For the documentation and history reasons here Im adding pictures of the first build. Wooden frame, low cost MCU STM32F05 and single layer PCB home made using toner transfer. Controlled with PC joystick. Errors made, lessons learned.

• No, even an automation engineer cant fix construction and HW flaws using very well tuned PID regulator
• Propellers are never truly balanced causing a lot of vibrations
• Frame must be solid, not bending much and not resonant around RPM frequencies
• Vibrations really mess with position measurement and PID regulation
• Big nope for controlling directly roll, pitch and yaw from sensor fusion - too slow and not stable

Idea was to use small PCB as central platform, above it control circuit and below battery with ESC.