Design, Analyse and Preparation for Manufacture of a Retractable Utility/Craft Knife Using an Integrated CAD/CAM Software SystemModuleTitle:Advanced CAD/CAM ModuleCode:16-7106-00S
Assignment:1(of1)
Hand-inDate: See AssessmentScheduler
CourseworkTitle:Design,AnalyseandPreparationforManufacture of a RetractableUtility/Craft
KnifeUsinganIntegratedCAD/CAM SoftwareSystem
1.0Coursework Rationale
This courseworkaims toprovideavariety of practicalCAD/CAM relatedexercisesusingCreo Elements Pro/5.0anditsintegratedapplications.Thetasksareintendedforanintermediateuser andinclude:solid andsurfacepartandassembly modelling;partoptimisation;detaileddrawing; injection moulding;computer-aidedmanufacture;andbasic partphotorendering.

1.1TutorialsClasses
Thetutorialsforthismoduleareintendedtodevelopandsupportyourpracticalunderstandingand useof atypicalintegrationCAD/CAM system. It is therefore importantthatyourattendanceis promptandregular. Furthermore, itis strongly advised thatall assignment workbecompleted usingtheUniversity’s computerfacilities. Thesoftwareusedtocompletethiscoursework is Creo Elements/Pro5.0; NO otherCADorCAM softwaremay beused.

1.2SubmissionofWork
Please submitasinglewrittenreport together withallyourCADmodelsviathemodule’s Blackboardsite. Thereport shouldevidence, throughdiscussion andselectedscreenshots,the successfulcompletionofthetasksstatedinthisassessment.Themaximum wordlimitforthereport is 3000words;pleaseensuretoobservethislimit.IMPORTANT, modellingactivities undertaken wherethereis novisibleevidencereportedby eitherascreenshot orCADdrawings in yourreport willnotbeconsideredandwilltherefore notreceivea mark.YoursubmittedCADfileswillbe checkedforownershipandauthenticityonly.

2.0DevelopmentofCAD/CAM Models/Analysis
Followingtheactivitiesdetailedbelowyourtaskis todesign,analyse andpreparationfor manufacturea retractableutility/craftknife(seeappendix) usinganintegratedCAD/CAM software system.

2.1ProductandPartRequirements
Theproductandindividualpartrequirements foryourCADassemblymodelof a retractablesingle edgeutility/craftknife aregivenbelow.

Part Weight (g) Material Dimensions (mm)
(LxWxH)
Body back cover
12.6 ±0.2 (combined) Unspecified–A materialof
yourchoice 145x5x35
Body frontcover Unspecified–A materialof
yourchoice 145x5x35
Lockingslider(1/2piece
assembly) 1.6 ±0.2 Polypropylene 35x10x13
(
Rearendcap 1.8 ±0.2 Acrylonitrilebutadienestyrene 23x10x40
Cuttingblade 5.0 ±0.2 Stainlesssteel 107×0.2 x17
Total 21.0 ±1.0

Thedesignof thebodyfrontcovermustincorporate thefollowing:

•Recessedlocatingnotches/featurestoincrementallypositionthelockingsliderandthusextend/
retract thecutting blade;
•Considerationof left andrighthandeduse;
•Ergonomic stylingforeasy andcomfortableuse;
•1mmclearancechannel fortheblade;
•Coolingfeaturesforreducingthecycle timeformouldingthepart;
•A throughholeforaattaching alanyard;
•Snap-fitfeaturesforaligningandassemblingthebodyback coverandrear-endcap;
•A slidechannel forthelockingslider;

Thedesignof thebodyback covermustinclude thefollowing:

