Throttle (RC3) is not neutral with QGC Herelink

Hi to all of you,
i have this issue and i’d like to have an opinion from you.
I need to use Herelink with a very expensive copter with cube orange ardupilot. I’ve alredy calibrated the herelink and set it up with all the pwm value that i need and already done the rc calibration in MP.
When i run QGC and i try to arm the copter with the “slide” option it comes to me with the “Throttle (RC3) is not neutral issue” and the copter will not arm but it arms if i use the stick combination.
p.s. i have not done the rc calibration in QGC because i fly in mode3 and i can only see Mode1 and mode2
The question are:

  • is safe to fly arming the copter with QGC open even if i have not done the rc calibration in QGC? the copter is connected also with MP on a PC
  • should i do the RC calibration in QGC? but if so, then it will also change the parameters on MP if i’m correct and i need MP for GS, and i also fly in mode3
  • It’s safe to use sbus flight mode channel5 on herelink if i’ve setup correctly all the FS parameters on MP?

I’ve read a lot of topic but i still have this doubt.
Thanks for your attention.


I think you will have to setup some parameters for it… but you DO need to calibrate your RC.

No, the sticks calibration is a mandatory step to fly it, never ignore it because if you need to assume your drone you can have unpredictable behaviours.

You need to perform the RC calibration and it will save the parameters into your FC and you can read them both on QGC or MP. In order to fly in mode3 probably you will have to change a couple of parameters that assign RC channels to movements control.

No, you should set your flight mode to zero and change the flight modes via mavlink by the buttons. You will have a specific tab on QGC for herelink inside Vehicle Setup to properly configure them.

Let me know if you have further questions.

Hi, thanks for the fast reply.
Just to be sure…i’ve already done the rc calibration in MP and Herelink setup, it’s then mandatory to do it even in QGC?
About the flght mode… yes i’ve seen that but i was wondering if the sbus could be safe as is the same connection of an usual rc receiver (but you have already answered…i’ll do with mavlink, it’s clear).


They should be equivalent as soon as it touches the same parameters, but when I was using herelink I always did it by QGC directly on app, it is super simple to do this.

Note that these herelink buttons are MAVLink ones. I think that if you lose your MAV communication, probably you will have lost also your RC link since they are dependent on the same device. Just be sure that you properly setup all your failsafe options.

Yes, i’ve done it, but now i’m getting through the throttle problem as it gives too much thrust from -100 to 0 even if i chang the rc3_trim value. I’ll read on the forum how to solve this one as i’ve seen that hapened to a lot of people.

Thanks again.

Check your RC settings under internal herelink configuration. Maybe you are just messing up with throttle auto-centered configuration. If the problem persists, try to perform again sticks calibration (internal to herelink).

I’ve done again the calibration but if i modify the rc3_trim doesn’t change anything and i still have the throttle to much aggressive before the center of the stick. If i flag “Throt cent 0” in the herelink setting i have the rpm that are the same from the stick in lower position till 0 but is too weak when i move from the center going up.

No reason to touch RC3_TRIM after calibrating sticks.

These flights you are trying are in stabilize mode right? Maybe your drone just has overpowered motors, so at some point of your sticks you will feel it much aggresive. There is a parameter that maps the ammount of thrust applied at mid-stick in stabilize flight mode, but I really do not remember now how to set it. I would have to take a look at documentation to remember.

I also think that there is no way to touch the rc3_trim but i don’t see any other parameters and i shouldn’t need to touch the esc setup. I just would like to regulate the throttle in the way that when the stick is at “0” the the copter is still at the ground and will not lift and when the copter is hovering and i move the stick below “0” the copter will loose thrust and goes for landing.
I’m doing all those things in stabilize mode.
In the old QGC version there was the way to “allow negative thrust” but i can’t see it anymore.

So you want a flight mode where throttle stick command climb/descent rate, like Alt Hold or Loiter:
But, to go from stabilize to these other modes, be sure that you complete all tuning steps of your aircraft, like stated here:

Stabilize flight mode will only perform attitude control for you, and thrust control is directly maped to your throttle stick.

I think this will only be available for very specific types of vehicles, not sure if it is an option for multicopters…

Let me know if you have more doubts.