It used to be quite easy to do this until the latest speed controllers came along! My Fishery cruiser model uses the undercarriage switch on the TX to operate an electronic switch on the RX to swap control from one to two sticks using a Y lead from one of the speed controllers. These older Astec units could be swiitched on and off without problems but most modern ones need to do a reset when the power is interrupted which takes several seconds and you lose control during that period.

The stock answer is to get an ACTion P94 of the required rating:

**LINK**

If you download the data sheet you will see that there are two mixer options, one of which allows a model to be spun on its axis. The unit isn't cheap but it does include two speed controllers plus a mixer.

Some TXs do provide inbuilt mixer facilities, usually known as V tail I think, but these are geared to aircraft use and you may not be able to assign the mixing to the two vertical stick channels.

I'm sure someone else can do a better job explaining this as the subject has come up before.

Colin

When trying to do something that the manufacturers never thought of, you will need a "magic box" between the receiver and the ESCs. The transmitter is set as simply as possible, the "magic box" takes its instructions from the receiver, considers them, and gives outputs to the various things plugged into it according to the instructions that you have written into it.

One of the boxes is called an "Arduino". Its a computer on a chip that you program. Rather a steep learning curve.

A unit like the P94 will only mix according to what was designed in, you get one stick for speed, another for differential and rudder.

Using another channel with a switcher with a change-over relay in the signal, rather than power, wires could perform the link/not link function without interupting the power to the ESC control circuits, so the need for a magic box is eliminated. Rather than a computer providing the logic, the operator does it manually. I'm fairly sure that I saw somebody doing something like this with a rather fancy Futaba awhile back, but what extras were in the boat I have no idea.

Using the FS-I6X Instruction Manual, dated 8/10/2018.

This Tx allows infinite experimenting with the various control functions and ultimately reverting to factory settings if dissatisfied with results.

After several attempts at setting the ELEVON function (V-TAIL could be similar, but the Tx channels would be different), decided this works best for me.

It puts both brushless ESCs on the RH control lever. Moving it up operates both screws in the forward direction and down into reverse.

Going from side to side speeds up or slows down the motors, so the boat goes in the direction the lever dictates.

This was accomplished by: 1) Page 14/57 Establish the Tx Stick mode, mine was # 2.

2) Considering ELEVON, need to determine which layout allows the Aileron and Elevator controls to be operated by same lever.

3) Use Elevator for throttle (fwd & astern) and Aileron to “turn”. The Aileron will accelerate the motor on the outside of a turn.

4) Plug Port & Starboard motor ESCs into channels 1 & 2 respectively.

5) Refer to Para 5.10 and set Elevon mode on Tx. 6) Use channel 4 (LH lever side to side) for rudder and Channel 3 (LH lever up / down) for any other function needing proportional control. I am using it for the centre brushed motor. This means that my control levers, which had previously had throttle on the LH lever and rudder on the right are now totally changed.

There is also an article in the March edition of Model Boats that explains the concept.