IntroductiontoAutoDeskInventor2013andAutoCAD2013:

Itiscommonforexperimentaliststoneedtodeveloptheirowninstrumentation,customreplacementparts,machiningjigsandthingsofthatnature.Thiswillusuallyrequireingenuityandcarefuldesignchoicesonbehalfofthestudent.Inthepreviousdecades,computer-aideddesign(CAD)programsweredevelopedtohelpengineersdesignparts,machinesandentiresystems.Importantly,theyalsoareusedtogeneratespecial2Ddrawings(CADdrawings)thatconciselyandintuitivelyprovidealltheinformationneededtomachine/manufacturethedesignedparts.

Inrecentyears,commercialCADsoftwarehasbecomeeasiertouseandhasbecomeastapleofinstrumentdesignamongscientists.Inyourownexperienceyoumayencountermanydifferenttypesofsoftware,includingSolidWorks(3Ddesign),Inventor(3Ddesign),MechanicalDesktop(aprecursortoInventor),andtheubiquitousAutoCAD(2Ddrawingsoftware).3Ddesignprogramsaregenerallyintegratedwith2Ddrawingsoftwaretoenablequickgenerationofaccurate,scaleandproperlylabeled2Ddrawingsfromuser-generated3Dmodels.

Fortunatelyforus,AutoDeskhasdecidedtoprovidefreeStudentEditionversionsofallitssoftware,includingInventorandAutoCAD.ThesecanbeaccessedfromAutoDesk’sstudentwebsiteandobtainedifyouprovideavalid.eduemailaddress.Thetermsallowyoutousethesoftwareaslongasyoulikesolongasyoudonotprofitoffofthedesignsanddrawingsyoumakeandareforyourpersonaleducationaluseonly.

Overview

Howmightyoufindyourselfusingthiskindofsoftwareinthelab?Youmayneedtodesignsomepartorcomponentforaninstrument,whichwillfirstrequireyoutodesignitina3DprogramsuchasInventor.Withinthatprogramyoucandevelopascale,precisemodelofyourpart,includingmaterialinformation,tap-holes,specialangularcutsandotherdetailedfeatures.Oncethe“design”aspectiscomplete,ifyour3Ddesignsoftwareisintegratedwith2DdrawingsoftwareasInventor/AutoCADare,youcantheneasilycreateascale2DAutoCADdrawingthatdisplaysthepartandalltherelevantdimensionsfromhowevermanyanglesyouwant,includingcrosssections!Withthisdrawinginhandyoucanthenuseityourselftomachinethepartinthemachineshoporsendittoprofessionalstohavethemmakethepartforyou.Thesoftwareisverypowerful,butitisstilleasytomakeuseless/verydifficulttounderstanddrawingsifyouarenotthoughtfulandawareofwhatsomeonewhohasneverseenorimaginedyourpartwillneedtoknowtomakeitcorrectly.

TherearefourtypicalclassesofdesignsyoumayneedtomakeinInventor.Thefirstthatyoumostoftenwillstartwithwillbethe3Dmodelofthepartorcombinationofparts(calledanAssembly)thatyouwanttomake.InInventorthesearedenotedbythefiletypes.iptforpartsand.iamforassembliesofparts.Nextyoumaywanttomakeexplodedassembliesofpartstopresentduringthedesignprocess,theseare.ipnpresentationfiles.Thesecantaketimetodevelophoweverandsooftenyoumayjustfinditeasiertopresenttheassemblyitselfandinteractwithitbyshowing/hidingindividualpartstoshowinternalstructures.Thelasttwoareindividual.idwpartandassembly2Ddrawings.Partdrawingsshowallthecriticaldimensionsandvisuallyrepresenttheshapeofthepartyouwantmade.

Assemblydrawingsshowhowseveralpartsshouldbeputtogether,andinsomesituationssuchaswhenweldsareneeded,willshowcriticaldimensionsneededfortheassemblyitself.Belowaresomeexamplesofeachdesigntype.

Fromlefttoright:(1)Anassembly(.iam)consistingofmanyparts(.ipt),(2)anexplodedviewpresentationshowinghowtheassemblyisputtogether(.ipn),(3)Anassemblydrawing(.idw)and(4)Anindividualpartdrawingfeaturingcriticaldimensions(.idw)

Theultimate“finalproduct”ofyourdesignprocesswillalwaysbethe2Ddrawingviews(assembly+individualpartsdrawings,the.idwfiles)whilethe3Dmodelsserveasadesignaid.TheonlyexceptionstothisrulewillbeifyourpartneedstobemadeonaCNCandtheoperatorwantsa3Dfileformatofsomekind(notnecessarily.ipt,youmayneedtoexporttoanotherformattheyrequest).Inspiteofthisyouwillinvariablyspendthemajorityofyourtimeworkingonandrevisingthe3Dmodelratherthanthe2Ddrawing.The2Ddrawingcommunicatesalltheinformationneededtomakethepart/assembly,butyouwillonlygettothestepofgeneratingthatdrawingonceyouhavegonethroughtheprocessofdesignandpossiblyseveralrevisions.Withthenewersoftware,itisofteneasiesttoconductallofthestepsinthedesignprocessinthevisuallymoreintuitive3Ddesignenvironmentwhichiswhyyouwillspendmostofyourtimethere.The2Ddrawingitselfisusuallyfairlyquickandeasytogeneratethankstohowwellthe3Dmodelingand2Ddrawingsoftwareisintegrated.

