Zipp J.A.E. Racing JAE21G2 Instruction Manual

ZIPPMANUFACTURING
ently Porter after smashing several IMPBA records with his JAE 21
JAE21G2
AZippkits R/CBoat
Building Instructions
2009 Zipp Manufacturing-Frankfort,New York 13340
www.zippkits.com
Toll Free(866)922-ZIPP

2
The JAE21G2wasdesignedanddeveloped asaresultofajoint venturebetweenIMPBA Hall
ofFamememberRodGeraghty,DavidHall, RonZakerJr.&MartinTruexJr.
The maindifferencebetweenthishull andall theothersistheuseof sharpedgesonthe bottom
ofthesponsonsandtub,asopposedtocurved surfaces.Thishelpsbreakanysurfacetension
ofthewaterandmakesforafasterboat.
Thisdesignapproachhasbeenbuilt, developedand testedagreatdeal.
The JAE21holdsmanyspeedrecords, andiscurrentlythefastestboat inthe worldon the¼
mileovalcourse(16.0seconds/ 2laps).
Theserecordswerebroken byanexpertboatracernamedKentlyPorter.
Hispictureisonthecoverofthismanual.KP hasset some35recordsinthepast, andcurrently
holds19. Heknowswhat heisdoing!
WeaskedKentlytowriteafewsuggestionsforbuilding andrunning thiskit…
“Thething thatI wanttoimpress themostistobuildthekitasthemanual shows!
Itisagood design, handlesexcellent(evenat84 mph)and hasno badhabits. Don’ttry
tosecond guess thedesigners!Thishullistheabsolutepinnacleofmodel hydrodesign.
Thereason thatthereareno adjustmentson thishull isthatitdoesn’tneedany.Thathas
all beendoneforyou.
Ifyou takeyourtimeand buildastraight,truehull, you will havemostofwhatittakesto
win.
Therestisup toyou.Makesureyou haveareliableengine,and burnlotsoffuel!
Testdifferentprops.I liketheABC H-7.
Getcomfortabledriving thishull. Itissofast(especiallyintheturns), itwillscareyou the
firstfew timeson thecourse.
You will learnthatyou candrivethishullinanylaneyou want,and rough“race”wateris
welcome!
Finally, make surethatyou pay attention tothedetails.Everyonealwaysaskswhatit
takestomakeaboatreallyfast. It’snotonething, it’shundredsoftinydetails,allworked
outand optimized.Tryanything, ifitgetsbetter, keepgoing.Ifnot, trysomething else.”
Well saidKP!
We areremindedofwhat someoneonceasked:
What canIbuytohelpmewinmoreraces?
Acaseoffuel…

3
Inadditiontoamarineengine,youcanuseanyaircooled3.3-3.5carortruggyengine, with
excellent results.
The kitisnothardtoassemble,asall of the hardstuff hasbeen doneforyou.
Thatisnoexcusetodo apoorjobwithassembly. The betteryoubuildthisboat,thebetteritwill
run.Often thedifferencebetweenan excellent buildingjobandapooroneisasimplesanding
block.
Anoteaboutoverhangs:
Thisboat isdesignedtoshearwaterandpreventanycapillaryactionof water. Todothisthe
tub, skiandsponsonshaverearoverhangs. Theseshearthewateroff and mustbeleftinplace
andnot rounded inanyway.
The boatalsohassideoverhangsonthe sponsons. Thesehelptheboat getuponplane
quicker. If youareusingapowerfulengine,youcansandtheseoff, but leaveall cornerssharp.
Takethetimetoreadthisentiremanual, sothat you arefamiliarwithall thebuildingsstepsand
theirproperorder. Takeyourtime; makesureyouunderstandeverythingbeforeyoudoitand
you will be rewardedwithanimpressiverunninghull…
Thiskit isnot atoy. Although R/Cboatingisafunandrewardinghobby,it canbedangerous
ifnot donewithcommonsenseand safetyinmind. Justaboutanyoneshouldbeableto
buildthiskit, butit shouldnot beoperated bychildren without closeadult supervision.
Themanufacturerassumesno liabilityfordamagesorotherloss intheuse ofthisproduct,as
wehavenocontrol overtheconstructionorend useofthisproduct.

