New racing car was designed on the base of the machine, the drawings and description of which was published in the “M-K” № 11 in 1986. It is considered to be a design boon for most young athletes involved in kordovye micro machines, and as we see it, only this scheme is able today to give the boys access to high sports results without the involvement of technology, completely made by hands of experienced craftsmen.
We constructed two identical racing through the drawings log. Both “ran” very well, not showing any whims, even on poor tracks. Resistance of movement of the unsprung machines to convince us of the rightness of the arguments about the effect of vibration on the grip of the wheels with the track, so the basic signs circuit “Vyatka” were transferred to the new model.
And changed this. First of all, reduced dimensions; base with 230 mm was reduced to 170 mm. due to this, managed to move from the power of the dural plate thickness of 5-6 mm to the steel nine-millimeter! Weight past after you cut the window in the rear — in the range of 350-400 g, and the main square and the weight concentrated in the area of the plant and is now no longer “smeared” along the length of the model. The engine is mounted on a strong heavy base that not only improves the conditions of work (light, flexible Motorama neobetonirovannymi the engine can lose due to vibration up to 30% power!), but is also almost complete cessation of the transmission of vibration to the wheel! But if you still remember the conversation about the benefits nezaboravnog engine with a horizontal cylinder axis, it becomes clear that now the path will be not trying to cling to the wheels over the asphalt, “shaker”, a normal moving speed model. To completely eliminate the effect of vibration on the clutch, new racing increased and the mass of the hub-flywheel, the inertia of which makes uniform rotation of the drive wheels.
In the sense of resistance against the “guapiruvu” even rough terrains cord was out of competition compared with other schemes. The main thing — do not introduce any damping elements in the suspension in the rear (driven) wheels. Then, in this scheme they will be constantly pressed to the track some force, the reactive torque from operation of the engine, and hitting the small bumps will not lead to a buildup of the body. Unlike the original version of the track of the rear wheels, we have reduced to a minimum. Due to the fact that the center of gravity of the model is very close to the axis of the drive wheels, the main influence on lateral stability is having their track. To meet the requirements of the rules on normal standing model without attached cords at the side position of the engine is a snap.
Control line racing car with an internal combustion engine working volume of 1.5 cm3 :
1 — power plate (steel with thickness 8-9 mm) 2 — M3 screws of fastening of a fairing, a 3 — strut with a fork under the leaf spring of an automatic stop, 4 — leaf spring machine (steel thickness 0.6 mm), 5 — pin-stopper “USA”, 6 — “us” the machine (steel thickness 1 mm), 7 — rubber “boot”, 8 — a nut of fastening of the engine, 9 — boss (to glue in the window of the power plate), 10 — axis bracket rear (steel) 11 — fairing models (Linden or birch with a thickness of 6 mm and 15 mm, the last before bonding to facilitate in-place), 12 — fairing power plant (Linden or birch), 13 — fuel tank 14 — jet engine 15 — engine MK-17, 16 — block drive wheel Assembly, 17 — cord strap.
After determining the main parameters of the new model sketches of individual units appeared quickly (and this is the advantage of the scheme “Vyatka”: so it is logical and complete; in fact, it is only one node in the power system). The only thing I had to retreat from previously published drawings in the locking system on the wheels on the hub. Several event models have been carping point of the rules, which requires the possibility of lifting the individual wheels. Rubber rings from sheet material for the wheels is considered not agreed by anybody. But if those same rings were carried inside a welded metal elements or would be framed by thin metal rings, then…
But think about it, what the conversation! And what we compare! And try to explain to the boys what we are trying to introduce such a far-fetched cord models for classification “wheel”, “wheel”.
Kordovye racing have long ceased to attract Western athletes and control line models remained the lot of modelers from the socialist countries. Have long passed the time when the international Federation was trying to at least halt the victorious March of the Soviet korovikov due to the introduction of new restrictions and requirements for the technique, which is the requirement of separation of the wheels (if it was an attempt to eliminate the benefits of applied Soviet athletes impacted the driven wheels). But still this rule is valid, and even “school” the competition! If the majority of technical requirements aimed at ensuring the safety of the starts or simply a logical, leaving the car with a car, the point about the separateness of the wheels turned into nonsense. Especially today, when all, without exception, the race became purely target devices, far from having similarity to real vehicles (and when these record-breaking machines have no relation to the ordinary mass!).
There is another point — the issue of accessibility of mass automodelisme, question painful and relevant. Many supporters of automodelisme right in saying that there was a situation, when your favorite kind of technical activities need to be rescued “from extinction”. Some, even small, part of the problem was removed development of the scheme “Vyatka”. She only gave the opportunity to engage kordovye racing models guys even in non-specialized conditions, and leaving them no hope to a good place in the competition of a high enough rank. Based on “Vyatka” it is possible to explain to young members the logic of the design, to show that the desired goal is achieved with proper design simply and effectively. In such a model we have to impose unwarranted complication, dramatically reducing the reliability of the chassis!
Hope I will have time to come a time when “Vyatka” will be able to start the original simple. And while were forced to work out a reliable option wheel with hub for each “bus”. Tried three options — all shown in the pictures. They were roughly equal in terms of reliability. Driven all three, as in the performance may be easier for one or the other depending on the machine equipment circles. The first option — with fatty rubber and brass or bronze hub (these metals crude rubber is welded securely enough). For the second option you’ll need to carve out of steel in two halves “hub”; on the surfaces in contact with rubber, to perform many small grooves, carefully round off the outer edges and to Polish them. Test Assembly of the wheels to hold the screws. The purpose is to check whether it closes the gap between the steel parts. The final Assembly of the contact point of the tire that is cut from a solid sheet of rubber, are degreased and covered with glue “Moment”, and then put rivets (12 pieces evenly around the circumference). The third option is similar in type to the second, only here vzaimosvyazi steel parts is carried out by expanding the inner ring. The axial clearance between the elements of the hub must also converge “to zero”, and the quality of degreasing of the corrugated surfaces and the gluing must meet the highest standards. The accuracy of these operations — the key to reliable service is very loaded items. Accurate dimensions of steel parts are not reproduced, as they depend on the type of rubber and the possible degree of deformation during Assembly and clamp “tire”.
