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DevelopmentInitiative:Procedure:

HowtoBuildaYouthPVCBow:

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TABLEOFCONTENTS1. Introduction. 32. RequiredEquipment. 3

a. Heatsources. 3b. Cutting. 4c. GrindingandShaping. 4d. Recurveforming. 4

3. Estimatedcostimplicationsforequipment&materialrequirements. 54. TheBasicConstructionofabow. 65. Typesofbowdesigns. 66. Material. 77. SafetyandaspectsofaPVCBow. 88. MaterialSpecification. 89. Stringlengthinformation. 1010. RecommendedPVCbowdrawlengths. 1111. DrawWeightIndication. 1212. Buildingaflatteningjig. 1213. Stepbystepinformationguidetobuilda22LB25inchdrawlengthPVC

bow 14a. Measuringoutthedimensionsofthebow. 14b. HeatingthePVCpipe. 15c. Taperingthelimbs. 16d. Bendingtherecurves. 18e. Formingthehandle/riserofthebow. 20f. Layoutofbownocks. 22g. ManufacturingofBowstring. 23h. Howtosafelystringthebow. 24i. Thearrowshelf. 25j. Bowstringandarrowknockingpoint. 27k. Easypointofreferencesight. 27

14. Beautifyingyourproject. 2815. Additionaleasytomaketools. 28

a. Servingbobbin. 28b. Simplefledgingjig. 29

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1. INTRODUCTION

Toensurethesustainabilityofarcherythesportmustbedevelopandmadeaccessibletothemasses.This initiative istomanufacturingPVCbowswhich isataimtosupporttheWorldArcheryDevelopment Strategy and tomake the sport accessible to the previously disadvantagedcommunities.A PVC bow is basic low cost tool to introduce archery that will be fun and shoot fairlyaccuratelyandcouldbemadeandplacedinachildshandforafewdollars(lessthanthepriceofahamburger).ThisdocumentisintendedasinformationalguideandisadetaileddescriptionoftheprocesstomakesimplebowfromPVCpipe.CognizancemustbetakenthatthesePVCbows is inherentlydangerousweaponsandcaremustbetakenduringthemanufacturingandtheintheoperationthereof.Nobowisindestructibleandcancausegraviesbodilyharm(hurt,maimandkill).

2. REQUIREDEQUIPMENT

a. HeatSources

The following heat source can be utilized in the process that is generating 148C(300degreesF):

Heatgunsisthemostcontrollable(ratedupto600C)andisrecommendedforthisprocess.

Gasandelectricalcockingtopsisregardedsecondbestalternative. Openfire,gastorchesandgrillscanalsobeusedasextracaremustbetaken

toavoidthesettingthePVCpipealight.

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b. Cutting

PVCisamaterialthatcanbeeasilyengineeredandformedthereforeanywoodworkapplicationtoolscanbesafelyutilizedintheprocess.

c. GrindingandShaping.

FortheformingandshapingofthePVCmetalfilesandsandpapercanbeutilized

d. Recurveforming.

Tobendtherecurveofthebowissimpleprocessandcanbedonewiththefollowingeasytofindproductswiththecorrectdiameterthatcanbeutilizedastherecurvingjig:

Anycylinder; CookingPots; Cans; Trashcans Barrels.

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Fortherequiredrecurveaformwithadiameterequaltothelengthofthetipbeingrecurvedwillbeideal.

3. ESTIMATEDCOSTIMPLICATIONSFOREQUIPMENT&MATERIALREQUIREMENTS:Tobeabletobuildeight(8)PVC1822LBS1500mmyouthPVCbowstheestimatedcostimplicationcanbecalculatedasfollows:

EstimatedCostImplicationtofabricateEight(8complete)PVC1822LBS1500mmBows

ItemNo ItemDescription Unit

CostPerUnit Quantities

TotalIncludingVat

1 WoodWorkBench Each $60.00 1 $60.002 MetalHacksaw Each $9.50 1 $9.50

3 RoundMetalfile(fine)8mmx150mm Each $5.50 1 $5.50

4 HalfRoundMetalfile(fine)25mmx150mm Each $5.50 1 $5.50

52000WattElectricalHeatGunwithTempcontrol Each $65.00 1 $65.00

6 300mmWoodWorkClamps Each $5.50 2 $11.007 3meterMeasuringTape Each $5.50 1 $5.50

