Throttle and pitch channels swapped


I’m trying to dronify my old Raptor E550, and I have an issue with the throttle and collective pitch channels, which seem to be reversed.

first, a word about my setup :

  • Transmitter : DX8
  • controller board : PX4 clone
  • reveiver : DSMx sattelite
  • firmware version : latest
  • swash type setting in DX8 : normal, 1 servo ( no CCPM mixing )

So here is what happens, in the “Radio Calibration” screen of mission planner, the throttle channel of my transmitter is correctly mapped to the throttle, and the pitch channel of my transmitter is mapped to the channel 6.

When I move to the “Heli setup” screen, the throttle channel of my DX8 is now mapped to the collective pitch.
I noticed this when trying to setup the pitch curve : changing it had no impact on the collective pitch displayed in mission planned, while change the throttle curve was affecting the collective pitch.

I’ve then looked for an option to change the channel mapping in mission planner ( it doesn’t seem to be possible with the DX8 ), found the RCMAP parameters, but it is not possible to change the collective pitch ( only throttle, pith, roll and yaw ).
On the otehr hand, I don’t understand the fact the the channel mapping is inconsistent between the “Radio Calibration” and “Heli setup” screens, so I’m suspection that this behavior may be a bug.

Any ideas ?

Thanks for your help

It seems like this throttle/ pitch curve problem keeps coming up at various times. You really need to use airplane mode with a ESC that has a governor. I used HELI mode briefly about a year and half ago. The big problem is failsafe’s being recognized by the FC and then handled properly. I waited a day to chime in on this to see if anyone else would. I think I am correct in saying that airplane mode is the way to go over heli. I also used a non governor ESC for a bit and it worked O.K. other than the fact that the headspeed slowed down a bit as the battery pack was used up.


David R. Boulanger

Hi David,

I think there is a misunderstanding, I didn’t reach the point where I need to configure the ESC, so I don’t have ( yet ? ) the issue you describe regarding governor mode on the esc.

My issue is, for now at meast, only related to the collective pitch / throttle channels reversed.

I’ll keep in mind what you say about the governor though, so thanks for the tip.


When you say:

Are you saying that when you move the left stick up and down (assuming Mode 2) that the Throttle channel in MP moves? Because that is how it should be.

I suspect what you have going on is that your classic helicopter throttle channel, is mapped to the “throttle” channel in Arducopter, and this is wrong. You want “collective” in your radio (left stick up/down) to go to “throttle”.

Yes, this is confusing. I’m really not sure how to to make it less confusing though.

Ok I get it,

If I understood correctly, throttle means collective pitch.
So what I’ll do is map my collective pitch channel to the “throttle” channel using the rcmap param.


P.s. : I think using the same terminology in apm as on helicopters would already help making it less confusing…

I’m not sure that using RCMAP is going to work, we’ve been having problems with it. The best thing to do, is change the order of channels in your radio.

Yes, that’s also what I had figured, unfortunately this not possible with my radio. I may buy the cheap turnigy if there is no other way.

Although this will sound confusing this is what I did when I used heli mode for a bit of time 1 1/2 years ago.
when I programmed my throttle and pitch curve I put my throttle on the pitch and my pitch curve on the throttle curve. I seem to remember then having to do something with the throttle hold because it was now a pitch hold. Running it in airplane mode with or without a governed ESC. is so much easier.

David R. Boulanger