Servers by jDrones

SingleCopter & CoaxCopter Support

(Gaurav Pal) #141

Can I use AUX_OUT for servo control in pixhawk? if Yes, what code change is required to do that? Any pointers will be helpful.

(Reyes De Jong) #142

Hi guys!
First time posting, i’m working and succesfully flown once a coaxcopter, with a smaller motor than the one in the picture.

Now i’m having issues with thrust power, and i’m pretty sure is because it’s not propperly calibrated, because the coaxcopter weights 1kg and the motor thrust is about 1.3kg (motor: .

i’m using an old APM 2.5 with a custom firmware installed version 3.2.1. Already did PID calibration.

I don’t quite understand these parameters, i think these are the problem but haven’t figured out yet.


Any help will be very usefull.

i attach also full param list
full_param_list.param (4.6 KB)

(Mike Boland) #143

Can you be a bit more specific about the “thrust Power” issues you are seeing?
Can you post a log from the craft?

You would be better served by creating a new topic here rather than tacking onto the bottom of an older and quite long topic.

Initially I would say you are short on thrust.
I would generally, for any copter, expect to have 2:1 thrust to weight ratio.
How many amps are your motors drawing compared to their maximum?
What props are you using and have you tried larger props?

(azlan) #144

Hi there, How ca I download the firmware for coaxcopter, the link does not work anymore.

(Bananaraman) #145

hi, i tired the singlecopter firmware for v2 pixhawk, but when i tired arming the motor, all the 4 servos started moving crazily without any inputs from the controller.
please advice.

(rmackay9) #146

I’ve updated the wiki page for singlecopter and coaxcopter. If some people here could have a look and then tell me of any issues I’ll fix it up (or you can actually probably edit it yourself). Thanks!

(Christopher Gehrich) #147

Hi Randy, @rmackay9

The wiki page looks good! Easy to follow and the flap channels are well explained.
I’m about to try setting up singlecopter on the ducted fan drone shown at the top of this thread. I’m going to be using Navio2 on a Raspberry Pi 3, so I’m sure that will have its own special challenges :slight_smile:. Coaxcopter worked pretty well when I tested it last fall so I’m hopeful for single copter.

As you can see in the OP picture, my frame is oriented in an X format, rather than the + configuration on the wiki. There is a choice in Quadcopter setup between X and + orientations. Is there a way I can setup my singlecopter to navigate in the X orientation?


(John Montoya) #148

Hello everyone!

I’m sorry if I’m posting kind of an obvious question here, I’m really a newbie in all this. I was wondering where can you set the FRAME_CLASS value to 9 in order to select the coax flight mode (I just got that from the updated wiki mentioned above). Mission Planner doesn’t seem to offer a “single” or “coax” class under the Frame Type tab, it just shows many diferent configurations of multicopters. (BTW I made sure my Mission Planner version is up to date) Again, sorry if I’m missing something obvious.

Thank you so much!

(Francisco Ferreira) #149

Hi John,

Have you installed the Copter 3.5 beta release? You need that.

Also, if for some reason MP isn’t showing Single or Coax, you can also change any parameter in the Full Parameter list - you might need to go to MP settings and change the layout to Advanced to see this list.

(John Montoya) #150

Thanks for your answer,

I was actually running the arducopter V3.2.1. The parameters list options only shows the following on the FRAME parameter:
0:Plus 1:X 2:V 3:H 4:V-Tail 5:A-Tail 10:Y6B (New)
But anyways, i’ll better try out the v3.5 before jumping into any wrong conclusion.

Thanks again!

(Francisco Ferreira) #151

Wow that’s old. I’m not even sure there was Single and Coax support in that version. You will only find the FRAME_CLASS parameter from version 3.5 forward, it didn’t exist before (because all vehicles were separate firmwares but are now merged).

(Martin Snaith) #152

Hello Leonard

Thanks to you and all the others who enabled arducopter to control a Coaxial frame. After a couple of years using quadcopters as research platforms I’m now working on an underwater coax frame. This has coaxially mounted props on channels 5 and 6 and gimbal servos on channels 1 and 2.
After a bit of esc tuning we can get some x y z control with a joystick which is great.
But I notice that the gimbal (x y) control is linked to the throttle. So on the bench all looks good. In the water we need high throttle to control the gimble.
Could you or one of the developers point me at the likely parameters or pwm driver code to tune this relationship?

Thanks again for your work. I’ve attached a photo of the prototype and will post a tank test video as soon as possible.

Kind regards


(Colorfuljune) #153

HI, How to solve this problem?

(Andrew) #154

Hello Leonard,
I’m absolutely new to autopilots and software they run so I hope for some advise. I hope I’m directing my question to the right person.
I’m building a small single copter. I’m about to buy the Pixhawk Mini because the PX4 is quite large for this drone. Would appreciate it if you could confirm for me whether the Mini is fully compatible with the PX4. Will Ardupilot/Arducopter run properly on Pixhawk Mini in the single copter mode?
If not, what hardware-software combination would you recommend?

One more question: if Mini is acceptable - can I mount it vertically instead of horizontally?

Thanks a million!

(Sergio Postigo Huanqui) #155

Hi there! I´m a little confused. Copter documentation says I shouldn´t connect Servos to MAIN ports. Nevertheless, the SingleCopter & CoaxCopter information says they should be connected to MAIN 1 to 4…
Can anyone clarify me this? Thanks!

(Leonard Hall) #156

The output frequency of the ports are defined in blocks of 4. So you should not put ESC’s and servos on the same block of 4 outputs.

I think that is the only issue…

(Leonard Hall) #157

Hi Andrew,

It should be fine. And you can rotate it with the AHRS_ORIENTATION parameter.

Just a warning. I have learnt more since I did the output mixer and I suspect we can do a better job than we have currently. I will hopefully get a chance to improve the controller soon for single and coax copters.

(Andrew) #158

Thank you very much Leonard!
Please keep me posted on any improvements you make for a single copter.


(Nam ) #159

Hi all, I’m building a singlecopter and was able to fly in stabilize mode. However, in Althold mode the barometer seems to be strongly affected by the prop’s airflow as it is located directly above the prop. I’ve already shielded the baro with dark foam but that doesn’t help. Is there any solution other than just re-locating the baro outside the prop’s airflow (which is not an option for me right now). Do you think if we tune the control gain carefully they will automatically compensate for that effect?

(Lester Wong) #160

Hi, do you mind sharing your coding? because currently i’m designing a singlecopter and hope to get your coding as reference.

Thanks in advance.