8 CurveTemplatemould200mm Each $12.00 1 $12.009 ServingBobbinholder Each $25.00 1 $25.00

10150mmx50mmx3000mmPinewoodenmould Meters $30.00 1 $30.00

11 Scissors Each $5.00 1 $5.00

12 HeatResistantGloves(thinpigskin) Pairs $4.50 2 $9.0013 StanleyBoxKnife Each $6.50 1 $6.5014 Dorehingewithsix(6)woodenscrews Each $2.20 1 $2.20

15 25mmxClass16PVCpipe6meterLengths $0.50 2 $1.00

16 Nylonropeforstrings Meters $0.25 15 $3.75

17 50mmHeatShrinkableTube Meters $1.40 1 $1.4018 Cableties5mmx150mm Each $0.12 8 $0.96

18ServingString100metersx0.052diamondback Unit $27.50 1 $27.50

Subtotal $286.31

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Thereforethecostcanbedefinedandanalysedasfollows.

InitialcostImplicationCostofMaterial $34.61 CostperbowforMaterial $4.33CostofEquipment $251.70

CostperbowforEquipment(onceoffcost) $31.46

Theaveragecostimplicatingperbowforthefirsteight(8)bowsforEquipment&Materials $35.79

4. THEBASICCONSTRUCTIONOFABOW:

ThebasicconstructionofaPVCbowconformstothefollowing:

5. TYPESOFBOWDESIGNS:

Thetypeofbowsdesignsandformsthatareknowncanbeindicatedasfollows:

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ThewonderfulpartPVCmaterialandtheprocessisthatifapersonapplieshismindanyoftheabovebowscouldbemanufacturewiththisbasicprocessandrelativeease.

6. MATERIALPVCpipeismadeofPolyvinylChloride,athermoplasticofVinylChloride.Itisstablepolymerthatiswhiteincolourandbrittleinitspureform.Thediameterthatisreveredtointhispresentationisreveringtotheoutsidediameterofthepipe(NotemustbetakenthatthespecificationofPVCpipingcouldvaryfromcountrytocountry).TherecommendedPVCpipetobeutilizediswithawallthicknessofthree(3)mmorthicker.ManyplacesinternationallyonlymanufacturingPVCpipewithwallthicknessoftwo(2)mm.Bowscanbeconstructed from thismaterials this thinnerPVCMaterialsas itwillbeweakandprone tobreakage andwillberequiredthatthedimensionsandthedesignofthebowmustbealteredaccordingly.KindlytakenoteofthefollowinghealthrisksapplyworkingwithPVC:

WhenPVCisheatedorsetonfireitcanalsoreleasehydrogenchloride,whichcanbefatalifinhaledinlargevolumes.HeatingofPVCpipewillnotreleasemuchofthegasses,whilesettingonfireitwill.AvoidburningPVCatallcosts(alwaysworkinawellventilatedarea):

WhenPVCheatedtothepointwhereitisflexibleitisalsohotenoughtocausesevereburns(useheatresistantglovesandclothing).

WhenPVCsandedthedustcanbeharmfulwheninhaled(AlwaysuseadustmaskwhensandingPVC)

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7. SAFETYANDASPECTSOFAPVCBOWPVCbowsareweaponsandshouldbetreatedwithrespect.Anybowcanfail,andwhilePVCbowsaremoreresilientthanmost,neverabuseyourbow.Anyabuseortheneglectingthisbowcouldcauseittofail,whichmayinjurethearcherandanybystander.Alwaysmakesurebystandersareasafedistanceawayandbehindyouwhenshootinganybow.ThefollowingbasicsafetyaspectsofPVCselfbowmustbehighlighted:

Neverfireabowwithoutanarrowonthestring. Neverpointabowatanotherperson,animalorobjectofvalue. Alwaysunstringyourbow. Keepthebowinacool,darkplacewhennotinuse. Ifyoutreatyourbowwithrespectandbuildit,shootitandmaintainitwithcare,itwill

rewardyouwithmanyyearsofservice. Treatasafinebowworthyofrespectanditwillreturnthefavour. Treatitlikeacheaptoytobebeatenandabused;thenitwillfailyoutoomiserably. Thesamecanbesaidforanyothertypeofbowaswell.