Itisimportanttomakeonefinalnotebeforegettingyourhandsdirtywiththissoftware.Fullmasteryofallthefeaturesinbothsetsofsoftwarewilltakeahugeamountoftime,sodon’tworrytoomuchaboutunderstandingeverythingthatisthere.Insteadfocusonunderstandingthefundamentals,andifatsomepointyouareattemptingtomakesomedesignfeaturethatseemsextremelycomplicatedortimeconsumingtomake,thenitmaybetimetolookintosomeofthetoolsyoumaynotknowmuchaboutsincelikelythereissomethingintheprogramtomakewhateveryouaretryingtodoeasier.Also,theseprogramshelpyoudesignpartseasilybuttheydonothelpyoudesignpartsintelligently.Yourpartorassemblynotonlyneedsto“work”oncemanufacturedbutitalsoneedstobemachine-able.Itcanbesurprisinglyeasytodesignapartthatlooksgreatonpaperbutisactuallyverydifficultorevenimpossibletomachine/weldwiththetoolsavailabletoyouinthemachineshop.Developingthatkindofunderstandingtakestimeandrequiresworkingwithmoreexperiencedgroupmembers,youradvisorandthemachineshoppersonneltoreallygetafeelfor.

Withoutfurtherado,let’smakeapart!

Tutorial1:3DBottle

OpenAutoDeskInventor2013.TherewillbeaWelcomepagethatincludesoptionstomakedifferentfiles,alistofrecentlyaccessedfilesandtutorialguides/videos.Selectthe3DBottletutorialandfollowthestep-by-stepinstructions.Hoveringyourmouseoverthedifferentitemsontheinstructionlistwillresultinshowingyouthelocationofmenuitemsyouneedtoselectforeachstep.Ifyoueverneedtoreturnthistutorialagain,clicktheGetStartedtabontheribbonandyoucanfindtheBottletutorialthere.

Tutorial2:ImportAutoCADDrawing

Workthroughthenexttutorial.ThiswillshowyouhowtoimportAutoCADdrawingsforuseinInventor.Asstatedbefore,itisentirelypossibletogenerateallthedrawingsnecessarytomodelyourpart(s)inInventorbutthe2DdrawingtoolsinAutoCADare(somewhat)morepowerful,sosomeprefertodothedrawingstherefirst.

Tutorial3:SplitWallPlate

Ok,let’smakeanewpartwithoutalltheconvenientstep-by-stepinstructions.Thisoneisreallysimplethough,soitshouldgoeasyandI’llstillguideyoutoshowyousomenewtools.DothewholethinginInventor,makinga2DsketchbasedontheprovidedPDFdrawing“6inchsplitplate.pdf”andthenextrudingtothespecifiedthickness.Notethatthegeneralflowofmakingparts(.ipt)fileswillalwaysbeCreateSketch->Extrude->MoreSketches->Extrude->Etc.untilyouarefinished.Whenlookingatthedrawing,noticethatnotalloftheholesarelabeled;youcansometimesaffordadegreeoflazinesstogainbrevityandkeepthedrawinglessclutteredwithannotations,butbecarefulaboutwhatyouomit.Fromwhatisactuallylabeled,theideaisthatyoucaninfertheotherthreesmallholesarethesamesizeandrelativepositionfromthecornersastheonethatislabeled.

It’sworthmentioningnowthatyoucanmakeanyoftheplanes(XY,YZ,XZ)oraxis(X,Y,Z)visiblebyexpandingtheOriginfoldertotheleft,rightclickingonanyofthemandselecting“Visibility”fromthemenu.I’veturnedallbutonevisiblehere.

Youwillwanttohidetheseplanes/axisattheend,otherwisetheywillappearinyourdrawingsandassembliesandlookugly.

Startoffbymakingthe6inchsquarebyextrudingasquaresketchofthatsize.Youcanchooseanyoftheplanestoformyour2DSketchonto.

NoticethatCreate2DSketchisthefirstthingyoualwaysseeonthetopleftinthefirsttabwhenyoucreateapart.YouwillprettymuchalwaysstartwiththistoolandInventorknowsthat.Alsoseethatnextto2DSketch,thereisatooltoautomaticallygeneratecertainprimitiveshapes(suchasaBox,there

aremorefromthedropdownmenuifyouclickonthearrowbelowBox)andtheExtrudetoolistheretoo.

Onceyouclickon2DSketch,suddenlytheviewwillrotateasnecessarytogiveyouatop-downviewoftheplaneyouaresketchingonto.Ifyouwantyoucanpanthecameratoadifferentviewofyoursketch.

NoticethattheRibbonoptionshavechangedtoo

Youhaveallthetoolsnecessarytomakeallsortsofprimitiveshapes,andforthoseofyoualreadyfamiliarwithAutoCADtheparametricdrawingconstrainttoolsareherenowtoo.InpastversionsofInventorthiswasnotthecaseandpeopleusedtobeabletomakeastrongercaseformakingsketchesinAutoCADfirst;inmodernversionsthisislesstrue,andIpersonallyneverneedtouseAutoCAD.

