Bengtson BE2C User manual

BE2c367/8”
Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
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BE2C 36 7/8” 1/12th Scale
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R/CScaleModelInstructions
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CONTACTINFORMATION
DesignedbyM.K.Bengtson
PrototypebyJohnO’Duffy
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ManufacturedandDistributedby:
BengtsonCompany
e‐mail:[email protected]
www.aerodromerc.com

BE2c367/8”Page1
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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
BE2C367/8”1/12thScale
Thankyouforpurchasingthe1/12thScaleBE2Cfor
electricflight.
FinishedModel
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ModelSpecifications
Morethan255lasercutparts
Scale:  1/12
Channels: R/E/A/T
Wheels:balsaandplywoodwithNeoprenefoamtires
Wingspan: 367/8ʺ
WingArea: 374.5sqin
Weight: ~25oz
PowerSystem:GWS300c
Prop:  10x7
AirfoilType: Flatbottomed;optionalundercamber
Cowl:  N/A
Spinner: N/A
Decals: Availableonwebsite
Designer: M.K.Bengtson
Prototype: JohnO’Duffy
Preparation
Layoutthe2plansheetsandlasercutkitparts.
Studytheplansandidentifyallsuppliedparts,you
mayliketomarkthepartnumbersbesidethepartfor
lateridentification.Asyougo,prepareyour‘stick
shoppinglist’ofstocknotincluded.Thislistwillinclude
butisnotlimitedto,suchaswingspars,leadingedges,
1/8”squareforrearfusesection,andsome1/16”and1/32”
balsasheeting.
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Plansandpartslaidout.
Duringconstruction,plansshouldbecoveredwith
somesortof‘planprotector’suchascommercially
availabletypes,or‘greaseproofpaper’orclingwrapor
eventheplasticbagthekitcamein.
Glueisuptoyou,somebuilderslikeCAglueswhich
certainlyspeedsconstructioningeneral,butensureyour
workareaiswellventilatedasmanypeoplehaveadverse
reactionstothepoisonousfumes.Epoxyglueshouldbe
usedforthefusefrontmainstructureforstrengthand
durability.‘White’woodglueisagoodalternativetoCA,
ittakeslongerwaitingforittosetbutgivesmoretimeto
preciselylocateparts,avoids‘stuckfingers’andis
generallyamorestressfreeexperience.
Tools.Notmuchmorethanasharpknifewithagood
supplyofreplacementbladesandsomesandpaperis
required.Veryhelpful,especiallywiththismodelis
havinganumberofset‐squares,straightedgesandrules
availablefortruinguppartsasconstructionproceeds.
Whenremovingpartsfromthesuppliedsheetsuse
careandaverysharpbladetocutthesmallbridges
holdingthepartintothesheetbeforeremovingit.Simply
pressingthepartoutofthesheetriskstearingorbreaking
it,especiallywithsomeofthefinerparts.
Thefuse,wings,tailsurfacesandundercarriage
sectionsareallconstructedseparatelyandbrought
togetherattheassemblystage.Itdoesnotmatterinwhich
orderthesesectionsareconstructedbutnormaladvise
wouldbetostartwiththetailplanesasthattendstobe
easiestandleadsintowingthenfuseconstruction.This
wouldbegoodadviseifyouarenotfamiliarwith
AerodromeRCkits.

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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
TailPlanes
VerticalFinandRudder
RemovepartsS1–S9fromthe1/8”sheet.Youwillalso
needsome1/16”x1/8”balsafromyourstickstock.After
coveringtheplanswithyourchosenprotectorlaythe
partsovertheplans.Whenyouarehappywithhowthe
finandrudderaretobeconstructed,startbypinningthe
twoverticalpieces(S3andS4)totheboard,thenwork
aroundtheruddergluingandpinningeachpieceto
completetheoutsideoftheframe.Fillinthethree
1/16”x1/8”piecesandS11tocompletetherudder.Finish
offtheverticalfinbygluingS1andS2toS3andaddthe
two1/16”x1/8”ribs.Makesureeverythingstaysflat.
