Coax Copter with Pixhawk

Richard Gardner January 28, 2016 at 9:45am

Hey out there

The subject of Coax copters has been bouncing around in my head for sometime.

Wondering if anyone can steer me towards any documentation that speaks to how to compile the code to support the Coax format of copters. I see links about how to connect to apm or pixhawk but nothing so far on compiling the code. I am not worried about the build, that's the easy part for me ish

Bodet June 9, 2015 at 7:34am

Hi

Ok thanks

do you have a direct link to the firmware for kk flight control board because there are many.
I do not know which one to take.

thanks

Andrea Zamuner Cervi June 2, 2015 at 4:43am

PS: But probabily you need some programming skill to complete the firmware works on PixHawk/APM. I think that the actual version is not very complete. (IMHO)

Andrea Zamuner Cervi June 2, 2015 at 4:41am

All my tests was done with KK Flight Control Board.
I can not procede in the next stage due to problem to finish my frame in a correct way.
But in the future I also wish to procede to try Pixhawk.

Here there are the original page from the wiki:
http://copter.ardupilot.com/wiki/singlecopter-and-coaxcopter/#load_...

They write this:

Load the Firmware

For the time being, the user needs to compile the source code themselves.
Add this line to the APM_Config.h: #define FRAME_CONFIG SINGLE_FRAME
In the near future this will be added as a downloadable binary to firmware.diydrones.com and likely as a Mission Planner loadable icon.

It seems that you only neeed to compile by yourself the code, and you need to add the frame confing code line in config.h.

I hope that this comment could help.

Bodet May 29, 2015 at 1:38am

Hi mens

I'm on the same type of project you already since several years.
I started by oversizing such drone CoaxCopter: engine, propeller, structure, power, battery, autonomy, according to my specifications.
I started the design of the 3D structure.
For electronics, I thought fully develop the firmware on a base dsPIC. This is partly done.
My IMU (inertial mesurement unit) works. I have the pitch angle, roll and yaw values via UART.
Drone management is yet to be tested.
The drone is controlled via a standard remote control.
But according to the website, the drone could be controlled with Pixhawk. But I can not find info on the firmware.
Is it available? The information is contradictory.

Ludo

The Sun May 15, 2015 at 5:13pm

Yep

I think its the best way to prove your config due to the ease of tuning and fast setup

Drone-University.com May 15, 2015 at 1:28am

Thx. Have you tried both 1m 4s and coax on the KK2 ?

The Sun May 14, 2015 at 1:44pm

I started with an Apm 2.5 on the single copter firmware but moved to a simple kk2 until I get all of the design legwork done

Drone-University.com May 14, 2015 at 1:26pm

Thx. Which autopilot have you been using ?

The Sun May 14, 2015 at 12:03pm

Single copters can be exceptionally stable (T-hawk for example) , and lets not forget that even coaxial copters are most certainly not intrinsically stable in yaw.

Generally single copters require a lot more engineering to fly properly, due to the high degree of necessary displaced air for control correction which requires louvers instead of simple single vane control surfaces in most cases.

Most single copters that fly poorly also have the CG at or below the propeller as well, which is detrimental to general stability unless you have enormous control surfaces.

In my opinion it is a much better idea to build a single copter if you are willing to put in the time to really get the control down. I have just finished one now with 3d printed louvers (2 for each of the four servos) that is incredibly stable.

The efficiency and much improved intrinsic safety of these two configurations makes them a really attractive choice once you get the dynamics of them figured out either way.

Coax copters are also neat, but tend to be a lot taller which makes them ill suited for my applications. That being said the two I have built flew fantastically and were much easier to get flying the way I wanted.

Some great single copter and coax copter info:

https://www.youtube.com/watch?v=IvAToG7GZPU

Beautifully maneuverable and stable single copter:

https://www.youtube.com/watch?v=Q7-X4hFmGQM

another excellent single copter:

https://www.youtube.com/watch?v=sBvmhWAXGe8

Really nice coax copter:

https://www.youtube.com/watch?v=8bNXXGGFESw

Another coax copter:

https://www.youtube.com/watch?v=WXCp1lPKFVY