AerodromeRC Fokker DVI User manual

FokkerDVI35.5”
Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11

Fokker DVI 35.5” 1/8th Scale


R/CScaleModelInstructions






CONTACTINFORMATION
DesignedbyM.K.Bengtson
Prototype:ChrisBaum
Model:RichardDery

ManufacturedandDistributedby
BengtsonCompany
e‐mail:[email protected]
www.aerodromerc.com

FokkerDVI35.5”Page1

Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11

FokkerDVI35.5”1/8thscale
ThankyouforpurchasingtheFokkerDVI35.5”1/8th
scalemodelforelectricflight.


ModelbyRichardDery
ModelSpecifications
Morethan240lasercutparts
Scale:  1/8th
Channels:  R/E/A/T
Wingspan:  35.5”
WingArea:  400sqin
Weight:  ~25ozreadytofly
PowerSystem: MPJet3.46:1BBGearboxLong
CanSpeed400ORAXI2217BL
motor
Prop:  10x7
Wheels:Balsa&plywood,Neoprenefoam
tires
AirfoilType: Flatbottomed
Cowl:  Builtupbalsaandplywood
Spinner: N/A
Designer:  M.K.Bengtson
Prototype: ChrisBaum

BUILDINGTHEMODEL
BeforeStarting
Anoteaboutthephotos:Thephotosweretakenofa
prototypeandthepartssuppliedmaylookslightlydifferent
fromthem.However,theconceptsillustratedarethesame.
WINGS
Buildthetopwinginthreepieces.Notethatthetrailing
edgesare1/32”plywoodandaresuppliedinthekit.Theleading
edgesarelasercut1/4”balsa.Thecabanemountsaresockets
formedbyepoxyingshortlengthsofbrasstubinginthecabane
mountingribs.

Putsmallscrappiecesof1/8”balsaonthenotchesintheribs
thatacceptthecabaneandIPstrutstoserveasreinforcements
andasabaseforcoveringlater.Theslottedsparsaligntheribs
sothattheyareinatrueverticalorientationwhenthewing
panelsareinraisedintoposition.

Theforwardsparalsoservesasanattachmentpointforthe
tabsofthesawtoothshaped1/32”plywoodleadingedge
extension.
Thisisascaleaswellasstrengthenhancementinthedesign.

FokkerDVI35.5”Page2

Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11

Buildtheaileronsandsandtheleadingedgetoshape.
Choosearoundedshapeforcenterhingingorabevelledshape
fortophinging.
Finishedlowerwings:
Finaltopwingassembly


Aileronservosareattachedwithshortthreadedrodstothe
ailerons.Aileronservosarefitinservocompartmentslocatedin
thelowerwingswiththesupplied1/32”plywoodservocovers.
Routeservowiresthroughholesinlowerwingribs.Usea“Y”
wiringharnessconnectortowiretheservostoasingleradio
connection.Alternatively,twoRCchannelscanbeusedwhen
mixedelectronically.Ifdifferentialaileronthrowsaredesired,
rotateeachservohornforwardabout20degrees,while
maintainingtheneutralpositionoftheaileron.Thisshould
counteranyadverseaileronyaw.
FUSELAGECONSTRUCTION
Thefuselageisbuiltastwoseparateboxstructures,thefront
sheetareaandtherearbuiltupsection,whicharethenjoined
overtheplan.Thissystemnotonlykeepseachstagesimple,but
italsohelpstoensureastraightfuselage.Somemodelersprefer
tobuildeachsidecompletelyontheplanandthenjoinboth
halvesoverthetopview.Bothsystemshavetheiradvantages
anddrawbacks.Thefollowingisthefront/backmethod.
Beginbybuildingtworearfuselageframesovertheplanand
allowtodry.Selecthardbalsaorlaminatedbalsaforthe
longerons.Adddiagonalsforarigidstructure.Repeatwiththe
otherside.Somebuildersbuildthesecondsideoverthefirstto
insuretheymatchperfectly.BesuretousewaxpaperorSaran
Wrapbetweentheseoryouʹllnotbeabletogetthemapart.Join
thesidesoverthetopviewoftheplanandaddthecross
membersandtailskidmount.Checkandcheckagaintoinsure
thatthestructureissquareandstraightoryouwillendupwith
abananafuselage.Finallyaddthewedgeshapedhorizontal
stabilizersupports.Waituntilthefrontfuselageisjoinedtoadd
theturtledeckformersandstringers.
Buildthefronthalfanddecking
Laythefrontsidesontheplanandgluethemtogether.The
alignmentnotchinsuresthattheymateproperly.Ontheinside
surfacesgluethe1/32”plywooddoublers.Useaheavyweight
andslowsettinggluelikeepoxy.Ifawaterbasedglueisused,
warpingmayoccursoallowthegluetodryundertheweight.
JointhesideswiththefrontF1andbackF3formersand1/8”ply
undercarriagemountcrossmembers.Addthedeckingandtop
formers,andcarefullytrimtosizeandfit1/16”sheeting.The
sidecheekscanbeaddedafterthefrontandbackofthefuselage
arejoined.Theribshapedpartsthatframethelowerwingroot
locationaretheretosupportthecoveringmaterial.