Clickontherectangletoolanddefineyourfirstpointoftherectangleattheorigin.Yourmouseshould“snap”toitasyoumoveclose,thisisaveryusefulfeatureyouexploittimeandagaininInventor.Assoonasyouclickontheorigin,therectangleiscreatedallowingyoutodefinethelengthsofeachside.Theeasiestandmostefficientwaytodefinethedimensionsofwhatevershapeyouaredrawingistoimmediatelyletgoofthemouseandtypethefirstdimension,inthiscase6,whichwillinstantlyreplacewhateveriscurrentlywritten.Don’thitenter,insteadhittabtoswitchtotheotherdimensionandthentype6againandthenhitenter.Youshouldhavesomethinglikethis:

Noticehowquickthatcanpotentiallybe,youmakeashape,clickastartingcoordinateandtypeanumber,tab,typeanumber,enterandyourshapeismade.

Nowyoucouldhit“FinishSketch”andcreateanewsketchfortheholes,butwecandotheentirepartwithonesketchsowhybother.Makethecentralholeusingthecircletool,whichfirstdemandsacenterpointandthenallowsyoutodefinethediameterofthecircle.Ifyouhoveryourmousenearthecenterofthe6”x6”squareyoumade,you’llnoticetwodottedlinesappearandyourcursorwillsnaptothecenterofthesquare.Convenient!Nowtoproveapoint,makethediameter2.5”insteadoftheactualdimensionthedrawingrequiresandhitenter.Oftenyouwillmakemistakeswhendrawingshapes.Ratherthandeletingtheshape(whichisaseasyasclickingtheshapeandhittingthedeletekey,bytheway),youcandoubleclickonthesetdimensionof2.5”,whichwillgenerateapromptforyoutochangeit.Setitto2.85”asitshouldbe.

Nowlet’smakethe0.180”holesinthecorners,butwe’lldoitefficiently.First,hitthecircletoolandmovethecursoroverthetopleftofthe6x6”square,asiftocenteritonthecornerbutdon’tclick/hitenterjustyet.Insteadwe’llexploitanotherniftytrick:youknowfromthedrawingthatyouwanttheholecentered0.5”awayfrombothedgesofthesquare.Thiswillbe+0.5”fromthexcoordinateofthetopleftcornerand-0.5”fromtheycoordinate;youcanactuallydialtheseintothecoordinateboxestodefinethenewcenterpoint!Itshouldlooklikethis:

Afteradding+0.5tothexcoordinateand–0.5totheycoordinate,hitenterthentypeinthediameterandenteragain.Nowwehaveoneoffourholes,andtheotherthreecouldbemadethissamewaybutthenyouhavetothinkaboutalgebraicsignchangesandthat’smessy.There’sanotherway.

Drawtwonewlines,onestraightdownthecenterverticallyandonestraightacrossthecenterhorizontally,makingsureeverythingsnaps.Itshouldlooklikethis

Wewillusetheselinesasaxisofsymmetryandwewillsimplyreflecttheholeyoumadeintheupperleftcornertwice,onceacrosstheverticallineandthenagainacrossthehorizontalline,toduplicatetheholeandcompletetheset.Notethatofcoursethisonlyworksbecausewehavesymmetrywecanexploit.

Toperformthiswizardry,clicktheMirrortoolunderthePatternsectionoftheRibbon.Youwillneedtochoosethecircle,thenselecttheMirrorAxisbuttonandclickontheverticalaxis,thenhitApply.Viola!Youhaveanewcircleonthetopright.NoticetheMirrorToolisstillopen;nowclickonbothofthesmallholesandchoosethehorizontallineastheMirrorAxisandhitApplytofinishthelasttwoholes.

Nowthesketchiscomplete,hitFinishSketchonthetopright.Noticethatyourviewsuddenlychangesbacktowhateveritwasbeforeyouinitiatedthesketch.

Asyou’veseeninthestartertutorials,3DshapesarebuiltsimilartoCOMSOLinthatvolumesareextrudedoutof2Dshapes.ClicktheExtrudebuttonandstartselectingsegmentsofyoursketch.YoumayencounteroneofthefewannoyingaspectsofInventor2013,assumingtheyhaven’tfixeditinInventor2014,whichisthatyoumayfinditdifficulttoexcludetheentirecenterholefromyourExtrusion.Ifyoucannot,donotdespair,justignorethecentralholeandextrudeitwiththerestofthesquare.YoucanfixthisaftercompletingtheextrusionbygoingtothesidebarandexpandingyourExtrusion,rightclickingtheSketchandselecting“ShareSketch”fromthemenu.Createanewextrusion,choosingthenewsharedsketchanditshouldallowyoutosubtractivelyExtrudetheholeoutofthe

middle.NotethatingeneralExtrudecanbeusedtoaddORdeletematerialaswellascreatesolidsorsurfaces.

Onethingyoumaynoticerightawayisthatafterdoingsomeoperation,suchasrotatingtheviewormakingadimensionmeasurement,youalwaysneedtohitESCtobeabletoinitiateanewaction.Thiswillseemannoyingatfirst,buteventuallyhittingESCwillbecomeautomatic.

