After my first experiences with a QAV250, I wanted to build something smaller and possibly foldable. I found a nice QAV180 frame which might work and started anew. This time, I had a faulty motor with some broken isolation resulting in smoke during the setup and a broken ESC which sometimes failed to start the motor unless given full throttle. After initial tries and a switch to BLHeli ESCs, I added an FPV camera and had some test-flights but calibration turned out to be really hard with a constant drift. I later figured out that one of the sticks on my 9XR remote had an abnormality: While moving straight along the Y-axis, it still showed some value-change to the X-axis as well in the form of a bump to the side reaching to about +15% near the 50% y-axis-setting but sticking to 0% for 0 or 100%.