Create the Sixsides of a Die

DrawingandAssembling

Description

Inthis activity the six sidesof a diewill bedrawn andthen assembledtogether.The intentis tounderstandhow constraints are usedto “lock” individual parts togethertoform anassembly.

LessonObjectives

The student willbeableto:

•Create the sixsides of a die

•Draw2Dsketchesusingconstraintsand dimensions

•Usevarious tools toeditthe2D sketch (trim,mirror,offset,rotate)

•Extrudea2D sketch

•Drawasecond2D sketch and extrudeit on theface ofan already extruded2Dsketch

•Assemble partsintoan assembly

Assumptions

The student will:

•Knowhow tologin toa computer and openup thesoftware

•Understandtheworking environment ofthesoftware andhow to navigate it

•Havealreadycreateda simple 2D sketch in thesoftware

•Haveextrudeda2Dsketchinto a3Dpart in the part-modelling environment

Terminology

Note: terms withan asterisk (*) are copyright theAutodesk Knowledge Network, licensedunderaCreative Commons Attribution-NonCommercial-ShareAlike3.0Licence(CCBYNCSA 3.0)

Applicationbutton:theiconinthetopleftcornerofthescreenthatcontainsNew,Open,Save,etc.

Assemblyconstraints*:rulesthatdeterminehowpartsinanassemblyareplacedrelative tootherpartsinthe assembly.Constraintsremovedegreesoffreedom.Assemblyconstraints

include angle, flush, mate, andtangent.Constraints may beplacedbetweenfacesof features,partedges,points,inferredaxes,andpartworkfeaturessuchasplanes,axes,andpoints.

Assemblymodelling*:twoormorecomponents(partsorsubassemblies)consideredasasinglemodel.Anassemblytypicallyincludesmultiplecomponentspositioned absolutelyandrelatively(as required) withconstraintsthatdefineboth size andposition.Assemblycomponentsmay includefeaturesdefinedinplaceintheassembly.Massandmaterialproperties may beinheritedfromindividualpartfiles.

Browser*:sometimescalledthemodeltree, isthegraphicalhierarchyshowingrelationshipsbetweengeometricelementsinparts,assemblies,anddrawings.Iconsrepresent sketches,features,constraints,orattributesforeachmodel.Objectsareshowninthebrowserintheorderinwhichthey werecreated. Objectsmayalsobeedited,renamed,added,deleted, copied,andmovedtoadifferentlocationinthe browser.

Constraints*:rulesthatgoverntheposition,slope,tangency, dimensions,andrelationshipsamongsketchgeometryorthe relativepositionbetweenpartsinanassembly.Geometricconstraintscontroltheshapesandrelationshipsamong sketchelementsorassemblycomponents.Dimensionalconstraintscontrol size. Applyingconstraints removes degreesoffreedom.

Drawing:a2Drepresentationofapartorassembly.Thedrawingfiletypehasan.idwextension.

Extrude*:a feature created by addingdepthtoa sketched profile.Feature shapeiscontrolled byprofileshape,extrusionextent,andtaper angle.

Fullyconstrained:whena2Dsketchor3Dparthashadallthedegreesoffreedomremovedanditcannotbefreelymoved anymore.

Graphicswindow*:theactivemodellingareainwhichsketches,constraints,features,parts,andassembliesarecreatedand edited. IntheGraphics window, modelscanbe rotated, zoomedinandout,andviewcharacteristicssuchas colour, material,andlightdefined.

Hardsnap:snapfunctionrepresentedbyagreendotthatappearswhensnappingtotheendpointofasketch line.Ahardsnapispermanentandcannotbe moved.

Homeview:anisometricviewofyourmodel.WhentheHomebuttonontheViewCubeispressed,itzoomsinandre-orientsthemodelintheisometricviewintheGraphicswindow.

Kerf:acutorincision (groove, notch, channelor slit)madein any materialby acuttingtoolsuchasasaw,axeorcuttingtorch.

Markingmenu:whenyourightmouseclickintheGraphicswindowinvariousmodes(sketch,3D model) amenucomesupwithenvironment-specificcommandoptionsarrangedinaradial,ratherthanlinear,display.

Navigationbar:atoolbarcontainingvarioustoolstomove orviewyour 2Dsketch or3DpartintheGraphics window.

Origin:thepointwherethex,y,andzplanesoraxesintersect.

Part:agroupof features andfacesthat havebeencombinedtocreateaclosed volumethatisrepresentedasa3Dobject.

Partmodellingenvironment*:theenvironmentwhereyoucreatesketchesandbyusingdifferentcommandseventually createa3Dpart.Inpartmodelling,you createsketches, usefeaturecommandstocreatethree-dimensionalfeatures,andthencombinethefeatures tocreateparts.