Thesplitlinedownthemiddlecanbecreatedbyexploitingthemirror-symmetryaxiswecreatedintheoriginalsketch.UsetheSplittoolunder3DModel>>Modify>>Split.MakesuretochooseSplitSolid,selectthesolid,thenselectthemiddlelineasthesplitaxis.NotethatthistoolwillbemoreusefulinAssemblieswhereyoucanmovearoundseparatedparts;inpartedityoucansplitapartbutcannotseparatethem.Fornowthisismainlytoshowyouthatthetoolisthere.

Nextlet’smakeadrawing.This“splitwallplate”isanactualthingwemakeintheHolab:Whenwedrilllargeholesthroughwallstotake2”steelvacuumtubingthroughawall,thesesplitplatesarefittedwitharubbergrommetthatsealsaroundthetubeandtheplateissqueezedaroundthegrommet/tubeandscrewedintothewall.Thismakesthepipepassingintothewalllookmuchcleanerratherthanhavingagapingholewithinsulationhangingout,andIthinkE&HSdemandstheseforfirecodereasonsanyway.

AnywayIsaidlet’smakeadrawingthenIwentonaboutsomethingelse.Nice.Ifyouhavejustcreatedapartorassemblyandhaveitopen,clickingtheicononthetopleftwillbringdownthefilemenu.IfyouchooseNew>>Drawing,anewblankInventorDrawingfile(.idw)willbecreated.OntheRibbon,clickBase.

AssoonasyouaskforaBaseViewfromtheRibbon,Inventorwillassumeyouwantaviewofthepart/assemblyyoujusthadopenratherthanmakingyoubrowseforitwhichisnice.Notethattherearemanytypesofviews,andtounderstandwhattheyactuallycorrespondto,moveyourmouseoutsidetheBaseViewselectwindowandyou’llseeanoutlineofthepartinthatviewappearonthedrawingcanvas.Createthetwoviewsseeninthepdf,thiswillrequiretwoseparateapplicationsoftheBaseViewtool.Youcanmovearoundviewsafterwardbythewayifyouhoveroveraview,causingareddottedboxtoappeararoundit,thenclickonthatboxanddragitaround.

UsetheDimensiontoolontheRibbontocreateallthedimensionsdepictedinthePDF.Noticethatbydefaultthedimensionlinesandnumbers/lettersareblackandsmall.Thisdoesn’tlenditselfwelltoeasyreadingbywhoeverwillactuallybeusingyourdrawing,solet’sfixthat.HitESCtoexittheDimensionfeaturethenrightclickononeofyourdimensionsandfromthedropdownlist,hitEditDimension.

There’salotofoptionsherebutwe’llonlybotherwithafew.Makethefollowingchanges:

- Onthefirsttabthatloadswiththewindow,Units,changePrecisionto4.1234.- ChangetotheDisplaytab,changetheColortosomethingotherthanblack.Ichosebright

blue.- ChangetotheTexttab,clickonthepenciliconnexttoNoteText(ANSI)underPrimaryStyle

Text.Anewwindowwillpopup,herechangethetexttoanewcolor,increasethefontsizeandifyoulike,changethefont(trytokeepitreadablethough).

- Hitsaveatthetop,andnowforthekeystep.Ontheleftthereisaverticallistofstuffwehaven’tmessedwithyet,oneoftheseitemswillbehighlighted(probablyDefault).RightclickthisandhitExport,saveitsomewhereyoucanfinditeasilyagain(suchasDocumentsorDesktop)andgiveitaname.Fromnowon,whenyoumakeadrawingyourdimensionannotationswilldefaulttothesmallblackunreadableones.IfyouclickEditDimension,nowallyou’llneedtodoishitImportonthebottomleftoftheEditDimensionmenuandfindthisstyleyoucreated.

OfcoursethiswouldbemucheasierifwecouldsimplysetournewdimensionstyleasthedefaultsoweneverhavetoEditDimension.Ihavenotfiguredouthowtodothisyet,ifyoucanfigureitoutletmeandeveryoneelseknow!

Awesome,nowyouhaveadrawing!Ifyouwantedtomakethesesplitplatesyou’dprobablystartwithalargeplate,useapermanentmarkertomakeagridof6”x6”squares,takethisplatetothebandsawtocutthemallout,thenuseyourdrawingtocorrectlypositionthecornerscrewholesbeforeusingaflycuttertocutthecenterhole.You’dfinishthiswiththebandsawbycuttingitdownthemiddle,onlyoncethelargecentralholehasbeencutout.

Thatwasaprettyboringpartandarguablyyouwouldn’tevenneedthedrawingtomakethis.Let’smoveontobiggerandbetterthings.

Tutorial4:STMChamberFlange

Let’smakeaREALpart.Ofcourse,thejumpincomplexitywon’tbetoogreatforbeingTutorial4(eventhoughitwilllooklikeit),butthisisanimportantpartandhassomenewInventortoolstointroduce.Openthe2Ddrawingscontainedinthezipfolder“8inchFlange”.ThisisanactualflangefromthetopofoneofourSTMs.Don’tlettheseemingcomplexityscareyou,modelingthispartwillbegreatlysimplifiedbyexploitingthe“CircularPattern”tool.Notethatthereare8holestappedontothebottom(sideexposedtovacuum)and24holestappedontothetop(thesideexposedtoair).

