foamboard Dornier Libelle simple seaplane

[Yawnsky24]

@Dr. Looping Looie we got to fly the Libelle with ailerons yesterday. No video yet but I will get some when I can. The ailerons made it a great flyer. It was very gusty yesterday and with that you can tell just how light this plane builds as it gets bounced around quite a bit but is a fantastic flyer. Here are pictures of one of my flying buddies with his Libelle taped to match his pontoon boat! Can't wait to fly in calmer winds and off the water.

Setup:
Motor

HeadsupRC Blue Wonder 24Gram 1600KV - https://www.headsuphobby.com/HURC-300-Blue-Wonder-1600kv-Brushless-Motor_p_1980.html
or​

Firepower 300 Speed motor - https://www.headsuphobby.com/Firepower-300-Speed-1600kv-Outrunner-Brushless-Motor_p_1768.html​

Prop

7x4 Slo Fly​

Servos

(4) 5 gram - https://www.headsuphobby.com/Power-Up-5g-SG-50-Analog-Sub-Micro-Servo_p_1876.html​

or​

(4) FliteTest ES9051 servo​

Speed Controller

12 amp - https://www.headsuphobby.com/Sky-Power-12A-ESC-with-Switchmode-BEC_p_1543.html​

Battery

800Mah 3S Glacier​

or​

650Mah 3S Tattu​

Aileron Modification:

Ailerons on outboard end of wing. 1.75 inches deep to hinge line, 9.5 inches long from wing tip.​

​

The heavier battery handled the wind a bit better but both flew great!

 

[Brett_N]

Sorry had to travel earlier, but I did fly mine last saturday.

LOVE IT. Super simple build, (just make sure it's the right way up LOL)

I did though find it to be a little susceptible to battery positioning and having to re-tune the elevator, but it does fly really well. 3S 1500 was a little heavy, 3S 1000 was about right, didn't have anything smaller.

At one point I set it with some right rudder, 1/4 throttle and put my transmitter down for a good 5 minutes and it just puttered around our field on it's own.

Time to build some more with a little more time spent

 

[Arcfyre]

Sad Libelle.

Not sure what happened. I had the battery in the same location as always, but she was flying as if she was extremely tail heavy. My first flight I managed to set her down without damage and I adjusted the battery forward a little bit to get the balance right.

Took off for the second flight and as soon as I reduced power she dove for the water. Not entirely sure why as I was holding back elevator before she went in. Hit so hard the bottom caved in and she flipped over.

I'm letting everything dry off overnight before I see what the damage is. I'm pretty sure the airframe is toast, but with some luck the electronics are salvageable.

 

[Apple Pie]

So I’ve had several flights now on my Libelle and I’ve really got a nice appreciation for this plane. Currently running a 2213 935kv (flite test power pack B motor) with a 8” x 4.5 prop on a 3s 850 mah battery. Balances nicely with this setup and flies very well at about 60% throttle. I have a 1000mah 2s coming which I’m interested in trying out. My setup has ailerons which I happen to like as it fits my flying style.

A few of my experiences that I’ll pass along to future builders.

1) waterproof all of your electronics if you are flying off of water. Including and especially your servos. I toasted an aileron servo on my first duck landing. Like all seaplanes you can expect things to get really wet!

2) when installing your skewers, push them through the foam board and glue them as you push them in. Just placing them on the surface and adding hot glue does not stand up well to the forces placed on them during landings.

I’m going to make another one this winter and be a little more precise in my assembly so it’s a long term keeper. I’m also going to try one with a solid deck as I tend to duck landings from time to time and fill the plane with water. Fortunately with the electronics sprayed in corrosion X I just dump the water out and send it up again! What fun 😄

 

[Mach60]

I just wanted to let you know that I built one of your Libelle planes and really enjoyed putting it together. I needed to have removable wings, so I built two towers that I could put skewers through and braced them from the inside with skewers. I just flew it for the first time and it was a huge success! Thank you for providing the plans.

 

[Sigma917]

I am a new member, with a total of one aircraft built (FT Tiny Trainer great starter plane) that I plan to put floats on. This looks like a good second aircraft, since my flying field is a lake. I have couple of questions. How much dihedral should I use on the sponsons, and where do I place them? I plan to start constructions this week, it is going to be cold and rainy all week here.

 

[synjin]

My sponsons have no dihedral. They just stick straight out from the sides of the fuselage. I haven't flown mine since last winter, and I flew mine off of frozen water. It is a great fun little bird to fly. I'm thinking of putting a 2212 1400Kv motor onto it just to see what it will do. Mine is the one made of blue foam on page 5 of the thread.

 

[Sigma917]

Thanks Synjin, I have to decide whether to build this or a Qwak later this week. Currently building some floats (85% Cub floats) for my Tiny Trainer.

 

[Dr. Looping Looie]

I am a new member, with a total of one aircraft built (FT Tiny Trainer great starter plane) that I plan to put floats on. This looks like a good second aircraft, since my flying field is a lake. I have couple of questions. How much dihedral should I use on the sponsons, and where do I place them? I plan to start constructions this week, it is going to be cold and rainy all week here.

Theres no dihedral on the sponsons, and they should be placed a little ahead of the wing and the bottom of the sponsons should have around the same angle of attack as the trailing edge of the wing.
If you need to decide between the Libelle or the Qwak, do you mean this one?