•Considerationof left andrighthandedusetomatchthatof thefrontcover;
•Ergonomic stylingforeasy andcomfortableuse,in order tomatchthatof thefrontcover;
•A throughholecontinuedfromthefrontcoverforaattaching a lanyard;
•Snap-fitfeaturesforaligningandassemblingthebodyfrontcoverandrear-endcap;
•A 2mm clearancefromtheundersideof thelockingslider;
•Coolingfeaturesforreducingthecycle timeformouldingthepart;
•Locatingfeaturesforaccuratelypositioningthefrontcoverreadyforadhesive welding; Thedesignof theremovablerearendcapshouldincorporate thefollowing:
•A recessedcavity,matching thewidthandheight dimensions (±0.2mm)of theblade, in order to insert(upto8mm)frontendof thebladeenablingittothenbesnappedoff manually;
•Ergonomic stylingforsimple andcomfortableuse;
•Considerationof left andrighthandeduse;
•Snap-fitfeaturesforaligningandassemblingthebodyfrontandback covers;
•Able toeasilyberemovedandre-attachedtotheassembledfrontandback covers;

Thedesignof thelockingslider(1/2piecepart/assembly) shouldcompriseof thefollowing:

•A working lockingmechanism which utilisestherecessedlocating notchesin thefrontcover;
•Ergonomic stylingforobviousandcomfortableuse;
•Considerationof left andrighthandeduse;
•A meanstoattachandsecurethecuttingblade;
•A meanstoslidingthe1/2piecepart/assemblywhennotlockingthebladein position.
•A roughtextured topsurface;

2.2DevelopmentandDemonstrationofCADModelling Techniques
TheCADmodellingof yourknife musteffectivelydemonstrate thefollowingtechniques,in order to observethepreviously defined productandpartconstraints/requirements:

•Definition of anoverallskeletonmodeltoestablish thetotalvolume requiredfortheknife
together withtheknife’sinitialassembly structure;
•Useof extruded,revolved, blended,patterned (atleast3different types), rounded,chamfered, shelled andholedfeatures;
•A top-downdesignapproachforthebodyback coverbasedonthegeometry(outerprofile) of thefrontcover;
•Definition of theindividualcomponentassembly interfacesforallpartstogetherwiththe completeassembly oftheknife;
•Theadditionof theflexibilityfeaturetotherearendcapin order tocopewithchanges tothe bladedimensions;
•Definition of ananalysisfeaturein order tocompletea dimensional optimisationof thebody frontcover,sosatisfyingthecombinedweight constraintforitandtheback cover;
•Interferencecheckingbetweenallpartsonceassembledtoensurenooverlappinggeometry;
•Useof basic surfacingandstylingfeaturestoenhancetotheappearanceof thebodyback cover;
•Creationof orthographicdrawings (.pdf format)forallparts(excepttheblade) detailingall dimensions, material,scale, units, partname,dateandauthor;
•Creationofa generalassembly drawing (.pdf format)of theknife,shownin explodedand unexplodedviews andidentifyingallpartstogether witha billof materials, scale, units, dateand
author;
•Useof basic (i.e.limited scenecreation)photorenderingtechniquestoshowyourknife assembly ona suitable worksurfacein aphotorealisticmanner;

As previously statedin order toevidencethesuccessfulcompletionof theaboveCADtechniques youmustprovidebothabrief criticalwrittendiscussion ofyourworkings, justifyingyourmodelling techniques,andtherelevant,clearandunambiguous screenshots ofyourwork.Please alsoensure theaboveCADdrawings areincluded as partofyourreport’sappendices.

NB:Thestainless steelcuttingblade willbeprovidedasanIGESparttodownloadanduse.

