In this post we will talk about the design of foam electrics.
In recent years modelers have gained access to great material to create flying models. This is a finishing foam ceiling panel with dimensions of 500×500 mm with a thickness of from 3 to 6 mm. a Large part of such panels from the front side is decorated with various raised patterns, but the market fall and the leaves with a smooth surface — that they should be given preference. From these panels, you can produce almost all the main parts of the model from the wing spars and ribs to of the fuselage frames and plating. By the way, if you could purchase a plate of 6 mm thickness, it is easy to do a 3-mm plate, spreading the workpiece on two 3-mm with a glow current of nichrome wire.
It should be remembered that the strength and modulus of elasticity of the foam is not too large, so the most critical (power) details should be enhanced. For the wing ribs and fuselage formers to paper drawing paper (Whatman) or a thin fiberglass using glue “Titan”, designed for mounting the ceiling panels to the ceiling. With its help you can also stitch the foam parts (both overlapping and butt), and the seam thus obtained is colorless and its high strength and elasticity — not lower than the foam.
In the manufacture of foam such power of model elements, such as wing spars, they can be used to enhance manorastroman strands of glass or carbon fiber. By the way, the modelers were able to detect quite a suitable replacement for this material in the cords, which are sold in hardware stores as a clothesline for drying clothes. This “rope” consists of a prisoner in a vinyl shell heavy-duty harness threads. To help strengthen them, for example, wing spars or ribs, the threads should reformulate with glue “Titan” to the upper and lower surfaces of these parts. Well, to increase the stiffness of the wing in bending and in torsion, it makes sense to stick on the bottom of the foam consoles two such strings, placing them diagonally.
Getting to design the foam models should take into account that the foam can be curved using suitable metal items such as cutting steel pipes round or square cross-section. For example, in the manufacture of the upper panels of the wings bend in the front part thereof can be obtained, pushing the foam plate-solid billet to a tube of suitable diameter, heated over a gas burner. The degree of heating will need to be determined experimentally, using scraps of foam.