Allowwhateverglueyouareusingtocompletelycure
andhardenbeforeremovingthecompletedpartsfromthe
plans.Don’tattachtheplycontrolhornuntilafter
covering.
HorizontalStab.andElevator
H5&H2arelongandsomewhatfragile,usecarewhen
removingthemfromtheirsheetsandwiththelightestof
sandingremoveanyremnantsofthelasercut‘tags’.
Usingastraightedgetokeepitdeadstraight,pinH5
totheplansinposition.GlueandpinH1,thenwith
anotherstraightedge,similarlyglueandlocateH2toH1.
AddthetwoH4sidepiecesandH3’stothecorners.Cut
andfitthe1/8”x1/16”ribs.
Tip:Cutthefirstrib,sandandfitneatlytothe
horizontalstabiliser.Cutalltherestfromthispattern
makingthemeversoslightlyoversize.Acoupleofstrokes
onsandpaperwillbesufficienttotunethesetolengthas
youfitthem.Donotdistortthestructurebytryingto
squeezeinaribthatisjusttoolong,acouplemorestrokes
onthesandpaperandit’llbeperfect.Ifyouover‐sandany
andit’stoolooseafit,putitasideandcutanother.The
shortonecanbeusedforanelevatorrib.
Horizontalstab.startandcomplete.
Whenalltheribsaregluedintothehorizontal
stabiliserremovethestraightedgeagainstH5.
Elevators.
PinthetwoE1totheplans,somethinspacermaterial
betweenH5andthetwoE1willmakethiseasy.Work
aroundtheoutsideontheelevatorstocompletethe
outline.Addtheribsandthetwocontrolhornanchorsto
completethissection.Donotaddthecontrolhorns
themselvesuntilaftercovering.
Wings
Thewingscanbebuiltwithorwithouttheoptional
undercamberwhichislasercutintotheribs.Itisnomore
difficulttohavethisoptionreally,theribsstillsitnicely
flatonthebuildingsurfaceevenafterremovingtheextra
material.Undercamberdoesrequirealittlemore
attentiontotheaileronservohatchareaandyou’llneedto
checkyourservo’sarethinenoughinthenarrowedwing.
Ifyoudowantundercamber,thelasercutlinesareeasy
tofinishwithasharp#11knifebladeandatouchof
sandpapertoremovethe‘bumps’.Don’toversand.Finish
eachrib’slowersurfaceasyouremoveitfromit’ssheet
andyouwon’tevenhavetosandtheundercamberonthe
completedwing.Otherthanalittlemorepreparationof
eachrib,andservorailfitting,wingassemblyisthesame
withorwithoutundercamber.Alsonotewithunder
camber,theply‘P’piecesthatmakethecarbanestrut
socketswillneedsomemoreattentionontheunder
surfaceoftheupperwingbeforecovering.

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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
UpperWings
Selectfourstraight¼”x1/8”bassorsprucesparsfrom
yourstock.Shapetheoutboardendsofthesparsasper
thedetailontheplans.
Foreachwing;
PinW1andW1ainposition.Cutsparstolengthand
fixtoplans.Glueandplacetheinboardoneofthetwo
R3’s,R5andthewingtipR6,checkallisflattothe
buildingsurface,straight,andtheribssquare.
Alsonotethatwiththeinboardribsoftheupperwings
thesparcutoutsarelargerthanthespartoallowlater
insertionoftheplydihedralbracesinfrontofthespar.
Whengluingtheseribstothespars,ensurethesparis
againsttherearofthecutoutintheribs,leavingroom
(1/16”)fortheplybrace.
‘X’pinningthesparswillholdthemdownanduprightwhile
fittingtheribs.
Positionthelowerinboardplytrailingedge.
LeavingribR2tilllast,glueintheremainingribsand
halfribstothewing.GlueinribR2usingtheRFGguide
supplied,thiswillhelpachievethecorrectdihedralangle
whenthetopwingsarejoined.ThetopofribR2leans
awaytowardsthewingtip.
Addtheuppersurfaceplytrailingedges,andapplya
littleweightsothetrailingedgestaysflatandstraight.
