Fourth Flight

by IGNNE
in Drone Flight Logs

The first flight with the new motor, and the first one I can call a flight without quotation marks!

Sadly, the video recording bugged out again. For the last flight, I switched to just recording the laptop screen, but then the video transmission died. I guess fate doesn’t want me to show a video here, sorry. Here is the result of the screen recording:

Also, the last crash landing of the day broke the backbone, of course right behind the part that I strengthened for the new motor. If any real bones ever look like the thing in the picture, go call a doctor.

Apart from that minor setback, I am going to call this a partial success. It (finally) flies, but it also showed some issues:

  • I made a few short flights, with the longest consisting of several rather large laps around the meadow. It obviously works.
  • The new power train provides more than enough thrust. I think it uses about 40 W at full throttle, and the battery went from 4,1 V / cell to only around 3,9 V / cell in roughly 30 minutes of testing (in other words, lots of energy left).
  • With all the new weight, the required airspeed to avoid stalls seems to be quite high. I don’t know how accurate the speed estimation from the IMU is, but from my gut feeling, it needs maybe 20-25 km/h to stay controllable.
  • I borrowed an XBox controller from a friend, which works surprisingly well. I believe it would have been almost impossible to control the plane with only the touch screen controls.
  • The plane is really hard to control without IMU stabilization. The one time that I tried to steer it in manual mode was a constant struggle to avoid crashing. I have a few theories:
  • First, the airframe is not made with high stability in mind. There are vibrations, it can twist quite a bit, and I think I need to “calibrate” the weight and drag a bit more (it constantly pulled to one side).
  • The WifiBroadcast transmission does not work too well. I feel like everything worked better at the beginning and got worse over time, so maybe it just caught some water. But in the one partial video I could recover, you can see that the attitude updates stutter a lot. This, combined with the first point, makes it pretty hard to appropriately compensate for wind gusts and non-ideal weight distribution.
  • I am not 100% happy with the IMU, too. I might have to tune the low-pass filters or something.
  • By the way, did I tell you that I have never really flown an RC plane or multicopter before?