Sikorsky S-40 Flying Clipper

[papermodelfan]

Hello all. Almost a decade ago, I enjoyed building the FG S-38 and S-39 models at the large scale version. I wanted to look at what comae next, and tried my hand at designing one, hand drawn with pencil and t-square. That convinced me that it could be done, but the results were never quite satisfying. So I was delighted when Aaron Murphy recently published his design at Murph's Models, with an inspiring test build by gomidefilho. I have built that model now at a scale of 1:50, to match the two previous ones. This gived a wingspan of 2.3 feet.



In the course of building I tried to add a bit more detail. Here are a few pictures of the finished plane and then a few details that I incorporated along the way. Thanks again to gomidefilho for introducing me to suture material, already attached to a very sharp needle. This made the rigging so much easier to accomplish.

[MacSongLi]

You did an amazing job. She is a beautiful flying boat. The rigging is amazing.


Gary

[papermodelfan]

So a few of the details and modifications. First - the wings have a slight dihedral, with the break occurring just outboard of the motors. This is, conveniently, where Aaron has a break in the structure, making it easy to add about 1.5 degrees of dihedral to the outboard parts. Here is a picture showing the dihedral particularly clearly: Google Sites
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[papermodelfan]

Sorry - I was not able to load the image properly. But here are a couple of shots showing the attention to add the dihedral to the inner spar.

[papermodelfan]

Second modifcation. There area a lot of struts supporting each of the motor nacelles - I had to add at least two beyond what was provided in the model for each nacelle. Here they are during the process and at the end.

[papermodelfan]

and on the finished model

[papermodelfan]

Another small detail was the nature of the struts for the tab assists on the ailerons and stabilizer. I see solid parallelograms, rather than the open framework the model offers. Also, there are two diagonal struts that strengthen the attachment of the floats to the outrigger structure.

[papermodelfan]

The motors themselves are real works of art, I built them just as designed, without the cowlings.

[papermodelfan]

One puzzle in attempting a realistic rigging was how the tail control cables lead. I found one picture showing 6 cables emerging from the back of the hull, going up to the underside of the wing, then emerging from the upper surface of the wing and going back to the tail in three pairs. This meant one pair for the left elevator horns, one pair for the right elevator horns, and a pair in the central that must be for the two rudders. This was a mystery to me, how to hook up the central pair to the rudders, and I could not find a photo directly of that linkage. However, I did see pictures of the S-38, which has a similar tail frame, where the two rudder cables go to a rocker bar underneath the stabilizer which has a mechanical linkage to the rudder on each side. So I am guessing the S-40 had the same arrangement, and that is what I modelled. This is a unique path for control cables, in my experience.

[papermodelfan]

The landing gear (eventually abandoned on the real craft) needs an additional middle pair of struts to have stability and strength to support the weight of the model. These are not imagined - they were present on the original. Mine came out a little heavy.


Then there is the search light on top of the pilots cabin, and the docking lights on either side of the bow. I just used silver paint, but these could be with plastic lenses. These are indicated on the Murph's model.



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