FokkerDVI35.5”Page3

Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11

CabaneStruts
Thecabanestrutsarefashionedusing1/16”diametermusic
wirebendasshownontheplans.Addbalsafairingsatassembly
time.Thetopofthecabanesformabarthatfitsintoslotsinthe
wing.Balsa,bassorscrapplywoodcanbeusedtofairthe
cabanes.

TAILSURFACES
Layoutandgluepartsofthetailsurfacesontheplans.
Sandthetailparts,roundingoffalledges.Don’taddthe
hornsorhingethesurfacesuntilaftercoveringiscomplete.
LANDINGGEAR
ThelandinggearisfashionedfromCAhardened1/8”
plywood.Sand,soakwiththinCAandthen,securely,epoxythe
geartothemodel.0.045”musicwireisusedtoreinforcethe
gear.UseKevlarthreadorstrongcarpetthreadandsecurethe
wirealongthegear.CAinplace.Ashockabsorbingmechanism
hasbeendesignedtoletthemodelhavealittlegivewhen
landing.Attachthe3/32”musicwireaxletothetopsideofthe
LGcrossmemberwithKevlarthreadandepoxyinplace.Small
holesareplacedinthisparttofacilitatethelacingofthisthread.
Addshortpiecesof1/8”brasstubingasbearings/spacersforthe
wheels.Userubberbandstoactasshockabsorbersbutmake
eachsideexactlyastheoppositesite.Otherwise,theshock
resistanceisunequalandyourmodelwillcanttoonesideon
everylanding.AddingKevlarcrossriggingwilldramatically
strengthenthelandinggear.
COVERING
Anylightweightcoveringmaterialcanbeused.Polyspan
withdopeorMinwaxPolycrylicmakesagoodchoice,Litespan
isalsopopular.
Decaloutlinesforthismodelareavailableon
www.aerodromerc.com/decalsinAdobeAcrobatpdfformatfor
printingoutondecalpaper.
WindsockDatafile“FokkerDVI“publicationhasdetailson
placementandmarkings.
Availableat
http://www.byrdaviationbooks.com/

FokkerDVI35.5”Page4

Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11

WHEELS
Gluingtheplysidesonthe3/8”balsacoremakesthebasis
forthewheels.Usethebrasshubforalignment.Epoxythehubs
inplaceandaddasufficientamountofepoxyaroundthebaseof
thehubtoreinforcetheconnectionofthehubtotheply.
Plywoodreinforcinghubsareprovidedthataretoslipoverthe
brasstubingasshown.Next,CAgluetheneoprenecording
togethertofroma“tire”.UsethinCAsparinglyastheCAbonds
veryaggressivelytotherubber.PresstheCAwettedends
togetherforaninstantbond.Thebestwaytoaligntheendsisto
gluethemwhiletheyareinplaceonthewheel.Thenattachthe
tirestothewheelsandCAinplace.AthinbeadofCAaround
therimmakesforasecuretire.
Paperconesarecutout.Useaballpointpentoscoreeach
lineonthebacktomakeanimpressionof“spokes”Itishelpful
todothisoperationonapapertabletsothatthepenmakesa
goodcrease.Foldthepaperalongthecreaselinestoexaggerate
theraisedlines.Oneofthesectionsformingawedgeiscutout.
Makecutstothecenterofthecirclealongapairofthespokes.
Closethepapercutouttoformaconeandtapethejointinside
thecone.

