Kona

!! FOR SALE !!

KONA180° a full acrobatic slope model by Benny Wachtelaer.
Last year 2011 I have designed the KONA and discussed with some slope pilots to get a good and cheap VTPR wooden glider. This choice did not make it easier to draw and to produce fusalage, but so far I'm not complaining ;-) The wings are foamcore with abachi- and stab balsa covered.
The stab turns 180° for full kulbutin manouvres and butterfly twists .
Also possibly for brushless motor, all parts are foreseen, thoug I prefere slope- or towing hook version, a longer axes that will be guided in a ballbearing must be turned for motor version.
So far I have worked 200 hours on designing and 50 hours to prepare cuttingfiles. Time for building around 200 hours also.
Span : 1800mm
Lenght : 1170mm
Wingsections : SB96V-SB96VS
Stab./fin sections : NACA 0007
Weight : +/-1250g
Wing ballast : 34.7g/dm² (nominal weight)
Fuselage: balsa light ply build up
Wings: styrofoam < 120g/dm³ abachi 0.6mm sheeted
Stab: styrofoam < 120g/dm³ balsa 1.5mm sheeted
Because of short of time I'm not able to construct shortkits at this time, KONA180 cuttingfiles and drawings will be propebly ready in the autumn,
if you are looking for a great winter project,... you just find one .
What you need to build:
- balsa 1.5mm and 3mm, lightply 3mm and ply 0.8mm, gfk 2mm plate for rudderhorns
- servo covers
- a foam cutting bow
- light foam < 15kg/m³ (standard plates from your local store)
- massive carbon rod 8 , 4 and 3mm
- hollow carbon tube4/3mm
- alu tube 8.1x9mm (or simmular)
- alu tube 4.1x5mm (or simmular)
- 4mm bushing or bearing for elevator (if full elevation is used) option for classic elevator is possible
- abashi 0.6-0.8mm or balsa 2mm
- glasfiber 80g/m² or carbon 90g/m²
- covering for finishing. I can recomend simply carwrapping sticker, you can stretch by heating and is extremely cheap and very quick, thoug a little be havier than the iron covering films.
- time !
- help and assistance via RC-groups forum step by step.
Discuss the KONA on RC-groups / Modelbouwforum.nl
KONA180 cuttingfiles and drawings can be sent by command or find files down this page (cuttings available on request)

8-03-12 Latest info :
Unfortunately no movie but maiden is behind me.
9am this morning in the dunes in Bredene NW 4-5 Bft, ideall for the test flight. But we had to be quick, wind was going down.
After the launch perfectly straight line after some trimming.
Constant speed in curves without flapperon mix with elevator.
Flown on lowest settings of dual rate + / - 35%. + / - 20 ° up / down
First do some testings to get used and try some manoueuvers.

Snap Roll : perfect
Fourpoint roll : perfect
Inverted : lightly downsteering
Knife-edge : no wind enough, next time
Wingover : perfect
Flicks at low speed : no, clean nose down in pulling up at low speed, perfect.
Slow fly later in the afternoon wind fell down. Ailerons slightly down 2-3mm, perfectly able to fly further.
Landing : perfect, ailerons slightly up and drops perfectly.


► Tis is the dreaming section,... KONA allready airborned here,...if you haven't build one allready,...start a little bit lower on the page,... it could be very helpfull,... and gives you more courage ,...









 Fuselage
The Kona is full 3D CADesigned model.
The protoype fusalage is made of balsa and light-ply build up in a sheetmetal structure. Nevertheless I’m thinking to mould the model to reduce weight of fusalage and speed for building. Though first I need the test for changes and/or modifications.
The wings are foamcore 0.6mm abachi sheeted , with flex-hinges of glasfiber 2x 80gr/m² for maximal performance and acurate manouvres.
The Fusalage height is +/- 170mm, good for a ballanced knive edge.




► It all begins with this,... the 3D design, have too many pictures to publish them all, but you'll get an idea,...


►  have foreseen an electric version also, but never came so far, perhaps in future, the KONA flies too good . The extended axes and hub can be home made or even available in the better modelshop. Motors exist with long axis but are not long enough for the Kona (as far as I found)


 ► Inner tail vision


 ► Servo pulley drive for rudder, later switched to carbon tube, because of huge flutter in high speeds. Should work perfect for foamversion.



 ►the final

 ►CNC cuttings


► Inner reinforcement panel of fusalage Ply 0.8mm

► Reinforcement parts and winglets. ply 0.8mm
 

► Stab reinforcementpanel


► Lightply piece for reinforcement of fusalage, also cnc cutted.

 ► 3 piece fusalage flank

► Start to position parts and glue,…

► Overview of building up fusalage, reinforcement parts and bulkheads
 

► A small strip of 3x3mm with an offset of 3mm from the edge is necessary to position the bottom part.

► Other position

► Positioning reinforcements

► The bottom part excist out of different parts, the 0.8mm ply for strenght and the front with a 90° nerve for better bending.

► Checking the elements

► Glueing side flanks
 
► Rectangling and justifying

► Closing the nose is perhaps the most difficult part . Making wet was the only option and close bit by bit. Patiance is needed like the real modelbuilder has. ARF pilots please skip this part ;-)



► Nose part in dry condition and bottom flank ready to glue



► Align an tape , very importend all holes should be perpendicular to avoid scew fusalage !


 ► All parts are glued with white wood glue


► The result




Servo pulley brings up constant rotation and a 180° rotation of stabilo



BEC system with 3300mAh/7.4v lipo pack

Some light filler helped me a lot to finisch surfaces


► Simply covered with polyester film



► Build in canopy lock


 ► Mounting the fin
 
Positioning the fin
 
Positioning the stab

► Theoryticly the stab can turn 180° , practicle there becomes too much tollerance on servo because of size of servo pulley. This means it's good for slow speeds, when you get high(er) speeds , flutter happen.

Wings

 Wings cutted by hand, all wood piece cnc cutted




► The flex-hinge , 2 layers of 80g/m² glasstissue , glued with whit woodglue instead of epoxy, this makes the tissue flexibble and does not brake



 ► cutting out the V-gap


► preparing to glue the inner basla to close the V-gap

► full size aileron , 50 mm wide



Checking out the servo tray



 ► V-groover to sctratch out V-groof for ailerons





pneumatic press up to 300kg will cover all I need

Download Cutting files here (pdf)
  1 - 2 - 3 - 4 - 5 - 6
All files are stored on our Google drive and safe !
You can also dowload and follow tread on RCgroup
and Modelbouwforum

Video channel
Elevator test


Elevator test in flight (with pulley)


2nd flight, testing kulbutin manouvres

► Still doin' great ;-)


Thanks for watching

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