Cardinal RTF … yellow wire question

[WilleeCraft]

I noticed that there is a yellow wire that is not connected. Should it be connected somewhere?

[WilleeCraft]

[ridgerunner]

Someone else asked pretty much the same question over in the Official Skynetic 1400mm Cardinal Glider Thread
. Here's my answer for what its worth:

It appears that the Skynetic 20A ESC in your new Cardinal has REVERSE functionality. The extra yellow wire on these reversing ESCs is provided to allow the user to select either forward or reverse direction for the brushless motor. This reversing functionality is typically used by pilots flying fast EDF aircraft to quickly slow the plane down after touching down on the runway. It is also useful for float planes to allow them to back up when floating around. This functionality is certainly not needed on the Cardinal motor glider! The single yellow wire carries the REVERSE function signal from the receiver (RX) to the electronic speed controller (ESC). The signal is essentially a binary switch that selects either forward or reverse.

You can plug this connector into any extra channel on the receiver (on the signal pin) and set up your transmitter to control it using that channel. Note that only one wire is needed because the other two wires are provided by the throttle cable. (The black wire is ground and the red wire is +5Volts, and together these two wires provide power from the ESC to the RX and servos. Since power is provided by the throttle cable, the reverse cable only needs one wire.) Alternatively, I do believe that you can just not connect it at all and leave it hanging disconnected - but I am not 100% certain on this point.

Have fun with your new Cardinal - its a nice motor glider!