Theplytailingedgepiecesrequirenoextratapering,the
narrowedribsaredesignedtolettheedgesoftheplyto
justmeetalongtheirbackedges.
Cuttolengththe¼”x¼”leadingedgefromyourstick
stock.Carefullyremoving/sandingoffonepointofthe
squaresectionforitslength,asindicatedbytheplans,test
andthenfittheleadingedgetothemouthsoftheribs,
glueinplace.Installtheply‘P’pieceseithersideofthe
1/8”ribstoformtheIPstrutsockets.FittheTEpiecesto
finishthewingattheaileronmount.(NottheLEpieces,
theybelongtotheaileron!)
Ailerons
Preparethe6aribpiecesandtheone1/8”6bpiece.Pin
W2andLEinpositionleavingasmallgapattherootend
foraileronclearance.Usingapinwillhelpkeepthegap.
Layaplytrailingedge(upperwing,lower=plywith
horncutout)ontheplanandfit6battherootendanda
6aatthetipend.

Gluetherestofthe6aribsinpositionandaplytrailing
edgeontop.Ensuretheplypiecesaresittingflatinthe
ribsandapplysomeweighttokeepitallflatastheglue
hardens.(Ontheupperwingsthistopsurfaceplypiece
hasnocutout)
TheWingWorks.Wingsatvariousstages.
LowerWings
Proceedasforupperwingsforthebulkofthe
construction.Lowerwingsparscanbeleft1/8”overlong
attherootends;therearecutoutsinthefusesidesto
receivethesesparends.
Withtheaileronsensurethecontrolhorncutoutsinthe
plytrailingedgesareontheuppersurfacethistime.The
BeWarned!Controlhorncutoutsinthe
plyailerontrailingedgesneedparticular
attention.Ontheupperwingthecutouts
areonthelowersurface,onthelowerwing
theyareontheuppersurface.Alsomake
surethecutoutisoveritspositiononthe
plans.

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lowerwingaileronsalsohavethebalsacontrolhorn
mountlabelled‘3’;thisisflushwiththelowersurfaceof
theaileron.
PartsW3andW4needshapingtosuit,W3being
taperedtosuitandW4trimmedtothewingcord
(thickness)beforebeingfitted.Sheettherootwingpanel
(uppersurfaceonly)with1/32”balsaasindicatedonthe
plan.Epoxyinthe1/8”dowelsleaving1/8”protruding
whichwilllocateintheholesprovidedinthefusesides.
Fourstrongwings
AileronServohatch/mounting
Ifyouarenotusingtheundercamberoption,gluethe
¼”x¼”servorailsinpositionbetweentheribsoverthe
plans.Ifyouwanttheplycoverrecessed,putsome1/32”
packingbetweentheplanandtherailasyoupositionit.
(Don’tglueinthepacking!)Alsoifyouarerecessingthe
cover,addanotherpieceof1/8”balsatothefrontservo
railflushwiththewingribs,to‘finishthebox’andattach
thecoveringmaterialto.
Servohatch,undercamberandrecessed.
Ifyouareusingundercamber,waittillthelower
wingsarecompletelydry.Markthepositionsoftheservo
railsonthewingribsfromtheplansthenliftthewings.
Testtherailsinthemarkedpositionsflushwiththe
sandedlowersurfaceofthewingribsbyusingtheply
hatchtocheck.Torecess,pushinthehatchsoit’sflush
withtheribs.Tacktherailsinplace,checkwiththeply
hatchallisniceandflush,removehatchandsecurethe
rails.Alsoifyouarerecessingthecover,addanother
pieceof1/8”balsatothefrontservorailflushwiththe
wingribs,to‘finishthebox’andattachthecovering
materialto.
Theservoisattachedtothehatchbygluingitdirectly
orscrewingittoblocksgluedtothehatch.Hereblocksare
gluedtothehatchtopositiontheservoandsiliconwillbe
usedtoglueintheservosothatitcouldberecycled.Some
builderswraptheservointapethengluethetapedservo
inplace.Latercuttingthetapewillreleasetheservo.