Ribbon:thepalettethatextendsacrossthetopoftheInventorinterfaceandcontainsmultipletabsforconvenienttoolaccess.

Shell*:aparametricfeature usedmostfrequentlyforcastormouldedparts. From aspecifiedface,materialis removed fromthepart, leaving acavitywithwallsofaspecifiedthickness.Shellsusually havewallsofuniformthickness,butindividualfacescanbeselectedandtheirthicknessspecified.Shellwallscanbeoffsettothe inside, outside,orbothsidesofthepart, relative totheoriginalpartsurfaces.

Sketch*:consistsofthesketchplane, acoordinatesystem, 2Dcurves,andthedimensionsandconstraintsappliedtothecurves.Asketch mayalsoincorporateconstructiongeometryorreference geometry. Sketches areusedtodefine feature profilesandpaths.

Sketchenvironment*:consistsofasketchandsketchcommands.Thecommandscontrolthesketchgridanddrawlines,splines,circles,ellipses,arcs,rectangles,polygons,orpoints.

Sketchplane:aplanarfaceorworkplaneonwhichthecurrent sketchiscreated.

Softsnap:snapfunctionrepresentedbyayellowdotthatisnotconstrained,andthereforecanbemoved.

Statusbar*:a displayacrossthebottomoftheactivewindowthatindicatesthenextactionthattheactivecommandrequires.Whena2D sketchor3Dsketch isactive, thestatusbarfor sketchdisplays commandsspecifictothe sketch environment.

STEPfile*:aninternationalformatdevelopedtoovercomesomeofthelimitationsofcurrentdataconversionstandards.FilescreatedinotherCAD systems canbeconvertedto STEP formatandimportedintoAutodeskInventor.

ViewCube:aninterfaceontheGraphicswindowthathelpsswitchbetweenstandard(front,side,top,etc.)viewsandisometricviewsofthemodel.

Workplane:thexy(front view),xz(top view), andyz(side view)planes. Sketchesand3Dobjectsaredrawnontheseplanes.

EstimatedTime

2–3 hours

RecommendedNumberofStudents

20, basedonBCTechnologyEducators’Best PracticeGuide

Facilities

Computerlabinstalledwith 3D modelling software (AutodeskInventor,PTCCreoParametric,SolidWorks,etc.)

Tools

Projectorwithcomputerandspeakers,Internet access

Materials

Handoutfor students withinstructions

Resources

Instructionalvideofor teacherand students to follow(Inventor2013):

•12.1: Drawing Side 1 of the Die

•12.2:Adding a Sketchto a Surface of a Part

•12.3:Assembling YourDie

Teacher-ledActivity

Useacomputerwitha projector and demonstratethe following:

1.Starta new part in imperial.

2.Create the sides ofthedie inthe 2D sketch environment. There are manywaystocreatethethree different sketchesneededtocomplete the die. Thesuggestion is tostartwitha2"

square, thenoffset and draw thelinesfor the tabs on one side. Next,mirror,copy, and rotatethem tothe three othersides. Onceonall four sides,usethe Trim command to remove theunwantedlines.

3.Extrudea2Dsketch into3Din thepart modelling environment.

4.Savethefirstcreatedpartasanotherfile. A suggestionistohavethestudentscreatethefirstdrawingand call itside1,then“SaveAs” so thattheydonothaveto restart from scratchtocompletetheotherfivesidesrequired.

5.Create asecond sketch and extrusiononasketch thathas alreadybeen extruded.

6.Assemblethe sketches together

StudentActivity

StudentswillfollowtheStudent Activity “Make a 3D Die”and/orthevideotutorialstomaketheirown3Ddie.

ExtensionActivity

Usethedrawingbelow(Figure1)foroutputtingtothelaserengraver. Insert thisdrawingintotheStudent Activity that follows. Havethe students change thetabs from .5" to.52" toallowfor the“kerf”ofthelaser.The kerf isbased on ⅛" MDF or ⅛"Balticbirchandmay vary depending onthe laserengraveryouhave.

Note: The male tab will be.02larger,so that when the die is lasercut it will fit snuglywithoutanyglue.

Figure1

Assessment

Students willshowthe teacher their completedassignment.Theteacher canhave theassignment printedout orlook at it onthe computer screen.If the student does notproduceexactly whatwasshown, then an associatedmark based on mistakes canbederived.

StudentActivity:Makea3DDie

Usingthe software,you are to drawasingle die that you willassemble onthe screen.Thedimensions ofthedie will be2"cubed. The die willconsistof sixseparate pieces. However,thetop/bottom(1and6),twosides(3and4),andtwoends(2and5)willeach be thesamesize(Figure2).