The rest of the chassis components special explanation is not required. The only thing I would recommend, — use more high quality steel; replacement of light alloys are generally unacceptable.
The automatic stay continues, the nerdy type with leaf spring insert is usually of the coil spring. Such replacement is justified only by the fact that it was easier to find material for the leaf “springs” that are well-hold the brake in inoperative position and a sufficient force to the hub after tripping of the mechanism.
The rear “axle” race car is simplified to the limit and, as already mentioned, does not contain damping elements. Wheels of any type, it is important only that they do not “beat” in rotation, very easy to operate and have reliable fastening of the rubber. The fact that such a model is much faster any other, is designed to use the MK-17, and any nodes it should be treated as seriously as “adult” race.
Cord strap is wider than the minimum allowed by the rules. This allows you to give it in cross-section a streamlined aerodynamic rounded profile that fits in the required section. The meaning of such decisions will become clear when you consider that wind resistance thin cords “eats” up to 85% of engine power and cord strap located in the zone of maximum speeds.
The engine deserves special discussion. Methods of crossing the MK-17 is known to many, however, after testing the samples, modified in accordance with the publications in the “Modeller-designer” in recent years, can be stated unequivocally: the greatest effect is the “obstruction” to the axis of the cylinder back to 0.4—0.5 mm along the landing to the plane of the flange of the sleeve. We managed to find a way not to cut the protrusions of the lugs on the crankcase under the screws securing the cooling jacket is in the processing of planting belt on the crankcase unnecessary case, which is on the bridge between the exhaust and the bypass window is made the notch-cutter. Rotation of such a “counterbore” manually it is easy to achieve the desired result. If there is another unnecessary defective cartridge, it’s useful to use it as a lapping for finishing the planting belt to the ideal state.
The power part of the model:
1 — the fairing of the power plant, 2 — modified engine MK-17, 3 — overlay threaded carburetor, 4 — nozzle, 5 — fuel tank 6 — fuel-drain tube 7 — M3 screw fixing fairings, 8 — cord strap (steel thickness 2 mm), 9 — angle (steel) 10 — driving wheel, 11 — notched nut (steel), 12 — wheel hub (steel), 13 — split cone (bronze), 14 — nut engine mounts (steel) 15 — spacer (steel), 16 — wall of the fairing (birch, Linden 6 mm), 17 — strength plate (steel), 18 — “mushroom”-nut M3, 19 — Central part of the fairing (birch, Linden, 15 mm thick).
The crankshaft of the engine is modified in accordance with the publication “M-K” № 12 in 1987. It should be noted that a slice of material from the cheek of the crank is very useful for models of type “Vyatka”. As a result of such “balancing” is balanced by only the crank pin and part of rod that is required for complete cessation of the transmission of vibration to the model in the vertical direction. How to finish the toe of the engine, is clear from the drawings. The advantage of our variant we consider the use of spacers between the ball bearings, which makes harder the crankshaft and clearly fixes it in the axial direction. The thread on the shaft end is ground, and to seal the toe of the crankcase in the bore is fixed with Teflon liner, having on the working surface of the dead of the threaded groove. After Assembly, the entire Assembly is checked for ease of rotation of the shaft and the absence of wobbling of the hub with the wheels (the last detail, of course, previously carefully balance). The cylinder liner is processed below the Windows for the formation of passageways to a depth of 0.7 mm, shortened the skirt and outside of the filing on the cone. Mirror casings useful to grind and otherout with subsequent grinding. Although MK-17 littered with the sleeve and have a longer lifespan, yet difficult improvement detail better to make a long (shaft is easier to change). The finished machined sleeve is fixed to the outside of the cooling jacket of “hot”, using the wrapper of aluminum foil with a thickness of 15 µm (baking foil), which significantly improves the thermal mode of forced engine. Spool after milling a new hole for the crank pin carefully balance, and the rear wall being finalized in accordance with the publications of the journal (No. 12 in 1987 and 6 in 1988). Homemade jet set as shown in figure 3 in No. 3. The inlet of the carb in the rear reamed to Ø 6 mm and glued short dural tube, performing the role of futorki. The living section of the carb about 12 mm2 . Final Assembly of the jet is made using epoxy resin.
It should be noted that the resulting all alterations and improvements to the engine according to the nature of the work are quite similar to the original MK-17. The stability of the regime and considerable power characterize these new models. Even when you are not using a resonant exhaust pipe, the speed of the model with such engines 200 km/h is not science fiction. Therefore, such a race model can be recommended for young athletes, age crossed the frontier “school” competitions. In some cases, especially in hot weather, adult athletes, exploiting their micromachines compression engines, we recommend you to enter in the composition of the fuel mixture from 5 to 10% methanol along with other well-known additives. Despite several published comments that the contact with glow fuel in a diesel leads the latter into complete disrepair, still try to make it! According to our observations, slightly worse start, but it is more than block the increase of power and rapidity of the motor. Another important factor is the effect of the internal cooling working MK-17 evaporating methanol, which is even with such a small content in the fuel has almost the same effect as all the other components combined.
V. NOVIKOV, candidate of master of sports
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