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1 Indiana University - Purdue University Fort Wayne Opus: Research & Creativity at IPFW Manufacturing & Construction Engineering Technology and Interior Design Senior Design Projects School of Engineering, Technology and Computer Science Design Projects Rugby Ball Launcher Joel Kumfer Indiana University - Purdue University Fort Wayne Mitchell Olney Indiana University - Purdue University Fort Wayne Follow this and additional works at: Opus Citation Joel Kumfer and Mitchell Olney (2017). Rugby Ball Launcher. This Senior Design Project is brought to you for free and open access by the School of Engineering, Technology and Computer Science Design Projects at Opus: Research & Creativity at IPFW. It has been accepted for inclusion in Manufacturing & Construction Engineering Technology and Interior Design Senior Design Projects by an authorized administrator of Opus: Research & Creativity at IPFW. For more information, please contact admin@lib.ipfw.edu.

2 Project Report Rugby Ball Launcher Joel Kumfer & Mitchell Olney MET 494

3 TableofContents DESIGN' 3 VELOCITY'A'TRAJECTORY'CALCULATIONS' 16 DRAG'AND'LIFT' 27 DEFLECTION'ANALYSIS' 32 ACQUIRED'COMPONENTS' 34 ASSEMBLY' 38 GANNTT'CHART' 41 TESTING'OBSERVATIONS' 42 TESTING'ASSESSMENT' 42 POSSIBLE'IMPROVEMENTS' 42 CONCLUSION' 43 REFERENCES' 43

4 Design Image1.1

5 Image1.2 Image1.3

6 Image1.4 Image1.1isourcurrentdesign;the2motorsareconnectedtoaquarterinchsteel plate(image1.2)whichisthanmountedtoanotherquarterinchsteelplate(image 1.3).Thesecondplateismountedtotwo15seriesaluminumt?slottedbars12.9 inchesinlength(image1.4).herewecalculatedthedeflectionfromjusttheweight ofthemotorhangingfromthe15seriesbars.

7 Image1.5 Image1.6

8 Image1.7 Thetwo15seriesbarsaretappedateachendandconnectedtotwounbearding s (Image1.5)ateachendwithastarhandlebrakekit(Image1.5)whichisconnected totheframe.theframeismadeofa15?seriesdoublewidebar10inchesinlength (Image1.6),thishastapedendsforendfastenerstobefitted(Image5).Theend fastenersaretightenedinonthethroughholesonthetwo15seriesbars15.75 inchesinlength(image1.7)whichareconnectedbyendfastenersandcorner brackets(image1.5).thisallowsustomovethemotorsclosertooneanotherto launchdifferentsizeballsandpossiblyflatballs.herewecalculatedthedeflection ofthemotorhangingfromtofixedends.

9 Image1.8 Image1.9

10 Thelastpartoftheframeisa15?series13inchbar(Image1.8)isconnectedto15? seriesdoublewidebar(image1.6)bythet?nutanda5/16?181.75inchlongbolt (Image1.5).Next,a10?inchlinearbearingpad(Image1.9)isboltedtothe15?series 13?inchlongbarwiththet?nutsand5/16?18bolt(Image1.5).Thisactsasatrackso thecradlecanslideforwardmovingtheballintocontactwiththetires. Image1.10

11 Image1.11 Image1.12

12 Image1.13 Image1.14

13 Image1.15 Image1.16 Thehinge(Image1.5)attachestheframetothebaseallowingustolifttheopposite endtoachievethedesiredangletoproceed.thebottompartoftheframe(image

14 1.10)ismadeoftwo15series13inchinlength(Image1.11).Thereatthree3.5inch 15seriesbars(Image1.12)onewhichhasathroughholeinthecenterofthet?slot (image1.13)whicharetapedoneachendandfittedwithanendfastener(image 1.5)tobetightenedtothe13inchbars.The13?inchbarshavefourthroughholesin themiddleoftheframetoallowtheendfastenerstobetightenedproperly.next,we attachedthelegs(image1.14)tothebottomofthebaseusingcornerbrackets (Image1.5).Weattachedtwotothefrontandonetotherearunderthehingewith twocornerbrackets.thanweaddedtwomorecornerbracketstobothsidesofthe frontofthebaseandaddedasupport(image1.16)itissecuredby5/16?18inch threadednutstokeepitinplace.thesewhereaddedforextrasupportfortheframe tokeepthemotorfromshakingtheframeduringuse. Image1.17

