“DOLPHIN” CLASS FSR | MODEL CONSTRUCTION

Is it possible to attract novice modelers that have passed the basics of learning sportsmanship, to build championship models class FSR? Some leaders of the groups say that is impossible: first, boys are required to accumulate a solid experience; others argue that such experience is much faster is in the process of making championship machines.

Perhaps, to reconcile both sides will help this publication, telling about the development model of the class FSR—3,5 Vlastislav Dvorak, well-known sportsmen from Czecho-Slovakia.

Do note that initially it RC boat was designed for younger modelers working in groups under the guidance of experienced athletes. Therefore, it will be unqualified references to the promised complexity technology: this development is easily reproducible even in the not-too well-secured environment; and good motors produces the desired class and our industry.

So, called the author of “the Dolphin”.

The case of the model designed by the classical scheme. Its basis is a set of plywood formers and wooden stringers, covered outside with a thin plywood. Immediately it should be noted that the main link to build the entire boat is plasticized epoxy, and other adhesives do not satisfy the requirements of strength and moisture resistance. The design model of the balsa is missing, except for the elements of the deck, which with equal success can be made of a light lime or even sturdy cardboard. Some compartments of the hull to reduce noise levels from the skin and to ensure the flooding filled and glued blocks of foam plastic or, if possible, after Assembly in these compartments are introduced foamed composition.

Frames, blanks which are cut out of plywood indicated on drawings thickness, stripped and brought to accurate size using emery paper of different grits. Axis all frames you need with maximum precision to perform the rectangular opening 5X6 mm, which items are placed on glued two strips of a cross section of 3X5 mm Assembly pin. After gluing the main part of the set pin is removed together with the pre-nedorezannye parts of some frames (these areas are shown in the upper dotted line).

Aligning the frames on the pin and controlling the mutual position of the parts with thin copper wire are tightened into place the rail stringers. Again after checking the correctness of the “dry” Assembly, the joints shed svezhenakleennyh epoxy resin. In some places where the bending radius of the rods is small (near the nose of the model), you may have to soak them to avoid cracking the wood. In this case, the resin should be applied only after complete drying of the drawn wire rods.

Then glued the nose of the keel, and the space between the stabilizer pitching stringers are filled throughout the length of the segments of strips of light wood. The forward part of the bar is made from dense balsa or foam. The zygomatic part vyklevyvajutsja from a set of rails and after the curing of the resin processed to almost exact dimensions.

Two symmetrical parts bottom trim, cut according to the drawings, a first control mounted on a frame with pins and clips. They are mounted on the resin only after you can be sure that the bottom sits on the frame in all joints with no gaps. Particularly noteworthy are the place of transition of skin in the zygomatic area. Similarly placed on the seat and the side elements of the casing. The design of the main body portion ends with the installation of the longitudinal planing steps of triangular cross-section 3X10 mm. raw stock vystragivaetsja of hardwood and, if necessary, Reiki pre-steamed and shaped on the bottom.

The design of the model:

1 — forward section of the hull (balsa), 2 — the nasal element of the keel (plywood 3 mm), 3 — gaskets, 4 — rear area motor, 5 — tube water intake for cooling the exhaust pipe of the engine, 6 — cushioning strip site for more support resonant exhaust pipe, 7 — wedge insert (beech), 8 — rear bearing of the propeller shaft, 9 — eyelets fastening the start number (set to starboard), 10 — antenna receiver, 11 — the lever of the rudder, 12 — a tube of a fence of water for cooling the cylinder head, 13 a shaft, 14 the rudder, 15 the transom (plywood 3mm), 16-21— frames (plywood 2 mm; frame 19 — plywood 3 mm), 22 side part of the sheathing (plywood 1.2 mm), 23 — the bottom part of sheathing (plywood 1.2 mm), 24 — silicon connecting element 25 — lateral corner of the hinge motor (aluminum), 26 — cover equipment (plexiglass), 27 — wiring of the water pipe in the wall of the compartment, 28 — pin wire fixing cover, 29 — jumper the motor (2.5 mm aluminum), 30 — spacer (2 pieces, beech 10 mm thick), 31 — engine mount (2.5 mm aluminum).

Parts for the engine mounts are cut using a jigsaw from a sheet of solid aluminum with a thickness of 2.5 mm. Between the assembled engine mount and duralumin angle brackets attached to the sidewalls of the compartment of the housing, invested sinking blocks of silicone rubber or micropore resistant to the effects of fuel compositions. It should be noted that the position of the propeller shaft is determined by the seal bearing, sealed at the posterior end of the deadwood and the propeller hub at the engine flywheel. Therefore, the stern tube can be pasted in the body only after the final binding of the engine and the motor, and the junction of deadwood with a bottom is further supported by the wedge-shaped insert of solid wood, and outside the site is covered with fiberglass. The angle between the axis of the propeller shaft and the keel plane should equal 10-11°.

Patterns of main parts.

The internal volume of the body all the surfaces covered with the liquefied epoxy, then free compartments in the nose and in the sides are filled with customized pieces of lightweight foam. The front part of the deck is executed from a sheet of balsa 3 mm thick and is covered with fiberglass. By the way, this type of external finish is good and for sides — with a view to their strengthening and increase “wear resistance”.

The finished model of the “Dolphin” prior to painting.

The picture in the Intro shows the accommodation of the resonance of the exhaust pipe.

Compartment equipment radio frame with beech slats, which are subsequently screwed the six screws M3. These screws have cut off heads, and underneath their top drilled cross holes Ø 1.2 mm, through which with the equipment of the boat is a steel wire fixing a plexiglass cover.

The fuel tank soldered tin of tinplate with a thickness of 0.4 or 0.3 mm. the volume of the tank is approximately equal to 0.5 L. the Wheel is cut from steel sheet of thickness 1.2 mm and copper are soldered in the slots of the stock Ø 4 mm.

Finishing is sanding with sandpaper exterior surfaces and a coating of epoxy enamels (in the absence of such, it is possible to use alkyd). After curing of the first layers of their advanced Proskuriv, then applied the remaining color the thinnest layers. In the end you still ulcerate the entire model.

The basic data model

Overall length, mm: 570

Overall width, mm: 206

Full weight, g: 1600

Engine capacity, cm³: 3,5

Controlled elements: rudder, carburetor engine (rpm control).

According to the magazine “Modelarz” (CSFR)

From the editor.

As shown by the “forced” practice of the domestic models, the only balsa, but even fine quality plywood is often a deficit, you can try to replace it with… cardboard. However, not the conventional packing, and hardened, called cardboard or presspan. This material is fully justified in the construction of “trains”. However, there is reason to assume that it will be suitable for boats with internal combustion engines. When gluing the covering of two layers of cardboard on the slow-curing plasticized resin is almost complete impregnation of the material — hence the increased humidity, even in comparison with plywood, and good strength characteristics.

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