"How many channels should RC helicopter Radios have?"
This is a question I get asked a lot by people who are just getting into the hobby and looking to purchase their first RC radio. The simple answer is “it depends on the helicopter”. I know that doesn’t answer anything – so here we go...
When you go RC heli radio shopping, your first decision is to determine how many channels you will require. Each channel controls one surface or component on the RC helicopter. In short - the more complex the helicopter, the more channels you need.
A two channel radio would be used for the most basic of toy grade helicopters , such as the Havoc Heli.
A few toy grade coaxial (counter rotating main rotors) RC helicopters use three channel RC radios.
Again, these are simple radios that are included with the toy helicopter so you don’t have to worry about getting the radio separately.
Four channel RC helicopter radios are required for
micro coaxial RC helis
with cyclic controls, hobby grade
single rotor helis with tail rotors, and most quad/multi rotors. Now we start getting into true
that uses a swashplate or on the multi rotors full speed control of all the motors to achieve lift, yaw, roll, & pitch movements.
For a hobby grade coaxial heli:
For a single rotor fixed pitch RC helicopter:
For most quad/multi rotors the same four channels are used to control lift, yaw, pitch, & roll; but it's done through the gyro control unit onboard the multi rotor aircraft to change the speeds that all the motors are spinning the propellers. By precisely changing speeds of the propellers, all the same four movements (lift, yaw, pitch, & roll) are attainable.
This is the minimum number of channels you need to control a hobby grade RC helicopter with collective pitch.
As in the explanation of the single rotor fixed pitch heli above, the first four channels are used for the same things:
Again, this is the bare minimum number of channels you need to control a hobby grade RC helicopter with collective pitch; but is very limited in practicality these days since the introduction of gyros or flybarless systems with remote gain and mode selection (pretty much the only option these days) – yup one more channel needed.
As I just stated, if you are getting into a hobby grade heli with collective pitch and have anything but the most basic gyro, you will need a six channel helicopter radio to select different gyro gain settings or to select between yaw rate gyro mode or heading hold gyro mode.
Most also consider 6 channels the minimum now for most quad/multi rotors if you are planning on flying FPV or using them for aerial photography. The two extra channels can be used for tilt and pan of the camera for example; or to activate GPS autopilot modes such as return to home, auto orientation, or various stabilization flight modes.
If you are looking to control more items on your RC heli or quad/multi than the basic flight controls and gyro/camera/flight mode features – you of course need more channels. These items include:
The options are really only limited by your imagination and credit card ;-)