15 Image1.18 Image1.19 Thelastpartiswheretheballswillbeplacedandpushedtowardthespinningtires (Image1.17);thisisallsubjecttochangesimplybecausewearelookingfortheright material.the15?serieslinearbearingpad(image1.9)allowsforthe15series.75?

16 inchlitebar18inchesinlengthwhichiscappedatoneend(image1.18)tobeslide on.thenextthroughholeabovetheoneforthegripisforaballholder(image1.19). Thisisslideontothelinearbearingpad. Image1.20 Thisisthefirstdesignwecameupwith,butdecidedagainstit(Image1.20).Atthe timethemotorsweplannedtousewheremuchsmaller. Ifwehadmoretime,wewouldagaingowithadifferentdesign.Themotorsattheir highestrpmsshaketheframe,toavoidthiswewouldmaketheangledassembly attachedtothemotorsmuchbiggerandextenditpastthemotors.anothersolution wewantedtotrywasshockabsorbersonthebaseandonthemotorsthemselves. Whenwetriedtochangethepositionofthemotorstocreatedifferenttypesofspin ontheballthemotorsdidnotexactlylineupandtheballwouldgofromonewheel totheother,thisendedwiththeballspinninginseveraldirectionsmakingit difficulttocatch.inordertoavoidthiswewouldcalculatethenecessarydistance andadjustthemotorsaccordingly.thismayhavetobesituationspecificduringuse. Theentirelauncherisparticularlyheavyanddifficulttomovearound,thisis somethingweplannedforintheoriginaldesignbutdidnothavetimetoaddtoour seconddesign.thebasewouldbedesignedtodetachandcarryseparately,andthey wouldaddwheelstotheendsofthebasetoallowtheusertomovethelauncher withlittleeffort.

17 VelocityaTrajectoryCalculations Image2.1

18 Table2.1 constant' R'(wheel)' 0.127' meter' Gravity' :9.8' m/s' RPM'of'motor' 3500' '' enter'angle'of'guide=θ' 10' degree' Inputs' enter'angle'of'left'wheel=α1' 35' degree' enter'angle'of'right'wheel=α2' 0' degree' Hight'of'launcher' 1' meter' ball'radius' 0.09' meter' ω=(2*π*rpm)/60' ' rad/sec' Vtan=ω*r' ' m/s' Vx'of'left'wheel=cos(α1)*Vtan' ' m/s' Vy'of'left'wheel=sin(α1)*Vtan' ' m/s' Vx''of'right'wheel=cos(α2)*Vtan' ' m/s' Vy'of'right'wheel=sin(α2)*Vtan' 0' m/s' Outputs' intial'velocity'of'ball=vi=max'vx' ' m/s' tanget'velocity'of'ball=max'vy' ' m/s' spin'of'ball=(vy*60)/(rball*2π)' ' rpm' Vh=horizontal'velocity=cos(θ)*vi' ' m/s' Vv=vertical'velocity=sin(θ)*vi' ' m/s' time' ' sec' distance=vh*(t)' ' meter' Thegroupmadeaspreadsheettocalculateandplotthetrajectoryoftheballafterit leavesthelauncherbecauseoftheadjustabilityoftherugbyballlauncherthereare manyfactorsthatgointocalculatingtheflightpathoftheballafteritleavesthe launcher.

