Hello guys, Rolf, Peter, I am interested also with this configuration. However I plan to change a little bit the configuration to be 2 motor at the front and one motor (Pusher) at the back. Please advice what parameter I should change based on your reversed Tricopter firmware.???
Thank you
TA
don’t use my firmware, its all in master now so use that. It sounds like just a standard tilt-rotor tricopter, loads of info on the wiki.
Hi Tony,
as Peter says, with 2 motors in front and one rear motor you should actually be able to use a standard tiltrotor firmware.
How do you want to control Yaw?
a) With the rear motor swiveling around 2 axes ?
or
b) Only the rear motor can be tilted fully 90° and both front motors control yaw by tilting back and forth a few degrees in opposite directions ?
Rolf
(The last 2 months we have unfortunately either had rain, storm or no time to test our “Mozart II” with new components . We are still waiting for better weather in Central Europe)
Hi Peter, Rolf, no I can not use standard til-rotor Tricopter, because I only want the rear (one) motor that will tilt 90 degree that will be the pusher motor. While the other two motor at front will only tilt -15 deg. to +15 deg. to control Yaw, same as your firmware. So basically the system similar to your reversed tricopter, (only one motor will tilt 90 deg.), however this tilt motor is installed at the back as Pusher instead of as tractor.
So , my question is what parameter that I have to change based on your firmware??
Rolf, this is same as option b of your reply.
Regards,
TA
Peter, why you said that I can not use your firmware ???
You even have to use the standard tri-tilt firmware.
Set Q_TILT_MASK to 8 (only rear motor no 4 is tiltable)
Set Q_TILT_TYPE to 0 (continous, due to vectored does not work properly if the vectored motors themselves are not tiltable)
Control both tilt servos of the front motors (in opposite directions) with SERVOn_FUNCTION = 39 and the tilt servo of the rear motor with SERVOn_FUNCTION = 41.
Rolf
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Rolf, thank you for your explanation, I will try later. How about configuration of Tilt servo of the Rear (#4) motor?? What parameter value (servo_n) I should use??
I assume the parameter is like this (correct me if I am wrong):
Servo3_ Function = Tilt motor Right
Servo4_Function=Tilt motor Left
But I still don’t know yet the Tilt motor (,motor #4
… parameter value…
Sorry, I made a mistake with the servo functions. Corrected the post now.
SERVOn_FUNCTION 41 is for rear tiltservo
SERVOn_FUNCTION 39 is for both front tiltservos.
Tilt motor right/left is for vectored yaw
In your case:
SERVO3_FUNCTION 39
SERVO4_FUNCTION 39
SERVOx_FUNCTION 41 (rear servo)
Thank you Rolf, I will try this configuration later. But would anybody (Rolf, Peter) advise me how to do SITL simulation of this new configuration ? I never used RF8 (but I have RF7) or Gazebo, so how is the easiest way to do SITL simulation for a new configuration copter or plane??? Thank you.
TREMENDOUS reply,
thanks, I was looking for this confirmation so much time
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Yesterday we successfully tested the reverse-tri function with 4.0.6 stable firmware. So the Master-version is no longer required. Thanks to @iampete Peter.
Flightcontroler is now a Matek F765 instead of the Pixhawk, mainly to use OSD and to have the possibility to use LUA scripts.
Rolf
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@Walter and I tested the Reverse Tritilt yesterday and the day before. It runs first class - in calm and windy conditions. Most impressive is the transition at 7 m/s wind speed and 9 m/s transition speed. Thanks to Tridge, Peter and others for developing this awesome firmware.
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We have updated the firmware to 4.09 stable. Because of the badly set YAW PID (for hovering) I have to be ashamed. Otherwise, we are very happy and will soon change to a 4.1 beta firmware.
Rolf
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One last test flight before switching to 4.10betaX
Rolf
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Hi Rolf,
I am currently working on a Tandem Bicopter which tilts its only front motor for forward flight just like Mozart 2.
Can you teach me how did you manage to adapt the code to turn 180 degree into Reverse Tricopter?
And how did you adapt the code for the front motor to tilt?
Here is my post! Tandem Bicopter transit into Cessna
Hope you can help me!
Peter
Hi Peter,
our trimotor VTOL can be thought of as a “backward flying tri with vector-yaw and the rear motor tiltable”. Therefore the motor matrix itself did not need to be changed. Peter Hall @iampete has helped and extended the code: Reverse Tricopter-VTOL Plane - #9 by iampete
More in your thread Tandem Bicopter transit into Cessna
Rolf
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Hi Rolf, Hi peter,
I am quite new to building drones. Recently i got an idea to try VTOL with Y6 and then to forward flight and cruise with minimal power usage, Then I got this wonderful thread which answered most of my doubts and encouraged to proceed further.
Main objective of the design is to have a payload capacity as well as a long range efficient flight. After going through your design and bit of calculation on my side I have decided to do a modification of the mozart 2. Below are the modifications i would like to do and need inputs and advice on the same.
- Going for Y5 2 coaxial rear rotors and 1 single tilt rotor in the front.
- moving the CG way back so most of the lifting to be done by rear 2 coaxials and the front tilt will be used for pitch stability.
- My doubt here is can the front single rotor be configured different (more focused for forward flight) than other two rear coaxials ? What modifications is required from Flight controller side ?
- Same as morazt 2 rear 2 coaxials will be turned off during the forward flight and front single rotor to provide all the thrust needed for forward flight.
So is it possible I can straight away start from arduplane 4.09 done for mozart 2 or does it require more modifications ?
Please advice.
Thanks and Regards,
ilay
Hi Ilay, welcome to the forum.
I have a question of understanding: Do you want to use the rear coax motors for torque compensation and not make them tiltable? (Not sure if that makes sense) . If you are making them tiltable, why coax motors ?
The front motor on our model has to generate less static thrust than the rear motors. The motor and propeller can therefore be better optimized for efficiency at cruising speed in fixed-wing mode.
If the rear motors are tiltable, it could work therorethically. But I wouldn’t start with a firmware that is now almost 3 years “old”, but use the latest stable. There have been many improvements in the VTOL area in the meantime. As a flight controller, I would definitely choose one with LUA script capability, because this gives you many options for making individual changes without having to change the complex firmware yourself.
Rolf
Thanks for the response.
Going for coax to add more lifting force to support a payload while remaining compact and not for the torque compensation. Since I plan to use a single rotor in the front, there will be anyway a net torque to counter. For which I have to make the coax tiltable like you did or I have to explore I can tilt the front prop around the longitudinal axis just like in a normal tricopter. I understand it will become complex as I have to tilt the same for forward motion as well.
Yes that’s what I am trying to achieve as well, optimising the front motor for forward flight for pretty long range. But my doubt still remains that with using a different motor and prop for the front than the rear 2 and still can the FC keep the vehicle stable in vtol/hover ?. Is it natively supported in ardupilot ? (Like a tricopter with 2 coax and one single rotor)
Thanks for the insight I will explore into LCU scripting if I can achieve this.
Thanks and regards,
Ilay
In order for the concept of carrying as little load as possible on the front engine when hovering to work, the center of gravity must be as close as possible to the rear engines.
We have therefore chosen a heavily filed wing.
You can see the center of gravity marked in the picture.
Rolf
Hi,
I am building a tiltrotor tricopter with a similar configuration as yours. Only difference is mine has two 90° tiltrotor instead of one unlike yours at the rear. Currently the FC thinks like those motors at front, so instead of stabilizing, it destabilizes the plane.
So I found the library that you used for changing the configuration. There is a problem for me about implementing the code.
Is there a chance to explain me how to upload the library on Mission Planner?