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Jan 21, 2003, 12:33 PM
Registered User

Futaba T6XA Super: Twin motor, throttle-rudder mixing


Here's my problem:

I have an electric twin motor plane and I want to use the motors to yaw instead of using a rudder.

Here's what I was thinking:

Plug the ESC for the left motor to channel 3 (throttle)
Plug the ESC for the right motor to channel 4 (rudder)

Radio mixing:

PMX1: Master channel = 3 (throttle), slave channel = 4 (rudder). mixing is 100%. This should allow the right side motor to follow suite with the left hand motor.

To get differential steering:

PMX2: Master channel = 4 (rudder), slave channel = 3 (throttle). Mixing is %80 for left rudder and %120 for right rudder. A difference of %20 either way. When giving left rudder the left motor would turn at %80 of the speed of the right motor. This would yaw left. When giving right rudder the left motor would turn at %120 of the speed of the right motor. This would yaw right.

Am I correct?
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Jan 21, 2003, 01:25 PM
Registered User
flyfalcons's Avatar
That sounds like it should work. One way to test is to plug a servo into channels 3 and 4 so you can see how the mixing will affect them. If you get the right servo movements then you should be good with the speed controllers.
Jan 21, 2003, 02:08 PM
Registered User
That's what I thought. Other than elevon mixing I haven't played with some of the more advanced features on my T6X so I'm kindof new to this mixing business.

I was wondering about something else: I currently have elevon mixing (tailless aircraft) and with the twin motor differential yaw setup (if I can get it working) I was wondering if I can also use aileron/rudder mixing. I think it's labeled "2-->6 mix" on the T6X?

If I can get that mix working too then that would help too. For example: When I roll right, the "2-->6" mix would steer the rudder right, which in fact would just make the left motor spin faster than the right motor, and the plane could make a smoother right hand turn.

By the way, this is the plane I'm talking about (dual ESC not yet done in this picture):

Jan 21, 2003, 02:32 PM
Registered User
flyfalcons's Avatar
That might be a tough one. You can definitely activate the 1-4 mix and see what happens, but I'm not sure what will happen when mixing to another mix. It may be worth a shot. If that doesn't work, then dial in some elevon differential so that when you use aileron control, the elevon that goes up will travel further than the one going down.
Jan 21, 2003, 09:35 PM
Registered User
I got it working. Check out this thread for details: https://www.rcgroups.com/forums/show...threadid=87418