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Toolsandsuppliesneededtobuild
§Sandingblockswith80 and150 gritpaper
§Drill with bits
§Square
§Flatfile
§FLATWorkbench
§1/2ounce MediumCAglueandaccelerator
§Goodquality5and30 minuteepoxy
§Epoxyfinishingresin
§Springclamps,paperclamps,cclamps,etc.
§RazorbladeorX-Actoknife
§Maskingtape
§Waxedpaper
§Woodfiller
§Primer
§Paint

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Additionalitemsneededtocomplete
§3.3to3.5air or watercooledNitroengine
§.187Colletandflywheelforengine
§Startingbelt
§.18718inchcablew/welded3/16stub shaft(Zipp3486)
§Headertofitengine
§Tunedpipe
§2channelsurfaceradiowith 2servos
§Throttleandrudder pushrods (2-56Size)with Clevises(Zipp)
§2pushrodseals(Zipp3404)
§8ounceFuelTank(SullivanSS-8)(Zipp 3473)
§.187strut(ZippZ21)
§.187drivedog(Zipp3485)
§1450Modprop(Zipp4008)
§Propnuts(Zipp3489)
§EngineMounts(Solinger 21recommended,Zipp 3488)
§Cablegrease
§Rudder(Zipp3483)
§12-18inchlength of1/4brass tubing

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Let’sidentifythepartssothat wecaneasilyfindthemwhen needed. Markthepartsthatare
insideotherparts.
/6 plywood parts:
/8 plywood parts

7
Miscellaneous parts

8
Foam parts
Doaninventoryofall the parts, tobe surethateverythingisthere. Ifanything ismissing
ordamaged, contactusassoonaspossible, sothat wecangetreplacementstoyou quickly.
Tub Jig
Werecommendthatyoumakeajigforthetub.
Thiscanbe assimpleastwostraight piecesof ½to¾inchthick wood.
It can be aselaborateas1/8by2inchaluminumanglewithadjustment slotsfordifferenttub
widths.
Eitherway,youneed somethingtoclampthetub sidesto.
Everycriticalcomponenton thishull dependsonastraight,squaretub.
Dowhateverittakestogetitdone correctly.
Left sponson has 2 holes
Right sponson has 6 holes
Foam nose block

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Tub sides marked before assembly.
Bulkheads glued in place (this is the 21FE).
Tub side marked for transom alignment.
Tub
Let’sbuildthe tub.
First, markthe insidesofthetubright
andleft. Thesponsonboomholeis
towardthe bottomof thetubside.
Makethesemarks inthefrontportionof
thesides, whereit won’tbeseen later.
Check thefitof thebulkheadsinthe
right tubside.
Useafiletotouchupthe insidecorners
on thebulkheads,tosquareoff thetiny
radiusleftbythecuttingbit.
Onceyouarehappywiththefitof the
bulkheadsinthetubside,gluethemin
withCA.Usethesquareprovidedinthe
kit toensureeachbulkheadisperfectly
square.
Makeamarkonbothtub sides(inside)
withaline that isanextensionof the
transomcutout.
Usethislinetoalignthetransom
correctlyon thetubside.

0
Using the square provided in the kit.
Tub sides glued to bulkheads.
Tub jig.
Assemblethetubsidesonaflatsurface
Check thefitof thebulkheadsintheleft
tubside. Ifall iswell,gluethebulkheads
inplaceoneatatime, usingthesquare
fromthekit.
Flipthetuboverand lightlysand the
bottom.
Nowisthe timetouseyourtubjig. If you
don’t havethe abilitytomakean
aluminumjig, seebelow.
Useapairofthickwoodensticks.Leave
theseclampedtothesideswhilegluing
theaft bottominplace.

Tub sub nose being glued in place. Tub extends just past jig.
Waxed paper prevents one piece tub/jig assembly. 21FE shown.
TD being glued in place.
Putalayerofwaxedpaperoverthejig.
Putthetubaft bottominthejigand set
thetubontoit.
Fullyclampthejigsidestothe jig.
Glue thetubsubnosetothe veryfront
ofthetub. Thissupportsthenosefor
sheeting,andprovidesasolidbasefor
thetubnoseblock.
Using epoxy,gluethetubaftbottomin
place. Makesurethat thebottom
extendstothe front bulkhead. It should
coverthefull 1/8inchbulkhead.Later
on,wewill sandthistomatchtheangle
ofthetubsides.Leaveasmall overhang
at therearofthetub. Donot sandthis
off.
The aftbottomsheet isprecuttothe
correct length. Makethefrontofthis
flushwiththefrontofthefirstbulkhead,
andthe rearoverhang will becorrect.
Glue inthetransomdoublerwithepoxy.
Makesurethat it fitsflatagainst the
transom,andthatit sitsfirmlyonthetub
bottom.
Clampuntil cured.

