SingleCopter & CoaxCopter Support

I’ve tried to get the profiles to build on APM2.6 with no success. Building on pixhawk wasn’t much better. It seems that progress on these frame types has tapered off, so I wanted to reignite the effort. I’m currently working on a ducted fan SingleCopter with 4 vanes, but I don’t have a usable frame binary to test and tweak. @Randy_Hills said that he and @Leonardthall are interested in completing implementation, but they don’t have frames to test. That’s where I can step in.

I also have a CoaxCopter X01 that I just finished. I could easily mount the Pixhawk on either frame once I get a binary to run it.

Here’s the CAD for my frame. Pixhawk mounted vertically on the front. I’ll obviously need to balance the motor until it runs smooth as silk, else the vibrations will kill the pixhawk guidance, lol.
Ducted SingleCopter

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Hi,

We have recently finished a rewrite of the coax and single copters so they should be completely compatible with Arducopter now and have the full functionality of a normal multirotor.

I would be happy to help you get this going and in the process we can polish up the code.

Thanks,
Leonard

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That’s excellent news, Leonard.

How can I implement this new code on my build? Can I use a tool like mission planner, or do you need to supply me with a binary that I can flash to the APM or pixhawk? I’d just need the bare bones in terms of firmware features at first, stabilize mode, logging, etc… The first few flights will likely be tuning out the quirks of my frame before we can begin to examine the impact of the code, so how will I best be able to edit the firmware settings for the firmware you provide to me?

I’m inexperienced with higher level troubleshooting of the code of an FC. I’m most recently familiar with CleanFlight and such although I exclusively used Ardupilot from 2013 to early 2015 for my big hex and a few delta wings.

Good afternoon everyone. @Leonardthall I have also been trying to compile and flash the coax firmware onto my pixhawk. I have successfully updated the firmware but when I connect to MP i constantly get rcmapping error on MP even after repeatedly recalibrating the rc controls via MP and all my inputs show up correctly on the GUI. But it will not allow me to arm the craft and I keep getting the rcmapping error. When I disable the prearm checks the craft has ZERO throttle or yaw control but I do have control of my pitch and roll servos. Heres where it gets weird…if I put in left aileron the craft arms and the lower motor spools up to 3/4 then when i apply forward elevator my top motor then spools up to 3/4. During this entire time i am unable to control the motor speed unless i either apply left aileron to slow the bottom motor and forward pitch to slow the top motor. The left stick has no throttle control or yaw control and I am also unable to disarm the craft without disconnecting the battery.

Im not sure what I am doing wrong but i have followed all the guides to a T.
@Leonardthall you had mentioned that you had finished the rewrite of the code. Is there anyway I could become a beta tester for the firmware? I currently have the platform built and ready for testing I just lack the working firmware to actually flight test the code.
I will add some pictures once my new member status is lifted :slight_smile:




@Leonardthall @rmackay9 @Randy_Hills This is just a working prototype at the moment…Its not designed for efficiency its just designed to “hopefully” fly. Baby steps lol But none the less I would be HONORED to have the opportunity to be a beta tester for the CoaxCopter firmware and help the community and help contribute whatever I can to the community.

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Hi maddmackx,

The servo and motor positions have been changed.
1 to 4 are servo outputs, 6 and 7 are motor outputs.

The servo and motor outputs are the same for both single and coax copters. The only difference is how they are mixed.

I think I may have found my first bug so the order below may change again.

Single Copter
Output 1: Servo 1: Back Flap: Right roll should push the flap to the right. Right Yaw should push the flap to the right.
Output 2: Servo 2: Right Flap: Up pitch should push the flap back. Right Yaw should push the flap back.
Output 3: Servo 3: Back Flap: Right roll should push the flap to the right. Right Yaw should push the flap to the left.
Output 4: Servo 4: Back Flap: Up pitch should push the flap back. Right Yaw should push the flap forward.
Output 5: Motor 1: Motor 1: Up Throttle should increase Motor 1
Output 6: Motor 2: Motor 1: Up Throttle should increase Motor 2 (not needed)

Coax Copter
Output 1: Servo 1: Back Flap: Right roll should push the flap to the right.
Output 2: Servo 2: Right Flap: Up pitch should push the flap back.
Output 3: Servo 3: Back Flap: Right roll should push the flap to the right. (same as 1)
Output 4: Servo 4: Back Flap: Up pitch should push the flap back. (same as 2)
Output 5: Motor 1: Motor 1: Up Throttle should increase Motor 1. Right Yaw should increase the throttle.
Output 6: Motor 2: Motor 1: Up Throttle should increase Motor 2. Right Yaw should decrease the throttle.

