This is me doing the first flight tests of my OhMini iV Quadcopter and some PID fine tuning to experiment with the flight characteristics. The OhMini iV is a single-piece inverted-V tail frame 3D printed on my MendelMax 2 3D printer. Some pics of the design are at http://smu.gs/1ajpTlp and it uses the same BoM as my OhMini H-Quad which is detailed at http://www.ohmeye.com/2013/ohmini-quadcopter-bill-of-materials-details/
This prototype has aft motors tilted at 30 degrees and is using a MultiWii Lite flight controller board running 2.2.1 firmware with a custom mix based on the Y4 config. My intention for doing an iV tail was to increase yaw rate, but so far the yaw rate on this prototype is slower than my OhMini H-Quad! I don’t think I can improve it any further with PID tuning and will need to experiment with tuning the motor mixing in the firmware.
I was doing the PID tuning in the field using a Bluetooth link between an android app on my phone and the flight controller. Changing the motor mixing ratios requires modifying the firmware source code and reflashing.