- Replacement of the ESCs with a 30 Amp quad ESC;
- Upgrade of the flight controller firmware;
- Building and programming the PPM Sum encoder;
- Building a BEC/filter with 12 V and 5 V outputs;
- Adding landing gear;
- Adding voltage and current sensor;
- OSD firmware upgrade;
- Change of LiPO battery from 11.1 V (3S) to 14.8 V (4S);
After some effort tuning the PIDs, this machine is becoming very obedient and stable, which is suitable for aerial filming.
While I haven't yet went through a full battery discharge, still I managed to attain 17-18 minutes from each battery, until I had to leave and do other things (e.g. parenting). This is a very promising figure, taking into account that the full weight of the quadcopter is currently around 1.9 Kg. I expect it to get past the 2 Kg after adding the gimbal with the Mobius camera.
Below is a video onboard the helicopter, with the current measurement working (for some reason the voltage display disappeared before this recording, to never reappear - this is not the first time it happens, and I suspect the MinimOSD extra firmware might be corrupting the EEPROM under some specific circumstances).
And here is the home-brew BEC in operation, powering the Video TX, OSD and camera: