Servers by jDrones

Looking for param files for rudder-elevator only planes

(Rob) #1


I’m looking for param files for elevator-throttle-rudder only aircraft - referred to as “ETR Plane” in Ardupilot.
– Aircraft such as Parkzone Radian (not pro version), and the Lynx UAV.
I’m especially interested in recent param files that activate and use the “RUDDER_ONLY” parameter.

I am a longtime RC pilot and have just gotten my first autopilot – a Pixhawk 2.1/RFD900/MissionPlanner.
I am installing it in an old Radian (rudder-elevator only) and am using my JR9503 for manual control.

I watched the 9-video series by Painless360 and have been using the online Ardupilot resources [WHICH ARE EXCELLENT] by the way. I have everything ready to go with appropriate flying modes programmed.

I’m currently plugging in the rudder servo into the aileron channel and FBWA seems to be behaving appropriately on the ground.

I did try to use the RUDDER_ONLY parameter and changed the RCMAP_YAW, KFF_RDDRMIX, and YAW2SRV_DAMP to the values described on the website. However, I got some strange behavior on the ground and I’m not sure if KFF_RDDRMIX is working – so I went back to just plugging rudder into the aileron port.

Anyway, rather than asking someone to take time to hand-hold a noob, just getting some similar param files (newer the better) should be enough to help me sort this out. :slight_smile:



(Samuel Tabor) #2

Hey Rob,

I have a Radian (non-profit) with ArduPlane. I started out with rudder plugged into aileron output, but I experienced yaw oscillations. To get around that I went back to using the rudder output with yaw damper enabled, and set a high value for KFF_RDDRMIX. I’ll post my parameter file tomorrow.


(Rob) #3

Thanks Sam!
That should be helpful.
It’s always good when learning something new to be able to refer to something that is known to have worked.

(Rob) #4

Sam, any luck uploading that parameter file?

I had my first flights today.
All in all it went really well.
Used Manual, FBWA, and Loiter – with upper level winds at least 15 knots.

I got a bit of tail wag in FBWA and Loiter, but not too bad.

Anyhow, I’d be curious what you are using for your PID values and your yaw damper.

Thanks for letting me know that you had problems with just using the rudder in the aileron channel – that saved me some time and it reassured me that other people were successfully using the RUDDER_ONLY parameter.


(James Stewart) #5

If you’re experiencing some wag in FBWA and other stabilised modes, you should do some flying in Autotune mode. It’s a flight mode that behaves similarly to FBWA, but tunes the PID values by reacting to aircraft movement.

(Rob) #6

Yeah I’ve seen a videos for autotune.
Will it work just as well for a rudder-only aircraft? – i.e. can it tune the yaw damper concurrently with the roll PID values?

(James Stewart) #7

That, I’m unsure of. I’ve never set up a rudd/elev plane for arduplane, I’ve only done ail/elev, full 4ch, and flying wings.
Best case, it does tune properly. Worst case, it tries to tune the roll values than you aren’t even using, and has no effect on flight. Either way it’s not going to hurt anything to try it, unless I’m missing something major.

(Samuel Tabor) #8

Hi Rob,

Parameter file attached. Test4.parm (22.3 KB)

The yaw damper won’t be tuned by autotune mode - only roll and pitch PIDs.