Short Stirling (scratch build)

[peaceglue]

Hello Papermodellers,

I'm far away from constructing a papermodel with an assembling instruction.
But I like to build that famous plane. As far as I know there do not exist a paper model from the short stirling. I found a lot of interesting stuff about this plane, but no satisfying 3d view with useful cross section of fuselage and wings.

So if you know a legal source for that, please let me know!

Thank you in advance
peaceglue

[legion]

Get Warthunder and the development kit for it, maybe you can export/view the Short Sterling from that. They recently added the Sterling.

War Thunder CDK - WarThunder-Wiki

[JohnM]

The Short Stirling featured in the MicroModels G1 Heavy Bombers Set. Long time ago I had the one my Dad made during the war.

G1 Heavy Bombers, Modelcraft, World of Micromodels

I've found that right clicking on these pictures and selecting 'save as' will give you as good a print as the originals were. These were not detailed models in the first place, but they were quite good, and may well be an aid to your design.

https://en.wikipedia.org/wiki/Short_Stirling Scroll right down to the bottom where there's a selectable four view.

[GaryPilsworth]

there's my Short Sterling in the download section here if it helps

this model was built by a fellow member

[peaceglue]

Hello all,

@legion, thank you for your tip! I'll give it a try.

@JohnM, I've had to correct my knowledge: there exist two models of the short stirling from micromodels (but the scale is too small) and from GaryPilsworth.

@GaryPilsworth, thank you for sharing your model (but the scale is too small). I build some years ago (40 years) the Airfix Stirling in the same scale. But now I want a bigger one: 1:33 and in paper/cardstock.

Thank you all for your engagement and fast reponses.

[peaceglue]

Hello all,

I found an information about the wing cross sections. The airfoil profil is described as "Goettingen 436 mod". I found the profil "Goettingen 436". I think "mod" stands for "modified". Does anybody know what kind of modification it is?

Sincerely
peaceglue

[maurice]

Hi PG
You are not alone in not finding essential info for a large scale Stirling.

The "incomplete guide" at
The Incomplete Guide to Airfoil Usage
early on starts by stating

"On designations: many of the airfoils listed here have "mod" at the end of their designation. Typically, this means that either the camber line has been modified, the leading edge contour has been modified or that the trailing edge thickness has been changed."

it then lists most of Short's contemporary designs as using "Goettingen 436 mod" including the preceding flying boats from which the Stirrling''s wing was derived.

So off to SEAWINGS - The Flying Boat web site and amongst their plans http://www.seawings.co.uk/images/Empireplansgal/0.jpg
shows the Goettingen 436 wing section at the wing root as having a thickness of about 20% as opposed to the 11% of the unmodified airfoil.
http://www.seawings.co.uk/images/Emp...1-fullsize.jpg
gives further wing sections progressivly reducing in thickness until the section two thirds the way out along the aileron is about 14% thickness.
I notice that the drawing shows little sign of washout along the span, was that the case or did the draughtsman not include it?

Pre-dating pressurisation, none of the Short boats were intended to fly at height for passenger comfort and I have wondered how much the airfoil choice was responsible for the Stirling's difficulties in climbing rather than, or as well as, the usually blamed enforced reduction in span.

Don't try and hold me to the validity of any of this.

[peaceglue]

Hello Maurice,

thank you for your fast and detailed response about this subject.

Even you told me to be carefully with your information, I get with that an idea how to handle this problem.

I own the kit "Short Sunderland" published by FLY. Maybe it is possible to scale proprotionally the wing cross sections and transform it for the use at the Stirling model.

I have the idea in the same way for the turrets. The Sunderland middle fuselage turret is the same as used for the Stirling MK II (or Mk I) version. And the Avro Lancaster has the same turrets like the Stirling Mk III.

It looks like a puzzle.

A nice challenge would be the fourteen cylinder Bristol Hercules engine, even you cannot see a lot from that gem, when the model is build.

[maurice]

Hi PG

Went back to the question - "Does anybody know what kind of modification it is?"

Image below suffers from low resolution of some source material but shows in order:-

Goe 436 at 9% thickness chord ratio

Goe 436 at 19% thick but with same camber line (the middle curve) as that for 9%

Goe 436 from the previously mentioned plan at http://www.papermodelers.com/forum/r...ansgal%2F0.jpg but with angle of incidence at zero

Then two ways of comparing the 19% section with that from Seawings

Finally the Seawings version of Goe 436 mod at 3.5 degree incidence as fitted to the airframe.

Points of note are that -
The under surface of the unmodified Goe 436 is flat from 10% of the root chord right to the trailing edge.
The camber line in the Goe 436 mod has been raised evenly and the contour of the leading edge has been modified.
The under surface is now flat between 15% and 70% chord and from 70% to the trailing edge it is curved slightly upwards.
The curve of the rear part of the upper surface is now more gentle.

With most available photos of the the Stirling the quality is too low or the angle of viewing wrong or the inner nacelle and u/c obstructs preventing a good enough look at the underside of the wing root.
However there are a number of modern high quality photos of the Sunderland around which, when you allow for the fact that the wing is intersecting with a curved fuselage surface, confirm the flat under surface of the Goe 436 mod used by Shorts.
A good example is at https://upload.wikimedia.org/wikiped...d_Auckland.JPG

Sadly Fly Model chose to substitute a near shapeless blob for the real life Goe 436 mod of the Sunderland.

[maurice]

Put a bit more effort into this. Found a couple of useful pics of the wing root and used a more complex (he means accurate) method for thickening the Goe 436 whilst keeping the same camber line. Thickened to 19.25% thickness/chord the undersurface becomes a slight convex curve.
In the pics below note that the wing root includes the structure of the wing root fairing and this has been discounted in the comparisons.
Shorts substituted a straight line for the slight curve of the undersurface between 15% and 52% chord, ie between the 2 wing spars, to allow for single piece doors for the inner wing bomb cells. The workers in the first pic are in those cells.

Next up, useable 3-view drawings and and cross sections - now there's some scope for fun - at present there don't seem to be nothing nowhere not nohow that's not in need of a great deal of reworking!