R/C TRAINER | MODEL CONSTRUCTION

First, the equipment management model. The use of well-proven systems of the type “Pilot”, “Start” or “RUM” is the only (unfortunately!) the opportunity to engage in sectarian terms radio-controlled model aircraft. They are characterized by functionality and a sufficient noise immunity, which can not be said about modern proportional systems available. Of course, digital is no longer considered “fashionable,” and start holders “Supernarrow” or “Navipromo” will look more professional. But… only as long as after a series of accidents model, they will not come to the conclusion that all the same old discrete is better “killer” is proportional to. Incidentally, this feature of proportionally could be used without quotation marks, if to remember, how many aircraft modeling technique, strength, enthusiasm and best creative time is really ditching because of the low reliability of available equipment (including a “Signal” from the GDR). And in favor of the simplest systems says 15-year experience trouble-free operation of radio in our circle.

To improve the reliability of the onboard part of the “Pilot” we’ve completely redesigned the most flawed unit — steering the machine and a separate power receiver (accumulator 7D-01) and actuators (flat battery “earth”).

New servos represent a simple mechanism with a motor and a centrifugal lever actuator, the design of which is well visible in the figure. With the shown sizes and two cargo traction machine from 0.25 to 0.47 kg, its total weight 35 g current consumption enabled machine from 70 to 150 mA. It should be noted that a simple increase in the number of goods it is possible to achieve significant gain traction. As the motor uses a motor from regular rulemaking or DK-5-19. By the way, for odnokolernyh models instead of the receiver “Pilot”, which is not always available to club members, and you can use the receiver equipment of the children’s “Signal”. With the transmitter “Pilot” the system works reliably.

Under a discrete instrument we can recommend two types of models for learning aerobatics. The first type is the simplest, with only a rudder. This technique is shown in figure 1. This model characterize the flat fuselage, in complexity close to the simple wing training airplanes basic force diagram and… good flying qualities. Besides learning the approach and take-off, it fails to execute and figures such as steep descending spiral and corkscrew, of which the model leaves itself.

Fig. 1. Training RC model airplane with a flat fuselage. Management — only course (in the absence of the signal of the rudder is rejected to the left when serving to the right); the steering mechanism of the machine is mounted on the keel.

Engine RITM 2,5 cm³, the screw 260Х100.

But more interesting is the RC of the second type, equipped at least with two-channel equipment. At the close structural and flight parameters, control capabilities is much wider, as this machine has flaps that are rejected by the machines down independently from each other.

Fig. 2. RC model airplane with dual discrete independent control of flaps.

Fig. 3. The actuator of the centrifugal type (servo).

The fuselage of this model is of mixed construction. Front is a solid plate made of 10 mm plywood, basswood or aspen, with a through window for the on-Board equipment. The tail boom is represented by two spars cross-section 6Х11 mm, a filling of a foam type of PVC and an additional stringer 4Х11 mm. the Finished fuselage is sheathed with thin plywood.

Fender classic design: with ribs from 1.5 mm plywood, front edge section of 4X10 mm, dvukhpolosnykh two side members of the rails cross section 4X6 mm and the rear edge of the 6X6 mm. Flaps cut from basswood and hung on hinges of the usual type. Wing Assembly is in the engine pylon separated from the fuselage finished, epoxy binder (resin assemble the whole model). The wing is removable; it fits the fuselage using the tongue of 10 mm plywood, bottom reinforced with sheet aluminum and two plates of D16T 1.5 mm thick, riveted to a centrally located pylon. The wing — Mylar film with a minimum thickness of 20 microns. Lateral stability models are provided with a foam “ears”, set at 45° to a completely flat wing. The deflection angle of the flaps is in the range of 20°.

Stabilizer: ribs from 1.5 mm plywood, front edge — 4X8 mm, the stringer (and the wing) — 3X4 mm, dvukhpolosnykh longitudinal rail 3X7 mm (as in wing, the plywood wall of the spar), the rear edge is 3X10 mm winglet — a foam type of PVC. Fuselage mounted with a U-shaped plate and M3 screw that allows you to easily adjust the mounting angle.

The keel is cut out of plywood with a thickness of 2 mm and firmly mounted in the beam of the fuselage. The entire model is unprotected Mylar film places covered with nitrocellulose lacquer and painted. The engine working volume of 2.5 cm³ (in good condition) or Kalinka the same volume.

Due to the separate or joint control flaps on this model easily manage many of the maneuvers, until the “dead loops”. During the last trajectory and position of the model is easy to adjust with the same flap. With all this, basic geometric parameters of the plane are chosen so that without the intervention of the pilot to control the model itself quickly restores a sustainable level flight even after the corkscrew, as in a motor-flight and planning. The speed settled motorless flight is about 50-60 km/h.

Of course, the feasibility of creating such a complicated technology with a discrete instrument may be challenged in favor of more modern solutions, designed for proportional control systems. But while in favour of our approach to the case said that at the regional competitions our members have for many years consistently been winners in the class RC.

V. SYCHEV, head of the society, Orenburg

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