Traditional Helicopter – Suggested Parts List¶
Electronics including flight controller¶
Flybarless electric RC helicopter frame¶
At this time, only conventional single-rotor collective pitch helicopter types are supported such as the Trex450.
The program can be configured to fly flybarred, flybarless, with CCPM swash mixing or single-servo (H1) swash types. Many different commonly available electric helicopters have been flown, from a 450 size, all the way up to 700 size. The system has not yet been proven to work on fuel powered helis, but it should be possible assuming adequate vibration damping is provided for the APM/Pixhawk.
8-channel Transmitter / Receiver¶
Your transmitter & receiver should ideally support 8 channels (elevator, aileron, collective pitch, rudder, flight mode, tuning knob, auxiliary function switch, main rotor speed) although it’s possible to fly with as few as 5.
A discussion of which frequencies are legal to transmit on in which region is outside the scope of this wiki.
ESC with built in governor¶
If you intend to use any Copter flight control modes other than Acro and Stabilize, it is recommended than the speed controller you purchase should have a governor mode. This is because Copter will be controlling the pitch of the main blades automatically, but does not have an internal throttle control system. As such, when AC is commanding high rates of blade pitch, the rotor disk will slow if increased throttle is not be applied. A governor mode in the ESC can be employed to automatically compensate for this. The radio throttle curve and ESC governor can be set up so that the rotor speed will be held at an appropriate speed in all cases.
You should use digital servos instead of analog. There are a number of important reasons for this. First and foremost is because analog servos do not center nearly as well as digital servos. They will always stop on either side of true center, depending from which side they approach center. This phenomenon will cause the PID control system used in Copter to struggle to accurately control the helicopter. Furthermore, digital servos respond much faster to small input changes than analog servos do. This effect is over and above specified transit speed of the servos which is measured for a 60° sweep. If two servos, analog and digital both have the same specified transit time (eg: 0.20sec/60°), and both are asked to move only 5°, the digital servo will move faster than the analog. This also has an effect on how well AC can control the helicopter. Similarly, faster servos will also benefit AC control. The only downside to fast digital servos, besides cost, is that they will naturally have a higher power requirement. This means you will need a larger BEC, and more battery capacity if using a seperate radio system battery. Make sure that your power supply system is capable of providing the power they need.
There are no special requirements for flight batteries. However, as a general rule, it is safer if you can have a separate motor battery and radio battery. Not only does this help prevent radio and Copter power loss when the motor battery drains, but also because disconnecting the power to the motor is one easy method to be absolutely sure that your motor will not turn while you are configuring the Copter system.