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1/72 Airframe Short S.20 Mercury


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I voted for "Made In Britain" GB with Contrail Mayo Composite in mind, but knowing my pace and determination I'm not sure that I could complete the whole stack in time so I decided to do one step at time and start with Mercury.

Contrail's Mayo Composite kit was a joint effort between Contrail and Airframe each providing one aircraft.

Airframe S.20 moulds look very basic but buildable, will require a lot of scratch building, scribing and detailing to look right.

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Looks as though you are in for a festival of scratch-building. Those propeller mouldings certainly seem to offer more trouble than they are worth.

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Does anybody have a photo of Mercury from above?

The point of interest is engine fairing - is it "round" or "square"?

These well known plans show "square" blending of engine nacelles into the wing

55-2.jpg

Mayo_Composite_70a207ad66d7b0cc830cc8f19

5082_1.jpg

as implemented on this model:

2.jpg

I don't trust these plans much as I have already spotted several inaccuracies.

This graphics shows more "roundeded" blending, although I don't have any photographic evidence

56-1.jpg

The best views I could get are from Flight archives

https://www.flightglobal.com/pdfarchive/view/1937/1937%20-%202424.html

https://www.flightglobal.com/pdfarchive/view/1937/1937%20-%202285.html

https://www.flightglobal.com/pdfarchive/view/1938/1938%20-%200353.html

but it does not answer the question

Again - this is just a sketch, blending is "round"

https://www.flightglobal.com/pdfarchive/view/1938/1938%20-%200448.html

Any hints?

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Nice choice - I'll watch buid with interest.

Does anybody have a photo of Mercury from above?
The point of interest is engine fairing - is it "round" or "square"?

These well known plans show "square" blending of engine nacelles into the wing




as implemented on this model:
2.jpg

I don't trust these plans much as I have already spotted several inaccuracies.

This graphics shows more "roundeded" blending, although I don't have any photographic evidence



The best views I could get are from Flight archives
https://www.flightglobal.com/pdfarchive/view/1937/1937%20-%202424.html
https://www.flightglobal.com/pdfarchive/view/1937/1937%20-%202285.html
https://www.flightglobal.com/pdfarchive/view/1938/1938%20-%200353.html

but it does not answer the question

Again - this is just a sketch, blending is "round"
https://www.flightglobal.com/pdfarchive/view/1938/1938%20-%200448.html

Any hints?

(opinion) I think that either: the engines in that build are too deep (top to bottom), or (less likley) that build set the engines too high.

Double check before rejecting the kit items - those nacelles may have been scratch built, even if the wings came from the kit.

Merc-MaiaAerial900_zps726843e1.jpg

Same image as your Flight page ( https://www.flightglobal.com/pdfarchive/view/1938/1938%20-%200353.html )

gadhj.jpg

Source: http://www.hampshireairfields.co.uk/airfields/mat.html

Once the tops of the engines are lower (or whole engine is less deep), a square-ish fairing would be more reasonable.

OT Did you find these links?

http://www.gettyimages.co.uk/detail/news-photo/the-mechanics-of-the-monoplane-hydroplane-short-s20-mercury-news-photo/104415444

http://www.gettyimages.co.uk/detail/news-photo/the-high-winged-double-floater-monoplane-hydroplane-short-s-news-photo/104414908

Right click on images in linls for a better/larger views

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Robert, thanks for your opinion, I agree - the engine nacelles are way too high on the model (and on the plans provided), either simply installed too high or the dimensions are wrong (or both). By all means - the engines from the kit are barely usable. The dimensions of Napiers are well know - will check

The shape of the fairing remains unclear though

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Just a thought.

Looking at the plans, (#10) and the thickness of the wing, perhaps the square fairing is not a faring at all but where the rise of the wing surface meets the depth of the engine nacelle. If so, this would give the squared off appearance as no aerodynamic faring would be needed to blend the nacelle and wing together, (i.e. as seen in the Bristol Blenheim).

just my :2c:

Christian, exiled to africa

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Hmmm, yet another problem with the plans shown above! You are quite right, the wing is not that thick and these photos do show a small step on the dorsal wing surface, which does look to resemble a rounded, pen nib style of aerodynamic fairing.

This site is great!

Christian exiled to the dark place.

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I was asked how I cut parts using rotary tool.

Here is my Proxxon Micromot magic rotary tool ( Dremel? Never heard )
PICT0640.jpg

PICT0640.jpg

As usual, I start with outlining the part with permanent marker
PICT0641.jpg

PICT0641.jpg

It is easier to cut from the opposite side where the edges are more clearly visible
PICT0642.jpg



I leave 1-2 mm. clearance from part edge, holding the cutting ring slightly inclined outside outer surface of the part
PICT0643.jpg



Stage one complete
PICT0644.jpg

PICT0644.jpg
PICT0645.jpg

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The next step is cut out "horisontal" excess of plastic. Again, the disc is sligtly inclined outside to prevent touching of outer surface
PICT0647.jpg

These "tails" tend to vibrate then they are too long, so I cut or simply tear them off periodically
PICT0648.jpg

The last step - remove remaining "white" margins
PICT0650.jpg

This time I don't cut but sand.
PICT0651.jpg

Melted plastic residue, easily breaking off with fingers
PICT0652.jpg

Sanding on the surface is still needed, but not much - a couple of frictions yield to smooth and flat part edge
PICT0654.jpg




The whole process from plugging the tool ( it shares power socket with airbrush compressor ) takes less than 10 minutes - quick and easy

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Thanks Pin

That looks more like it, I've always been put off building my vacforms, by the thought of dying of old age slumped over a sheet of sandpaper surrounded by banana shaped bits of plastic !

However this method although not for the faint hearted looks much more do-able.

Cheers Pat

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  • 2 weeks later...

Cockpit. Not much will be seen once closed so I did not spend much on it

1453640319_PICT0688.jpg

Glazing. Will be polished to transparency once closed

1453640323_PICT0689.jpg

Old trick to make trailing edges razor sharp - literally - "use metal blade"

1453640329_PICT0693.jpg

1453640340_PICT0694.jpg

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