Servers by jDrones

SingleCopter & CoaxCopter Support

(Leonard Hall) #121


Here are mine if you are still having trouble:

let me know how you go!!

(Christopher Gehrich) #122

The CoaxCopter flies! Have only tried Acro mode so far, but intend to test GPS soon!

Thanks @Leonardthall and @rmackay9!!

(Leonard Hall) #123

We need a video!!!


(Christopher Gehrich) #124

Hope to record some flight this afternoon. Then I will try a 6S ducted fan singlecopter!

The coaxcopter is kinda funny because my landing gear is too flexible. I have to punch the throttle to take off or else the copter will do the Twist and shimmy on the ground. I could probably tune it out in PIDs, but it’s not really a problem.

(Christopher Gehrich) #125

Here’s the video! Sorry that the copter falls out of frame a few times.

(Giorgio Rinolfi) #126

Great! Thanks for sharing, why don’t start to improve the single/coax copter in the wiki to spread the world with this new frame/design type inspiration and attract mekers to join testing ?

(Christopher Gehrich) #127

@Leonardthall @rmackay9

On my EDF singlecopter (see top post) I have my fins installed in an X configuration rather than the typical + configuration. Is there a setting that will allow be to rotate the copter’s coordinate system so that pitch forward will cause forward motion of the X orientation? I know how to rotate the AHRS orientation of the board to the frame so that the PX4 and copter are aligned, but thats not what I’m asking here.
It’s basically the same transformation between flying a quad in the + config and the X config.

What do I do?


(Joe) #128

Hey all! This is an awesome thread and I am excited to contribute in any way I can. I have a Coax Copter setup with 4 fins (4 HS-125MG servos on each fin) and two 6s packs running in parallel. I am using a Holybro Pixhawk which takes V2 of the code in this thread. I have uploaded the most recent coax code from dropbox via QGC and I have two questions for this forum.

  1. How do you guys do the compass/accel calibration for a coax copter? My pixhawk is oriented with it’s arrow pointing toward the motors. The motors are at the top plugged into ch 5 and 6. When I try to arm it says it can’t arm because it’s leaning (even though it’s pointing straight up). Makes me think I have performed the calibration incorrectly. SOLVED: Calibrate as if when the copter is in the normal flying position (props on top) and the “nose” of the aircraft is parallel to the ground

  2. My servo is buzzing (I only plugged in channel 1 cause I had read earlier that servos had been burned and I didn’t want to do that) and gets very warm after a while. Based on the thread I was under the impression that this issue had been fixed. SOLVED: But it may be a bandaid fix. I had to change MOT_SV_SPEED to 50 in MP @Leonardthall @rmackay9

Let me know if anyone has any ideas.

(Joe) #129

Regarding Issue 1. Dissabling the IMU pre-arm check allows me to arm both motors and to see them spin. More of a band aid then a solution so let me know if you guys have lean issues. SEE ABOVE: Don’t dissable pre-arm checks. Simply calibrate correctly.

(Joe) #130

When you say you borked the Pixhawk for a bit. How exactly did you fix this? I have done the same thing where the Pixhawk boots fine but then the Main LED turns off and I can’t connect to it. I have re-flashed the firmware to factory standard but still the Main LED doesn’t change. @Droner

(Paul May) #131

Hi Everyone - My 1st post. In fact 1st everything really. I am building a coax copter to my own design - about 60% complete, but the first un-tethered flight is many months away… It has 4 motors - 2 for each rotor, and 4 servos - at 90 degrees - activating a shared swash plate. Phew !
It has an Arducopter 2.8, and I’ve just got Mission Planner past the Pre-Arm checks. I chose the standard Heli frame, because nothing else is close, so obviously it’s not going to work like this. Can somebody please advise me how to download (not upload ?) the Coax firmware ? Is there a central source of information, or is it too early in the development cycle for that ? I’m a semi-retired developer, and fancy looking into the code at some stage, but for now it has to be binaries only. Also, I’m happy to beta-test.

(Joe) #132

I used one of the most recent links to Dropbox in this thread. That will give you 4 files you can download. You would select coax v1 or v2 depending on your board.(I just used trial and error for this).

(Paul May) #133

In Mission Planner, I select Load Custom Firmware, and choose ArduCopter-v1-coax.px4. It then scans the comports and reports that it can’t find the board. I then tried the Force PX4 Bootloader option beforehand, with the same result.

I read somewhere that QGroundControl should be used for PX4 files, but this doesn’t find the board either. I’ve tried different USB cables - also no result.

Mission Planner seems very happy with the standard firmware options - I can load any of the standard options.

Is there another binary format that I should be using, or am I doing something wrong ?

(Francisco Ferreira) #134

If you have a Pixhawk you should use v2.

(Paul May) #135

I have the Arducopter vr 2.8

(Francisco Ferreira) #136

I have no idea what board that is, but I’ll bet it is a Pixhawk clone and you need the v2 anyway.

EDIT: Or is it an old APM clone? If it is, you can’t use this firmware. The old APM boards are limited to old firmware, 3.2.1

(Paul May) #137

I don’t like the sound of this … You’re going to tell me I’ve wasted my money. If so, where do I buy the latest recommended flight controller ?

(henrik04) #138

Why are you using an old APM? This hardware can’t take the latest software (Not enough memory space)

At present (OCT 2016) The best one is :slight_smile:

But if vibrations aren’t too much of a problem and you want a small unit then :slight_smile:

There are so many clones of all sort of the pixhawk that the choice is yours!

(Francisco Ferreira) #139

Like Henri said that’s old hardware, a clone of the old APM boards. There are a lot of different supported boards:

  • Pixhawk (production was ended by 3DR, but they had some units recently; also
    Northox has them; mRobotics will also start producing the Pixhawk)
  • The Cube (more commonly known as Pixhawk 2, is going to be released in November, although you can pre-order now)
  • Pixracer
  • Navio2
  • Erle-Brain 2
  • PXFmini
  • VR Brain
  • Intel Aero
  • and more…

(Paul May) #140

Thanks for the advice everyone. But I only bought that “old APM” a few weeks ago ! This is all new to me, so I made a bad decision. I’m saving up for a real one now …