Fokker FG-2 - Congrès 2017 Vauville

[michel]

belle structure, c'est quoi comme profil ?

Michel

[bocorvin]

Merci Vincent et Michel pour les comments encouragieus!
Le profil est Eppler E174.
The weight of the wings at this moment is 640 grams, I think the whole plane will be about 3000 to 3500 gramms. Gives a wingload of 22- 26 gr/dm.

Vincent

[bocorvin]

Hello everyone,

Erstens, Christian , danke fur dir kommentar, es war schon lange da, befor wir zu hause waren, Ich war vergessen darauf zu reagieren.

This week I assembled the top wing,




I'will make the internal crossbracing only cosmetic, because I made the girders a bit heavier.



Top and bottom wing together;




Laminated the wingtips out of two 2mm X 3mm spruce .


Both wings



Now I am going to finish the wings and start with the fuselage.

To be continued.

[Frédéric]

Salut Vincent !

C'est magnifique ! Très joli travail !


Amicalement
Frédéric

[michel]

Magnifique structure,

Michel

[bocorvin]

Merci Frederic et Michel! It is very encouraging
I am waiting for the tubes and puzzling about the fuselage, how did Fokker connect the wood with the tubes etc?

Vincent.

[VincentB]

Que fais tu exactement en tube? tout le fuselage avec les haubans des ailes et les poutres arrières qui maintiennent l'empennage? ou seulement la partie avant du fuselage qui est entoilée?

[bocorvin]

Bonjour Vincent,
Excuse moi, je continue en Anglais, the tailboom, horizontal and vertical stabilizers, wing struts, struts for the skid and the tubing to support the skin of the nacelle are of tube.
The " A " which you can see on the view from above on my plans is from wood, but I think it is interconnected with metal fastenings. In the coming week I am going to visit the "Aviodrome " (a museum) to have a close look of the Fokker Spin (spider) which is displayed there. The Spin is also a bit of hybrid construction, timber with metal. I hope that I understand a bit more of his , don't know how to say, construction pattern? just the way he worked with wood & metal. I ordered the tubes at "tubos capilares", very nice service, hope to get them on short notice.

Vincent.

[VincentB]

Pour des connexions tubes/bois, tu peux braser une tôle de 1mm et boulonner. Le bois peut aussi rentrer dans un tube si ce n'est pas une partie soumise à des efforts.

[bocorvin]

Je ne comprends pas, helas, je ne connais pas le mot "boulonner".
On one of the photo's you can see (guess) how support tubes are fastened to the skid, it looks a bit like this.
The tubes are silver soldered to the "U "plate.


The bolt is M2 , that would be M10 true scale. I guess he connected those quite big timber parts with metal plates and bolts. Its only educated guessing

Vincent

[VincentB]

[bocorvin]

Bonyour a tous,

I started with the fuselage, first the nacelle. That is built of wood and steel. I tried to make a drawing based on the existing plans, photo's, thinking and guessing!




To get a better idea how fokker bolted all that wood together I visited the Aviodrome, the Dutch aircraft museum. The plane I like to see was the Spin (Spider).I was allowed to make photo's of details (thank you!). There is a snag, this was a replica of a replica, I think the basic construction of the fuselage was 90% correct.










As you can see, rather big steel profiles and big bholts are used, I'll try to keep this in mind!
I glued the wooden frame, first out of 10mm X 10mm spruce, but looking at some photo's of the original I changed it 8mmX 8mm.

Laminated the skid, first 3 layers 3mm X 8mm spruce, later one extra layer at the bottom. I drenched the spruce in boiling water before bending. Clamped it without glue together


and put very thin cyano on it, no mess!
Now I had to start with the metalwork. I ordered stainless steel tubes at "tubos capillares", as recommended on the forum and within a couple of days I received a 2m long package, very good service!

I made the supports for the skids an the piece of metal at the nose to connect the 'nose'of the 'A' and later the tubing of the nacelle. It was long ago I used silver solder and it took some time to get used to it.

After using a bigger torch thing went better, but it was sometimes difficult to keep all the parts correctly placed!






Later it will be bolted with M2 trough the wood.

Just to get a better idea to make the tubing of the nacelle, the placing of the rc equipment and the pilots I put it temporary together.

Never built someting like this
My idea is next to make the tubing of the nacelle and a bit later detailing the wooden structure. I am not used in constructing wood with metal and there is a lot of thinking and guessing in it!

to be continued.

[CHAUSSEBOURG]

Very good building and many thanks for all the détails!
Pierre

[de Schaetzen Harold]

Prachtig! Zeer indrukwekkend. Alles is goed nagedacht.
Doe zo voort.
Harold

[bocorvin]

Thank you Pierre for your nice comments and Harold hartelijk bedankt en inderdaad ik moet me soms suf denken, maar dat maakt dit soort projecten spannend!

Vincent

[bocorvin]

Bonjour a tous,

I started with the tube frame of the nacelle, made it from 6 mm stainless steel tube with a wall thickness of 0.5 mm. Luckily I had some steel wire to prevent buckling.

(found that idea in Pierre Delrieu 's article) I bend it on a workmate with a hole saw clamped in.


When I fitted this on the wing it didn't look good, the tube was to thick. (see the photo on page one of the frame of the nacelle).


I tried now to make it from 4mm tube, also with a wall thickness of 0.5 mm. It appeared to be bendable without steel wire in it! No buckles!
Onother problem was the absence of frames, so I had to make some supports to solder it.



I planned to bolt the ballast lead on the steel plate



I think it's now too flimsy so it will be deformed when covered. I made 4mm tube vertical struts, but I think I will make 3 vertical struts of 2mm solid steel, which is less obstrusive.





I also made the three central wingstruts (first of 10 mm, changed that in 6 mm, that is better looking) and spent a lot of time fitting the puzzle together. This is a sketch of qall the small metal parts I still have to make.


In the meantime I turned a pulley which comes on top of the rear central wingstrut.





To be continued.

[bocorvin]

Hello everyone,

This week I made a lot of small metal parts;


and tried to make a proper support for the "wing warping servo" a very strong servo which Claude gave to me, thanks Claude! 13.6 kg... should do the yob.


It will be attached with a couple of M3 bolts to the metal plate, so which is connected almost directly to the rear wingstrut.
From 10 X 8 mm spruce I planed a more or less tear-shaped strut to connect the nose with the center wing struts.


all connected with metal plates and M 2 bolts.
Now it was time for the tailboom, made from 6.0mm with a wall thicknes of 0.5 mm. It was a bit of a puzzle to hold everything in place, but in the end the tailboom was straight and could be fitted.












It's looking allright, but to my disappointment the tailboom is to heavy . I read some stories about the vulnerabilty of the stainless steel, but this is definitely going to be too heavy. The positive thing is that I know how it all fits together, I learned quite a lot. So I ordered the tube with thinner wall (0.25mm instead of 0.5 mm) and next week I will build a new and lighter tailboom!

To be continued.

[sebastian92]

very good job
It's a pity for the weight but the arm of lever of the nose is important … of what to compensate for the weight in the back, no ?
you build very fast

[bocorvin]

Thank you Sebastian for your comment!

About the weight, I didn't estimate it correctly. The tailboom weighs about 330 grams and the horizontal and vertical stabilizers should be about the same. It would need more than 1000 gram as ballast in the nose. I think it will give a hard to fly plane . Halving the wall thickness of the tubes give about half of the weight I think. I don't like to do things over again, but I know there is no other way. I hope to get a good flying plane now

Vincent.

[GARCIA]

Félicitation pour cette construction