Blade Flyer

Remotely Controlled Model - Page 8

Disassembled the transmitter, and installed the pitch-roll joystick at the center of the bottom of the vehicle, and the motor control and yaw control adjacent to it. Bolted pipe coupler to the pitch-roll joystick.

Moved the power switch to the side of the pitch-roll gimbal. Having the weight of the entire vehicle supported on the joy stick is a major concern. That's why the secondary support from the top.

Moved the roller servo and receiver more to the aft. Installed the transmitter circuit board. Moved the battery forward to balance the vehicle in pitch.

During the test, the power is enabled with the switch, and the throttle is advanced to maximum. When the rotational velocity is high enough for the roller counter-weight to keep the roller down, the yaw control will be actuated with a stick to release the roller. The truck accelerates until the translation velocity exceeds the rotation velocity, and the engines and blades transition into the conventional flight configuration. During the last few rotations, the roller weight cause the roller to engage the slot in the top, so the vertical stabilizer on the top stops the rotation, and maintains the vehicle pointed into the translation air flow in conventional the flight configuration.

Message to Dionysus Design for later use here:

It takes people a while to get their head around this concept. The lifting surfaces are like helicopter blades during vertical flight and wings during conventional flight.


Google Air Hogs Switchblade RC Plane to see a Canadian design that could be construed to violate the Blade Flyer patent. It is a symmetric airfoil design that uses a spring to flip one blade relative to the other once per flight. It must be manually reset. Its blades are directly connected to each other on a common axle. Its engines are fixed on each blade/wing.

The following text explains the photos and videos at

The Blade Flyer is variable camber and uses translation air flow to flip the blades into wings, so it automatically transitions between flight modes as a function of its translation velocity. Each blade is independently connected to a common hub by way of an axle. The engines are on the wing tips and freely pivot about their center of gravity. For maximum efficiency, a vane on the engine keeps the engine pointed into the dominant air flow, regardless of whether it is due to rotation or translation.

The engines begin flipping as their translation air speed exceeds their rotation air speed. When the translation velocity of the retreating blade exceeds its rotation speed, it flips. The engine and blade flipping slows the rotation to zero, and the vehicle achieves a conventional flight configuration. A torque motor on the hub axle or a vertical stabilizer on the hub engages to maintain the conventional flight configuration. These are disengaged and the vehicle pitched up or otherwise slowed to reverse the process, and revert to vertical flight configuration.

To avoid roll during transition, the dihedral on the engine vane always causes the engine on the retreating blade to flip with its thrust vector down to compensate for the reduced lift the retreating blade relative to the advancing blade.

The blade/wing airfoils are symmetric. Articulating leading and trailing edges provide camber to improve lift efficiency. A single servo in each blade actuates both the leading and trailing edges. Each blade has its own receiver and battery pack.

Each blade pivots on an axle along the quarter chord (center of lift) of the blade. A photo detector on each blade reflects its light off the blade axle. Electrical tape on half of the circumference of the axle absorbs the light, and deactivates the photodetector as the blade rotates about its axle. When again exposed to the shinny brass of the axle as the blade continues to rotate on the axle, the photodetector reactivates.

By way of other circuitry, the photodetector accordingly includes your servo reverser and glitch reducer in the circuit between the receiver and servo, or excludes the servo reverser and glitch reducer from the circuit between the receiver and servo. This assures that the blade camber is always producing positive lift, regardless of the orientation of the blade (flipped or not).

I need only demonstrate to DARPA that the Blade Flyer does not lose lift during transition from vertical to conventional flight mode and back. The wind tunnel I built for testing the components was under-sized to test the entire model, so I will mount the test platform and model on a truck, drive it along our straight and flat deserted desert roads, and video-tape a scale and the model during translation at about 35 mph.

The model must be relatively free to roll and demonstrate that it can maintain level flight during this test, so I mounted the transmitter pitch-roll joystick gimbal inverted in the center of the bottom of the hub. I secured the stick to a to bearing in a pedestal on the test stand such that a roll of the model causes a roll command from the gimbal that increases the camber on the low blade and decreases the camber on the high blade to correct the roll of the vehicle during rotation in vertical flight mode or during translation in conventional flight mode.

I mounted the yaw-thrust joystick gimbal inverted in the bottom of the hub as well. I mounted the transmitter, battery, engine control and a receiver in the middle of the hub. The engine control wires thread through each axle, and connect to the male side of telephone cable detangler in the end of the axle. The engine nacelles mount to bearings on the end of the axle such that the female side of the telephone cable detangler in the nacelle connects to the male side to provide power to the freely pivoting engines.

I mounted the yaw servo in the middle of the hub such that it holds the axle of the roller horizontal (in the plane of the hub) in counteraction to weights on the other end of the roller axle, which pivots on a fulcrum near its middle. The upper third of the hub freely rotates on a ring bearing such that its vertical stabilizer is free to orientate the upper hub into the wind caused by translation. The upper hub has a rectangular slot in it that is slightly larger than the roller.

I mounted a master switch in the bottom of the hub to interrupt the circuit between the battery and the transmitter, yaw servo and engine control, so the transmitter switch could be enabled and engine thrust could be set before the test with the master switch off to preclude anything from happening before I'm ready to start the test by enabling the battery packs on each blade and the master switch on the hub.

The blades and engines will be manually set in their vertical flight orientation, and the engine thrust will be set to maximum before the test.

Movement of the yaw stick by me in the back of the truck with a pole after maximum rotation velocity is achieved will release the weighted roller in the hub. Centrifugal force will keep the roller from engaging a slot in the upper hub. As the rotation of the hub declines during transition, the roller will raise to engage the slot in the top section of the hub. The vertical stabilizer on the top section of the hub will then stabilize the vehicle in conventional flight mode.

Dionysus Design)

The servos on both blades must be signaled to cause some camber and some corresponding lift to unweight the pedestal scale on the test stand during vertical flight mode. I can do this with the pitch potentiometer on the pitch-roll joystick by removing it from the gimbal, and manually setting its position before the test.

The servo on each blade must receive this fixed pitch signal as well as any roll signal caused by the roll of the model on its pedestal. Hence the pitch channel and roll channel on the receiver on each blade must be mixed on its way to the photodetector circuit that supplies the servo with its signal.

Is your V-Tail mixer appropriate for this purpose? If not, what is?

Working mixers finally received and installed.

Adjusting battery position to nutralize pitch.

Covers for receiver and other electronics.

The hub power switch and power LEDs cleared the original support, but a new start-up support that clears the thrust and upper hub release joy stick in its zero thrust position was required.

Safety support.

Top support

Full test assembly with model weight scale and air velocity meter on slide.

View from video camera showing support release string attached to pin in pedistal.

View from video camera

Contact: Bill Holmes via email or 661-305-9465

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