(Marks40)

3.0BodyBackCover MouldingAnalysisandTool Preparation

3.1MouldingAnalysis
Forthefirstpartofthistaskyouarerequiredtodeterminethemouldability,orthesuitable for moulding,of thebodyback coverpartforthepurposeof injection moulding.This mustbedoneby usinganintegratedapplication within CreocalledMoldFlow. In order toanalyse andcommenton theperformanceofyourpartyouwillneedtodemonstrate thecompletionofseveralsteps,which include:

•Identificationofa suitable injectionpoint(orpoints);
•Establishing thebestlevels of confidenceof fillandquality;
•Identifyandreducethelocationandamountofair trapsandweldlines;
•Determinethebestshrinkage factorforyourchosenmaterialanditseffect onpartgeometry;

Onceyouhave obtaintheresultsofyourstudyyoushouldcriticallydiscuss, in nomorethan300 wordsandusingsuitable screenshots,any issues relatingtohesitationandrace-tracking(i.e.injection pointsandpartgeometry),cooling(i.e.warping &shrinkage),flow disruptions(i.e.weldlinesandair traps),partejection. Afterwhich youshouldaddressany issues encountered, in order toimprove yourpart’smouldability(i.e.zeroorveryfew (<10)air trapsandweldlines,andhighlevels confidenceof fillandquality)andthenconclude,in nomorethan200words,thechanges toeither theprocessparametersand/oryourpartgeometrythatyouhave made.Please include MoldFlow’s initialandfinalanalysisreports of yourback coveras partof yourappendices.

(Marks15)
3.2MouldTool Preparation
Forthenextpartofthemoulding preparationtaskyouarerequiredtodevelopa suitable mould tool(i.e. coreandcavityparts)fortheback coverof yourknife,usinganotherintegratedapplication within CreocalledPro/Mold.In ordertofulfilthecompletionof thistaskyouneedtodemonstrate thefollowing:

•Correct application ofashrinkage ratio;
•Definition of asilhouettecurve;
•Establishment of aparting surface;
•Generationof bothhalves (coreandcavity)of theback cover’smouldtool;
•Completionof thecoreandcavitypartsby theinclusionofaninjection point(s),runner(s), raiser(s)(baseduponthepreviously determinedpositionof theair traps)andclampingboltholes;
•Creationof orthographicdrawings (.pdf format)forthecoreandcavityparts(excepttheblade) detailingonly themajorouterdimensions, injectionpoint(s),runner(s),raiser(s),bolthols, material,scale, units, partname,dateandauthor;

Againyouwillneedtoevidencethesuccessfulcompletionof theabovemouldtoolgeneration activities.Thereforeyoushouldprovidebotha brief criticalwrittenexplanationofyourworkings together withtherelevant,clearandunambiguous screenshotsofyourwork.Please alsoensurethe aboveCADdrawings areincludedas partofyourreport’sappendices.

(Marks15)

4.0MachiningoftheBackCover’s CavityMouldTool
Yourfinal activityis topreparethemachiningactivities forthebottomhalforcavityof yourback cover’smouldtool.This mustbeachieved usinganotherintegratedapplication within Creocalled Pro/Manufacture. In order tosuccessfullysatisfythistaskyouneedtodemonstrate thefollowing:

•Definition of thereferenceandwork-pieceCADmodels;
•Definition of anoperation(s),in order toidentifythecorrect machine toolselection,establish fixturingrequirements,machine zeropoint/reference,retraction plane andpartorientation;
•Creationofanefficientmachiningsequence(s)toremovematerial;
•Useof nc-sequences,such asvolume, face off,andadrilling,in order toproduce individual featuregeometry;
•Definition of allrequiredmachiningparameters(basic),cutting toolgeometryandtoolpathsfor eachnc-sequence;
•A tabularsummary recordofeachnc-sequence’smachiningtime,%air timeandatotal machiningtimeforthework-piece;

Onceyouhave completedtheaboveactivities youwillneedtoevidencetheircompletionin your writtenreport. Again,providebothabrief writtencriticalexplanationof yourworkings together
withrelevant,clearandunambiguous screenshots of eachactivity.Please alsoensuretheaboveCAD
drawings areincluded as partof yourreport’sappendices.

