The prototype model has served as a snowmobile amphibian created in 60-ies a group of young professionals under the leadership of the Soviet aircraft designer A. N. Tupolev. This car attracts the severity of the contours (see “M-K” No. 11 of 1978), do not break any complex suspension system of the ski or tubular enclosure of the propeller. And this is a significant advantage Because each protruding element design increases the aerodynamic resistance. It is better to have a bulky, but streamlined body than compressed to the limit, but with the “stork” legs of the undercarriage. In addition, the housing of such a model creates the effect of aerodynamic unloading, manifested even at low speed. Amphibians have relatively small diameter propeller.
This allows you to make copno moderate dimensions, focusing on the optimum propeller diameter 160 mm for the engine with working volume of 2.5 cm3. Hence selected, and the minimum allowable scale of this model — 1:12 on the prototype.
The case of the model can be applied to the wall of the fiberglass, but easier to make from plastic. It is extruded from a heated Plexiglas, alternately stamping the four parts that form the outer skin. The case weighs just 400 g. Details adjust to each other, glued, pre-cutting hatches and doors. There is a saving of time and effort. Imagine how much trouble would it Vileika of fiberglass, not to mention time-consuming operations for surface preparation of fiberglass “crusts” for painting. And cut the “glass” in them requires a lot of effort. Housing made of plexiglass after stamping is immediately ready for painting. He has a good gloss, and the “glass” is inserted. They won’t fly out when you shake or to form prominent ledges PRN imprecise fitting.
Thus, the material chosen. Now you need to make a wooden disc-punch for each part. Such blanks will need three: for the body (it can be used with the hood top and bottom), torch n of the engine hood. The shape of these punches you need to understate 2 mm, considering the thickness of the plexiglass. A plywood thickness of 15 mm on the exact contours cut out of the matrix window. Wooden parts lubricate with machine oil, heating it to 50 — 80°. Acrylic must be heated to 115 — 135°, to impose on the matrix and push the top of the punch. This work should be performed together — so it turns out faster. The cooled semi-finished products cut to size limits saw with fine tooth. After adjustment, the parts with a jigsaw, cut out holes, separated hatches and shutters of the lantern.
The prototype model has served as a snowmobile amphibian created in 60-ies a group of young professionals under the leadership of the Soviet aircraft designer A. N. Tupolev. This car attracts the severity of the contours (see “M-K” No. 11 of 1978), do not break any complex suspension system of the ski or tubular enclosure of the propeller. And this is a significant advantage Because each protruding element design increases the aerodynamic resistance. It is better to have a bulky, but streamlined body than compressed to the limit, but with the “stork” legs of the undercarriage. In addition, the housing of such a model creates the effect of aerodynamic unloading, manifested even at low speed. Amphibians have relatively small diameter propeller.