Flying Wing with Rudder

[nolis]

Hey, I have a small Multiwii controller flashed with the Flying Wing Mode. Everything is working fine so far, but in this mode I don't have rudder funktion. I know that basically the flying wing mode don't need for rudder setup but in my case I need it.. So is there a way to active the rudder funktion in the firmware and if so, how can I do it ?

[PatrikE]

There's no rudder in Flying wing mixer.
Easiest is to connect rudder direct to Receiver.
Otherwise you need a modified mixing with a extra servo.

[nolis]

yea this is how I did for now, just connected the rudder directly to the rx, but it want to control it by the mwc because it makes the plane more stabe and in line, especially by takeoff and landing.. how can I do that mixing, can somebody advice me or give me an tutorial therefor...

the extra servo must be just for the rudder...

[theailer]

Or you could do a little hack and just use a heli gyro for the rudder. Maybe not the prettiest solution but it works

[PatrikE]

Easiest way is putting Rudder on A2 for ProMini
Find this part in def.h

Code: Select all

#elif defined(FLYING_WING)
  #define PRI_SERVO_FROM   4

Change it to 3



And in Output.cpp
Add the rows marked rudder.

Code: Select all

    /*****************************             FLYING WING                **************************************/
    if (!f.ARMED) {
      servo[7] = MINCOMMAND;  // Kill throttle when disarmed
    } else {
      servo[7] = constrain(rcCommand[THROTTLE], conf.minthrottle, MAXTHROTTLE);
    }
    motor[0] = servo[7];
    if (f.PASSTHRU_MODE) {    // do not use sensors for correction, simple 2 channel mixing
      servo[2] =  rcCommand[YAW] * 1;                  //   Rudder
      servo[3] = (SERVODIR(3,1) * rcCommand[PITCH]) + (SERVODIR(3,2) * rcCommand[ROLL]);
      servo[4] = (SERVODIR(4,1) * rcCommand[PITCH]) + (SERVODIR(4,2) * rcCommand[ROLL]);
    } else {                  // use sensors to correct (gyro only or gyro+acc according to aux1/aux2 configuration
      servo[2] =  axisPID[YAW]   *  1;                    //   Rudder
      servo[3] = (SERVODIR(3,1) * axisPID[PITCH])   + (SERVODIR(3,2) * axisPID[ROLL]);
      servo[4] = (SERVODIR(4,1) * axisPID[PITCH])   + (SERVODIR(4,2) * axisPID[ROLL]);
    }
    servo[2] += 1500 ;   // Rudder
    servo[3] += get_middle(3);
    servo[4] += get_middle(4);

Change to *-1 ro reverse.

Totally utested so...
BenchTest thoroughly before flight!..

[nolis]

yea it works perfectly with the hack of Patrik E.. just added the lines and connected the rudder to A2, now rudder is fully working over the mwc.. much better flying now thanks a lot

[devinv]

I am doing the same thing: a flying wing with drag rudder.
I anticipate that I will need automatic yaw control all the time since my wing has no vertical stabilizer. It can't be that hard to change the code to have yaw control still active in passthru? Otherwise, I have acro mode on all the time, which isn't a big deal except I still has some oscillations to work out.