2
Tub sleeves sanded, ready to glue in.
Tub sleeves, doublers and booms in place. 21FE shown.
Fwd. sleeve and doubler detail. 21FE shown.
When thetubbottomhascured, lets
moveontoboomtubealignment.
Thisisprobablythemost criticalstepin
theassembly,sotakeall thetime
needed toget thisright.
Removethetubfromthejig.
Grab thetwobrass boomtubesleeves,
anduse80 gritpapertoroughthelast ¼
inchorsoof eachend.
Putthereartubedoublersinplaceand
slipaboomtubesleeveandcarbon
boomtubethroughthetuband doublers.
Measurethecarbontubeoneachside
ofthetub,andcenterit. Makesome
pencil marks on thetube,onthe
outsidesof thetubsothatyoucan
quicklycenterthetubelater.
Dothesamefortheforwardboomtube
anddoublers.
The forwardboomtube doublerslineup
withthe forwardboomtubeholes.They
onlyaligncorrectlyoneway,sobesure
that the orientationiscorrectbeforeyou
mixanyglue.
Weightthetubsothat it isflaton the
bench.

3
Measuring boom tube distance above flat bench.
Tub sleeves sanded flush with tub side.
Clampthe doublersinplace without
glue andmeasurethe endsofthetubes.
Bothsidesofthetubesshouldbethe
samedistancefromthebench.
Ifnot,loosenthe clampsand adjustthe
doublersuntil theyare.
Ifthe doublersorholesnowhavetobe
sandedtofit, youmust sandthemand
repeatthemeasuringprocess.
Thisisacriticalstepintheassembly,
andifdone incorrectly, yourhull will
neverhandleproperly.
When youarehappywiththeheightof
thetubesabovethebench, check tosee
that the tubesaresquarefronttoback
withthe boomsquareprovidedinthekit.
When youhavechecked anddouble
checkedthattheboomtubesare
straightandsquaretotheworld,remove
theclamps, butleaveeverythingin
place.
Mixup some30minuteepoxy, andcoat
thedoublerswheretheywill bein
contactwiththetub sidesandbottom.
Align therailsandclampinplace.
Quicklycheckyourmeasurementsand
squareseveraltimes,andmakeanytiny
adjustmentsbeforetheepoxy startsto
cure.
Useanyexcessepoxytobuildasmall
fillet around thesleevesanddoublers.
Clampinplace.
Setasideforat least3hours.
Repeatforthefrontboomtubes.Be
sureeverythingisperfectbeforeyou
walkaway…
Onceeverythinghascured, sandthe
brass tubsleevesflushwiththe tub
sides.

4
Radio box lid support glued in place behind bulkhead 2.
Foam nose block being test fit.
Foam sanded to match tub sides. Note angle sanded on aft sheeting.
Glue inthelidframesupport. Thisgets
attached totherearof bulkhead2,and
isflushwiththelowerportionof the
sides.
Check thefitof thefoamnoseblock. If
all iswell,gluethe foamnoseblock in
placewithepoxy orpolyglue.Allowto
cure.
Sandthefoamflushwiththetubsides.
Becarefulnottosand thetubsidestoo
much.
Thisfoamisneededforfloatation, in
caseyoushearoff bothsponsons…

5
This is what makes a JAE a JAE… Sponsons are similar.
Engine rails glued in 3 inches in front of bulkhead 2.
Engine bay with lower tri stock in place.
Glue theforwardbottominplacewith
epoxy.Besuretosandtheangleinto
theaft sheet sothatit matchesthetub
sides.Theforwardbottomsheetshould
coverthebevelonthe aftsheetingand
be leftsquare. Donot sandtherearof
theforwardsheeting; itneedstohavea
sharpedgeforthe watertoshearoff.
Seedrawing.
Using epoxy,gluethetwomapleengine
railsinplace, 3inchesinfrontof the
middlebulkhead2.Notethat the engine
railsarenot square(3/4x5/8).Besureto
laythemon the¾side(theyare5/8
high)
Allowtocure.
Fit andgluethe ¼balsatristockinside
thetubbottom.
Cut the¼balsatristockasfollows:
(2)13-1/4
(4)9-1/2
(2)5-1/2
(2)3-1/4
(2)1-1/2
Cut thelongestpiecesfirst.Seecutting
guideinback ofthismanual.
Theseareslightlylong. Trimforanexact
fitintheradioboxand enginearea.
Usethe twopiecesof5/16x4balsatri
stock toreinforcethetransomoneach
side, insidethetub.
Savethescrapbalsatristock forthe
throttleservomounts.
Install yourengine onitsmounts,then
set theengine andmount inplaceonthe
enginerails.
Find anail orametalrod that slipsinto
thecollet.
Usethistomakesurethat theengineis
aligned withtheholeintherear
bulkhead.

