I'm newbie too. I want to ask, what are the differences between the coaxial and the tail rotors heli?
The difference is quite simple. On the single rotor helicopter (with tail rotor) you conrol rotation about the rotor mast by the tail rotor. It is used for anti torque as well as directional control. The swash plate (on the rotor head) along with the pitch mixer assembly control the pitch change of the blades as they rotate about the mast. A true helicopter is "flown" continuously. While flying it a pilot has to compensate for roll, pitch and yaw all the time. Failure to do so will most likely result in a crash. Modern gyros and IMU controls have made this much more stable. Although, when autopilots and IMU's are off it reverts to a "Real Helicopter" flight pattern again. Think of the pitch control as the elevator of a plane, roll is similar to ailerons and the yaw control is similar to a rudder on a plane. Coaxial rotor copters are much easier to fly since counter rotation of the rotor head compensates for the torque of the rotor. Meaning you do not need a tail rotor for them to fly. They also have very little roll problem because of this since the rotors have a gyroscopic effect that is different from a helicopter. G- forces are counteracted and there is very little, if any roll.
Fixed pitch main hub is a good start. If you get a full collective then you must deal with the angular difference between retreating and advancing blades when maneuvering from a hover into lateral flight... lets say in a left lateral shift from a hover. One of my soldiers in the barracks crashed an electric full collective helo. He got it down after he kept losing lift when he tried to fly left lateral causing it to hop up and down as he juiced it to recover. But then he set it down and bumped the juice stick and it jumped off the table into some furniture.
definitely start with a glider lol
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