RK - 800 ("tandem" sliding wing areal fighter)

leaded50

Legendary member
I didnt had a plane build this at this time, but since needed to show some of my buyild techniques, i started anyway...

The RK - 800 .In 1937, the Soviet aircraft designer G.I. Bakshaev created a project of a promising aircraft with a variable-area wing. The stationary wing of the traditional design was supplemented with special devices, with the help of which it was possible to increase the area of the plane, thereby affecting the flight data of the aircraft accordingly. The first experimental aircraft, it was found that retractable sections of the wing, increasing its area, really improve the basic parameters of the aircraft. First of all, there was an increase in takeoff and landing characteristics. According to the test results, it was decided to continue work and create a new version of the aircraft with a variable-area wing.
The aim of the project now was to create a high-speed fighter for the armed forces, and one prototype was buildt created as a machine designed to establish a world speed record. , but never tested flying, because it didnt get the motor the designers wanted, and the designer was moved to other airplane projects by the Russian government.

The fighter was to become a single-engine piston midplane with a tandem arrangement of two wings, additionally equipped with retractable sections. In this regard, the aircraft design also proposed some new ideas of a layout and technical nature.

The aircraft received a fuselage streamlined spindle shape with the minimum possible number of protruding elements. This design of the machine made it possible to maximize aerodynamic characteristics and reduce air resistance to a minimum. In the forward part of the fuselage was placed a conical screw pitch, smoothly mated with a streamlined engine hood. Bottom under the engine there was a fairing of one of the radiators, output to the stream. The central part of the fuselage was given for the installation of various elements of the wing. In particular, there was a compartment for storage of sliding sections. The tail of the fuselage was made tapering and equipped with two symmetrical air intakes of radiators. In the tail were the keel and stabilizer.

The layout of the fuselage had a number of characteristic features. The nose part of the case was given for the installation of a piston engine, behind which were some additional devices. In the space between the consoles of the main wings there was a compartment for placing the sections and drives for bringing them to the working position. There, with a shift to the tail, placed a single cockpit. Behind the cabin there were additional engine radiators placed under the fuselage skin. Air was supplied to them by means of concave intake devices.

Sliding wings/ sliding wings of a variable area , have over time been done by a few more, both eg. French and Italian aeronautical engineers, but its little info on how good it did function.
The RK - 800 had approx. 30 sections who was moved electrical in and out. I dont gonna build with 30 pieces, since that gonna make my wing all to thick, but planned 4-6 sections at each side. electrical moving... and perhaps i cant get it so much as the original into fuselage sides.
Its a totally unique airplane idea, and never seen as even RC model. If will function good? Who knows, at least i gonna try :)

Fighter in landing/take-off configuration :
rk-i-5.jpg


"High-speed" wing configuration :

rk-i-6.jpg
 

BlockerAviation

Legendary member
Sliding wings/ sliding wings of a variable area , have over time been done by a few more, both eg. French and Italian aeronautical engineers, but its little info on how good it did function.
The RK - 800 had approx. 30 sections who was moved electrical in and out. I dont gonna build with 30 pieces, since that gonna make my wing all to thick, but planned 4-6 sections at each side. electrical moving... and perhaps i cant get it so much as the original into fuselage sides.
Its a totally unique airplane idea, and never seen as even RC model. If will function good? Who knows, at least i gonna try :)
What if you used poster board for the wing plates and used a 360 servo to drive them in and out?
 

GrizWiz

Elite member
i wonder about perhaps use a worm gearbox pushing wingpanels out/in. @BlockerAviation , posterboard could perhaps be used if treated with a thin layer epoxy eg.. then it stiffen it, and perhaps get it slicker for easier sliding in/out too...
You could make some sort of slider mechanism then just use the servo with a pushrod to push it forward and backwards. Or like you said just use a worm gearbox to push it back and forth!
 

leaded50

Legendary member
linear servo would be "big".... im planning approx something that pushes/drag from 20mm to 350-400mm + , in movement. Wormgear i think is best solution. I cant use anything that goes over to other side of fuselage either, and by a dual wormgear shaft system, where they turn differently (one side right turn threads, and other side left turn threads) , it seems could function.
Then could use a normal retract controller for DC motor.... and wormgear motorsystems is easy to find in 3-12V.
Wormgear axle could be placed just in back of front wing.
 
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leaded50

Legendary member
solution: 10 sliding parts at each wing... "mylar sheets! Eg, X-ray film. :) Thats thin , 10 parts will be 3.5mm , but a bit stiff anyway, at least when each part would have a former, and an edge under next one at 50mm wide., and slides nicely on carbonfiber tubes in front of each wing :)
Then awaiting return info from a office machine service guy on internal content to fit for retract/push out parts :)
Retract controller for dc motors is already fixed.