The quak is smaller and has a little bit more wing loading. So I think the Libelle can fly a little bit slower. The quak is going to be more durable, except for the pontoons because the wing is attatched to the fuselage. I think the quak is more nimble while the Libelle is very stable and pretty much flies on its own. The quak has more aerobatic capebilities while the Libelle is more scale. I havnt seen the quak in real life, but I know the original depron quak and on the water, the quak is way more stable, but it cant do the drifting because of the pontoons vs sponsons. The Libelle really needs a big 8" slowfly prop and it works best on 2S. Something important is definitly the thrust angle. Your prop needs to be on a 90 degree angle to the trailing edge.
One big difference is the parasol wing which offers great flight caracteristics, but its mounted on skewrs. This might make it hard to install the wing, and you have to reglue the skewers after some time in the water, but If you crash, you dont destroy your wing because the force is soaked up by the skewers. The parasols big advantage is that theres more airflow from the prop under the wing, which means not only more efficiency, but also allows more airflow over the control surfaces, which is important for low speed water handling.

In the end, you need to decide for yourself, they both are great beginner designs.

 

[Sigma917]

Dr. Looping Looie. Thank you for your insightful reply. I think I will build the AP Qwak next, since it should be a little more rugged. I might lengthen the wing slightly to lighten the wing loading. And, I will use sponsons since they should provide better water handling and be more rugged. On the Libelle I was considering mounting the wing on towers like Mach60 for strength. Thank you again for your reply and your wonderful design.

 

[Dr. Looping Looie]

Dr. Looping Looie. Thank you for your insightful reply. I think I will build the AP Qwak next, since it should be a little more rugged. I might lengthen the wing slightly to lighten the wing loading. And, I will use sponsons since they should provide better water handling and be more rugged. On the Libelle I was considering mounting the wing on towers like Mach60 for strength. Thank you again for your reply and your wonderful design.

Then go ahead!
Instead of increasing the wingspan, I would scale the whole thing up by around 150%, depending on the power system you have.
What power system do you have? Prop size and battery is especially important.
Maybe making it a twin engine woult help with lots of problems, especially clean airflow and extreamely good manuverability.

 

[Sigma917]

Dr. Looping Looie. I will probably use the power pod off of my Tiny Trainer float plane (2200kv motor 1000mah 2s lipo and HQProp 6x4.5x3 or HQProp 5x4.5x3). I was thinking of adding 2 inches to each wing to lighten the wing loading, that should be easier than scaling up the airframe. I did scale down the cub floats by 85% to fit the Tiny Trainer. They work great, but it probably doubled the build time adding 1mm to all of the fold cuts.

 

[Dr. Looping Looie]

Dr. Looping Looie. I will probably use the power pod off of my Tiny Trainer float plane (2200kv motor 1000mah 2s lipo and HQProp 6x4.5x3 or HQProp 5x4.5x3). I was thinking of adding 2 inches to each wing to lighten the wing loading, that should be easier than scaling up the airframe. I did scale down the cub floats by 85% to fit the Tiny Trainer. They work great, but it probably doubled the build time adding 1mm to all of the fold cuts.

That prop size fits the Qwak better than the Libelle with its 1 Meter wingspan vs the Qwaks 0.68 Meter. With such a light setup you can build your Qwak with the original wingspan very easily. Have you tried the TT on the water yet?
Once you get a little more experience, I think my recommendation for the perfect Qwak would be to scale it up by 200% and power it with two B packs. That would give it slow speed and great water handling since it doesnt sink deep into the water.

 

[Sigma917]

Dr. Looping Looie I haven't tried the TT on the water yet, I finished the floats yesterday. I have flown once off wet grass, which went well. And I did a float test in a tub of water, and the TT sits nice and high with the floats. l will hopefully fly the TT off the water this week, if it stops raining.

 

[FoamyDM]

You did such an amazing job with this design. I'm not sure where I was when you did this...and how I missed it.
I'm glad I caught your youtube video of you doing water donuts..

wait. - February... I know what I was doing.

 

[Dr. Looping Looie]

UPDATE!

Ive got a new project: Im building a 200% monster Libelle. The fuselage will be the exact same, but 200%, but I will change the wings. They will get a real profile, ailerons and a wing foldback mechanism, just like on the real Libelle. This allows for much easier transportation.


Ive already tried this concept with my ultralight and it works pretty well:

Heres the progress of the fuselage:

 

[Apple Pie]

UPDATE!

Ive got a new project: Im building a 200% monster Libelle. The fuselage will be the exact same, but 200%, but I will change the wings. They will get a real profile, ailerons and a wing foldback mechanism, just like on the real Libelle. This allows for much easier transportation.


Ive already tried this concept with my ultralight and it works pretty well:

View attachment 170001





Heres the progress of the fuselage:

View attachment 170002
View attachment 170003

Oh yes, yes, yes! This is exactly what I need! The libelle is the plane I fly the most in my collection. Its such a great flier on a calm day off the water. Are you going to make plans for this one too? Following your progress closely ...

 

[Apple Pie]

UPDATE!

Ive got a new project: Im building a 200% monster Libelle. The fuselage will be the exact same, but 200%, but I will change the wings. They will get a real profile, ailerons and a wing foldback mechanism, just like on the real Libelle. This allows for much easier transportation.


Ive already tried this concept with my ultralight and it works pretty well:

View attachment 170001





Heres the progress of the fuselage:

View attachment 170002
View attachment 170003

I just noticed what appears to be flaps in the first photo???

 

[Dr. Looping Looie]

I just noticed what appears to be flaps in the first photo???

Yes, those are flaps, but the Libelle does not have flaps, so they wont be on the model too. The photo is the wing of this ultralight, which uses the same feature.

 

[Dr. Looping Looie]

Todays progress:

Added cockpit and sponsons, started with the wing.