How to test motor and servos on a fixed wing?

Hi all,

I have started to build a flying wing with px4 on a PixRacer. Servos, motor, ESC, RX, GPS, PixRacer are installed, connected, configured and communicate with each other.
I configured px4 with QGroundControl so far that nothing “red” is shown to me anymore. I skipped only air speed and current sensor. I know it’s not recommended, but I hope it’s enough to make first experiences with px4.
I configured a few flight modes, which I can activate via TX.

When I move the plane the servos start to work. (after arming)

However, in manual mode they don’t respond to stick commands from the TX. Also the motor hasn’t turned yet. But the motor does the typical sounds on first power.

Is there a way to takeoff an airplane completely manually with PX4? Or at least to bench test motor and servos? I had hoped that this would be possible in manual mode. But this manual doesn’t sound like it.

Am I on the wrong track? Did I miss something? I would be very happy about any clue. What’s missing?



Yes, this should be possible. Which airframe did you select in QGroundControl?

I have selected a TBS Caipirinha, in fact it is a TekSumo.

Who is using px4 on a fixed wing and can help me?

Make sure that your servo connections to the Pixhawk is as follows:

MAIN1: left aileron
MAIN2: right aileron
MAIN4: throttle
AUX1: feed-through of RC AUX1 channel
AUX2: feed-through of RC AUX2 channel
AUX3: feed-through of RC AUX3 channel

If everything is good there, for initial setup and testing purposes, change the Airframe Type to Generic Flying wing.

Good luck.

Thanks, I will test it with the generic wing preset.

Servos and ESC are connected as described here. The servos are working. (see my inital post)

My main problem is that the servos and throttle don’t respond to the stick commands while the plane is armed.

I’d like to pass the stick commands through the flight control. just a simple manual mode. But that’s not exactly what happens in manual mode.

Then choose the Wing Wing airframe instead or just the Generic Flying Wing.

What flight modes did you configure? I normally at least have Altitude, Stabilize and Manual.

That’s odd.

  • If you have it in Stabilize mode, do the control surfaces respond accordingly, i.e. bank it to the left and the right aileron goes up and left aileron goes down or pitch up and both surfaces go down?
  • Then if you input from the Tx, the control surfaces respond accordingly?
  • Once it working in Stabilize, when you switch to Manual mode, the control surfaces do not respond from your Tx?
  • Have you calibrated the ESC directly with your Rx and Tx?
  • Typical sound is 1 beep when powered on, then beeps corresponding to Lipo cells, i.e. if 3S you’ll get 3 beeps, then after a few seconds, you get the musical tones. This last part is crucial because it indicates it has sensed low throttle and ready to arm. If you don’t get that, calibration might fix it or adjust PWM_MAIN_DIS4 = 900 so that its disarm value is less than whatever the calibration set it for.

Good luck.

Great. it works. the selection of win wing was the trick. Thanks a lot!

But what’s different about Caipirinha? I would have expected that wing wing from the basic configuration is the same as Caipirinha. This kind of config is not very reasonable to me…


I’m not really sure as I still consider myself a noob but I’ve come to learn that when there’s no specific output specs on a particular airframe, it doesn’t seem to be fully implemented so I either use the generic or one that specifies the outputs.

Good luck.

While doing the motor test using the motor slider menu , did you get the servos working on their respective channels or was it only the esc motor which works. I have a similar issue where only the esc motor works on all channels but in manual or stabilized mode, the flight controller responds to the RC transmitter input !!