My quadranger refuse to hover

This is my first try in quad plane. Basically follow the Quadranger example from the manual. I’ve double check the motor rotation and configuration. I’ve also completed ESC calibration as per manual. As the Ranger EX is a tail dragger, at Q stabilise mode, once I start to advand the throttle, the rear motor provide enough lift to level the plane. But once I advance the throttle further and try to lift off, the plane drift to RHS very fast and I can not control it even with full left aileron stick. I’m using 3.71. Is there some very basic things I miss out ? Apprciate if anyone can offer some suggestion to rectify the issue. Thanks in advance.

Look at my example for the Ranger EX QuadPlane under the “Plane 3.6” category. It may give you some help.

Thanks Greg. I’ll try and see. Thanks for the great post.

Hi Greg

Thank you very much for your great artical. It does help a lot. I follow your recommandation and most of the param. I also rectified that I’ve make some basic / stupid mistake. I actually test the param with a DJI F 450 quad rotor. The only param that I change is the pitch / roll rate I from 0.15 to 0.07 because I found that it had some low frequency oscilation.
Now I can hover my QuadRanger in QStabilise mode. However, when I try QLoiter, it drift a lot and actually worse than stabilise mode. Do you know what param or the possible cause of this problem ?



I’m glad that you are seeing progress now. For Q_Loiter, I would first recommend testing Q_Hover mode which is similar to the Copter Alt. Hold mode. This verifies BARO performance without using the GPS features. Then you can test Q_Loiter mode.

Before switching to Q_Loiter mode, verify via telemetry and Mission Planner that you have a sufficient # of satellites and hdop reading. Using an M8N GPS module, I typically see readings like in the image below. If all looks good, try the Q_Loiter in an open area and be prepared to switch modes back to Q_Hover or Q_Stabilize if the plane does not stay in one place. Other issues can be that the compass direction is incorrect so verify proper compass setup and calibration in Mission Planner. I typically just use the external compass on the M8N module as using dual compasses has caused unneeded issues.

Good luck!

Dear Greg

Thanks for your advice. I’ll try it out next week and see how things go. I actually had successfully test the Qloiter mode with my F450, therefore I’m sure it should work. During the " debug " I notice that I need to set up the channel as per arducopter in terms of normal or reverse. But since I set it up according to the need for air plane mode, the roll and yaw were reverse in Quadplane mode. What should I do ?
Merry Christmas and Happy New Year

Hi keeyen,

There are reasons to try testing in the order of Stabilize, Alt. Hold, and finally Loiter. Further, I have always setup the Plane functionality first. Once the plane is properly calibrated and tested in Manual and FBWA modes, then it is ready to continue conversion as a QuadPlane. In fact, this process has made my two conversions quite easy using v3.6.0 firmware.

In the initial QuadPlane Q_Stabilize mode testing, this is where you would find channel reversals. I don’t recall having any issues nor do I see and special Q parameters to reverse direction for just the QuadPlane function. It is important to set the Q_FRAME_CLASS and Q_FRAME_TYPE correctly and follow the QuadPlane Frame setup wiring diagram.

Good luck and Happy Holidays! :slight_smile:

Dear Greg

Let me express my sincere thanks for all your advice and your build log. After confirm everything had set correctly, I manage to hover it in both Qstabilise and Qloiter. The reason why I can’t hold a stable Qloiter is because of aeliron reversal. Once rectify and ensure good 3D Fix, it hover nicely with little movement. I also try some transition. For my current set up, when I switch from Qstabilise to FBWA, it drop may be 1 meter then fly forward. I think I may need to adjust the throttle midpoint. Other than that, I’m quite happy with it for now. The next step is to try some simple auto mission and see how things goes.
Here I share a short video clip of my first VTOL flight

Hi Keeyen,

Somehow I missed this video…great job! Can you post your power system setup and .param file? Also, are you using APM v3.7 or v3.6?


Hi Greg

I’m using 3.7.1. Power system for quadrotor is DJI E 800 with Hobbywing 30 A Plantinium ESC. I have solve the altitude loss during transition issue by increase the Q_M_THST_HOVER from 0.5 to 0.7. Now it won’t drop at all. I also try some auto mission, while I had a few successful flight, I think I need to fine tune two area.

  1. After the transition completed, the forward motor seems to slow down for 1 or 2 seconds before it rev up again. No idea where to tune yet.
  2. The take off is quite slow and looks struggle a little before reaching the desire altitude ( 20 meter ). It seems like it hover around 18 to 19 meters for a while before finally reach 20 meter and start the transition. I’ve try to increase the value of Q_VZ_P, Q_AZ_Pand Q_PZ_P and see if this help. The param file attach here is with the new value but has not tested yet. Will let you know how it work after the test flight.

Cheer…QuadRangerparam.param (12.7 KB)