foamboard Dornier Libelle simple seaplane

[Dr. Looping Looie]

Update!

The foamwork is pretty much done, the wings are build and I sealed the bottom of the fuselage with some hot glue.

I build the wing in three sections, in the end, the outer sections will fold backwards for easier transportation.

At 2 Meters of wingspan, this thing is absolutely massive. Thats more than 78 inch! It used 8 sheets of foamboard!

To power it, I took the largest motor and the largest prop I could find. At 16"x6", the prop is twice as large as the one from the small Libelle. Im only going to use a 3s 2200 battery.

Here you can see how the wing is made. its an undercamber design with ribs and a bottom spar to give it lots of strenth.

I still have to do a lot of work to attach the wing, but I hope I can finish it next week.

 

[Apple Pie]

Update!

The foamwork is pretty much done, the wings are build and I sealed the bottom of the fuselage with some hot glue.

I build the wing in three sections, in the end, the outer sections will fold backwards for easier transportation.

At 2 Meters of wingspan, this thing is absolutely massive. Thats more than 78 inch! It used 8 sheets of foamboard!

View attachment 170328


To power it, I took the largest motor and the largest prop I could find. At 16"x6", the prop is twice as large as the one from the small Libelle. Im only going to use a 3s 2200 battery.
View attachment 170329

Here you can see how the wing is made. its an undercamber design with ribs and a bottom spar to give it lots of strenth.
View attachment 170330

I still have to do a lot of work to attach the wing, but I hope I can finish it next week.

Wow this is coming together great. I like what you have done to keep the undercamber wing and made it nice and strong. This is the only undercamber wing plane I have and it has a nice docile flight characteristic which makes it relaxing to fly. I suspect a larger version will handle the breezes better and be a real winner. Keep going!

 

[Dr. Looping Looie]

Update!

The new engine pod is done, its more scale and curved, it hides the motor and has a better aerodynamic. I also added echaust tubes for a better appearence.

I also installed the center section of the wing. The only thing left is to install the outer sections of the wing and the pivoting mechanism and the control surfaces. I think Im done in one or two days.

 

[Crawford Bros. Aeroplanes]

Update!

The new engine pod is done, its more scale and curved, it hides the motor and has a better aerodynamic. I also added echaust tubes for a better appearence.

I also installed the center section of the wing. The only thing left is to install the outer sections of the wing and the pivoting mechanism and the control surfaces. I think Im done in one or two days.

View attachment 170724
View attachment 170725

What did you use for exhaust tubes? That looks fantastic.

 

[Dr. Looping Looie]

What did you use for exhaust tubes? That looks fantastic.

Its some sort of chrome cardboard. It has a very strong mirroring effect.

 

[Dr. Looping Looie]

I glued all wooden parts in place. The wing will not only fold back, but is completely removable. All the mechanisms are using simple materials like wood and skewers.

I hope that I can finish it today.

 

[Dr. Looping Looie]

The wings are attached!


Now the only thing left is the servos and some details!

 

[leaded50]

nice build, nice airplane! (more sceptical though if the wing hinges will keep up the forces in flying.)

 

[Crow929]

Oh Wow! This really looks great!
The folding wing set-up is brilliantly done. How strong does it "feel"? Just looking at it from the outside, I would think the hinge area to be an easy failure point. Well done though.

 

[Dr. Looping Looie]

Oh Wow! This really looks great!
The folding wing set-up is brilliantly done. How strong does it "feel"? Just looking at it from the outside, I would think the hinge area to be an easy failure point. Well done though.

Every hinge connection is wood on wood, the wooden pieces are glued in. Each wing is attached on 4 points and each connection is fully removable.

+ this thing is super lightweight and will only do slow cruising and scale flying, so there are not much forces.

+ the wings need to be removable because otherwise it wont fit through the door.

+ it worked really well already with the ultralight I made.

 

[Dr. Looping Looie]

Heres a reference pic of the original

 

[Crawford Bros. Aeroplanes]

Every hinge connection is wood on wood, the wooden pieces are glued in. Each wing is attached on 4 points and each connection is fully removable.

+ this thing is super lightweight and will only do slow cruising and scale flying, so there are not much forces.

+ the wings need to be removable because otherwise it wont fit through the door.

+ it worked really well already with the ultralight I made.

I noticed the spars you had on there, they look really durable. That wing's not going anywhere.

 

[Rhaps]

Your original Libelle article made me start my own scratch design (not libelle but something along the lines)
If that folding sytem holds up I'll use it too if I ever get to make a Walrus.
Anyways this build looks seriously good, keep pushing the boundaries, I'll follow (slowly)

 

[rockyboy]

This is so awesome! I love the exhaust stacks too - very nice touch!

 

[leaded50]

Sorry, but didnt see the hinges was glues on woodspars. , Plane looks dam nice anyway

 

[FoamyDM]

I noticed the spars you had on there, they look really durable. That wing's not going anywhere.

You are really killing this on. I just got in maker foam... Sound like a perfect model for the stuff

 

[Apple Pie]

After you have a chance to maiden this beauty, please please make a set of plans. I’ll build one too! Love the folding wing mechanism. It’s got that unique feel to it that you don’t see in many foam board planes. 😀

 

[Occhielli di rinforzo]

Back in 1950 me and the boys used to camp in a wreck of one of those a few miles from my home town. And now thanks to you Im able to recreate these childhood memories in foamboard. Amazing thanks!

 

[Dr. Looping Looie]

Its pretty much done! All electronics installed and working.

With all electronics installed, this thing weights only 1.45kg, which means less wing loading than the small one! Its also less weight than the E-Flite Timber, which has only 1.55 Meter wingspan!

Here are a few pictures of the whole thing:

Engine detail

Battery hatch

Elevator and rudder controls

Top wing mount

Bottom wing mount

Rear support

Wing folding. The back support is still attached

The rear part of the center cection moves up to allow the wing to fold back

The two wing sections with wing supports

These parts secure the wings. Six skewers with clips and two collars

It takes about one minute to take the wings on/off.

The maiden will happen whenever the weather is good enouth. I want zero wind, because its so light and will get buped around by every little turbulence.

Things I still want to add: a pilot figure, a part to lock the wings together when they are folded together, a foil under the belly for better protection and a box to store all the extra parts so that I dont loose them.

 

[Dr. Looping Looie]

Small update!

I added this tiny piece, which secures the wings when folded together.

And this box inside the fuselage to keep all the important stuff, so that I dont forget anything when Im taking the plane to the next lake

Heres a little size comparison (everything in metric):

	E-Flite Timber	Fat Biplane	Small Libelle II	200% Libelle II	Real Libelle II
Wingspan (Meter)	1.555	2	1	2	9.8
Wing area (Meter ^2)	0.357	1.6	0.2	0.8	14
Weight (Kilogramm)	1.5	2.2	0.388	1.45	650
Wing loading (Kilogramm/Meter^2)	4.201	1.375	1.94	1.8125	46.4

Its really crazy how light the DIY planes are compared to the Timber, which is considered one of the best STOL planes. Its also interesting that the wing loading stayed roughly the same when increasing the size. Im surprised that this huge thing is still lighter than the Timber. I think it will fly extreamely slow, but only in very calm conditions. Thats the disadvantage of beeing light, the Timber for example can fly in much more wind. But I think that the big libelle is perfect for a calm evening at the lake.

Im super excited and cant wait for the maiden. But weather is not good right now.