Slingsby Gull scale 1/4

[Johannes]

Hi Vincent,
enifach super wie du baust

Johannes

[caralp_laurent]

Hi Vincent,
Good job, it's magnificent !

Friendly,

Lolo

[bocorvin]

Thanks Johannes and Lolo for your encouraging remarks!
Its slowly becoming a glider!

Vincent

[de Schaetzen Harold]

Beste Vincent,

Proficiat met jouw vooruitgang. Ik bewonder al jouw oplossingen. Indrukwekkend!

Ik maak mij een beetje zorgen met de aansluiting tussen de voorkant van de vleugel en de romp. Een gevoelige plek bij een brutale landing. (kan bij iedereen eens gebeuren). Zou jij daar geen extra harde houtstuk gebruiken. En ook een versterking aan de binnenkant van de romp voorzien?

Ik volg aandachtig het einde van jouw constructie.
Mvg.
Harold

[bocorvin]

Beste Harold,

Allereerst dank voor je lovende woorden!

Over de vleugel ben ik helemaal met je eens en ik maak vaak genoeg harde en "minder gecontroleerde" landingen . Vervelend genoeg zit in dit geval het hoofd van de vlieger in de weg, zie onderstaande foto.


Omdat ik een gebroken koolstof pen heb gehad ( zie de reparatie van mijn Nemere 1:6 en ook de recente discussie van Clifton over zijn grote Fafnir)) heb ik besloten stalen pennen te gaan gebruiken (in elk geval 1, deze vleugel heeft twee pennen, dat weer door de V-stelling..)
Hopelijk zijn deze pennen zo stijf dat de romp heel blijft. Maar ik had liever een stevig stuk hout ertussen gehad. Het spant achter zijn hoofd heeft wel een versterking, buiten de romp met een triplex plaat verbonden aan de rib, die het vloeistuk naar de vleugel gaat vormen. Aan de achterzijde heb ik iets dergelijks gemaakt. Op deze foto van de binnenkant zijn de versterkingen beter te zien.


Ik hoop dat het sterk genoeg is!

Met vriendelijke groet,

Vincent

[bocorvin]

Hello everyone,

The discussion with Harold stayed constantly at the back of my head.
(It was in Dutch; Harold was worried about lacking a transverse support for the leading edge)
The position of the pilot had surprised me, half his head behind the canopy, in fact between the leading edge of the wing. I also didn't like the missing of this support.
Then I discovered small triangular reinforcements in the real thing

It brought me upon this idea


and placed in the fuselage

The leading edge glued in with gap-filling epoxy


covered with ply


Hopefully this problem is solved, thanks Harold for your thinking!
I went on with the vertical fin, first some photo's about the retaining wire for the rudder, so it can be easily taken off.





covered with ply

the rear of the fuselage made fit to the horizontal stabilizer

and the lower front of the fin covered with strips

I couldn't find proper pictures of the covering of the real fin, maybe on this photo of the prototype (look also for the pilot, almost hidden in the fuselage)



Next was the fuselage/wing fairing, difficult to find pictures
There is no fairing at the underside and front topside

but the rear top is hard to find out. On the above photo of the prototype, there seems to be a quite big fairing, but on the other photo's.....


This funny part is a kind of lid, fitting on top of the fuselage, between the two wings, practically no fairing..


I decided to make the best of it and after a false start I made balsa fill-inns and covered it with pieces of pre bent ply













Still not sure if it is correct, but it looks quite appropriate.

To be continued,

Vincent

[de Schaetzen Harold]

Dear Vincent,

Congratulations for your final leading edge solution, Inside the hull.
And it leaves sufficient space for the pilot head.

And now, again, congratulations for the central fuselage head. Nearly an artistic work.

Best regards.
Harold

[bocorvin]

Dear Harold,

Thanks for your nice comments and also for your leading edge remarks.

Best regards,

Vincent

[bocorvin]

Hello everyone,

Now it was time to get the cockpit done. I couldn't find a proper drawing, so I thought to make the pilot first. Scaled a drawing of a man down to the proper size

sawed the basic form out of 20 and 10mm balsa sheet

and after some cutting got the basic pilot.

the knee and elbow hinges are fron Robart, the shoulder and hip joints are from 4mm shockcord. A few tricks, make a knot first, stretch it and cut it then, melt it, so the knot stays put.




