Gremlin60”(1.5M)“BIBOC”Slopefunaerobat. BIBOCisanacronymthatwehavecoined:“BungInBackOfCar”–inotherwords,itmeansasmallandreallyeasytobreakdownmodelthatismeanttobecarriedaroundwithyou–justforthosechanceopportunities,andtimeswhenyoujusthavetoflysomething.

Above:OneofthefirstGremlinsoutofthemoulds.Below:LoboffbyDavidWoods:Thefirstflightbegins!

DaveWoods’(UK)GremlinhidinginthebackofhisAudi.

1. Wheretostart?AllAeroicplanesarethoroughlyinspectedandtestassembledbeforeshipment,howeveritsbestittomakeatrialassemblyofallthepartsasafirststep.Thiswillletyouknowifthereisanyminorfittingtobedone,orifanyofthepartshavebeenoverlooked.Runafingerovertheleadingandtrailingedgesofthewingsandtailhalvestomakesurenoroughnessorflashingremains.Ifanyarefound,thennormallyalightscuffwith600to800gritwetanddrypaperonasandingblock(NEVERuseabrasivepaperwithoutasandingblock)willbeenoughtoeliminateit.Makesureallofthecontrolsurfaces(Rudder,elevators,aileronsandflaps)movefreelywithoutsnaggingandagainlightlysandanythatmightbenot100%.Atthistime,youmightwanttocheckthewing,tailplaneandruddermovements.Sandtheinneredgesofanywipers,ortheuppersurfacesofthewingetc.backslightlyinordertoincreasemovement.

ExampleoftrimmingtheAileronwiperstogivealittlemoremovement

HeretheRuddermovementhasbeenadjusted.

2. Wings:Ialwaysstartwiththewingsbecausethatwayseemstogivethat“halfdone”feelingquitequickly.

Installingthewingservos:ServoscanbeinstalledusingthenowpopularDDS/IDSsystem,orusingcommercialservotrays–orsimplyaswehavedoneherebymakingsomeplywoodmountings.Thekeypointistoinstalltheservossecurelyandtocarefullymakethelinkagesandthefitsasgoodaspossiblesoastogivenocontrolslop.

Notethatbecauseoftheaileron/flapgeometry,theservosappeartobenotstraight.ThisisperfectlyOKforthisairframeasthehingelinesareatanangletotheleadingedgeofthewing.

3. Fuselage.Thefuselage,orrathertheinstallationoftheservosinthefuselageoffersanumberofchoices.AglassfibreCNCcutservotrayandelevatorbellcrankassemblyisprovided,withservocutoutsofthatisthewayyou

wanttogo,andcarbonrods/snakesarepre-installedofyouwanttousethissimplemethod.Ifnot,thenyoucanuseservosinthetailfinareaforbothrudderandelevator.Ahatchiscutandahatchcoverprovidedtogiveaccesstothebackofthefuselage.

Noteifyoudon’twanttousethesnake/bellcrankmethod,agoodwaytoactuatetheelevatoristosoldertheballfroma3mmballlinkontothemiddleoftheactuatorwireandleaveitintheplaneondisassembly.

Herearesomeexamplesoftheelevatorservowithdirectdriveinstalledjustinfrontoftherudder.

Ballasttube:

A20mmIDballasttubeisprovidedforthefuselage.Alternatively,orinadditionandifrequired,theroundcarbonwingjoinertubecanbeeitherfilledwithremovableballastrods/spacers,orsimplyreplacedwithheaviermaterialsofthesamediameter.HollowCarboncouldthenbecomeaglassfibrerod,oranaluminiumrod,orabrassrod,stainlesssteel,uptodepletedUraniumintheory.

HereisaCarbontube/UraniumballastsystemfromAeroicDistributorAloftHobbiesintheUSA.