ThistutorialwillintroducetheuseofAssemblies.First,thelargecircularbaseoftheflangewillbecreatedalongwithmostoftheholes.Noticethattheflangeasaholeactuallyfeaturesseveralsmallflangesprotrudingfromthetop:therearefour1.33”ODflanges(called“miniflanges”bysome)andasingle2¾”flangeinthemiddle,alongwithfoursetsofholesthatmatchtheminiflangedimensionsbutwhicharedirectlydrilledintothemain8”flange.Forthefourminiflangesandone2.75”flange,ratherthandrawtheseyoushouldtrackdownactual3Dmodelsprovidedbythecompanythatsellsthem.We’llgettothatstepalittlelater,fornowlet’sworkonthemainflange.Makeanew.iptcalled“8inchflange.ipt”

Createa2DSketchonwhicheverplaneyouprefer(honestlywhowouldchoosethoseotherplanesanyway)andcreatethe8”circlethatwillbecomethemainflangebody.Oncethisisdone,wecanexploitthecircularsymmetrytooltomakealltwentyoftheoutermostflangeholessimultaneously.Todothis,makejustoneoftheholes,saysittingonthey-axis.Thenclickthe___andselecttheholeyoumade.Thenclicktheredarrowandselectthecenterpointofthe8”circle.Finally,replacethenumberofduplicatestomakewith“20”andleave“360”whereitis.Itshouldlooklikethis

Clickokandwatchthemagichappen.You’reawizardHarry!

Ok,offwiththetrainingwheels.FromnowonI’llprovideinstructionsinmoregeneraltermsandshowlesspicturesunlessabsolutelynecessary.Noticethatthenextsetofholesalsohascircularsymmetry,thistimethereare8holesyoucanmake.Youmaybeconcernedthatsomeoftheholesaresimplyholesinthe8”flangebodywhiletheotherswillhaveseparateflangesattached;don’tworryaboutthisdetailfornow.Makethenextsetof8miniflange-sizedholesandcontinueonwiththe6smallscrew-holessurrounding4ofthe8holesyoujustmade,payingcarefulattentiontothepdfdrawingstoseewhichonestheseare.Tobemoreclearhere,fourofthesemini-flangeholeshave6screwholessurroundingthemandfourdonotasthe“screwholes”willbelongtoseparateactualmini-flangesinstead.ThisiseasiesttoseefromtheTopFlangeConvert.pdffile;thepinkholesareactuallyboredintothis8”flangebodyyouaremakingandnoticeonly4ofthe8havethem.Alsonoticetherearestill8otherpinkholestomakethathaverectangular,andnotcircular,symmetryonthispiece.Maketheseaswellandfinishthesketch.Tip:Itistotallypossibletomakecircularpatternsoutofcircularpatterns!Also,don’tforgetthelargeholeinthemiddle.

Next,you’llneedtoperformadditionalextrusions;boringtheeightrectangular-symmetricholesonthebottomandthetwentyfourflange-styleholesonthetop.Theproblemisthatneithersetofholesisboredallthewaythrough,meaningyou’llneedasketchonbothsidesoftheflangetodothis.Noworry,wecansimplyduplicatethedrawingandplaceacopyonthetopoftheflange!

Todothis,createaworkplaneoffsetfromtheplaneoftheoriginalsketchby+/-0.875”(chooseyoursigncarefully)sothatitsitsontheothersideofthe8”flange.Thenrightclickyoursketch,hitcopy,thenrightclickyournewworkplaneandhitpaste—presto!Usethesketchonthebottom(youhavetoshareitfromtheveryfirstextrusion,butyoushouldknowthisbynow)toborethebottomrectangular-symmetricholesanduseyournewsketchonthetoptoborethe24flangeholes.

Yourflangeshouldlooklikethisnow

(Leftisthetop,rightisthebottom)

Ifitdoesn’t,don’tfret;youcanalwaysgodiggingaroundinyourextrudesandeditthesketchestheyarebasedonifyoumadeamistake.Youmaythenalsohavetoopenuptheextrudeandclicknewholesyouhavemadeinthesketchtoaddthemtotheextrusionprofile.CTRL+rightclickwillun-selectholesfromaprofilebytheway.

Whew!Almostdonewiththebase,wejustneedsometubestoprotrudefromthisflangeforthesmallerflangestoconnectto.Nowinrealitytheflangeswewillattachtothesetubestohavesomeinternaldimensionwedon’tknowyet,sodon’tworryaboutgettingthelengthsofthesetubessuperprecisejustyet,we’llcomebacktothat.Makethecentraltubeandthefourmini-flangetubes,thelengthsaren’ttoocriticalyetbutmakesureyoumaketwoofthemini-flangetubeslongerastheyaredepictedsoyoudon’tforgetwhichonesbytheend—comparethepositionstotherectangularholesonthebottom.