Asallwoodselfbows;PVClosesflexibilitywhenitgetscold.Asthetemperaturedrops,theplasticwillbecomelessforgiving.Itcantakeagreatdealofpracticebeforeastableshootingcoldweatherbowcanbemadeasittakesafeelofthematerialtogetittoperform.Ifshootingintemperaturesbelowfreezing.Trytokeepthebowaswarmaspossible.Andbeforeshooting,takeacouplehalfdrawstohelpgetthebowusedtobendingagain.Asanadditionalnote,PVCgainsspeedandpowerasthetemperaturegoesdown.PVCcanbebrokendown,likeallpolymers,byUVlight.Overtime,exposuretoUVlightcancausetheplastictobecomebrittleanditcanbreakifstrungordrawn.OnewayofknowingifapipeisUVdamagedisitwillappearyellowcomparetonewPVCpipe.RegardlessofthefinishyouchooseorifyouwanttoshowofftherawPVCpipe,UVblockingisimportant.ThereareafewqualityplasticspraypaintsandclearthathaveUVblockers.Ialwaysapplythisunderawrappedorgluedonfinishandoveranypaintedordyedfinish.8. MATERIALSPECIFICATION

ThefollowingtableisonlyanindicationandapointreferencetogiveanindicationwhatcanbeexpectedfromPVCandwhatthelimitationistothematerial.Notemustbe taken that theundermentioned information isderived fromPVCwithwallthicknessof3mmandmore.IfanyPVCisusewithanyotherdimensionsthanindicatedbelowthenchanges; thereforealteration to thedesignand theagronomicsof thebowmustbemade.

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TheareasonthetablesthatareindicatedinredareareaswherethePVCwillreachhighstresslevels at that particular design application. It is therefore recommended that thesedimensions application must be avoided as the PVC bows material will be at levels ofintroducedstressthatitwillbepronetobreakageandcollapse.

PVCPipewith20mmexternaldiameterandWallthicknessof3mm

LengthofBowininches LengthofBowinmm 24 25 26 27 28

50 1277 510 10 1015 15 152049 1251.46 10 1015 15 1520 2048 1225.92 1015 15 1520 20 202547 1200.38 15 1520 20 2025 46 1174.84 1520 20 2025 45 1149.3 20 2025 44 1123.76 2025

PVCPipewith25mmexternaldiameterandWallthicknessof3.3mm

LengthofBowininches LengthofBowinmm 26 27 28 29 30

50 1277 2530 30 3035 35 354049 1251.46 30 3035 35 3540 4048 1225.92 3035 35 3540 40 404547 1200.38 35 3540 40 4045 46 1174.84 3540 40 4045 45 1149.3 40 4045 44 1123.76 4045

PVCPipewith32mmexternaldiameterandWallthicknessof3.5mm

LengthofBowininches

LengthofinBowinmm 26 27 28 29 30

60 1532.4 3540 40 4045 45 455059 1506.86 40 4045 45 4550 5058 1481.32 4045 45 4550 50 505557 1455.78 45 4550 50 5055 56 1430.24 4550 50 5055 55 1404.7 50 5055 54 1379.16 55

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Notemustbetakenthatthemostaccuratebowsarenotalwaysthebowswiththehighestpoundageorthatshootsthefastest.Abowmustbecomfortableandfunforthearchertoshootthenaccuracywillbeeasiertoachieve.

9. STRINGLENGTHINFORMATION:

Thetablegivesanindicationoftherequiredstringlength(frombowstringloopendtoloopend)foraparticularbowlengthapplication:

RecommendedStringLengths

Bowlengthininches BowlengthinmmMinimumStringLengthininches

MaximumStringLengthininches

60 1524.6 56 5759 1499.19 55 5658 1473.78 54 5557 1448.37 53 5456 1422.96 52 5355 1397.55 51 5254 1372.14 50 5153 1346.73 49 5052 1321.32 48 4951 1295.91 47 4850 1270.5 46 4749 1245.09 45 4648 1219.68 44 4547 1194.27 43 4446 1168.86 42 4345 1143.45 41 4244 1118.04 40 41

NotemustbetakenthattheshorterthePVCbowismadeinlengththehigherthepoundagewillbeperinchofdrawlength

10. RECOMMENDEDPVCBOWDRAWLENGTHS

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ThefollowingsafedrawlengthsarerecommendedforPVCBowsastothelengthofthePVCfrompinnocktopinnock:

RecommendedBowLengthforDrawlength

Bowlengthininches Bowlengthinmm MaximumDrawLength68 1727.88 29.56521767 1702.47 29.13043566 1677.06 28.69565265 1651.65 28.2608764 1626.24 27.82608763 1600.83 27.39130462 1575.42 26.95652261 1550.01 26.52173960 1524.6 26.08695759 1499.19 25.65217458 1473.78 25.21739157 1448.37 24.78260956 1422.96 24.34782655 1397.55 23.91304354 1372.14 23.47826153 1346.73 23.04347852 1321.32 22.60869651 1295.91 22.17391350 1270.5 21.7391349 1245.09 21.30434848 1219.68 20.86956547 1194.27 20.43478346 1168.86 2045 1143.45 19.56521744 1118.04 19.130435

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11. DRAWWEIGHTINDICATIONThe under mention table give a ruff indication of what the bow draw weight will becomfortableforwhatsizesofarchers:

Weightarcherinkg ProposedDrawWeightinLB2535 5103550 10155065 15256575 20357590 305090+ 4065

12. BUILDINGAFLATTENINGJIG:

TheflatteningjigisusedtotaperthelimbsofthebowandthereforeitisanintegralpartoftheconstructionofthePVCbow.Makeuseof50mmx100mmx2438mmlengthwoodenboard.Cutoff915.5mmlength,leavingtheotherlengthat1524mmlong.Thelongerlengthwillbethebasesandtheshorterboardwillusedastheflatteningboard

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Fromtheedgeofthelongboardmeasure609mmand762mmwhichwillbeusedtolinethePVCpipeuptothejigwhenflattening.

Placethelongandshortboardontopofeachotherandinstallthehingesonthetopendoftheflatteningjigwithwoodenscrews.

Installthehigh20mmspaceratthe609mmlineasperillustration.

Thecompletedflatteningjig:

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13. STEPBYSTEPINFORMATIONGUIDETOBUILDA22LB25INCHDRAWLENGTHPVCBOW

a. Measuringoutthedimensionsofthebow.

Startwith25mmouterdiameterPVCpipewithawallthicknessof3mmwhichis1500mminlength.

Markthecentreofthepipeat750mm.

Mark75mmonbothsidesofthecentrelinewhichwillbethehandleofthebowandsettheboundarieswheretaperingofthelimbswilltakeplacefrom.

25mmPVCPipe

HandleorriserofbowRecurvepartofthebow

75mm

150mm150mm 150mm

1500mm

750mm

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Mark150mmfromeachendofthepipewhichsethowfartherecurveswillstartfrom

b. HeatingthePVCpipe.Heatsourcesasindicatedinparagraph2(a);

Stove Fire GasBurner HeatGun

Forthebowmakingprocess,beginheatingtheonehalfofthepipefromthecentremarktothetipofthepipetopreparefortheflatteningprocess.Foranystationaryheatsourcelikeastovetoporanopenflameistopassthepipeslowlyovertheheatsource.

Heating

25mmPVCPipe

HandleorriserofbowRecurvepartoftheBow 75mm

150mm150mm 150mm

1500mm

750mm

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Always keep the pipemoving so to avoid the burning of the pipe (always avoidexposuretothefumes);asevenslightburnscouldweakenthebowandcausethebowtobreak.

Themethodthatworksextremelywellisamanoeuvrablehandheldheatsourcelikeaheatgun.Theheatgunispassedoverthepipeandthepipeisturnedturnaftereachpass.Theeffectivenessoftheprocesscouldbe increased ifdoneoverapoorconductorofheatlaswoodservice.

When the PVCpipe is soft as illustrated in the photo it is ready for the taperingprocess.CognizancemustbetakenthatatthispointthePVCpipe isextremelyhotandcancausesevereburnsandmustbehandledwithcareandheatresistantgloves.

c. Taperingthelimbs

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Whenthesectionofthepipe issoftandcanbeflattenedwithsoftpressureofthefinger,itisreadytobeplacedinthejig.

Linetheouterhandlemarkthat is75mmfromthecentre lineofthebowwiththerelevantlineonthejig.MakesurethePVCpipeisstraightandisproperlycentredinthemiddleofthejig.Theflatteningboardwillstartfromthemiddleofthehandle inordertoobtainaneventaper.

Placetheflatteningboardontothepipe. IfthePVCpipe issoftenough itwilltakeapproximately7.5kgtoflattenthepipetotherequiredtaper.Itwillbeadvisabletoclampthejigasillustratedinthephototoensureauniformtaperisachieved.

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After the PVC pipe has been allowed to cool down the flattening boardmay beremoved.Thereshouldbeaneventaperfromthetipofthebowtothemiddle.

Thesameprocessmustbefollowedfortheotherhalfsectionofthebow.

d. Bendingtherecurves.Tobale tobend the recurveson theendsof thebow limb the following toolsberequiredasindicatedinparagraph2(a)&(d):

Aheatsource. A 200mm to 250m diameter round object as (cooking bot, round tin or

wheelbarrowwheel). Heatresistantgloves

HeatthetipoftheflattenedPVCpipeupanduntilthe150mmmark.

Applyheattothetipuntilitstartstodroopandpuffupslightly.Stopheatingthetipand let theheatpenetrate thematerial inanattempt toprevent the tip losing itsflattenedcrosssection.

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Bend the tipof thebowaround the formbyholding the tipagainst the formandpullingthebowaroundform;untilthe150mmmarkreachtheformscurvature.AtthisstagethePVCwillbeveryhotthereforeitwillberequiredthatheatresistantglovesmustbeusedinthisprocess.Ifthetipisnotbendingsmoothlyitcanbegentlyheatedwhilethetipisontheform.Noticehowtheoutsidecurveofthetip isslightlyconcaveandslope inwards.Thisconcaveareawillhelptokeepthestringfromslippingoffthebowwhenthebowisstrungandshot.Repeatthesameprocessforotherlimb.

Bothofthecurvesshouldbeinlinewitheachother,ifnotgentlyheatthebaseoftherecurveandbenditfromsidetosideuntilthetipslineupacrossthebow.

Thephotoillustratesthecompletedcurvebow.

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e. Formingthehandle/riserofthebow.

Placethebowontheflattening jig,heattheentirehandlesectionplus25mmovereachsideevenlyuntilthepipereturnstoitsoriginalform.(Oncethepipereachesthecorrecttemperatureitwillreverttoitsoriginalform).AlwayskeepstheheatsourcemovingoverthisareasotopreventanyburningofthePVCwhichwillcauseaweakpointwherethebowmightbreak.

Whenthehandleissoftandflexible;byusingheatresistantglovesthehandleareacanbeformedtogiveitamorecomfortablegripwhilealsostrengtheningthehandleandreducingtheabilitytoflex.

Whenthepipecoolsdownandstartstosetchecktomakesureitshapesupproperly.The150mmhandlesectionsshouldbe fairlyuniformwithagentle taperofabout25mmonbothsidesofthehandleandshouldbe12mmwide.

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Makesurethattherearenocreases inthehandleareaandthatthere isasmoothtransitionfromthehandletothelimbs.Anycreasesinthehandlewillresultinweakpointsthatwillcausethebowtobreak.

Oncethehandlestartstosetandtheplasticisstillslightlysoft.Sightdownthelengthofthebowtoensurethecorrect limbalignment.Inthe instancewherethehandlewasnotstraightorifthelimbsweretwistedbeforeyoucancorrectitnowbyflexingthehandlegentlyuntilthelimbscorrectlylineup.

ThephotoillustratedthecompletedPVCbow

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f. Layoutofbownocks

Pinstylenocksareasimplemethodtoallowacommercialstringlooptofitsafelyoverthewidetipofthisbow.Thedimensionofthisnockpinsis20mmlongand12mmwide.Thepinnockmustbeinthecentreofthelimborotherwisetherecurvewillnotlineupproperlywhenthebowisstrungandthelimbsofthebowmaytwist.Cutthenocksoutwithahacksawandfinishoffwithametalfile.Sandorfilethepinknockstringcontactedgestohelpkeepthebowstringfromwearingoffovertime.

Onthebellysideofthebowfiletwostringgroovesinthelimbofthebowasillustratedsotoensurethatthebowstringproperlytracksovertherecurveofthebowlimbs.

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Toincreasetheformofthebowcutandgrindtheedgesdowntoapointasillustratedinthephoto.Cognisancemustbetakenthatthetipwillloseitsstrengthiftheedgesofthelimbarecutthroughtoofar.Followthesameprocedureandfinishthepinknockontheotherlimbwhereafterthebowwillbereadytobestrungforthefirsttime.

g. ManufacturingofBowstring.

Takea2.5mmx1600mmnylonstringandburnbothofthetipsofthestringwithacigarettelightertopreventitfromunravelling.

Maketwoknotsasillustratedonbothsidesofthestringatapproximatelydistanceof1400mm(55inches)apart.Cognizancemustbetakenthatthebowstringlengthcanbealteredwhenstrungbytwistingthestringupordown.

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h. Howtosafelystringthebow

Therearevariouswaystostringabow.Becauseofhowshortandaggressiverecurvedthesebowsare, the step throughmethod isoneof the safestand recommendedmethods.Theseinstructionsareforrighthanders,soifyouarelefthanded,reversetheinstructions.Tocommenceloopthelowerstringloopontothebottomnock.Bracethebacksideofthelowerbowrecurveagainstyourleftleg,holdingtheinsidecurveoftheotherrecurveinyourrighthandandthestringloopinyourleft.Stepoverthebowwithyourright legandbracethebackofyourkneeagainstthehandleofthebow.Keepyourkneeagainstthebowshandlewhilepushingthebow limbforwardwithyourrighthand.Bringthestringloopuptothenock,preparingtoslipitontothebow.To increase leverage rotate yourupperbody slightly, flexing thebow inward anddownward.Slipthestringontothenockandmakesurethestringistracking,alongbothrecurvesevenlybeforereleasingpressure.

Whenthebowisstrungupitwillbeatwhatistermedatbrace.Whichisthedistancebetweenthestringandbowhandle,thebraceheightwillbesomewherebetween150mm(6inch)and200mm(8inch)(asyoucontinueshootingyourbow,youwillfindthecorrectbraceheightthatwillsuitsyouthebest).

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Sightdown thebow atbrace toensure that the string tracks straightdownbothrecurvesandthroughthecentreofthebow.Itisimperativethatbothrecurvesshouldproperlylineupattherequiredbraceheight.

Atbrace,oneofthelimbswillusuallybebendingmorethantheother.Thislimbwillbethetoplimb,asthelowerlimbneedstobeslightlystiff.

i. Thearrowshelf

Startwitha75mmlengthofPVCpipethesamediameterandmaterialasyourbow.Markalinefromwaydownoneendtoabout3mmontheoppositeside.Youshouldendupwithawedgeshape.

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Cutthewedgefreeandfilethetopedgedownsothatitisatarightanglewiththeinside of the rest and then round the bottom off from 3mm to insure a smoothtransition.Place the rest onto the bow. If the handle is not going to bewrapped a cleanertransitionisneeded,wrapapieceofsandpaperaroundthehandle,withtheabrasivesidefacingoutwards.Placetherestontothehandleandrubitacrossthehandleuntiltheinsideoftherestmatchesconformstothecontoursofthehandle.

Gluetherestinplacewithflexibleandwaterproofglue.Makesuretherestisontheleftsideofthebowforrighthandedarchersandontherightforlefthandedarchers.Thetopoftherestwherethearrowwillmakecontactwiththerestshouldbe25mmto32mmabovethecentremarkofthehandle.

CoverthehandleandtheshelvewithPVCtapeandheatshrinkabletubeasillustrated.

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j. Bowstringandarrownockingpoint.

Servethebowstringfrom75mmunderandoverthecentrelineofthehandlewith0.5mmservingstring.

Makenockingpointat3mmhighoncentreshotofthestring.

k. Easypointofreferencesight.

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Attachedcabletieasillustratedonphotothatcanbeusedandfinetuneasasimplereferencesight.

14. BEAUTIFYINGYOURPROJECT.

IfPVCpipeisproperlysandeddownandaproperbasecodeareappliedanycolouranddesignscanbespraypaintedontothebow.ToensurethedurabilityofthespraypaintandtoprotectPVCagainstultravioletsunlightitisrecommendedthatasuitableclearcoatbeapplied.

15. ADDITIONALEASYTOMAKETOOLSa. Servingbobbin.

Cutalengthof25mminch,schedulePVCpipe132mmlong.Makeamark37mmfrombothends.Thiswillresulta58mminnersectionlikethepictureabove.HeatandcompletelyflattenthePVCpipe.Measure37mminfrombothends,centredalongthesheetofPVC.Alsomarktheverycentreoftheflattenedsheet.Drilla8mmholeoneachendonthemarks.Drilla3mmholeinthecentreofthePVCsheet.Withametalfileorsandpaper,removetheinsideedgesofthedrilledholestoremoveanysharpedges.

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HeatthePVCpipeagainandbenditata90degreeangleontheinsideofeach37mmmark.(Thetopendofa50mmx100mmwoodenboardworkswellforthis.Theedgesoftheservingjigmustberounded.Withafilecuttwogroovesacrosstheserving jig.The linesshould intersectatthe3mmholeinthemiddleoftheservingjig.Thesegrooveswillallowtheservingtotrackthestringwhiletheservingbobbinisused.A62mmlong,8mm(M8)hexagonboltandnutwillbeusedtocompletetheservingjigandholdtheservingspoolinplace.Placetheservingspoolbetweenthetwoarmsoftheserverandpasstheboltthrough.Thentightenthenutuntileverythingistight.Threadthelooseendofservingstringthroughthecentrehole.Theservingjigisnowreadytobeused.

b. Simplefledgingjig.

Tobuild a feather clamp, startwith a 158mm thinwallpipe, commonlyused forelectricalapplications.Forfeatherslongerthan132mmlong,startwithalongerpipe,leavinganextra20mmoveryourfeather length.(Forexamplefor150mmfeathersuseda170mmPVCpipe).Heatthepipeandcompletelyflattenit.MakesuretheboardsyouusetoflattenthePVCpipearetrueortheflattenedpipemayendupwithsomeunrequiredcurvatures.FileoneedgeoftheflattedPVCpipeuntilaveryfinelineappearsthatwillindicatethatthesidewallhasbeencompletelycutthrough.Heat thepipegentlyuntil there isaslightseparationbetween the twosides.Thisshouldnotbethickerthanasheetofpaper.

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Forthemainbodyoftheclamp,startwitha50mmx100mmwoodenblockthesamelengthasyourfeatherclamp,or150mm ifyouarefollowingthisspecification.Youwillrequirefurther4woodenclothingwashingpins.Gluethepinstothe50mmx100mmwoodenblock,placingoneateachcorner,lineduptothebottomandoutsideedgeoftheblock.Thiswillbethemainbodyoftheblock.Toestablishtheproperanglesfor2,3and4fletchedarrows,byusingahexogennut.Useaboltthatwillgoovertheendofthearrowyouwillbefletching.Youcaneitherplaceitonanarroworonadowelofthesamediameterandlength.Opentwoofthewashingpinsononesideoftheclampandplacethedowelintothejaws.Thewashingpinswillholdthedowelinplace.Usingthehexnutasaguide,drawa linefromthecentreofthedowelouttoeachpointofthehexnut.These lineswillserveasareferencetomeasuretheanglesoffletches.Thisjigisconvenientastwoarrowscanbefletchedatonetime.

THEEND