19 Image2.2 Table2.1startswiththeconstantsofthelauncher,whicharethewheeldiameter andgravity.thenitasksfortheinputs(rpmofmotor,angleofguide,angleofleft wheel,angleofrightwheel,heightoflauncher)theseinputsareusedtocalculatethe trajectoryoftheballthelocationoftheinputscanbeseenonimage2.2. Firstitcalculatestheangularvelocityinradianspersecondusingtheequation below = (2 "#)/60

20 Image'2.3' This'angular'velocity'is'then'used'to'find'the'tangent'velocity'of'the'wheel'at'the'point' that'it'will'strike'the'ball'this'can'be'seen'in'image'2.3.'the'two'tangent'velocities'look' like'different'magnitudes'but'they'are'not.'the'tangent'velocities'are'just'at'different' angles'because'of'the'change'in'angle'of'the'wheel.'using'the'equation'below'with'the'r' being'the'radius'of'the'wheel'we'are'able'to'find'the'tangent'velocity'at'each'side'of'the' ball.' "# = ω r '

21 Image2.4 TheCalculatedVtangentisthenbrokendownintoitscomponentsvelocityinthe lateraldirectionvxandvelocityintheverticaldirectionvydependingontheangleof thewheelandthetangentvelocitythesecomponentscanbeseeninimage2.4.the VxandVywillbecalculatedforbothwheels.Theangleofthewheelisinrelationto theangleoftheguide,whichcanbeseenonimage2.4. = "#() "# = "#() "#

22 Image2.5 VxisthenusedastheinitialvelocityoftheballasitleavestheguideandVyisused asthetangentvelocityoftheball,whichcanbeseeninimage2.5.thetangent velocityoftheballisthenusedtocalculatetherpmofthespinoftheballwiththe equationbelow. spinofball = (V 60)/(r "## 2π)

23 Image2.6 Usingtheinitialvelocityoftheballandtheangleoftheguidewhichisinreference tothebasewhichisparalleltothegroundwhichcanbeseeninimage2.6through thisweareabletocalculatethecomponentsofthevelocityintheverticaland horizontaldirection. = cos(θ) = sin(θ) Theverticalvelocityisusedtocalculatethetimetheballistravelingintheairwith theequationbelow. 0 = "#$%h"#h = ± 4. 5 "#$%h"#h 2. 5g Thehorizontalvelocityandthetimeisthenusedtocalculatethedistancetraveled usingtheequationbelow. distance = (t)

24 Thisgivewheretheballwilllandbuttobeabletopredictwherethepersonwill standtocatchtheballweneededtomakeagraphoftheheightversusthedistance oftheballtodothiswemadeatabletocalculatetheheightanddistanceevery.1 second.giveninthetablebelow. Table 1.2 t'sec calculated'value'y' (meter) y'meter calculated'value'x'(meter) x'meter ' ' ' : On'Ground This is then put into a graph that can be seen in figure 2.1 below to show the flight pattern of the ball after it leaves the launcher.

25 Figure 2.1 Flight'Pattern' vertical'hieght'(meters)' Horizontal'Distance'Traveled'(meters)' The inputs on table 2.1 can be changed to get the desired distance and height for example to get a relatively short pass flatter more direct pass can be achieved by lowering the guide angle and increasing the RPMs of the motors and the angle wheel can be decreased like in table 2.3 to make the flight path have less of an arch. This can be seen in figure 2.2 below. If the desired height to catch the ball is approximately 1.4 meters off the ground and the pass has to go 20 meters before the player catches it then then the launcher will be passing the ball with the motors at there max speed of 3500 RPM and a short guide angle of 4 degrees with a small wheel angle of 5 degrees giving it a slower spin of 430 revolutions per minute. This will give the flight of the ball a max height of 1.53 meters and at 20 meters away the ball is 1.4 meters above the ground. Which are the desired results for a perfect pass.