Joiningtheupperwings
Assemblethecentresectionoftheupperwing,joining
the3ribstotheplytrailingedgepiecesandasectionof
preparedleadingedge.Installapieceof1/8”x¼”spar
materialtothebackofthespacesintheribs.Prepare1”x
6”blockswhichwillgounderthewingtipsastheyare
assembled,toestablishthedihedralangleofthewings.
Trailfitthefourplydihedralbracestotheupper
wings.Asmallfilewillhelprelievingtheslotsinthewing
ribsiftheyaretootight.Thebracesmayneedtrimmingso
theymeetatthecentrelinewithoutinterference,check
thisovertheplan.Whenthefitisgood,epoxythemin
place.Locatethewingsovertheirpositionontheplan
withthe1”blocksunderthetips,applyepoxytothe
assembledcentresectionribsand‘spar’andslideitdown
betweenthewingribsslottingtheplydihedralbracesinto
position.Checkthatthecentresectionissittingflatonthe
worksurface,thewingtipdihedralblocksareincorrect
positionandthatthewingsatthatpointaresittingflaton
theblocks.Checkyouhaveanicestraightlinealongthe
leadingedge.
Upperwingcentresection.

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FuselageConstruction
Thefuselageisbuiltintwosections,afronthalfanda
rearhalfwhicharethenjoinedovertheplan.This
simplifiesconstructionandhelpsensureastraight
fuselage.
Cowl
GluepartsC1andC2together.The‘top’(flatter)
surfacesandsidesareflush,thelower(morerounded)
surfacesaresteppedforlatersandingtotheprofileonthe
plans.
FrontSection
Startbypinningone1/8”balsafusesidetotheside
viewplanandepoxyFCBandRCBcarbanestrutsinto
theirslotsinthefuseside.NoteFCBandRCBare
different.Ensureeverythingispreciselyovertheplanand
thestructurestaysflatwhilethegluesets.Wing
alignmentwilllaterdependontheaccuracyofthis
assembly.
EpoxyFCBandRCBintofuseside.
Whenthegluehascompletelyhardenedonthefirst
side,eitherremoveitandrepeatforthesecondside,or
buildthesecondsideoverthefirstwithapieceofcling
wrapinbetweensothetwodon’tgluetogether.Either
waytheintentistoachieve2identicalsideswiththe
carbanestrutsalignedandvertical.Thereisnoleftorright
sidetoworryaboutheretheyarethesame.
WhilethesecondsidesetslocatepartsF2,F6,F1Dand
cutthe1/8”x1/4”crossbracesinpreparationforjoining
thefusesides.CleaningouttheU/ClacingholesinF1D
(andF1C)witha1/16”drillwillbeeasiernowthanlater.
Formingthebasisofthefrontfusesectionbeginswith
pinningF1Dtotheplanviewoverit’slocation(note
orientation–lacingholestotherear).Usingepoxy,attach
thetwofusesideswithF2andF6between,toF1Dand
thenthecrossbracestothetop.Taketimeatthisstage,
andusestraightedgesandsquarestoensureeverythingis
deadstraightandsquareandthatthecarbanestrutsand
fusesidesareverticaltothebuildingsurface.
Mainfusepartssetting.(Smallbagofshotweighingthings
down)
Therestofthefuseformersetccanbegluedinafter
thetruenessofthebasicstructurehasbeenachieved.
Nowtheplansideviewhasbeenvacatedconstruction
ofthetaillatticecouldbeginwhiletheepoxysetsinthe
fronthalf.SeeTailSectionbelow.
Whenthebasicfrontstructurehascompletelyset,
continueaddingtheremainingformersF1,F3,F4andF1C
(lacingholestothefront).CheckF1isvertical,withthe
fuseonits‘flat’(ieF1Disflattothebuildingsurface).
Checkcarbanestrutsremaintruewhenattachingthefour
F3formerseithersideofthesestruts.NotetheformersF3
&F4arenarrowerthantheoverallwidthofthefusesides
toallowforthelater1/16”sheetingoftheupperhalf,
ensuretheyareevenlyspacedeitherside.
