Design and build of a coaxial drone

LOVE ARDUPILOT TEAM!..such a great community. I wish I got involved in early stages…but its never too late :slight_smile:

I will look at the files tonight and see if I can start the prints before I go to sleep which I never do…lol

Latest flight video here: https://youtu.be/3eR_veaWPsU

Might be time to take it outside :slight_smile:

First flight outside: https://youtu.be/s1GRncR6_KE

I’ve noticed a few more things:

  • Wind performance is pretty poor.
  • It tends to develop a roll oscillation with fast forward flight - I haven’t looked at the logs yet to determine if it’s a P, I or D oscillation. But more worryingly:
  • It’s now apparent that there’s quite a lot of cross-coupling between yaw and roll/pitch. This occurs with either roll or pitch output is non-zero (ie. the servos are tilted away from the centreline of the body) and yaw is commanded. Because of the off-axis application of yaw torque with respect to the body, this applies a pitch or roll torque. This is definitely more of a problem with outdoor flight due to wind.

Apart from all the issues it’s still possible and quite fun to fly provided you learn all the quirks :slight_smile:

This is like total Si Fi machine :slight_smile: looks awesome flying.

I will try to print the parts today and build it.

What size motors and props are you using?

Thanks, motors are T-Motor F40 PRO II 1600kv, props are HQProp DP 7x3.5x3.

But I’m thinking of going to a two-bladed prop with a more aggressive pitch (such as the APC 7x6E and 7x6EP) because they should in theory spin much slower for the same amount of thrust, reducing the gyroscopic forces and making the thing fly better.

Any advice on 3D printing so I get them printed right the first time.

Support or no support? what side should face down for bigger complex parts or you printed them in parts?

if you have the stl files, just upload them with correct lay down positioning. I use Cura for printing.

Thanks

Congratulations @jasclarke308 on making this fly!
Could you post a log from this flight?
I assume you created a new frame type to support this; could you post a link to your fork of ArduPilot?

I’m sure you will need to add some support (or redesign) to use an FDM printer:

I have the cheap Creality 3D printer but so far never failed to print parts at least the complexity I put it through…

Should be ok?

Hi Guys,

got the Link to that Thread from iSkyMaster, thanks for that.

I’m working on a similar build, bot with a single rotor. So far I cannot select Singlecopter as Frame. Please find the detailed description of my issue here: Singlecopter Frame

Do you guys know how to solve my issue?

Thanks and congrats to your successfull project jasclarke 308!

Thanks Mark, I’m quite new to github but have created a branch here: https://github.com/jasclarke308/ardupilot/tree/Coax_Thrust_Vectoring. It’s still based on the Coax Copter code with an additional parameter.

I wiped the logs from that flight but will try to fly more this coming weekend. I expect them to look quite bad though; it’s definitely not flying anywhere as well as I’d like. It was however quite fun to test my test piloting skills.

Can you share a parameter with me? I can’t use your firmware because I am using F4 v3

Greetings @jasclarke308. I was wandering if you can explain how you designed the thrust allocation matrix for this vehicle.

Can you share your parameter files for setup! I am going to start printing one this week!!

Ryan

can it work with apm 2.8 controller

@Asty_Official No, APM 2.8 is no longer supported by ardupilot. You could load older version of the code but they did not have this functionality when the APM 2.8 was supported. I believe the last version that was supported was ArduCopter 3.6.9, but I am not sure of that.

Im saying that can i make coaxial drone with apm 2.8

A coaxial helicopter or coaxial copter? For a coaxial helicopter, you would not be able to do it because the firmware would not have the updated motors library that supports independent swashplates for a coaxial helicopter. However You could do it if you used a ganged swashplate that uses mechanical mixing.

I don’t know anything about coaxial copters.

This model is in the code of that folder

@jasclarke308 the solidworks file are not accessible (page doesn’t load). Please reshare