26 Table 2.3 constant Inputs Outputs R'(wheel)' meter' Gravity' :9.8 m/s' RPM'of'motor' 3500 '' enter'angle'of'guide=θ' 4 degree' enter'angle'of'left'wheel=α1' 5 degree' enter'angle'of'right'wheel=α2' 0 degree' Hight'of'launcher' 1 meter' ball'radius' 0.09 meter' ω=(2*π*rpm)/60' rad/sec' Vtan=ω*r' m/s' Vx'of'left'wheel=cos(α1)*Vtan' m/s' Vy'of'left'wheel=sin(α1)*Vtan' m/s' Vx''of'right'wheel=cos(α2)*Vtan' m/s' Vy'of'right'wheel=sin(α2)*Vtan' 0 m/s' intial'velocity'of'ball=vi=max'vx' ' m/s' tanget'velocity'of'ball=max'vy' m/s' spin'of'ball=(vy*60)/(rball*2π)' rpm' Vh=horizontal'velocity=cos(θ)*vi' m/s' Vv=vertical'velocity=sin(θ)*vi' m/s' time' sec' distance=vh*(t)' meter' Table 2.4 t' sec' calculated' value'y' (meter)' y'meter' calculated' value'x' (meter)' x'meter' 0' 1' 1' 0.00' 0.00' 0.1' ' ' 4.64' 4.64' 0.2' ' ' 9.29' 9.29' 0.3' ' ' 13.93' 13.93' 0.4' ' ' 18.57' 18.57' 0.5' ' ' 23.22' 23.22' 0.6' ' ' 27.86' 27.86' 0.7' ' ' 32.50' 32.50' 0.8' ' ' 37.15' 37.15'

27 Figure 2.2 Flight'Pattern' vertical'hieght'(meters)' Horizontal'Distance'Traveled'(meters)'

28 DragandLift FindingdragandliftforceactingontheballandMagnuseffect Thedragandliftforcecanbecalculatedbyusingtheformulabelow = ""#$% 2 = "#$% = "#$$%%#&' = "#$%&'"#""#$% = "#$%&'( = "#"#$%&' TocalculatetheSurfaceareaeffectedbythedragandliftcoefficientwehadtouse thedimensionsofaninternationalrugbyballwhichwasacquiredthroughtherugby unionlawswhichcanbeseeninimage3.1. Image3.1

29 Image3.2 Referenceimage3.2fordecidingwhichdimensionisAandBontheballtheshorter radiusisalwaysbforthesurfaceareaofanellipsoid. circumference = π Diameter = ("#/)/2 =." /2 = meters =.15meters m = sqrt(1 (B/A)^2) m=sqrt(1?( /.15)^2) m= meters Surfacearea = 2 pi Surfacearea = 6.09meters arcsin ^2 EffectedSurfacearea = 3.045meter Thisisbecausetheairresistancewillonlybe actingonhalftheballasitfliesthroughtheairbecauseafterthatitgetsoverthe curve of the ball there will actually be a significant drop in pressure causing cavitation. Thevelocitycanbetakenfromtable2.1 TheCoefficeintofliftanddragisgiveninMartinPetersComputationalFluid DynamicsforSportSimulationonpages112?114.Thecalculatedforcescanbeseen

30 belowintable3.1. Table3.1 θ' Drag' Coefficient' Lift' Coefficient' Drag'force' (N)' Lift'Force'(N)' 0' 0.18' 0' ' 0' 1' 0.183' 0.01' ' ' 2' 0.186' 0.02' ' ' 3' 0.189' 0.03' ' ' 4' 0.192' 0.04' ' ' 5' 0.195' 0.05' ' ' 6' 0.198' 0.06' ' ' 7' 0.201' 0.07' ' ' 8' 0.204' 0.08' ' ' 9' 0.207' 0.09' ' ' 10' 0.21' 0.1' ' ' 11' 0.212' 0.108' ' ' 12' 0.214' 0.116' ' ' 13' 0.216' 0.124' ' ' 14' 0.218' 0.132' ' ' 15' 0.22' 0.14' ' ' 16' 0.222' 0.148' ' ' 17' 0.224' 0.156' ' ' 18' 0.226' 0.164' ' ' 19' 0.228' 0.172' ' ' 20' 0.23' 0.18' ' ' 21' 0.237' 0.19' ' ' 22' 0.244' 0.2' ' ' 23' 0.251' 0.21' ' ' 24' 0.258' 0.22' ' ' 25' 0.265' 0.23' ' ' 26' 0.272' 0.24' ' ' 27' 0.279' 0.25' ' ' 28' 0.286' 0.26' ' ' 29' 0.293' 0.27' ' ' 30' 0.3' 0.28' ' ' 31' ' 0.288' ' ' 32' 0.319' 0.296' ' ' 33' ' 0.304' ' ' 34' 0.338' 0.312' ' ' 35' ' 0.32' ' ' 36' 0.357' 0.328' ' '