Figure 3 showsthedimensionsofthethree pieces youwillneedtocreate.The thickness ofthematerialwill be ⅛". After thethree pieces havebeencreated,youwillsave a copyofeachandthenchangethenumberof dotstorepresentthemissing sides ofthe die.

Figure2

Figure3

ProcedureforCreatingtheSidesofYourDie

1.Opena new imperialpartfrom theApplicationmenuorfrom theGet Startedtabontheribbon (Figure4).

Figure4

2.Create a2Dsketch andhighlightANYplane.Theprogram will now enterinto the sketchenvironment(Figure5).

Figure5

3.Inthe sketch environment,createa2"by2" square usingthe Rectanglecommand(Figure6).

Figure6

4.Offsetor draw a linethatis .125"infrom oneofthe edges. Draw thestartof atabbydrawing2 linesthatare .25" eitherway from thecentrelineasshowninFigure7.

Figure7

5.Trim outthe excesslinesthat are not needed to form the “female” partwhere atab willjoinlater(Figure8).

Figure8

6.Addamirror lineon the y-axissoyou willbe abletomirror the femaletab to theotherside(Figures 9 and10).

Figure9

7.Usingthe Mirror command,selectthepartsyouwantto mirror andthen select the mirrorline. The endresultwillbe that the tabendsupon theotherside.Trimout the excess tomakeit look likeFigure10.

Figure10

8.Usingtheknowledge from step7,createthe“male” tab atthetopasshowninFigure11.

Figure11

9.Mirror and trim outthe bottom tab tocompletethesketchasshown(Figure12).Thenexitsketch mode.

Figure12

10.Extrudethe sketch to .125".Theend resultwillbeapart looking likethe one showninFigure13.

Figure13

11.Addtheholes or indents for thedots.Todothis,select “Create 2DSketch”andthenselectthesurfaceyou want.Youwill enterintosketch mode again. Each dot on thedie willbe .4" indiameter.They will ALLbe .4" from the outsideedges or in thecentreofthedie as shown inFigure14.

Figure14

12.Once thedot(s)is/arecompleteforthesideofthedieyou’reworkingon,finishthesketch(Figure15).Saveyour work asSide 1– Die.

Figure15

13.Youhavecompletedoneofthesidesofthedie.Nowyoumustcompletetheotherfivesidesusingwhatyou have learnedabove.To createthe other sidesofthe die,you can either starta new drawingand copy and paste the sketch from onedrawing toanother, OR“Save As”thefirstdrawingtostartthenextsideofthedie.

ProcedureforAssemblingYourDie

1.On the Application menu, select “CreateNewFile,”andthistime choose “Assembly.”

Figure16

2.If youhave doneeverything abovecorrectly,you should haveadirectory containingthe sixfiles listedinFigure17.Whenyou select a file,thePreviewwindowshouldshow a partthatcorresponds tothe file nameyou’veselected(Figure17).

Figure17

3.Placethefirstpart on thescreen(Figure18).Thispart can be called thegroundedpart.Itisthepart thatevery other pieceis connected to.All other pieces will bebased off it.

Figure18

4.Place the secondpart.On the Ribbon, select “Constrain.” The “Place Constraints” dialog boxcomes up,asshowninFigure19.

Figure19

Remember which sides are opposite toeach other:

•1isopposite 6

•3isopposite 4

•2isopposite 5

5.Select thetwofacesofthe pieces asshown so thattheyarealignedflush,asshowninFigure20.Youmayhavetoswitch from “Mate”to“Flush”underthe“Solution”inthedialogbox to get the faces oriented therightway.Select “Apply” when they are linedup correctly.

Figure20

6.Select thenexttwofacesofthe pieces asshowninFigure21 so thattheyarealignedflush.Youmayhavetoswitch from “Mate”to“Flush”underthe“Solution”inthedialogboxtogetthefacesorientedthe right way.Select “Apply” when they are linedup correctly.

Figure21

7.To ensure thetwoparts are aligned “Centred,” thistime you are goingto alignthemtotheirplanes.IntheBrowser,expandthepartstoshowtheirplanesunder“Origin.”Pickingtheplaneswillhighlightthem(Figure22).

Figure22

8.Oncebothplanesare picked,theywillalign sothat theyare mated.Select “Apply”(Figure23).

Figure23

9.Continuethe process ofconstrainingeachpart(Figure24).

Figure24

10.Once youhaveplaced all thepartsandconstrained them,you should endup with thecompleteddieasshowninFigure25.Saveyourwork.

Figure25