** These will need to change to make the order more sensible but we will work with this for now **

Here are two binaries for those of you who can’t compile it yourself.

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@Leonardthall THANK YOU !!! :heart_eyes: I’ll give that a try once I get back to the shop tomorrow. Quick question? On my Coax setup im only running single servos to control the control veins . can I just use the first 2 outputs? or do I need to have a 4 vein setup or a pair of servos to control each control surface ,to allow it to work properly?

Thank you very much for the speedy reply. I will post all my findings :grin:

@Leonardhall
Thanks so much for this.
Its fantastic to have some working code to put on my Single Copter frame. I am downloading now and will let you know the results.

@Jacko1 Do you have any pictures… ive very interested in making a prototype single copter as well for some testing. Thanks

MadD MacKx

Here’s a binary for single copter built from master today (25-Apr-2016). You should be able to load this using the mission planner’s install firmware page’s “load custom firmware” link.
https://dl.dropboxusercontent.com/u/3852647/leonard/singlecopter/ArduCopter-v2-singlecopter-34dev.px4

…and here’s a link for a coaxcopter binary also produced today from master.
https://dl.dropboxusercontent.com/u/3852647/leonard/singlecopter/ArduCopter-v2-coaxcopter-34dev.px4

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Thank’s Randy. So many goodies after such a long wait! :grinning:

maddmackx
I’d be to embarrassed to post the birds nest of wire and servos I’m looking at right now! If the prototype works I will put up a video.

I tried a quick test… loaded as custom firmware OK. But servos were buzzing loudly once I managed to arm the single copter.
Then servos started to warm up very rapidly so I had to shut down. Possibly wrong update freq.?

Okay so I managed to squeeze in a few mins in the shop today to test the coax…And i have some good news and some bad news :innocent::smiling_imp:. Good news first. IT WORKED!!!..“well sorta worked lol”. The servo outputs worked as described. But the motors would not adjust there speed or spool down for any yaw control when commanded. I was able to arm and disarm the craft with the regular stick inputs which is another good thing lol But unfortunately I only have a few minutes here at my space to test before I have to pick up my son but im going to bring the craft home with me tonight and trouble shoot. I will also post a video tonight if I have enough time.

Once again thanks for all the info it really helped :heart_eyes:
@Leonardthall @rmackay9

I will also add the logs if anybody wants to look over them

Hi Maddmackx,

What code do you have loaded? Did you get it from Randy or me (if you got it from me, try Randy’s).

I can see your motors are going up and down and responding to yaw so it is strange that you don’t see that. You are getting full throttle output too so you should be taking off.

The really strange thing is your throttle response, you seem to go from minimum throttle to maximum throttle through the centre 10% of your throttle range.

Is there anything else you can tell us?

Thanks,
Leonard

Randy just noticed that your dead zones are set to zero. Can you load Randy’s version of the code (it is more up to date). Then set your dead zones to 30 and try again.

Thanks,
Leonard

@Leonardthall yes the firmware was your version. @rmackay9 Randy I cant seem to be able to access your firmware through the Dropbox link you provided. Would you be able to directly add it to my Dropbox requests by clicking on this link https://www.dropbox.com/request/kKRadpXPsaSwOsOrvf2d and Ill give it a try whenever you have a chance to link it for me. I require the coaxcopter version. please and thank you.

Thank you very much guys for all your help.
Im just finalizing my test bench and ill post more photos tomorrow :smile:

Also the dead zone? is that configured in the parameters tree??

@maddmackx,
Ok, I think the reason you couldn’t access it was because your browser probably tried to open the .bin file. Here’s a new link with the firmware (for both single and coax copters) in a zip file.
https://dl.dropboxusercontent.com/u/3852647/leonard/singlecopter/ArduCopter-v2-singlecopter-34dev.zip

The Deadzones can be returned to their defaults by setting these parameters:
RC3_DZ = 30
RC1_DZ = 30
RC2_DZ = 30
RC4_DZ = 30

Ah! I was using Leonards version of the code as well. I will try the zip and report back. Although the throttle was fine on the single copter version it was just the servos misbehaving . (I have not tested the coax.)

OK, Single copter is much, much better now.

  • Servos are responding to inputs. Directions seem incorrect.
  • Servos still buzzing very strongly. (Signal freq problem?)
  • Servos respond to attitude changes. Directions seem incorrect.
  • The throttle is unresponsive to inputs, though motor beeps as if no signal on boot - then beeps much faster on arming.

Here is log. Tlog as well as the DFlash, because the log bitmask seems a weird setting by default.

Thanks for all the help with this.