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Alula in Foamboard

Hai-Lee

Old and Bold RC PILOT
#1
I have noticed a number of forum posts in relation to the Alula and some posts showing them being built in FB BUT no one seems to have posted any plans of their endeavors! If anyone has any plans for the Alula in FB on this forum please advise.

One of my student pilots wants one and before I start the whole design and build process I was hoping to just build one from someone's existing plans. I do not mind if the plans did not work out properly for any reason! RC groups have a few but they also have their own design and performance issues.

I thank you for your time on this matter.

Have fun!
 

Michael763

Well-known member
#2
I have liked this design for a while. Here is what I have started, it is a little rough. I have not built this revision yet, but this should give you a starting point. It will be nice to see what you come up with.
(Edit just noticed I forgot to change the color on the wings control surfaces to red lines.)
 

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Hai-Lee

Old and Bold RC PILOT
#10
@Hai-Lee - what size are you going to build? :D
Well, I am hoping to build one standard size with a target of making it as light as is possible! This is for a particular client who has severe health problems. Once the techniques are developed I may use the same techniques on a scratch design, (I still owe you a glider design:unsure:).

Have fun!
 

Hai-Lee

Old and Bold RC PILOT
#12
@Hai-Lee - 1m would be nice (two sheets of FB)!

my sailplane is sitting half-built waiting on some tailfeathers - I have been enjoying some FG work lately, so I am contemplating a V tail with these techniques from the Ridge Rat project
Sorry for the delay in my response as I had the internet disconnected by some painters here and they stuffed it when they tried to reconnect it. It has only just been fixed so I will post my reply written just after the internet failed.

My Alula will be done in 3mm FB, (it can be scaled up to 5mm if needed. I.e.166%),

I am aiming for a proper reflexed wing profile with the wing tips curled up as in the original. Using the master series curving technique with a few ideas of my own to keep the build weight down. I also want as much air in the wing as I can engineer.

I posted so that others could show their work and perhaps provide an idea that would be applicable to my design/build, and perhaps trigger them to complete their builds as well.

Have fun!
 

Hai-Lee

Old and Bold RC PILOT
#14
Well just a bit of progress. Building to standard wingspan. Wings cut out and the gentle upsweep of the wing tips sorted.
All paper removed from the wing internals. Wing pieces sculptured as per the Master series techniques and a wedge shaped balsa wing spar fitted. Servos glued to the inside of the wings, (inboard), and the wires run forward. When joined the wings will have a slight dihedral for a little added stability, (it is a beginners plane after all).

The battery is to be a 500mA 2S with a UBEC so the nose may need to be extended but then I may use 5MM FB with paper left on for the nose section. The wing and fin are all 3mm FB for weight saving.

No pics or real procedure is to be posted until the design is satisfactory in weight and performance, (developing techniques as I go).

I may post a pic of the completed prototype if it all works out OK, (prior to maiden).

Have fun!
 

Hai-Lee

Old and Bold RC PILOT
#16
Finished both wings with curved surfaces and upturned wing tips. Fitted the 2, (5 Gram), servos along with the control horns, pushrods, and the linkage stoppers.

Weighed the wings before joining them with a strong dihedral brace and the pair together.

The specs so far:- Wings alone weighed in at; 105 Grams or 3.68 ounces, (Fitted with servos and all associated hardware).

Wing Span:- 900 mm
Max cord:- 225 mm.

Original specs:-
Wing Span 900 mm (35.4 in)
Wing Area 16.7 dm2 (259 in2)
Weight 156 - 170 grams (5.5 to 6 ozs)
Wing Loading 9.3 to 10.2 gm/dm2 (3.1 to 3.3 Ozs/ft2).

The wings appear quite strong with a little extra flex in the wing tips under high "G" loading, (something they will never experience except in a crash).

I may have overdone the spar strength by using 5 mm thick solid though tapered spar. Next one may be reduced to 3 mm to reduce the weight a little further.

Have fun!.
 
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Hai-Lee

Old and Bold RC PILOT
#19
Well a rough fuselage later with the full setup before finishing it weighs in at 182 Grams (6.45 ounces).

If the owner had selected a lighter UBEC instead of one that is the same size as a 35 Amp esc it would have been lighter I suppose.

Have fun!