Bynowyourfinishedbasepieceshouldlooklikethis

Noticethatnotonlyaretherenowtubesjuttingfromthisthing,butitlooksalittlelighterandmoreshiny,likeithasachromepolish.Ichangedtheappearanceasfollows:Left-Clickonthetop-mostnameonyourmodeldirectoryontheleft(ifyouusedthenameconventionIuseditshouldsay“8inchflange.ipt”.Theentirebodyshouldbehighlightednow.Atthetopthereisarainbowwheel,expandthisandlookforamenuofmaterialstochoosefrom.LookforSteelPolishedandselectittomakeyourpartpretty.Thereisactuallyavastarrayofmaterialsyoucandigthroughthematerialbrowsertofindandyoucanevenmakecustomskins.

Onemorelittledetailbeforewegetstartedontheassembly:weneedtotellInventorthatthescrewholesyoumadeareactuallyscrewholesandnotjustregularholes.Thereisatoolunder3DModel>>Modify>>Threadthatwillcreatethesethreadsforyou.Makesureyouchoosethecorrectsize,youmayneedtodigaroundabunchofoptionstofinallyfindit.

Atotaloffiveflanges(four“mini-flanges”andone2.75”flange)willmounttothetubesyou’vemade.Saveyourbaseflange“8inchflange.ipt”

Nowforthoseotherflanges,whichfortunatelyforushave3Dmodelsprovidedbythemanufacturer.

ThecompanyinquestionisMDCVacuum,andforthisfirsttimeI’llsomeofthedirtyworkforyouandprovidedirectlinkstothepageswiththeflanges.Inthefuture,andinourownexperienceinyourlabsomeday,itwillbeagoodideatolookaroundonmanufacturer’swebsitesifyouareusinganystore-boughtparts(suchasflanges,bolts,valvesetc.)McMaster-CarrsometimeshasCADmodelsyoucandownloadaswell;you’llknowbyclickingonaproductandifthereisaCADoptionthatpopsupwiththeotheritems,youcandownloadamodel,otherwisenot.

Oneachofthefollowinglinks,clickonthelittleFloppyDisciconnexttothedesiredpart(inhowmanyyearswillthisinstructionutterlyconfusestudentswhodon’tknowwhataFloppyDiscis)?You’llneedtomakeanaccountwithMDCVacuum,nobigdealjustuseyouruciemail.

Grabthe0.75”NominalIDversionofthe1.33”RotatableFlange,part#100004,fromhere

http://www.mdcvacuum.com/displayproductcontent.aspx?d=MDC&p=m.1.1.1.2(CTRL+clickthislink)

Makesuretotakethe.stp3Dmodel.

Grabthe1¾”NominalIDversionofthe2.75”RotatableFlange,part#100034,fromhere

http://www.mdcvacuum.com/displayproductcontent.aspx?d=MDC&p=m.1.1.3.2(CTRL+clickthislink)

Againgrabthe.stp3Dmodel.

Nowyou’llwanttoopenthesetwo.stpfilesandsavethemas.iamfiles.MakesuretochangethebodyappearancetoSteelPolishedsoitlookspretty,notingthatforeachflangeyou’llneedtoCTRL-clickbothbodiestoselectbothbodiesoftheflangefromthemodellistontheleft.Whereveryouhavestoredyour8inchflange.ipt,savethesetwonewflangesthere.

GotoFile>>New>>Assembly.It’stimetoputthisthingtogether!

Buildinganassemblyisaltogetherdifferentthancreatingapart,butinmyopinionmorefun.Hereyouwillliterallyattachpiecestogetherusingconstraints.

ConstraintstellInventorhowthesepiecesaresupposedtosticktogetherandtheycomeinseveralflavors.Youcanconstraintwoflatfacesoftwoobjectstohavetotoucheachother(calledaMateconstraint)orbeparalleltooneanother(calledaFlushconstraint).Youcanalsoconstraintcylindricalbodiestoshareanaxis(anotheruseofMate)andyoucandefineflatfacestobeoffsetfromotherfacesbyspecificangles,thoughthisoneistrickiertopulloffproperly.

Anyway,withamomentofthoughtyoushouldbeabletoforeseethatwewillneedtwotypesofconstraintshere:aMateconstrainttophysicallyattacheachflangetoeachtube,andaMateconstraintonthecylindricalaxistocentereachflangeoneachtube.Let’sbegin!

Firstlet’splacethemainflange.ClickPlacefromthetopandbrowseforthe“8inchflange.ipt”fileandloaditup.Itwillappearalongwithaghostofitself;theghostisincaseyouwanttoplacemorethanone.Justhitescapeandyou’llhaveyouronepart.Nownoticeonthemodellistontheleftthattheiconfortheflangehasathumbtackoverit,thismeansitis“Grounded”sothatitcannotbedraggedaroundandmoved.Next,placetheotherflanges—itdoesn’treallymatterwherefornow,justsortathrowthemoutthere.Yourscreenmaylooklikethis:

Theideaisthatwewanttomateeachflangetoeachtubenow.Thereisaquickandeasyshortcutforstartingaconstraint:justpressC!Firstyou’llneedtohavethecamerarotatedtoviewthefirstfaceyouwanttoconstrain,however.Thiswilltakesomegettingusedto,asyouwillneedtoefficientlyjugglebetweencameramodeandmanipulatingconstraints.EventuallyyouwillgetfastandwillbeabletoquicklysnaptogetherstufflikeLEGOs.

