New bicopter airframe

Hello everyone,

I’m building a bicopter that has two rotors and two servos that tilt them. Going through the diydrones forum I was told to contact Ardupilot Dev team if I want to add it to the ardupilot. Website states to contact through discussion forum. Therefore, I was wondering if this is the right place to contact Dev team.

Thanks in advance


Here or in Gitter ( is fine. So you want to develop code to support bicopter?

Let me tag @rmackay9 and @Leonardthall as they are the ones that can help with this.

Hi ayertay,

I am sure I can help you get going. There are good examples with single and coax copter at the moment. You only need to make changes in the motors libary.

Do you have an aircraft ready to go?

@OXINARF, @Leonardthall thanks for the quick reply. I would appreciate your help. Yes, I want to develop code to support bicopter. I have the bicopter built and flying. It was tested with KK 2.1.5. I also wrote my own code with Arduino. Someone told me that Dev team can tell what I need to change. I noticed people change AP_MotorSomeairframe.cpp and .h, also, files called SITL. Currently, I am comparing code of AP_MotorSingle.cpp with AP_MotorTri.cpp and trying to take from there and there. What should I start with?

Thanks in advance

I have a question regrading output_armed_stabilizing().

How would I need to limit the pwm signals? Is there a way to limit only pitch or roll?

Hi, has there been any progress with this bi-copter support? I have a bi-copter airframe but no code to fly it with.

You can run a bi-copter on plane as a thrust vectored tail sitter,

not ideal but should work OK

Hi. Yeah I was looking at that option, however it has no easy support for servo control with regards to yaw etc. I’m thinking of going with the coaxial copter mixers. I have fixed pitch rotors and the servos that would normally control the swash plates can be retasked to yaw and pitch control. Roll will be differential thrust. Only question is how to do that. I’m a newbie to coding this stuff. University of YouTube, here I come. Haha :slight_smile:

it should do servo control of yaw fine, see:

From what I’ve seen, still no Bi-Plane support. The best I’ve been able to work is a vtol plane with a tricopter frame and vectored yaw with either front two motors or single rear motor. This works like a charm.

I have done a pull request for bicopter support. Works reasonably well.


Great job @iampete! I’ve had this on my wishlist for some time now. Out of curiosity, are you using vectored yaw with servo motors?

Yes, its one of these

I had to add a spacer to lower the CG and get it to fly, could still do with a bit more fine tuning.