselectedfromtheconceptscoringmatrix.Adisadvantagewiththematricesisthatitisdifficulttoranktheconceptsincomparisontoeachotherwithouttalkingtothemanufacturers of the machines in the concepts. Also the weighting was an issue because of thedifficultytoknowwhichrequirementthat ismoreor less important.SincetheresultbetweenCNCgantrymachineandADUmachineisveryequalitisdifficulttodecideiftheresultiscorrect.Onlybychangingonerankingtheresultcanbechangedtotheopposite.HoweverbothconceptsseemstobesuitablesolutionsforSaab.

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7.3 EthicsSinceSaabGrouparemanufacturesofmilitarydefenceandsecurityproducts,servicesandsolutionsthere is an ethic aspect to consider when working for Saab. Saab Aeronautics are for examplemanufactures of themilitary aircraft Gripen, and T-X Boeing is also included in the business areaAeronautics.However,T-XBoeing isanaircraft trainer forpilotsandwillnotbeusedasamilitaryaircraft. Also Saab are constantly working with building and maintaining trust of customers,authorities,ownersandpartnerswhichisimportantforadefenceandsecuritycompany.SaabGroupsvisionisthatitiseveryhumanrighttofeelsafe,andthattheirworkcontributestoincreasedsafety.Forexampletheyalsoproducesecuritysystemsforprisons,protectionagainstChemical,Biological,RadioactiveorNuclearweapons.Thisthesisisaboutautomatingthedrillingstationofthewing-andfininterface,whichmeansthattheworkingprocessdonebyanoperatorfortheprototypeswillbeautomatedbyusingamachine.Alotofoperatorsarereplacedbymachinesandrobotsinindustriesbecauseoftoday’stechnology.Thisisanethicaspecttoconsiderwhenautomatingindustries.However,inthiscasethemachinewillmostlikelyrequireanoperatoranywayandsincethereisnoproductiontodayitwillonlycreateworkingopportunities,notreplacing.7.4 ConclusionRQ1: Howcanthedrillingofthewing-andfininterfacebeautomatedandmoreeffective?

- Whichconceptismostsuitableregardingtotherequirements?ThemostsuitableconceptistouseaCNCgantrymachineforthedrillingatthewing-andfininterface.Withthisconceptthedrillingcanbeautomatedandmoreeffective.ACNCgantrymachinecanhandlelargepartsand iscapableofmilling,drillingandboring,whichmeansthat itcanbeusedformoreoperationsexceptfromthedrillingatthewing-andfininterface.Itisfullyautomatedwithhighspeedandextremelyhighaccuracyandfulfillsmostoftherequirements.RQ2: Howmuchof themanufacturing shouldbedone indetailmanufacturingandhow

muchshouldbedoneinfuselageassembly?

- HowwillthefininterfaceavoidCMMmeasuring?TheCNCgantryconceptisdescribedbyleavingacutsonthefinholesinDT.ThedrillingandpredrillinginDTwill be the same as for the prototypemanufacturing. The difference is that the CNC gantrymachine in SB performs the counterboring at thewing- and fin interface, which leads to that nomeasuringneedstobemadeinaCMMafterthedrilling.However,ifinvestinginaCNCgantrymachineitcouldbeanadvantagetoperformmoreoperationsinSB.IfalldrillingstepsaremadeinSBthecutsforthefinholesisnolongerneeded.

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7.5 FutureworkandrecommendationsThethesiswasdelimitedtofindaconceptforSaabtomoveforwardwithandexaminewhichconceptstoexcludeforSaab’sfuturework.ThereforewerecommendSaabtofurtherstudiesinthesubject.OurrecommendationisnottoexcludeADUmachines,thesefulfiltherequirementsandaboveallthebudget.ACNCgantrymachineontheotherhandisaninvestment,especiallyiftheproductionvolumewouldincrease.Thisissomethingthatneedstobeconsidered.ItisconsiderablyeasiertoincreasetheproductionvolumeinaCNCmachinecomparedtoADUmachines.AnotherrecommendationistoconsiderifmorestepsandoperationscouldbedoneifaCNCgantrymachineisinvested.ForexampleifthedrillingmadeinDTcouldbedonecompletelyinSB,orifthereareotherpartsonthefuselagethatcanbemachinedinthesameCNCgantrymachine.IfSaabdecidestocontinuewithADUmachinesinsteaditisalsoworthtofurtherstudymeasuringthefininterfacewitha laser tracker in SB.A laser trackerwill afterallbepurchased forotheruses in the fuselageassembly.

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8 ReferencesThischapterreportsthereferencesusedforthethesis.