Rotateyourcameraviewsoyoucanseethebottomofoneofthesmallerflanges.HitCtopulluptheconstraintmenuandselectthefaceasdepictedbelow:

Noticeafewthings.ForoneI’vechosenthispiecefirst,andnottheflangefirst,forareason;normallythefirstthingyouchoosegetsmovedtothelocationofthesecondthingyouchoosetojointogether.Wedon’thavetoworryaboutthissomuchbecausewegroundedthemainflange,butstillgetintothehabitofthinkingaboutwhatorderyouselectyourconstraints.Next,noticethatwhenyouclickthefaceasmallredarrowappears,thisisthenormalvectortothefaceyouhavechosen.Thiscanbeausefuldisplayfeatureinsituationswherethereareseveralfacesnearbyorthefacesaresimilarinangle.Nowwiththisselected,clickthecamerarotatebuttonandfocusononeofthesmalltubes.HitESC,butonlyonce,andclickonthefaceofthetubeandhitOK.Themini-flangeshouldgomoveandsnapontothetube,althoughitmaybewildlyoff-centertothepointofnoteventouching.Whatyouhavedonehoweverisguaranteedthatthefaceofthemini-flangeisinthesameplaneasthefaceofthetube.Tofinishconstrainingthisflange,hitCagainandthistimeselecttheinnerwalloftheflange.Youshouldseeanaxisappearlikethis:

NoticethatIleftmymousehoveringovertheobviousnextchoice:theinnersurfaceofthetubeIwanttocenteron.IfIclickonit,thenclickok,thentheflangeisaffixedthewaywewant.

Repeatthisfortheotherflanges.Itmaybetrickytofigureoutwhichsurfacetosnaptoonthelargerflange,playaroundwithitabit.

Nowtofinishthismodel.Everythingisset,exceptthattheheightsoftheflangesarelikelyallwrong.Tofixthis,wecandoasloppysortofpost-fixasfollows:

OntheRibbon,clicktheInspecttabandclickDistance.Thisisaveryhandytoolyouwillmakeregularuseofwhenmakingassemblies.Distancetellsyouthedistancebetweentwofaces,thediameterofanycircularshape,andwithsomefidgetingandyellingatthescreenyoucansometimesevengetittotellyouthedistancebetweenafaceandtheedgeofacircle/centerofacircle.

Whatwewanttodoismeasurefromthetopfaceofeachflangetothebottomsideofthemain8”flangeandmakesuretheheightsarecorrect.Inspectthepdfdrawingtoseewhattheyshouldbe:someare2”andsomeare1.5”.Figureoutwhatthecurrentheightsare,thenadd/subtractasnecessaryfromthetubeextrusionlengthsaspossibletomakeitwork.Youmaywanttowritethesenumbersdown,bytheway.

Onceyouhaveallthenumbersyouwanttoadd/subtractfromeachtubelengthdeduced,gotothemodellistanddoubleclickthe8”flange.Itwillopenupnowwithotherpartsturningsee-through.Youcannoweditfreely.Hoveryourmouseovereachextrusiontoseewhichonecorrespondstowhichtubes(youcanalsonametheextrusionsoranyotherthingyoumake,partorsketchorotherwise,forcomplicatedpartsthiscouldsaveyoutimeinthelongrun).Doubleclickontheextrusionyouwanttomodify,thensimplyadd+___or-___tothecurrentnumbertocorrectit.Repeatthisfortherest,savethe8inchflangepart,thenhitReturnonthetoprighttoreturntotheassembly.

Allyourlengthsshouldworknowandshouldappearlikethiswhenmeasured:

Yourmodeliscomplete!Ornearlycomplete,ifyoulikeyoucanaddasmallChamfertotheouter8”diameteredgesforrealism.IfyouweremodelingtheentireSTMchambertobesentoutforcustommanufacture,you’vejustmadetheSTM’shat!

Nowdependingonwho/what/howthiswillbemade,the3Dmodelmaybeenough.Tobesurethough,it’salwayssafesttogeneratethat2Ddrawing.Herethoughyouwillneedtothinkcarefullyabouthowyouwanttolabelyourdrawing,howmanyseparateviewsyouwantandsoforth.Remember,thegoalistoconveytosomeonewhohasneverseenorevenimaginedthisthingbeforealltheinformationneededtounderstandhowtomakeitfromscratch.

Nowhere’ssomethingimportant:whenyouplaceviewsyoumaynotice,toyourfrustration,thatyoucannotseetheholesunderneaththeflangeliketheviewsgiventoyouinthePDFshow.What’sgoingonhereisthat,whengeneratingaview,youactuallyhavetheoptionofshowingwhatarecalled“hiddenlines”,basicallyanyfeaturesthatarehiddenfromdirectlineofsightviewsuchastheseholes.

Toactivatethisfeature,clickherewhenplacingaview:

Forsomeoftheviewsyoumaywanthiddenlinesturnedon,forotherswhereyouwanttoshowtheoverallshapeofthethingyoumaynot.Ihaveincludedthe“final”drawingPDF,withnoannotations(that’syourjob!)butwithcertainviewsthathavehiddenlinesandaviewthatdoesnot.Doyouthinkthisistoomany/notenoughviews?Also,youcanchangethescaleofyourviewstoallowmoreroomforannotations.Ilookforwardtoseeingyourfinaldrawings!