Hold it under a bit of tension





This pilot is quite flexible and also rugged


I couldn't find much of the instrument panel, but the one one the photo looks it looks very similar to one of the Petrel (I found photo's of different instrument panels )

I found this photo on scale soaring UK

I made a mockup to get the right size and it appeared big enough to house the receiver battery


Having found a place for the battery, I could make the interior. With all kinds of jigs from cardboard I made the backrest, seat and floor.










All the pieces in place




In the meantime I made the wooden construction of the canopy, taking the forms from the fuselage and from the canopy mold



Laminated the frames in the same way as the fuselage frames



Holding it flat to get no distorsion when glueing in the stringers

Sanded it all flush



The clothing and the head are a different chapter!
Now I know all fits I can get on with the plane itself.

To be continued,

Vincent

[Claude Moinier]

Bravo Vincent

[bocorvin]

Thanks for your nice comment Claude .

Vincent

[Johannes]

Hallo Vincent,
sehr schön mit wieviel Geschick du das Cockpit ausgebaut hast
Es macht Spaß deinen Baufortschritten zu folgen

Liebe Grüße und einen guten Rutsch ins neue Jahr
Johannes

[de Schaetzen Harold]

Cher Vincent,

Magnifique, impressionnant.
Le travail d'un artiste qui est heureux de faire une belle œuvre.
C'est finalement le résultat de beaucoup de réflexions et d'habilités.

Indrukwekkend!
De grootste vreugde van een artiest is het eindresultaat. Jij ben niet bang om oplossingen te zoeken en te vinden.
Iets bouwen met zijn eigen vingers in de grootste voldoening van een modelbouwer.
Gellukig nieuwjaar aan jou en jouw famillie.
Harold

[bocorvin]

Hallo Johannes et bonjour Harold,

Vielen dank fur das positieve commentar, es macht mit auch Spass daruber zu reden . Gutes 2020!

Merci Harold thanks for your encouragements, I can't stop this proces to find solutions, but in this hobby its nicely put to use.

Gutes Neujahr, Happy Newyear, bonne Anneé en gelukkig nieuwjaar

Vincent

[bocorvin]

Bonjour a tous,

It was time to make the struts. Now I like to fly it as a Gull I, with struts and also as a Gull III (also known as Cantilever Gull) without struts.
So the brackets should be completely demountable. I made the brackets from 0.5 mm mild steel (a side panel of an old computer ), cut roughly and drilled the holes



Fold it twice, so it became a "U"





soldered with 145 degr solder a M3 nut on it

and cut, file and sanded it into shape


I drilled holes in the main frame

reinforced the frame and glued the plate with nuts with slow epoxy at the inside


A similar job in the wing. Earlier I had filled up the space between upper and lower spar to fix two plates for the strut, but I could not make that demountable
Now I also had to reinforce the lower spar to compensate for the holes




A clean wing when the brackets are screwed off and I have to tidy up the spar....



The original struts were made of metal tube and I had some 4mm stainless steel left. Soldered a piece of tube as an attachment with silver

and after the soldering I cut it of.


It appeared that left and right were just as long, that was a good thing for my mood!






It had to be streamlined and also a bit stiffened

with balsa, LE spruce and carbon strips of 0.8mm, 3mm wide

sanded into shape. Glued on 0.4mm ply (unfortunately I had quite a bad spot in these sheet, it was not good glued at some spots )


When I fly it with struts, I can use carbon wingjoiners, without I need steel wingjoiners
The struts are 52gr a piece, carbon wingjoiners are 120 the two, total weight is about 230 gr. The steel rod joiners are 600gr
I am curious ho it will affect the flying characteristics....

To be continued,

Vincent

[bocorvin]

Hello everyone,

A friend had some doubts of the reinforcements I had made me at a weak point, which I had created in by drilling in the lower mainspar. I had a bit of a blind spot . Glad he told me that, it was easy to improve now So I took out the webbing plate, cleaned up the spar and chamfered the extra layers.




made also doubler on the top spar and put a double webplate at the front of the spar.


I couldn't put extra wood at the rear of the spar, (it was not on the real thing) so instead of that I put on some glasrovings with epoxy on the webbing plate. Later I laminated some short sections of glastape on the webbing to reinforce that also.



Its looking better, so I could go on with all kind of details of the wings.

