Flamingo build

[Alan Alderwick]

As I said previously on the forum I have just resumed work on the Flamingo after a two year break. So as not to induce too much stress to the air frame during the plywood sheeting of the fus I decided to produce a steaming jig/former. The Flamingo is relatively symmetrical around the longerons so the jig will allow me to pre-form pretty much all of the sections of the sheeting. The attached pictures show the first piece of sheeting on the top deck of the fus after it had dried, clamped to the jig for 36hrs. The steaming and forming process takes the 'sting' out of the ply and once dry sits on the air frame very comfortably with the minimum of clamping required ( well that was the theory and thus far we are doing OK).

If folks are interested I can post pictures of the jig and a very simple steam chest which was knocked up from a few pieces of gash ply and batons.
This is where I am with the build at the moment having completed the Tailplane/elevators and the fin/rudder. Pictures of which I will post retrospectively.

[Shane]

Good Luck with the build!

Really like the look of that plane. Will build one myself some time I think.

Shane.

[ARUP]

Keep posting pics! The Flamingo is a pretty sailplane rarely modeled. I plan a 'round' fuse ply covered sailplane in future so await posts eagerly like a child on Christmas Eve!

[john greenfield]

Please post details of the steaming jig. Always keen to see how others work.

Thanks

AEB

[Alan Alderwick]

Details of steaming jig:
Will include text later today.

[Alan Alderwick]

Former was built onto the ply base which was a plan view profile of the fuselage longerons.
10mm ply formers were then added from F6 to F16. 20/20 hindsight being a wonderful thing, given time over again I would have just produced it from block timber and profiled it.
Anyway the former was planed/spoke shaved and then blocked down with 80 grit paper.
Top bar was contoured on the underside to give the ply an initial push into shape. this was achieved by covering the top of the former with release film, smearing the underside of the top clamp with body filler and clamping in-situ until set. the release film was then peeled off.
Test pieces were steamed for an hour to achieve plasticity and to check that there was no delamination (didn't really expect there to be a problem as I have all my building materials from Balsa Cabin and their stuff is always top notch)

Will post more details later. Typed quite a detail description earlier and somehow lost the lot!!!

[Alan Alderwick]

Attached shot shows fully dried ply just placed on the airframe. Quite a nice 'kiss fit' on all the formers.

[chris williams]

And that was last of my 'pencil & ruler' drawings! Which reminds me that some of the Flamingos I have seen seem to have a certain amount of anhedral, for reasons I cannot fathom, having checked and re-checked the plan and re-measured the prototype. My advice to Flamingo builders would be to make up the basic wing panels and check the dihedral angles before glueing the wing joiner box in the fuselage. If there isn't enough dihedral, then it would be a simple matter to modify the angles in the joiner box at this early stage...

Note that the lower surfaces of the outer wing panels should be flat at 180 degrees, with just the taper of the wing providing a small amount of anhedral

[Alan Alderwick]

Yes thanks for that Chris. I do recall a email conversion that we had over two years ago when you highlighted the fact that some Flamingos were coming out with anhedral. Fortunately I took heed of your warning and altered the box accordingly.

[Alan Alderwick]

I differed slightly from the recommended construction method and made the fus in two halves. instead of using 1/2 x 1/4 for tK3 & K4 and building the second side onto the first I used two halves made from 1/2 by 1/8 and then joined the two halves together. Much more fiddly I know but it produced a thingy on straight airframe with no twisting or mis- alignment