Note:Ifyoudodecidetoinstallthefuselagemountedtube,pleasedon’tforget:• Toplugtheendswithplywoodorasimilarstopperthatissecurelyglued–andpreferablyPinned• Thatthecentreofmassoftheballast(notthecentreoftheballasttubeasitwillhaveanopeningto

inserttheballastandmayhavedifferentsizeplugsintheends)hastobeinthesamepositionasthecentreofgravity.(Approx.78mm)

Retainingthewings:ThewingsarebestretainedbyfittingMultiplexwingretainers:

Orifyoudon’tlikethose,asimplehookandelasticbandretainingsystemcanbemadeup.

Above:Anexampleofawingretainingsetup.

Makingthenoseweight:

Aftereverythingiscompletelyinstalledincludingservotray,servos,wiring,receiver,ballasttube,andbatteries,hangweightsonthenoseuntiltheplanebalancesat85mmfromtheleadingedgeofthewing.Manypeopleusestripsoftyrebalanceweightsforthisjob,butanythingwilldoaslongasitsheavyenoughtobeconcentratedoverasmallarea.Remember85mmfromtheleadingedgeisyourstartingpoint.Itwillbetoofarbacktoflywell,buttheintentionistoaddmoreweightbeforetestflying.Notewritedowntheweightyouneedcarefully.Itwillbearound180-200grammesbutDONOTGUESS.OK,havingfoundouthowmuchweightyouneedtostart,nowrubsomeVaselinearoundthenoseofthefuselageandstickitintoapapercupfullofwetwallfiller.Suspendthefuselagesothatitdoesnotjustsinkdowntothebottomofthecup/filler.

Whenthefillerisdry,removethefuselageandyoushouldbeleftwithacrudebuteffectivenoseweightmould-probablyabitbiggerthanyouneed.Thekeypointisthattheshapewillbeexactlythesameasyourplane’snoseshape.Nowputthemouldinanovenatabout60to70degreestothoroughlydryit–orleaveitinadrywarmplaceovernightatleast.Note:Pouringmoltenleadintoamouldthatisnot100%drywillcausetheleadtoeruptandspatterandwillverylikelyburnyou.Leadmeltsat327.5 degreescentigrade,andthiswillcauseSEVEREburns.Notrecommended…

WhenyouaresurethemouldisCOMPLTELYdry,meltthesameweightofleadyouhavenotedandcarefullypouritintothemould.Whenthemouldiscool;youwillhaveashapednoseweight.

Usetheweightyouhavemade,heldinthenoseoftheplanebyapieceofhardEPPorotherfoamplus10grammesoflooseweightstosetuptheplaneforthefirstflights.StartCGis75mmfromthewingleadingedge.

Note:DONOTEPOXYTHEWEIGHTINTOTHENOSEATTHISSTAGE,instead,waituntilyouarecertainitiscorrectoratleastnottooheavy.Thereisnothingworsethantryingtodig,drill,hack,cutorotherwisegetexcessleadoutofafuselage!

4. Setups:Generalflying:CG 75-78mmfromLeadingedge.Setup,GeneralAerobatics,etc.:Aileronup: 10mmAilerondown: 7mmFlaperonsup: 5mmFlaperonsdown: 3mmElevatorup: 10mmElevatordown: 10mmSetup:LightAirStooging:Flapsdown: 2mmAileronsdown: 2mmElevatordown: 2mm

Setup:Landing:Flapsdown: 70degreesAileronsup: 35degreesElevatordown: 8mmNote:Thesesettingswillvaryfrompilottopilotbutwillbeagoodstartoffpoint.PlaywiththesettingsandtheCGifyouarenot100%happywiththem,andpleaserememberthatthereisareallylargevariationinwhatsuitsdifferentpeople.MakeadjustmentstotheflightsettingsandCGuntilyouthinktheplaneisdoingexactlywhatyouwantitto.

Oh…andremember…DON’TGETITWET!

ConstructionandflyingphotoskindlyprovidedbyDavidandGrahamWoods.