31 37' ' 0.336' ' ' 38' 0.376' 0.344' ' ' 39' ' 0.352' ' ' 40' 0.395' 0.36' ' ' 41' ' 0.373' ' ' 42' 0.416' 0.386' ' ' 43' ' 0.399' ' ' 44' 0.437' 0.412' ' ' 45' ' 0.425' ' ' 46' 0.458' 0.438' ' ' 47' ' 0.451' ' ' 48' 0.479' 0.464' ' ' 49' ' 0.477' ' ' 50' 0.5' 0.49' ' ' 51' 0.511' 0.493' ' ' 52' 0.522' 0.496' ' ' 53' 0.533' 0.499' ' ' 54' 0.544' 0.502' ' ' 55' 0.555' 0.505' ' ' 56' 0.566' 0.508' ' ' 57' 0.577' 0.511' ' ' 58' 0.588' 0.514' ' ' 59' 0.599' 0.517' ' ' 60' 0.61' 0.52' ' ' 61' 0.617' 0.521' ' ' 62' 0.624' 0.522' ' ' 63' 0.631' 0.523' ' ' 64' 0.638' 0.524' ' ' 65' 0.645' 0.525' ' ' 66' 0.652' 0.526' ' ' 67' 0.659' 0.527' ' ' 68' 0.666' 0.528' ' ' 69' 0.673' 0.529' ' ' 70' 0.68' 0.53' ' ' 71' 0.673' 0.515' ' ' 72' 0.666' 0.5' ' ' 73' 0.659' 0.485' ' ' 74' 0.652' 0.47' ' ' 75' 0.645' 0.455' ' ' 76' 0.638' 0.44' ' ' 77' 0.631' 0.425' ' '

32 78' 0.624' 0.41' ' ' 79' 0.617' 0.395' ' ' 80' 0.61' 0.38' ' ' Thiscanthenbeusedtoadjustthetrajectoryoftheballdependingontheangleof theguide. Westillneedtheaccelerationoftheballtofinditsforcetocalculatehowmuchthe ballisactuallybeingeffectedbyairresistance. WewillalsohavetotakeintoconsiderationtheManguseffectbecauseofthespiral ontheballcausingadifferenceinairpressureactingononesideoftheballcausing aslightcurveinthepassdependingonthedistanceandrpmoftheball.

33 DeflectionAnalysis Thedeflectionofthemotoratthecantileverfixedtothe15series13?inchbaris veryslightgiventheweightofthemotor.itisthesameinthexandydirection,but itisonlyonehundredofaninch.thistellsusthemotorswillrotatethebarout slightly.thiscanbeseenintable4.1 Table ;ULSCantileverMiddle' Variables Measurements Units ' ' ' ' Profile'Length' 13' in' ' Maximum'Length'of'Profile' 242' in' D'='(L^3*W)/(48*E*I)' Profile'load' 30' lbs' Profile'weight/foot' 0.936' lbs' ' Deflection'x' ' ' Cross'Sectional'Area' 0.781' in^2' Moment'of'Inertia'X' ' in^4' ' Deflection'y' ' ' Moment'of'Inertia'Y' ' in^4' Yield'Strength'' 35000' lbs/in^2' ' ' Modulus'of'elasticity' ' lbs/in^2' ' ' ' ' Next,wecalculatedthedeflectionofthesamebarbutfixedatbothends.Themotor restinginthecenterasasingleload.thedeflectionisagainthesameinthexandy direction,butatseventensthousandsaninch.thebarwilldeflecttowardsthe groundattheplacementofthemotorbutonlyslightly.thiscanbeseenintable4.2 Table ;ULSFixed2Ends' Variables Measurements Units ' ' Profile'Length' 13' in' ' ' Maximum'Length'of'Profile' 242' in' ' D'='(L^3*W)/(48*E*I)' ' Profile'load' 30' lbs' Profile'weight/foot' 0.936' lbs' ' Deflection'x' ' ' Cross'Sectional'Area' 0.781' in^2' Moment'of'Inertia'X' ' in^4' ' Deflection'y' ' ' Moment'of'Inertia'Y' ' in^4' Yield'Strength'' 35000' lbs/in^2' ' ' Modulus'of'elasticity' ' lbs/in^2' ' ' ' '