8.1 ElectronicreferencesAdams,D.(2016).Notchedtestingofcomposites(HTML)Available:<http://www.compositesworld.com/articles/notched-testing-of-composites>ApexToolGroup,LLC.(2016).AdvancedDrillingEquipmentfortheAerospaceIndustry.(PDF)Available:<http://products.quackenbushtools.com/Web%20Assets/Recoules-Quackenbush_SP-1300-EN_ADE.pdf>Bouchard,S.(2014).RobotEndEffector:DefinitionandExamples.(HTML)Available:<http://blog.robotiq.com/bid/53266/Robot-End-Effector-Definition-and-Examples>Directindustry,(2017).Drillingunits(HTML)Available:<http://www.directindustry.com/industrial-manufacturer/drilling-unit-73539.html>EmeraldGroup,(2006).Benchmarking–Aninternationaljournal.Performancemeasures,benchmarkingandbestpracticesintheneweconomy.(E-book)Available:<https://ebookcentral.proquest.com/lib/linkoping-ebooks/reader.action?docID=258155>ESAB,(2013).Whatisagantrycuttingmachine?(HTML)Available:<http://www.esabna.com/us/en/education/blog/what-is-a-gantry-cutting-machine.cfm>Exechon,(2016).TheXMini,aParadigmShiftinAutomatedAerospaceManufacturing.(HTML)Available:<http://www.exechon.com/xmini/>Exechon,(2016).WelcometoExechon.(HTML)Available:<http://www.exechon.com/welcome/>ExechonWorld,(2008).Whatisaparallelkinematicsmachine(PKM)?(HTML)Available:<http://www.exechonworld.com/document/200804/article22.htm>ExechonWorld,(2008).WhyParallelKinematicsMachine(PKM)?(HTML)Available:<http://www.exechonworld.com/document/200809/article69.htm>Güdel,(2017).Linearaxis(HTML)Available:<http://www.gudel.com/products/linearaxis>Güdel,(2017).Robots(HTML)Available:<http://www.gudel.com/products/robots>Hexagon,(2017).LaserTrackerSystems(HTML)Available:<http://leicageosystems.com/products/laser-tracker-systems>IselGermanyAG,(2017).ThemostimportantquestionsaboutCNCmachines.(HTML)Available:<https://www.isel.com/en/products/cnc-systems/cnc-milling-machines.html#faq1>Levy,Y&Ellis,T.2006.ASystemsApproachtoConductanEffectiveLiteratureReviewinSupportofInformationSystemsResearch.(HTML)Available:<http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.98.2369&rep=rep1&type=pdf>Lübbering,(2017).Drilling.(HTML)Available:<http://www.luebbering.de/en/drilling>

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Lübbering,(2017).LADU.(HTML)Available:<http://www.luebbering.de/en/more/media/brochures?task=document.viewdoc&id=13>Manufacturingguide,(2017).Orbitalborrning.(HTML)Available:<https://www.manufacturingguide.com/sv/orbitalborrning>Meagher,H.(2014).WhyLaserTrackersfor3DPrecisionMeasurement?(HTML)Availeble:<http://www.oasisalignment.com/blog/laser-trackers-3d-precision-measurement/>Mellgren,E.(2002).Novator:Jaktenpådetperfektahålet(HTML)Available:<http://www.nyteknik.se/startup/novator-jakten-pa-det-perfekta-halet-6448932>Mellgren,E.(2011).Trebentsvenskrobotfamiljerövrarvärlden(HTML)Available:<http://www.nyteknik.se/automation/trebent-svensk-robotfamilj-erovrar-varlden-6420217>Novator,(2017).History(HTML)Available:<http://www.novator.eu/about-novator-/history__9>Ribeiro,L.;professoratLinköping’sUniversity(2015).LectureRobotTechnologyTMPS33.SaabGroupAB,(2016).BoeingochSaabhargenomförtdenförstat-xflygningen.(HTML)Available:<http://saabgroup.com/sv/Media/news-press/news/2016-12/boeing-och-saab-har-genomfort-den-forsta-t-x-flygningen/>Ståhl,F.(2014).Svenskuppfinningmedhögtflygandeplaner.(HTML)Available:<http://compotech.se/blogg/2014/06/svensk-uppfinning-med-hogtflygande-planer/>8.2 WrittenreferencesKalpakjian,Serope&Schmid,StevenR.(2001).Manufacturingengineeringandtechnology.4.ed.UpperSaddleRiver,NJ:PrenticeHallUlrich,KarlT.&Eppinger,StevenD.(2008).Productdesignanddevelopment.4.ed.Boston,Mass.:McGraw-Hill/IrwinWilson,Chauncey(2013).InterviewtechniquesforUXpractitioners:auser-centereddesignmethod.Waltham,MA:MorganKaufmann8.3 VerbalreferencesAlmé,Leif.18thApril2017.AssemblyEngineerGripen&TX,Saab,LinköpingAndersson,Hans-Petter.18thApril2017.CEONovator,Novator,StockholmCristalli,Gustav.4thMay2017.Variationmanagement,Saab,LinköpingEngström,Magnus.26thApril2017.ManufacturingEngineer,Projectleader,Saab,LinköpingGustafsson,Karolina.10thApril2017.Gripenoperator,Saab,LinköpingNilsson,Klas.3rdMay2017.Associateprofessor,Lund’sUniversity,LundWikström,Tommy.10thMay2017.Cuttingtoolmanager,Saab,Linköping