VTOL Tri-Copter Torque balance mechanism

Good morning everyone.
I am trying to build a VTOL Tri-(Tilt)Rotor for university project. I am following the design given below:

The link for video is: [VTOL Tri

Rotor drone](https://www.youtube.com/watch?v=mm9Rh6wPDVM&t=36s)

I am a little bit confused by the fact that this aircraft doesn’t have a tilt servo in aft. rotor in order to balance the torques. I have following questions and it would be a great help if someone answers. I am a newbie in the RC aircrafts.
Does Pixhawk support this configuration(VTOL Y3)?
-If yes, then can we change the tail configuration, on Mission planner/QGroundControl, to inverted V-tail as given in the design.
-If no, then can I use Y6 configuration(VTOL-Firefly-Y6). If so, what about torque balancing, Y6 design has no torque balancing issues, while the Y3 design that I am following has torque balancing issues. Do I have to introduce a Yaw-Tilt servo to manage the torques or can I given fixed tilt to rotor, as given in the video.
Thank you in advance. :slight_smile:

Hi @umer
Welcome to PX4 :). This configuration is no problem as we’ve just added support for the E-flite Convergence which is essentially what you need to get started. The mixer will need to be changed in order to add the V-Tail support but all the pieces to do that are there. You’ll notice that also the Convergence doesn’t have a servo on the aft motor. Yaw is controlled by tilting the front motors in opposite directions (which also compensates the torque from the motors).

  • ada
1 Like

Thank you @AndreasAntener, I have ordered Pixhawk from Mrobotics, When it arrives, I will check the configuration. From your reply, I have gathered that I don’t need to have Yaw mechanism in Aft. mechanism to balance the torques. Differential motion between the front rotors will be used by pixhawk to stabilize the aircraft. Am I right?

That is correct.

  • ada

Thank you for your help. :slight_smile: I will start working and ask if I need further help. :slight_smile:

Hello, i need a little help,
Can anyone tell me IS AIRSPEED SENSOR NECESSARY FOR EFLITE CONVERGENCE configuration??? Can’t we use gps module’s indicated speed? I have been trying to complete callibration without it and qgroundcontrol is asking me to attach airspeed sensor.
Thank you in advance. :blush:

@AndreasAntener any help would be appreciated

You should be able to set FW_ARSP_MODE = 1 to fly with vehicle ground velocity as airspeed. At own risk though

One more thing that i wanted to ask is that since our aircraft’s weight is 3kg and we are using 10kg servos for transition, Will Pixhawk be able to supply current for servos transition or not? and if it can, should we use AUX or MAIN ouputs?
Thanks in advance for help. :slight_smile:

@CarlOlsson @AndreasAntener any help would be really appreciated.

The servo rail of the Pixhawk has limits but I would be surprised if you exceed those with your plane. @LorenzMeier what’s the current limit of the rail?

Hello, my name is Roberto Dominguez,
and I’m developing a VTOL Tiltrotor prototype using a Pixhawk flight controller using the QGroundControl platform.
My prototype is very similar to what you say in this post, so I would like to know how I can incorporate the software that uses this model in my Pixhawk controller and also know how I can access the code to make the necessary modifications to adapt it to my prototype.
I am new to this subject.

Thank you very much for your time.