34 Next,wecalculatedthedeflectionofthe15series15.776inchbarswiththeweight ateachendofthebarsbutfixedinthecenter.thebarswillhavesomedeflectionin thexandydirectionboththesame2hundredofaninch.theweightofthemotors atthefurthestpointonthebarswilldeflectslightlytowardstheground.thiscanbe seenintable4.3 Table ;ULSCantileverends' Variables Measurements Units ' ' Profile'Length' ' in' ' ' Maximum'Length'of'Profile' 242' in' ' D'='(L^3*W)/(3*E*I)' ' Profile'load' 30' lbs' ' Deflection' ' Profile'weight/foot' 0.936' lbs' x' ' Cross'Sectional'Area' 0.781' in^2' ' Deflection' ' Moment'of'Inertia'X' ' in^4' y' ' Moment'of'Inertia'Y' ' in^4' Yield'Strength'' 35000' lbs/in^2' ' ' Modulus'of'elasticity' ' lbs/in^2' ' ' ' '

35 AcquiredComponents Image5.1 Wehavepurchasedtherequiredfootageofbarsfrom80?20seeninImage5.1

36 Image5.2 Wehavetwo10indiameter2inthicksolidrubberwheelsthatneedtohavethe bearingsweldedtokeepthemsteadywiththemotorshaft.seeimage5.2.

37 Image5.3 ThisisourThreePhaseinductionmotortoturnthewheels(Image5.3)ithas 3500rpm.5hpwitha5/8indiametershaft.Weareworkingonthecircuitdiagrams forthewiringonallelectricalcomponents.wehopetohavethemotorandvariable frequencyacdrive(image5.4).motorschematicswillbeattachedatendofreport.

38 Image5.4 ThisisthevariablefrequencyACdriveitwillconverttheDCinputintoaACoutput forthemotorandalsoallowustovarythespeedofthemotorwithaspeedcontrol. SeeImage5.4.

39 Assembly Image6.1 The80?2015seriesbarshavebeencuttotheneededsizethe3.5inchbarsseenin image1.12havealsobeentapedwitha5/16tap,andthe15?30seriesbarhashad allholestapedwitha5/16tap.cutthree3?footbarswith45?degreeanglesonthe toptoattachtothebasetocreatethetripod.

40 Image6.2 ThemotorsseeninImage5.3havebeenwiredtoaspeedcontrolwhichis connectedtothevariablefrequencyacdrive(image5.4),whichisthenconnected toapowersourcethisassemblycanbeseeninimage6.2.

41 Image6.3 Thisisthefinishedassembly.Itisplacedonatripodsupportedby2X4woodboards topreventthebarsfrommovingatall.theangleofthelauncherischangedby crewingupanddownonthethreadedrodsonbothsidesofthefrontproviding supporttothemotors.thewheelsanglescanalsobechangedandthedistance betweenthewheelscanbeextendedandreduceddependingonthesizeoftheball. Theassemblydoeseverythingthatweneeditto.

