LUNGING — SPEED A-1

Speed kordovye models are very popular among modelers of the USSR. According to the classification of models of the ships they are United in group a-and are divided into four classes: A-1 — speed cord model free design with internal combustion engines working volume of 2.5 cm³, with the propeller; class A-2 — speed cord model free design of the internal combustion engine up to a volume of 5.0 cm³, with the propeller; And-3 — speed control line model free design of the internal combustion engine up to a volume of 10.0 cm³, with the propeller; In-1 — speed cord model free design with internal combustion engines up to 1.5 cm³, with a propeller.

 

In the process of developing high-speed cord models and diagrams of their design have undergone several changes, and now they are built in one common scheme.

 

Modern with korost Julia model class And represent a tai-called “three-point” planing system located in front of the two floats and related back propeller. This scheme allows the model to dynamically slide on the heel of the outer float.

 

The conditions apply to design models are quite stringent. First, according to the rules, the noise model should not exceed 80 dB, and noise measurement is made at a distance of 15 m from the model. Because of this design, it is necessary to introduce a special device opposing the spread of noise from the engine. These include mufflers on the exhaust of the internal combustion engine, the screens in the form of a hood and a soft engine mount.

 

In the design and manufacture of the velocity model depends on the type of engine. For model class A-1 can be used DVS “Rossi 15”, and the motors of a domestic production “Talka-2,5”, “CSTOM-2,5 CU” and “CSTOM-2,5 CU as”. However, remember that the specifics of operation of the engines on the models of the class A-1 makes make serial motors a number of significant changes.

 

Most suitable for use in class A-1 engine “CSTOM-2,5 CU as” the world’s micro — motor with a working volume of 2.5 cm³, which shaft and the exhaust hole lie in the same plane, it is easiest assembled in the narrow, low by midlevel cross-section, the casing cord a speed boat. Reconstruction of engines “Rossi-15”, “Talka-2.5” and “CSTOM-2,5 CU” more complex — we can not do without high-quality machining equipment and special skills.

 

The hull is made from balsa, plywood and basswood and covered with fiberglass with a thickness of 0.03 mm using epoxy resin K-153. Then primed with glue AK-20, and after appropriate preparation of the surface is covered with epoxy paint.

 

Chassis model includes a combustion engine with a flywheel, the elements of the driveline, intermediate and propeller shafts and bracket. The flywheel is made of brass, elements of the driveline from steel St. 45, 30HGSA, an intermediate shaft is used the heat treated wire material PT. 65G Ø 2,5— 3 mm. the Propeller shaft is made from St. 65, bracket — material D16T. On both sides of it are pressed bronze bushings.

 

 

High-speed control line model class A-1:

 

1 — float, 2 — cowl, 3 — engine, 4 — resonance tube, 5 — body, 6 — silicone tube, 7 — rubber rings, 8 — silencer 9 — elements of the driveline, 10 — propeller shaft 11 — propeller shaft bracket, 12 — intermediate shaft 13 — stabilizer, 14 — mounting screw, 15 — Traversa, 16 — fuel tank, 17 — spring planing heel float, 18 — guide sleeve of the rod 19, rod floats, 20 — gliding heel float, 21 — lime, 22 — balsa, the 23 plywood 24 — soft engine mount, 25 — supply pipe of the internal combustion engine, a 26 — body fuel tank, 27 — the drain pipe of the fuel tank, 28 — tube air release, 29 — insert the muffler.

 

Balsa floats are secured on the dural cross-screws M2,5. The floats pasted in guides for installing rods planing heels. The rods are fixed by steel springs St. 65G Ø 1,5 mm.

 

The fuel tank soldered sheet tin-plated tin thickness 0.2—0.3 mm. soldered it In three pipes: supply the internal combustion engine, the drain pipe and release the air when filling the tank. The last run through the drainage tube. During startup of the engine and sea trials up the issue of air cover. To exclude the pricing of fuel during sea trials tank is fitted with two rubber buffers.

 

The muffler and insert — aluminum alloys. The silencer is connected with the resonance tube with silicone tubing and rubber rings suspended in the housing.

 

Propellers need to have several. Parameters: step —130—150 mm, Ø 40-44 mm, maximum width of blade is 9 mm. the Best material for the manufacture of such propeller is steel 65G.

 

Cord, and bridle made of wire, St. 65G 0.5 mm. Ø With the requirements of the rope, the bridle and waters for the model runs can be found in the “Regulations of the competitions in ship modeling sport”, in “Additions and revisions to the rules of competitions in ship modeling” (M., 1977, part I and M., 1979, p. 4-5).

 

The start-up of A-1 requires certain skills, and if your first attempts to “revive” the engine fails, then the case is in adjustment, and that skill comes with practice, hard practice on the water.

 

After skills training run, you can start configuring A-1 in dynamic mode. The goal is the creation of conditions of motion of the model in which the hydrodynamic resistance will be minimal, and the unit will go smoothly, without jumps. In this case, the efficiency of the propeller and accordingly the speed will be maximum.

 

Model configuration is performed by changing the angles of the stabilizer and bracket. The final configuration step adjustment of the power system and selection of the propeller. Moving-chamber of the tank in the transverse direction of the machine affects the operation of the engine. During its movement from the center of the circle tank “bedsit”, but rather “Bogatic”.

 

The design speed recommended models 170-175 km/h.

 

K. PACHKORIA, master of sports of the USSR