To be continued,

Vincent.

[Mad Doc]

How nice it is to watch you working!!!
I definetely have to learn to do some of that soldering!

Christian

[bocorvin]

Hello everyone,

Thanks Cristian for your nice comments! The silversoldering is not that difficult, reading a bit, the right stuff and a lot of try and error (sometimes burnt fingers )

Next was with the nose of the wing.



I was a bit worried about that, there are about 12 joints in the ply covering of each wing (there is a bend in it; 4 seams). Scarf joints is very difficult to do it properly because of all curved surfaces. I build fuselages with butt plates instead, wich worked OK. In the wing it would be easier solved with thin glass/epoxy, instead of much thicker ply.
On a flat, (non sticking) surface I soaked 25mm glasstape with epoxy and let it cure. I took that off and cut it in the middle, getting strips of 12mm wide, 0.2mm thick and very flexible. I glued that with cyano an the ribs were the joint was needed. Sanded the rib first slightly down a bit (just the 0.2mm).





The panels were prebended, using boiling water and dried for some time. I fitted both sides and left a overlap at the main spar. Glued it with thick cyano on the leading edge, put the panel on, fold it in its correct position and let that harden


The wing is held vertically just for easier gluing


Now I put the wing flat, opened up one side, put glue in it and closed it while pulling it back.





Turned the wing over and glued the other side. Cut of the surplus


After a lot of gluing..



Still a lot of fiddley things on the wings to do.

To be continued,

Vincent

[Olli]

Hi Vincent,


nice wood work

Best Regards Olli

[Eric Spore]

Nice work ! One more devotee for skin laying with thick cyanoacrylat glue.

[bocorvin]

Hi Olli and Eric

Thanks for your nice remarks Olli !

About the cyano Eric, thats because of the building story of your Nemere .
Besides, it appeared to be quite strong, see "atelier reparation, Nemere 1/6"

Vincent.

[patte de loup]

Nice work Vince
Pat'

[bocorvin]

Bonjour,

Thanks a lot for your remarks Pat' .

I went on with all the control wires, first the wing, I changed the wires for a bit thinner wire, 20 KG, about 0.53mm thick. It was 30KG and that was a bit stiffer and the pulleys are not that big, now its working better.
From 1mm steel wire I bended a loop, which locks the aileron and which I (hope) to unlock via the slot for the control wire .





Th pull-pull wires for the elevator attached at the bellcranck


and also the wires for the rudder with a kind of homemade kwiklinks




Now it was time to put the lower ply panels on the fuselage, first I glued on the strips which acts as butt-plate



sanded everything and started to glue the panels

prepared, put on the thick cyano

put it in position and pressing it with a batten of 10X10 with non adhering tape on it (the brown parcel stuff)


there are some more panels to do...
The wings are now 975gr, servo's included and some minor panels missing.

Vincent

[sebastian92]

Hello Vincent,
you should put on gloves to stick with the cyano… it's safer for your fingers !
Good luck for the future ; it looks good

[caralp_laurent]

Hi Vincent,
Congratulations, it's superb

Friencly,


Lolo

[bocorvin]

Merci Sebastian et Lolo, and I'll put my gloves on .

Vincent.

[Clifton]

Hi Vincent,

I'm coming back to the forum after a long time.

Very nice build, I love this sailplane. I hope I'll see your Gull flying one day.

Friendly,

Philippe

[bocorvin]

Hi Philippe,

Nice to hear from you again . Thanks so much for your comments.
The planning is to fly the Gull at retroplane 2020, hopefully you see it there. It can fly as a "strutted" Gull and also as a "cantilever" Gull or Gull III.


Friendly,

Vincent

[bocorvin]

Hello everyone,

Next was the fuselage, a lot of panels!
The doublers low in the fuselage are to reinforce the fuselage were you hold it to hand launch it.


and a look at the inside with the steering cables in place



I also put some weight between the side panels in the front.

and it began to look a bit like the Gull



Now the nose (pif? )

and the real thing


this was presumably the prototype, it has the short canopy. what I liked was the difference in tints. So I choosed to put different veneers in the nose. Hopefully it will tone down after the staining, I will see.


I use veneer (massive thin wood) instead of ply, its possible to sand it.



and sanded






To be continued,

Vincent

[Sed]

Superbe, comme d'habitude !