Installthemotormount3/8”squarestock,usethe
planstohelpestablishthe2‐3degreerightanddown
thrustangles.Completethisstagebygluinginthefour
servomountingrailsasindicatedontheplans.Allowglue
tosetcompletely.
Nextthefusesidesneedtobescoredandcracked
behindF6totaperthesidestothenarrowerF7.
AfterscoringtheinsidesofthesidesjustbehindF6,
locatethefuseovertheplansandbend/crackthesides
behindF6inwardsevenlytoconformtothewidthofF7
keepingitallalignedandpositionedwiththeplans.Glue
andtemporarilytapeF7tothesides.Gluereinforcesyour

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score/cracklines,ensureeverythingconformstotheplan
andallowtoset.
FusecrackedforF7
Tohelpavoidhangerrashlateronafewothertasks
canbecompletedatthisstage.Epoxythetwo1/8”brass
bearings(cutfrom1/8”brasstube)intotheirholesinthe
fusesidesjustforwardofF6.Usealengthon3/32”rodor
tubethroughbothbearingstokeepthemalignedasthe
epoxysets.Thebearingsshouldbeflushtotheoutside
andcaneachbe3/8”longsoastogive¼”ontheinside
forglueattachment.Ensureyour‘alignmentrod’through
thebearingsdoesnotgetgluedinplace!
Sheettheundersidefrontofthefuselagewith1/32”
balsa.Usecardtomakeapatternoftheshaperequired,
trimminguntilit’saperfectfitapartfromthefront,which
canbeleftover‐lengthandtrimmedlater.Cutapieceof
1/32”balsasheettothispatternandsoakunderawater
soakedpapertowelfor20‐30min.Thatshouldmakeit
flexibleenoughtotakethecurvedshape.Glueandtape
thesheetinposition.
(Tip:Ifyouarenotexperiencedinsheetingcurveswithbalsa,
thisisafairlysimplecurvetostartwith.Usecardtocreatea
pattern,you’llfind,balsabendsawayfromthewetside,balsa
expandsasitsoaksandshrinksbackasitdries.Bepreparedto
havemorethanone‘go’atyourfirstsheetingattempts,ifit’s
wrong,orthebalsacracksthrowitaway,startagain,it’lltake
onlyaslongasittakestogetright.)
Lastlythemotorcanbefittedtothemountstickwitha
screwortwo,screwsskewedtothefrontsothatthey
couldberemovedthroughthefrontforservicing.The
motorcannowbetakenoutagainsoitdoesnotgetfilled
withbalsadustlater.
Frontandrearsectionsreadytojoin.The‘bar’throughthefuse
iskeepingthebearingsaligned.
Thefrontsectionisnowreadytojointotherear
sectionwhenthatiscomplete.
TailSectionofFuselage
LocatepartsFS1andFS2.Pinthe1/8”square
longeronstotheplanandglueinthecrosspieces,andFS1
andFS2atthetail.Apieceof1/8”squarestockhasbeen
usedinthephotobetweenFS1andFS2tomaintainthe
spacingrequiredforthelaterinsertionofthehorizontal
stabiliser.Makesureitdoesnotgetgluedin!
Fusetailconstructionstarts.
Whenthefirstsidehashardenedremoveitfromthe
plan,turnitover,coverwithalayerofclingwrapand
buildthesecondsideoverthefirstsothetwoare
identical.


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Thenthereweretwo
Jointhetwosidesovertheplans.
Notethesideshaveatopandbottomnow,established
byFS1&FS2.
Dothebottomsurfacefirst,pinSF7inpositiononthe
plan,buttthetwosidesuptoSF7keepingthemvertical
andlocateSF5andthesmall1/8”sq.crossbrace(between
SF7andSF5),betweenthetwosides,addthe1/8”sq.to
thefrontofSF5.Addtheremainingfivecrosspieces.Keep
everythingflatandthesidesvertical,allowtodry.
