Abstract: To configure the yaw axis control mechanism of a coaxial counter-rotating unmanned helicopter to be able to accurately control the pitch angle of the upper rotor blade by a simple configuration even if the precise adjustment is not performed. A rudder control rod is inserted into a main mast of a coaxial counter-rotating helicopter, a lower end portion thereof is connected to an output lever of the rudder servo, and a mixing rod head is fixed to an upper end portion. A link mechanism connected to the upper swash plate is attached to a side surface portion of the mixing rod head, the vertical displacement of the mixing rod head moving up and down together with the rudder control rod is converted into a displacement for tilting an upper blade holder around the spindle via the link mechanism, thereby changing the pitch angle of the upper rotor blades.

Abstract: To further stabilize the flight operation of an R/C helicopter, thereby improving operability, based on the finding that a position of appearance of gyro precession is different from the conventional R/C helicopter. A rotor head of a coaxial counter-rotating R/C helicopter is configured so that upper and lower main rotors MR are provided, in response to gyro precession of the main rotors as an output to an operation input from the swash plates appears within a range smaller than 90°, mounting positions of the upper and lower main rotors are provided to become an angle smaller than 90° around the main masts and with respect to the input positions of each of cyclic controls to upper and lower main rotors using the upper and lower swash plates, and the upper and lower main rotors and the upper and lower swash plates are connected via a link mechanism.

Abstract: To configure the yaw axis control mechanism of a coaxial counter-rotating unmanned helicopter to be able to accurately control the pitch angle of the upper rotor blade by a simple configuration even if the precise adjustment is not performed. A rudder control rod is inserted into a main mast of a coaxial counter-rotating helicopter, a lower end portion thereof is connected to an output lever of the rudder servo, and a mixing rod head is fixed to an upper end portion. A link mechanism connected to the upper swash plate is attached to a side surface portion of the mixing rod head, the vertical displacement of the mixing rod head moving up and down together with the rudder control rod is converted into a displacement for tilting an upper blade holder around the spindle via the link mechanism, thereby changing the pitch angle of the upper rotor blades.

Abstract: A remote controlled helicopter of a single rotor type to be used indoors, having a flying operation that can be stabilized and operability that can be improved. The helicopter includes a center hub that supports a rotor head to a mainmast, and is divided into an upper center hub and a lower center hub. The upper and the lower center hubs are fixed around the shaft of the mainmast with a predetermined angle. A phase angle of a main rotor as an output with respect to an operation input from a swash plate becomes an acute angle, and the main rotor and a stabilizer are mounted to rotate with a phase difference of the acute angle.

Abstract: When an R/C helicopter of a single rotor type is configured to have a small size and light weight to be used indoors, a flying operation thereof can be stabilized and operability can be improved. A center hub that supports a rotor head to a mainmast is divided into an upper center hub and a lower center hub, and the upper and the lower center hubs are fixed around the shaft of the mainmast with a predetermined angle. A phase angle of a main rotor as an output with respect to an operation input from a swash plate becomes an acute angle, and the main rotor and a stabilizer are mounted to rotate with a phase difference of the acute angle.