(Marks30)

2.2DevelopmentandDemonstrationofCADModelling Techniques Marks(40) FeedbackComments
Correctlyapplyinganddemonstratingtheproductandpartdesignconstraints/
requirementsin allresulting CADmodels. /8Marks
Definition of anoverallskeletonmodeltoestablish thetotalvolumerequiredfor
theknifetogether withtheknife’sinitialassembly structure; /2Marks
Useof extruded,revolved, blended,patterned (atleast3different types), rounded,
chamfered,shelled andholedfeatures; /4Marks
A top-downdesignapproachforthebodyback coverbasedonthegeometry
(outerprofile) of thefrontcover; /1Marks
Definition of theindividualcomponentassembly interfacesforallpartstogether
withthecompleteassembly of theknife; /2Marks
Theadditionof theflexibilityfeaturetotherearendcapin order tocopewith
changes totheblade dimensions; /2Marks
Definition of ananalysisfeaturein order tocompleteadimensional optimisationof
thebodyfrontcover,sosatisfyingthecombinedweight constraintforitandthe back cover; /3Marks
Interferencecheckingbetweenallpartsonceassembledtoensurenooverlapping
geometry; /1Marks
Useof basic surfacingandstylingfeaturestoenhancetotheappearanceof the
bodyback cover; /5Marks
Creationof orthographicdrawings (.pdf format)forallparts(excepttheblade)
detailingalldimensions, material,scale, units, partname,dateandauthor; /4Marks
Creationofa generalassembly drawing (.pdf format)of theknife,shownin
explodedandunexplodedviews andidentifyingallpartstogether withabillof materials,scale, units, dateandauthor; /2Marks
Photorenderingof yourknife assemblyonasuitable worksurface; /2Marks
Written criticalexplanationof yourknifedesignandjustificationof CADmodelling
techniques; /4Marks
3.1MouldingAnalysis Marks(15) FeedbackComments
Identificationofa suitable injectionpoint(orpoints); /2Marks
Establishingthebestlevels ofconfidenceof fillandquality /4Marks
Identifyandreducethelocationandamountofair trapsandweldlines; /4Marks

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Determinethebestshrinkage factorforyourchosenmaterialanditseffect onpartometry;

Written criticaldiscussion ofyouranalysisandworking; /2Marks
3.2MouldTool Preparation Marks(15) FeedbackComments
Correct application ofashrinkage ratio; /1Marks
Definition of asilhouettecurve; /2Marks
Establishment of aparting surface; /1Marks
Generationof bothhalves (coreandcavity)of theback cover’smouldtool; /2Marks
Completionof thecoreandcavitypartsby theinclusionofaninjection point(s),
runner(s),raiser(s)(baseduponthepreviously determinedpositionof theair traps)andclampingboltholes; /3Marks
Creationof orthographicdrawings (.pdf format)forthecoreandcavityparts
(excepttheblade) detailingonly themajorouterdimensions, injection point(s), runner(s),raiser(s),bolthols, material,scale, units, partname,dateandauthor; /4Marks
Written criticalexplanationof yourworkings; /2Marks
4.0MachiningoftheBackCover’s CavityMouldTool Marks(30) FeedbackComments
Definition of thereferenceandwork-pieceCADmodels; /1Marks
Definition of anoperation(s),in order toidentifythecorrect machine tool
selection,establish fixturingrequirements,machine zeropoint/reference, retraction plane andpartorientation; /5Marks
Creationofanefficientmachiningsequence(s)toremovematerial; /2Marks
Useof nc-sequences,such asvolume, face off,andadrilling,in order toproduce
individualfeaturegeometry; /8Marks
Definition of allrequiredmachiningparameters(basic),cutting toolgeometryand
toolpathsforeachnc-sequence; /8Marks
A tabularsummary recordofeachnc-sequence’smachiningtime,%airtimeanda
totalmachiningtimeforthework-piece; /2Marks
Written criticalexplanationof yourworkings; /4Marks
Total /100Marks NB:Theminimum pass markis 40%.

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