Gluingthecrossbracesbottomsurfaceofthetail
Thetailpiececannowbeturnedoverontheplanand
thetopsurfacedonesimilarlyusingFS6thistime.Note
‘leaveout’twoofthecrossbraces,theonesatlocations
F10andF11arekitsuppliedpartsandwillbeattached
later.
FinishoffaroundthetailareawithpartsSF3andSF4
oneachside.(Apieceof1/8”scrapsheetwrappedincling
wrapstandinginforthehorizontalstabiliserwillhelp
keepeverythingalignedandinposition.)TheendsofSF3
andSF4willneedlightsandingtoneatlymeetatthepoint
andsides.MakingSF3andSF4slightlyproudwillallow
sandingofthisareatotheprofileformedbythetwoSF7
Tailsectionreadytojointofront.
Joiningfrontandtailfusesections.
Thisimportantstepisrelativelyeasy,inthattheunder,
rearsection/planeofthefrontfuseandthebottomsurface
ofthetailsectionareaflatplaneallowingbothtobeflatto
thebuildingsurfaceduringconstruction.
Usestraightedgesorblocksfixedtotheplanseither
sideoftheforwardfusesectiontokeepitaligned.Rock
thefusebackbetweenit’sguidessothatitsitsflatonthe
backfacetoftheunderfuseshape.Usesomeweightto
holdthefuseinthis‘noseup’attitude.Nowslidethetail
section(dry,noglueyet)intopositionlocatingthe4
longeronendsintotheirsocketsinthefrontfuse.The
bottomsurfaceofthetailsectionisflattothebuilding
surfacejustliketherearoftheforwardsection.Check
everythingovertheplansforlengthandalignmentand
thatthe‘point’ofthefusetailisexactlyoverit’sposition
ontheplans.Trimlongeronsiftheyaretoolong.When
youarehappyallisasitshouldbe,slidethetailoutagain,
applygluetothesocketsinthefusefrontandslidethetail
backintoposition,checkthepointofthetailagain,and
allowtoset.Standbackandadmireyourperfectlystraight
fuselage.
Finishoffanyremainingformersandthecockpitfloors
inpreparationforsheetingthetopofthefuse.
Uppersheetingstarts
Cutsomelengthsof1/16”balsafortheuppersidesof
thefuse,wideenoughtofillbetweenthe1/8”lowerfuse
sideandthe‘chine’lineoftheupperformers.Sandor
planeanangleonthetopedgeofthesetocontinuethe
lineoftheformertops,thiswillhelpwithfittingthetop
sheet.Cutthesidestocorrectlengthandfitthe3pieces
eithersidetothefuse.Theaftsideswillrequiresome

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bendingtoconformtotheroundingshapeoftheformers,
soakingwithwetpapertowelfor20‐30minswillhelp.
Rear‘sides’curvedtofollowformers,cardtemplatefortopsheet
readytogo.
Thetopsheetingforthismodelwasdoneintwo
pieces,forwardandaftofthelastF4former.Usecardto
maketemplatesforcuttingthe1/16”balsasheeting.Start
withapieceabout1“wideandlongerthanyouneed.
Benditintopositionbetweenthecarbanestruts,markthe
positionofthestruts,removeandcutstrutnotches.Test
fitthenotchesandmarkthelengthrequired,leavingsome
overatthefront.Makethereartemplatebytaperingto
thewidthrequiredatF7.Whenthetemplatesare
complete,layover1/16”balsasheetandcarefullycutto
shape.Onceagainsoakingthebalsashapesunderawet
papertowelwillmakeitsufficientlyflexible.Layingthe
balsaoverasuitableroundshape(e.g.aspraypaintcan)
asit’ssoakingwiththepapertowelontopwillhelpeven
more.Preparetheformertopsandfusesideswithglue
andinstallthetopsheetsholdingitalldownwithplenty
ofmaskingtape.Thetopsheetshouldbeoverhangingthe
sidesbya1/16”orsooneithersideandmorearoundthe
aftcockpit.Sandsmoothwhenthegluehascompletely
dried.
