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Part 2: Nearly Ready for Action

The control surfaces were a particular issue with this build. Initially I used the aluminum landing struts from R/C aircraft. I cut these in half and widened the existing holes in the sides of the aft hull. I bashed up some rudders from plastic and aluminum stock.

Original rudder and elevators

I decided I really didn’t like this. The angle of the horizontal parts looked good but the rudders were terrible and there were no horizontal control surfaces. This is when I took the two Ryan Spirits and decided to use their wings. For the 1:48 scale kit I took the top half of the wing, cut it in half and glued it together as a top and bottom of a single airfoil. I used Green Stuff and sanded until I had a single long smooth airfoil. This provided a really nice “generic” airfoil for use as a rudder or other control surface. The 1:72 scale had a solid single piece wing. I cut this in half at the center line and then sanded the bottom sides off both pieces. Once these were flat I glued them together and puttied the leading edge to sand it smooth as well.

 

Two sizes of Spirit of St Louis wings as masters for airfoils

This gave me a pair of masters for the production of resin parts. I sent them up to Wayne in Michigan who provided really excellent castings. Once the parts had arrived back in St Louis I had to decide what to do with them. One thing that a lot of VSF designs lack is enough control surfaces. The ships will be moving slowly and will have a lot of mass. Combined that with the limited resistance of air compared to water and a lot of control surface will be needed. I decided to do a fairly complex set of surfaces. I wanted to make maximum use of the pieces I had. The main surfaces would be made from the larger airfoil and I would fill in with the smaller one.

On the full scale machine the basic design idea was for the horizontal surfaces to be a single piece; what is called a stabilator because it is both a stabilizer and an elevator. This would pivot along its center line. Through the pivot point axle would run a structural member and gearing to control the rudders. This would connect to a gear box upon which the upper and lower rudders would be attached. The Upper rudder would be the larger of the two and the lower would be able to swing out 90 degrees and act as an air brake (if both were swung out at the same time) or as a drag rudder if only one was extended. The lower rudder would also be connected to a box on its lower end and from there back to the main hull buy a long brace piece. This brace piece and the axle of the stabilator would form a strong structure for the control surfaces.

I used the two chop saws to cut the large airfoils into the correct shapes. The rudder was easy. I just marked up the ten pieces and cut the same length off each of the outboard ends. The stabilators were cut out on the outboard side to allow the rudders to swing without interfering and had an angled cut on the inboard side to natch the angle of the hull. This required a paper template to be made and the chop saw to be marked so i could use its mitre guide. All worked well. Now I drilled all the necessary 1/8 inch holes for brass rods in the big pieces and 1/16 inch ones for the small rudders.

The three airfoils and one of the gear boxes in place. Note the shapes used. These were cut on the chop saws

Control Surface sub assemblies

 

The gear boxes (two per control surface assembly) were made from acrylic square stock. The larger gearboxes were from 1/2 square stock and the others from slightly smaller material. The central boxes got three holes drilled in them and the lower boxes just a single one.

A main gearbox. This has been drilled and all three rods are being tested to ensure proper fit

The paired assembles were put together. I had to make certain there was a “left” and a “right” for each ship and that all the airfoils were lined up in the correct directions.

Once assembled and primed they were set aside to dry and to ensure the glue was set.

 

Next I detailed the upper hull with Mirco Engineering girder pieces.

Micro Engineering girder in place on deck house

The places for turrets were drilled. I assembled the Male sponsons, but left off all the bits that allow the 6 pdrs to elevate and traverse. With the close space behind the sponsons these parts will not fit. In fact I had to snip off the entire breech to allow it to fit. Even then the circular gun shields only fit if the weapon is traversed to a near broadside firing position. I cut the gun tube short as well, to me this represents a howitzer, not a long 6 pdr.

Sponson in place

 

Sponson is close enough to the hull that it doesn't interfer with the massive 9.2 inch rocket batteries.