Scratch built 1/72 Short S 80

Evening All,

The Parnall Peto has stalled for the moment so I have started another project: this time I am back in my comfort zone with a real aeroplane, the Short S 80. In 1913 Frank McClean, who was an important member of the Royal Aero Club of Great Brotain and a very wealthy individual, decided that he wanted to fly from Cairo to Khartoum to investigate the Nile cataracts from the air. Given the state of aero technology at the time this was a considerable undertaking which required a purpose built machine. McClean commissioned the Short Brothers to design and build a machine in which he could achieve his aim. The result was the Short S 80 whcih when it was completed in early 1914 was the largest aircraft built in the UK to date. Only one was built so there is no kit of what was a very remarkable aircraft which means that I will have to scratch build one.

The wings and tail plane on the S 80 were large because the warm air in northern Africa would reduce the lift properties of the horizontal flying surfaces. The top wing of a 1/72 scale model is 10 3/4 inches (27cm), - this was cut from 30 thou card, as were the lower wing, tail unit and rudders. There was a tiny elevator mounted in front of the nacelle - this too was cut from 30 thou card: all surfaces were sanded and shaped to aerofoil section and the ribs added from 10 x 20 thou Evergreen strip:

The strip was in turn sanded and the trailing edges of the wings and horizontal tail surface scalloped with a round file:

The fuselage nacelle was made from plastic card using 30 thou card for the base and sides: because the front of the nacelle was curved I had to glue one side of the fuselage to the floor and allow to dry before I could curve the plastic sheet around the nose:

The front upper part of the nacelle was curved so this had to be moulded by shaping a male mould from basswood and making a female mould in a sheet of plywood. The male mould looked like this:

The moulding was made form 30 thou card after it had been heated under a grill - I have still to attach it to the nacelle.

The engine was a two row 140 hp double Gnome Omega rotary engine. Unfortunately there are no kits of such an engine available, and I do not have two single 70 hp Gnome Omega kits which I could use to make up one, so I have made a crankcase from a piece of sprue and cylinders from 60 thou plastic rod:

The main floats were made from wood on the original machine. These were constructed by cutting the sides, top and bottom from 30 thou card. I glued some supports from scrap plastic along the edges of the float sides and glued two spacers in the middle to make the box structure stronger. I glued the top and bottom of the float to one side and allowed this to dry before I glued the bottom into place:

I will post more on this project when I have made more progress. Until then thanks for looking.

Stevef.

Evening All,

Life has been getting in the way of modelling recently, and that coupled with my incompetence has caused delays in progress on the Short S80. In short I made the fuselage nacelle too small, the engine too big, and painted the whole the wrong colour! Apart from that I have now reached the stage when I can start on the main assembly....

The engine parts were assembled and painted - the push rods were made from stretched sprue:

The engine was mounted on a frame which was held between the fuselage longerons: I managed to find a photo which showed what the frame looked like and cut one out from a piece of 30 thou card:

After I had moulded the top of the nacelle I glued it into place and applied filler before sanding:

The interior of the nacelle is based on imagination and assumption as there are no photographs that I can find which show any details, except the steering wheel on the control column. I know that 4 seats were fitted, so I used some resin seats sent to me by @BlackKnight (thanks Fred, they were very useful). The box between the seats is shown on drawings and in photos but I do not know what its purpose was. I also added a fuel/oil tank behind the rear pair of seats - I am not sure if this is realistic but I could not think of where else it could have been located. The longerons were made from 20 x 30 thou strip:

The booms were soldered brass rod:

The boom on the right in the image has been corrected to make all the cross pieces parallel.

There were two airbags under the tail so I made these from sprue which was filed to shape and painted in a fabric colour. I originally painted the fuselage and flying surfaces in a mix of white and Revell Beige (314) to represent the off-white of linen, and the struts (which had been cut from 20 x 30 thou strip), in Revell SM 382 enamel. Then I discovered that the machine had been painted overall white, so I had to repaint the fuselage and flying surfaces in Revell acryllic white and the struts and floats in Revell white enamel:

The ailerons have been cemented to the top wing in the rest position: on the original aircraft they only operated downwards as there was no return cable or springs to bring them back to the horizontal position when the aircraft was stationary.

I am now hoping that I do not make any more mistakes when I carry out the assembly of the parts- fingers crossed!

Thanks for looking.

Stevef.

Evening All,

When I was test fitting the engine mount and engine to the fuselage longerons the engine mount broke so I had to make a new one. The second time I got the engine and mount to fit:

NB not all of the bracing at the rear of the fuselage had benn added when I took the last photo.

The fuselage nacelle was cemented to the lower wing and when this had set I attached the lower boom frame to the wing using superglue:

The upper boom frame was fixed to the upper wing in the same way:

I have a procedure for attaching the upper wing sub-assembly to the lower wing assembly which I have used on many ocasions in the past: I attach two outer inter-plane struts to the lower wing and while these are still flexible I lower the upper wing on to them. I add a support to the rear of the booms and allow the assembly to harden. However this time I found that I could not carry out this procedure because of the weight of the upper wing assembly, so I cemented the outer wing struts to the lower wing and allowed these to dry out overnight. I put small drops of cement into the strut holes under the upper wing and gently lowered it on to the struts while supporting the rear of the booms while I inserted a single central strut. I used a highly sophisticated jig to support the assembly until the cement had set properly:

With the struts in place I added most of the remaining interplane struts and all of the boom struts and bracing:

The next steps will be to rig the booms and wings, add the cabane struts and.the last of the interplane struts, the rudders and horizontal tail surfaces, and then rig those parts of the model. The floats, propellor and other details will follow.

Thanks for looking.

Stevef.