In models, we encounter parts that need to be shaped. In this article we will talk about shaping parts such as aircraft wings, tire treads, etc.
There are many ways to shape parts. Personally, I prefer to shape parts with a rod on a soft pad. The diameter of the log determines the size of the radius of the part to be shaped. It is possible to shape parts from a diameter of about 1mm (depending on the thickness of the paper). Any rods that have stability in bending can be used. For small diameters, these are for example injection needles of various diameters, for larger diameters these can be various metal tubes, wooden rod, etc.
Place the piece that needs to be shaped on the backing and run the rod over the piece. This gradually forms a radius. The size of the radius is influenced by the pressure of the rod on the pad. It is also advisable to moisten the parts slightly before shaping. Saliva wetting is widely used as it gives the part specific properties compared to water. The part does not get as wet and is easier to work with.
Long and small radii are a special case. The classic example is the leading edges of aircraft. Such a part is difficult to shape mechanically, as small diameter rounds bend over a longer length. When using a larger diameter, we get a bend with a large radius, which we then reduce (e.g. by squeezing) usually results in a creased or cracked part. This problem can be easily solved. All we need is masking tape. On the reverse side of the part, we transfer the radius boundary. Stick the masking tape so that a strip of uncovered paper is formed at the radius. Moisten it and wait a few minutes. Once the paper has softened, bend the paper with feeling to the desired radius. Once dry, remove the masking tape and you are done. The result should be a radius with a constant radius along the entire length of the bend. You can also choose to remove the tape immediately after wetting and shape without it.
A variety of objects can be used to shape complex, double-curved surfaces, from metal balls to special shaping tools that can be bought, for example, in model shops.