Topsheetingdoneandcockpitsmarked
Nextmarkthepositionandshapeforthecockpitcut
outs.Atechniqueforgettingsymmetricalshapesisto
startwithcard,cutarectanglebiggerthanyouneed.Lay
overthefuseandmarkthelengthyouneedtohave
crosswaystogetthelowestpointsofthecutoutsinthe
correctpositiononthefuseside.Thewidthofthe
rectangleisthefore/aftdimensionofthecut‐outmeasured
fromtheplans.Foldthecardrectangleinhalfsuchthat
thefoldisthecentrelineofthefuse.Transferthecockpit
shapeshownonthesideviewplantoonesideofyour
template.Cutthetemplate,bothsidesatonce,tothis
shape.Openoutthetemplateandalignthefoldlinewith
thecentrelineofthefuse,positioningforeandaftasper
plan.Markaroundtheoutsideofthetemplatewithpencil.
Putanewbladeinyourknifeandwithlightpressure
followthepencilledline.Twoorthreepasseswiththe
bladeshouldseeaneatcutout.Toomuchpressurewill
‘break’thebalsa,toolittleandit’lljusttakeanotherpass,
butyou’llgetaneatcut.

1st stringer and F11
Stringerreardecking
FitandgluepieceF11inpositionbetweentheupper
longerons.Cutthe1/8”x1/16”centrestringertolength,
glueeitherendtoF11andF7.Usingthisasyourguide
assembletheotherupperdeckformersbetweenF11and
F7ensuringtheformersarevertical.Installtherestof1/8”
x1/16”stringers,apairoftweezerswillhelppositioning
theoutboardstringswhichrequiremoretwistbetween
formsF10andF11.Thecutoutsintheformertopsthat
separatethestringersareextremelyfragile,especiallyin
partsF10andF11,useasmuchcareasyoucan,whenyou
breakoffapiece(oh!youwill☺),reattachwithCAas
youassemblethestringertomaintainthespacingbetween
thestringers.

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Upperdeckstringers.
Undercarriage
Usingtheplansasaguidecutandshape1/16”music
wiretoformthetwoUCsupports.Gluetogethertheply
UCsidesandsetaside,thesecanbesmoothed/sanded
afterbondingtothewirelegs.Makeyourselfa‘jig’toaid
assembly,asshowninthephoto.
Bindtheendsofthe1/16”musicwirewiththincopper
wireorKevlarthread,usingtheplysidestoguidethe
shape.The‘front’legsshouldbeverticaltothejig,usea
squaretocheck.Somere‐bendingandtuningwill
probablyberequiredtogettheshapeevenand
symmetricaloverall.Whenallisasitshouldbe,bindand
CA/Epoxytheplysidesinplacesecuringthemtothe
1/16”musicwire.
Assemblewheelsbysandwichingthe¼”balsamiddle
piecebetweenthe1/32”plysides.Useapieceof3/32”
tubetoalign/centretheparts,thenremovethetubeand
‘squash’thewheelundersomeweighttomakesureit’s
flatasthegluesets.Whenthisisdrycuttwowheel
bearingsabout5/8”longfrom3/32”brasstube.Usingthe
1/8”plyhubsandawheelbearing,completeeachwheel
usingepoxy,makingsurenoepoxygetsintothebearing.
Beforegluesets,spinthewheelon1/16”musicwireaxel
andrealignbearing/hubsasrequiredtoensurethewheel
spinsstraight.
Toformthetyresmassageonesideoftheneopreneso
itstartstocurl,continueanditwillformacircle,near
enoughanyway.UseCAtogluetheendstogether,butbe
carefulasCAandneopreneisaVERYstickycombination
andiffingersgetinvolveditcangetverymessy.Placethe
neopreneflatonaprotectedpartofyourworksurface.
UseonesmalldropofCAononeend,bringtheotherend
aroundtomatewiththegluedendtryingtoachievea
smoothjoin,you’llonlygetonechance.Whenthetyreis
formedrollitontothewheelandwithatinydroporthree
ofCAsecuretotherim.Onceagainbecarefulwiththe
CA,ifyoustickafingerorthumbtothetyrematerial
you’lllikelytearachunkoutoftheneoprenetryingto
releaseit.