6
Engine test fit.
Engine mounted on Solinger mounts.
Rough initial bending of shaft tube.
It shouldlineupperfectly.Ifnot, findout
whyandcorrect it.
Mount the enginesothat the glowplug
isabout4-1/2inchesinfrontof bulkhead
2.
Onceyouarehappywiththeengine
placement, screwtheenginemountsin
placewiththescrewsprovidedwiththe
mounts. Drill pilot holestoavoidsplitting
theenginerails.If usingtheSolinger
mounts,drill 3/32 pilotholes.
Withtheengineinplace, wecan move
on totheshaft tube.
Thisisanotherareathat will needtobe
done perfectlyforagood runninghull.
Bendingtheshafttubeisapieceof
cake,ifyou knowthe secret.
The ¼inchbrasstubingneedstobe
annealed.
Thiswill makeit easy tobendbyhand,
without kinks.
Toannealthetube, simplyheat it with
anypropane torch,until itchangescolor.
You will seethe brasscolorchange toa
sort of blue. It onlytakesacoupleof
seconds, sowatchforit.
When yousee thetubing changecolor,
movetheflameslowlydownthetube
until thewholethingisdone.
Putascrewdriverinoneend of the
tubing toholdit whileyouheatit.
Trynottoannealthelast inchorso.
You caneitherset the hot tubeon aheat
proof surface(concretewill do), oryou
can quenchitwithwateruntil cold.
When thetubinghascooledoffwewill
be bending it intoan “S”shape.
Whyan“S”shape?
Testshaveproventhatatubewithtwo
bendshaslessdragthanatubewith
one.

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Shaft tube in place.
Bottom.
The reason isthattwobendssupport
theflexcablebetter,reducingcable
whip,anddrag.
Measurefromtheendof theengine
collettotherearbulkhead.
Removetheengine.
Puttheshaft tubethroughthe holeinthe
rearbulkhead,andtheholeinthe tub
bottom.
Puttheendthatyoudidn’t anneal
towardsthe engine.
Letthetubestick throughtherear
bulkheadbythesameamountthat you
measured,minusabout3/8inch.
Markthe shaft tubehereforreference.
Nowstudythesideviewof the shaft
tube,andcarefullyandslowlybend the
“S”shapeintothetube.
Trytomakesurethatthetubesticks
throughthe bulkheadtheproper
amount,and therearof the tubeisabout
¼inchfromthe tubbottom.
Takeyourtime,and goalittleatatime.
Ifyoutrytorushit, andkinkthe tube,
you will havetostartoverwithanew
tube.
When youfinish,youshouldhaveanice
“S”tubethat startsabout 3/8inchbehind
theenginecollet, andcontinuespastthe
rearof the boat (wewill trimit later).

8
Be sure to leave enough shaft tube for the strut.
Take your time with the shaft tube.
Strut in place on ski. 12G kit shown. 21 the same.
Glue theshaft tubeinplacewithepoxy
andfiller(tothicken). Besuretoget
insideand outsidethe tub,andboth
sidesofthebulkhead.Allowtocure.
Leaveall the excess shaft tubeinthe
rear. Don’t cut it.

9
Ski parts ready for assembly.
Ski side glued to bottom (rear).
Ski side glued to bottom (front).
Ski
Assemblethe4partsof the skiusing
epoxy orCA.
Glue theaft skibottomontothe sides.
Matchthebottomsheetingtothefront
endof the sides, andlettherear
overhang. Clamportapethisassembly
until cured.
Sandthefrontoftheaft sheeting sothat
it matchestheangleoftheskiforward
portion.

20
Note long bevel sanded in front of ski.
Just like the tub bottom.
Drill in the center of this hole.
Glue theforwardskibottominplace,
andletthefront overhang. Thisisdone
exactlylikethetubbottomsheeting.
Sandasharpbevelonthefront of the
skibottomsheet, sothatit blendsinto
thetubbottom.Donot glue theskitothe
tubyet.
Servos
Bolttherudderinplace. Thisshouldbe
asfartotherightaspossible.
Makeamarkonthe transomwherethe
rudderpushrod will exit.
Sight thisfrombehindtheboat.
(see drawing).