Tutorial5:STMSampleHolder

We’reactuallygoingtomakethefirstthingImadeinInventorwhenIjoinedthelab.ThisisanSTMsampleholder,itisusedtoclampontosmall,thinultra-flatSTMcrystalsampleswhileprovidingamechanicalmeansforourSTMtiptoapproach/retractfromthissample.

Startbyopeningthe2Ddrawing“SampleHolderBase.pdf”Asbefore,ourultimategoalwillbetocreatea3Dmodelthatcanbeusedtoreproducethesedrawings.

Atfirstglancethismodelseemsdeceptivelysimilar;indeeditshouldtakelesstimethanthelasttutorial.ThereissomethingtrickyherethatIwillgiveyouhintsabouthowtofigureoutbutwillleaveyoutostrugglewith.

Thewayoursampleholderswork,therearethree“ramps”whichsitontopofthreetungstenspheres(notpictured).Therampsneedtohaveaslopeforoursampleholderstowork(I’llexplainlaterwhy).

Theslopeis3degreesasgivenbythedrawing,butyouwillneedtofigureouthowtomakethesecuts.I’llgiveyouahint:

Thisiswhatyoursketchshouldlooklike:

Thisiswhattheendresultofextrudingfromthatsketchshouldlooklike:

Herearesomeotherthingsyoumayliketoknow.Youcandrawtwolines,onestraightalonganaxisandtheotheroneoriginatingfromthesamepointthefirstlinedoes,butdefinetheendpointofthesecondlineintermsoftheanglebetweenthetwolinesinsteadofjustafixedcoordinate.You’llhavetoplayaroundwithittogetthattowork,butyouknowtheendgoalis3degrees.

Also,youcanCircularPatternanyExtrusions!Inotherwords,youcanapplyCircularPatternwhennotinsketchmodeaswellaswithin.Soonceyoumakethisangularcutinoneramp,youcancloneitwith3foldsymmetrytoeasilydotheothertwo.

Thetrickypart,Iwouldargue,isfiguringouthowtogetthatsketchonthatplaneinthefirstplace.Youwillneedtoverycarefullythinkaboutsymmetriesandyouwillneedtodefineaworkplanethatistangenttothecircularshapeofthesampleholderatthepointthathappenstobeintheexactmiddleoftherail(fromasideview).You’llwanttoinvestigateallthedifferentwaysyoucandefineaworkplanebyhittingthedownarrowunderworkplane,andlikelyyou’llalsowanttothinkaboutallthewaysyoucandefineaxisandpoints(thosearerightnexttodefineworkplane).Similartricksareneededtoproducethesixthreadedholesonthesidesofthesampleholder(alongwith,ofcourse,aCircularPattern)

Generatethedrawingsfortheseasbefore.Thistimethough,Iwillblow.Your.Mind.No,seriously.

WhenyoucreateaBaseView,placeitbutbeforehittingok,tabovertoDisplayOptionsthencheckthe“AllModelDimensions”box,thenhitok.Likemagic,Inventorwillattempttoautomaticallycreatealltheannotationsforyou.Nowwhydidn’tIshowyouthatbefore?Wellforonething,youneedtolearntothinkaboutplacingannotationsyourself,balancingbrevityandclarity.Inaddition,thistrickwon’talwayswork,ifyouhavetoocomplicatedadesign,Inventorwon’tletyouselectthisoption.It’sgoodtoknowthatit’stherehoweverasitcansaveyoutimeinthefuture.

Bytheway,incaseyou’rewonderinghowImanagedtogetoneofthesideviewshorizontal,youcantotallyrotateanyviews.Ifyouhoveroveranalreadyplacedview,causingthereddottedoutlinetoappear,thenrightclickandselectRotatefromthemenu,youcanrotatebyanyangleifyouchangetheoptionatthetopfromEdgetoAbsoluteangle,thenspecify90or180orwhateveryoulike.

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Bytheendofthis,youshouldbeabitconcernedabouttheefficiencyofcreatingdrawingsthisway.Afterall,wouldn’titbefastertojustdothisin2Dbyhandorevenjustdrawitandannotateitreallywell?Forsomedesignsthatwillbetrueactually.WhereInventorreallyshineshoweverisitsabilitytogenerateperfectlyscaledrawingsfromarbitraryangles,witharbitrarycrosssections(wehaven’tcoveredthatyet).Perhapsmoreimportantly,Inventorservesasadesignaidthatallowsyoutomodelseveralcomponentsofacomplicatedsystematonce.You’llappreciateInventorthemostonceyouhavesomecomplicatedinstrumentdesignandyoucanseehowallthepiecesfittogether—ordon’t,inawaythatleavesyougratefulyoudidn’tjustleaveituptosketchesandimagination.

Inanycase,bygettingcomfortablewiththissoftware,youwillseethemostbenefitsfromthisifyouareaninstrumentationheavylab.Eventuallyyouwillbeabletochurnoutdrawingsanddesignssofastthatitwon’tfeelcumbersomeanymoreandyourlabwillbenefitfromalegacyofgreatmodelsinyourdatabasethatyoucanusetoteachnewmembersaboutyourexperiment.