42 GannttChart Plan Actual didn't,do 1/1/17 1/8/17 1/15/17 1/22/17 1/29/17 2/5/17 2/12/17 2/19/17 2/26/17 3/5/17 3/12/17 3/19/17 3/26/17 4/2/17 4/9/17 4/16/17 4/23/17 Form,group Find,project Write,proposal find,motor create,parts, list,from,80/20 complete, velocity, calculations Order,wheels order,80/20, parts Machine,Bars Assemble, electrical, components Weld,Wheels create,speed, marks,on, speed,control Assemble, Launcher Test,Launcher

43 TestingObservations Ourtestingstartedoutverywellthelauncherwasabletolaunchsmall20meter passeswithconstantprecisionwithaleftandrightspiraldependingonwhich wheelwasatanangle.itconsistentlyhookedtowhicheverside swheelwastilted. Werealizedthisisbecauseithitsthewheelsatdifferenttimessotheballactually shootsawayfromtheflatwheelbecauseitisactuallyalmostaninchaheadofthe tiltedwheel. Aswespedupthelaunchertoahigherrpmwerealizedthewheelsweren tperfectly circularcausingcentrifugalforceonthemotorsandmakesthembegintovibrate evenwiththespacersweputontopreventthat.asweacceleratedtherevolutions ofthemotorstheassemblywouldbegintovibrateatthehinge.thiscausedtheball tobegintoshakeandbounceontheguideplatemakingitnearlyimpossibletofeed theballstraightthroughthewheels.thismadeitsowecouldnotlaunchtheballat thehighspeedsthatwewantedandstillgetacleanspiral.theballwouldflyout veryhardbutinanerraticandunpredictablespiral. Wealsorealizedafterlaunchingasmallamountofballsthemotorsanglelocking systemwouldbecomeloosefromthevibrationandimpactandwouldstarttotryto settlebacktoparallelwiththebase.thiscausedustohavetoretightenourlocking systemeveryfewlaunches. AswewerestartingtoactuallyrecordourteststhevariablefrequencyACdrive seeninimage5.4failedduetoashortcircuiterrorindicatedbyaflashingredlight. WetriedtocorrecttheproblemandfriedthevariablefrequencyACdriveultimately endingourtesting. TestingAssessment TheRugbyBallLauncherworkedatlowspeedsverywellandlaunchedconsistent spirals.highspeedscausevibrationsinourassemblyandmakeiterratic. PossibleImprovements Wewouldconsiderthisagoodprototype.Withmoretimewecouldmakemany improvementstothisproject.wewouldliketousehydrauliccylinderstochange theanglebecausetheywillmovefasterandwontfalldownaftermultiplelaunches theywouldalsobeabletorotatefreelywheretherodsgetstuckatthehigher degrees.wewouldalsomakethehingeandslidingactionmorestabletoprevent somevibratingwhilealsomakingthebasebiggertoencompassthemotorsandhold themsteady.anotherchangewewouldmakeisapeggingsystemwiththemotors angletopreventslip.andalsomakesurethatthewheelslineupwhentheyare rotatedstilltopreventtheballfromcomingouttoonesideortheotherdepending onwhichwheelisatanangle.alsoifweusedlargerwheelsthenwewouldn'tneed asmanyrpmsfromthemotorssothemotorscouldbesmaller.another improvementwouldbehavingdcmotorssowewouldn tneedthevariable frequencyacdriveseeninimage5.4becausethecomponentsinthecircuitare opentotheelementsandwiththisbeingconsideredsportingequipmentithastobe abletowithstandabitofmistreatment.

44 Conclusion Wemademanyimprovementsthroughoutourconstructionandformationofour seniordesignprojectandusedmanyskillslearnedindynamicsclasswhilecreating atrajectorypathfortheballsflightpattern.wealsousedmachiningskillslearnedin basicmachiningtoconstructthefinalassembly.andweusedtheskillslearnedin strengthsandmaterialstocalculateourdeflectionofthematerialsunderthestress ofthemotors.thisprojectusedmanyskillslearnedthroughoutbothofour educationalcareersatipfw. References (1)Peters,Martin.Computationalfluiddynamicsforsportsimulation.Springer, (2)Beer,JohnstonandFlori.MechanicsforEngineers,Dynamics.FifthAddition, December3,2007