Theinsideconesmaynowbeattachedtothewheels.The
outsideconesmaybeattachedatthispointifwheelcollarsareto
beused.Alternatively,afterinstallingthewheelsonthelanding
gear,awashermaybesolderedtoholdthewheelinplaceand
thentheconeisattached.Thismethodmakesaverynicescale
appearance.
Underwing
Theunderwingisbuiltaroundtheaxlewitha1/8”balsa
leadingedgeanda1/8”balsabottomwithribs.Ifdesired,sheet
thetopwith1/32”balsainsteadofleavingitopentocover.Be
carefultosettheincidencecorrectly.Theunderwingaddssome
lifttothemodelinflight.
COWLING
Thebackpartofthecowlingisofbuiltupconstructionusing
C1andC2and1/32”plywood.Theholesareforthelocating
dowelsthatextendfromthefirewallformerF1.(Alternatively,
twoofthesecanbeenlargedandusedasmountingholesforneo
magnets.)Constructthefrontpartofthecowlbygluing
C3,C4,C5partsmakingsurethattheyarealignedproperly.
Makeacardboardtemplatefromtheplanasaguideforsanding
thebalsaintoshape.
Thecowlshouldnowbesealed,sandedandprimeduntilno
woodgrainisleftshowing.Baby(Talcum)powderincleardope
makesanexcellentbalsasealer.
Talcumpowdermixedinwhitegluemakesexcellentfiller
forgapsorgouges.Sanddownafteritdries.

DUMMYMOTOR
ApartialDummymotorisincludedinthekit.Itisthepart
thatisvisibleunderneaththecowling.Makeupthecylinders
usingcardstockandoptionallyusethedoublethreadmethodof

FokkerDVI35.5”Page5

Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11

attachingthreadtotheoutsideofthecylinderstosimulatefins.
RemoveonethreadafterwindingandCAtherestinplace.
FittingTailSurfaces
Attachtheruddertotheverticalstabilizerusing1/8”stripsof
CAhinges.Similarly,attachtheelevatortothehorizontal
stabilizer.Gluethehorizontalstab/elevatorassemblyontothe
fuselage.Thengluetheverticalstabilizerandrudderassembly
intotheslotinthehorizontalstabilizer.SincetheFokkerDVI
hasaveryshortnose,pullpulltailsurfacecontrolsare
mandatory.
AileronServos
Thismodelusesinwingservosmountedon1/32”plywood
servocovers.
NOTE:Chrisdecidedonaninternalpullpullaileronlinkage
instead.
Afterassembly,connecttopaileronstobottomaileronswith
1/16”musicwirepushrods.Connectthemtothe1/16”plywood
controlhornsfittedinthebottomoftheaileron.
Rudder/ElevatorServos
Apull‐pullsetupforconnectingthesecontrolsurfacestothe
servosisrecommended.Connectthemtothe1/16”plywood
controlhornsfittedintheelevatorandrudder.

FittingtheRiggingWires
UsestrongthreadorKevlarfishinglineorelasticbeading
cordingtosimulateriggingwires.Usesmallscrews,fishing
hookeyes,straightpinheadsorsmalleyeletstoattachthelines.
These“wires”canaddadegreeofstrengthtoyourmodel.
Batteryhatch
Fashionabatteryhatchfrom1/32”plywood
ASSEMBLY
ThelowerrootriblocatingholesprecutIParedesignedto
makealignmentofthetopwingeasy.Firstattachthelowerwing
tothefuselage.Thisisbestdonebeforethelandinggearis
permanentlyattached.Takethedimensionsfromthesideview
ontheplanandmakeafoamboardtemplatetosupportthetop
wingontopofthefuselage.Whentheepoxysetsforthelower
wings,insertthesandedandpaintedIPstruts.Inadryfit
processaddthetopwingandtheninsertthecabanewiresand
testforfit.WhensatisfiedepoxytheIPstrutsandaddadropof
CAintothecabanemusicwiremountstosettheminplace.
BalancingtheModel
Balancethemodelatthepointshown.Choosingalarger
batteryispreferredtoaddinglead.
HereisChrisBaumʹs“inthebones”shotoftheFokkerDVI.
FLYING
1.ThemodelshouldROGongrass,pavementorhard
surfaces.
2.Letthemodelgainaltitudeslowlyofftherunway.
3.Applyingtoomuchupelevatoratslowspeedsrisksa
stall.
4.Makeyourturnsgentlyastightturnsrisktipstalling
inanymodel.
5.Don’texpecttheelevatortomakethemodelclimb.
6.Thinkoftheelevatorasadevicetochangethe
attitudeofthemodel.
7.Thewingandairspeedultimatelymakethemodel
climb.
8.Oftendownelevatorappliedatstallingcanavoida
majorcrash.
Themostimportantdetailsforproperflight
operations:CorrectCGlocationandStraightnon‐warped
wings.
CONTACTINFORMATION
Distributedby:BengtsonCompany
e‐mail:[email protected]
WebSite:www.aerodromerc.com