UCandwheels
Thecardconesrequiredtodressthewheelsshouldbe
cutfromcardtothesizeshowontheplans.Scorelines
deeplyintothecutcirclewithapenandcutoutonepie
shapedsection.Foldtheshapesateachscorelinetomake
these‘spokes’moreobvious.Drawtheendstogether
formingaconeandtapeinsidetomaintaintheshape.
GluetheinsideconetoeachwheelandinstalltotheUC
structure.Ensureitspinsfreely,someshortlengthsof
3/32”tubemayberequiredtospacethewheelawayfrom
theUCstructure.Thewheelcanberetainedontheaxelby
asmallwasherandCA/binding.Trimaxeltolengthand
glueoutercardconetowheeltocomplete.

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Tailskid
Bendapieceof1/16”musicwiretotheshapeshown
ontheplans.Cuttwopiecesof1/16”balsa3/16”x1‐5/8”
andtwopieces1/16”x1/16”x1‐5/8”.The1/16”kitsheet
thatheldtheaileronribsisagooddonorforthesebalsa
parts.Asshownontheplansforma‘box’aroundthe
1/16”musicwirewiththebalsastrips.Fittheskidtothe
wirewithasmallwashereitherside.Ensuretheskidis
goingtositcorrectly,youmayhaveto‘fix’theinside
washertothemounttogeteverythingtositstraight.
Whenyouarehappyinstalltheoutsidewasherandbind
theendoftheaxel.Trimaxeltosuit.Makesuretheskid
stillmovesontheaxel.Arrangeamountnearthetopof
thestructurefortheelastic‘shockabsorber’shownonthe
plans.Thisshockabsorbercouldbethindressmakers
elasticorevenasuitablysizedrubberband.
TrailAssembly
Usingnoglue!Thisisadrytestassemblyrunto
ensureallmajorcomponentsfitwell.
Placethetopwingupsidedownonyourworksurface,
supportunderthemidsectionwiththe1”dihedralblocks
weusedtosetthetipssothatthewinghassomesupport.
Fitthefusetothetopwingbyinsertingthecarbane
strutsintotheirsocketsinthetopwing,makesurethey
seatallthewaydown.Usesomelighttapetoholdin
place.Placesomesupportunderthefusetailtolevel
thingsup.Checkthedistancebetweensomefixedpoint
oneachwing,saytherootendoftheaileronspace(or
wherethelastwingtipribmeetsTE)andthepointofthe
aftendofthefuse.Thisshouldbethesameonbothsides
andtellshowwellyouputthecarbanestrutsandfuse
sidestogether.Ifthere’sanydiscrepancyitwillneed
adjustmentduringfinalassembly.Withtheassemblystill
upsidedown,installfourIPstruts(notethereareForward
andAftIPstrutsFIPandRIP)inonesideoftheupper
wing.Positionlowerwing,locatingIPstrutsbetweenthe
wings,andwingdowelsandsparendsintothefusecut
outs.Repeatfortheotherlowerwing.Usetapetohold
everythinginplace.Tapetheundercarriageinplace.Turn
theassemblyoverandslidethehorizontalstabiliserinto
place.LocatetheverticalfinintoitsslotinFS6.Installthe
tailskidassembly.There…looksgreat!
FLYING
• ThemodelshouldROGongrass,pavementor
hardsurfaces.
• Letthemodelgainaltitudeslowlyofftherunway.
• Applyingtoomuchupelevatoratslowspeeds
risksastall.
• Makeyourturnsgentlyastightturnsrisktip
stallinginanymodel.
• Don’texpecttheelevatortomakethemodel
climb.
• Thinkoftheelevatorasadevicetochangethe
attitudeofthemodel.
• Thewingandairspeedultimatelymakethe
modelclimb.
• Oftendownelevatorappliedatstallingcanavoid
amajorcrash.
Themostimportantdetailsforproperflight
operations:
• Correct CG location.
• Straightnon‐warpedwings.

CONTACTINFORMATION
Distributedby:
BengtsonCompany
e‐mail:[email protected]
WebSite:www.aerodromerc.com