Simple way how to build self balancing cube with reaction wheels.
No programming knowledge required.
You need a little skills to use ESP32 with an Arduino (or other) IDE. If you not familiar with ESP32 use Arduino nano.
You need a little electronic and soldering skills.

Also needed:
ESP32 or Arduino nano controller,
MPU6050 sensor,
three Nidec 24H brushless motors,
500 mAh 3S1P LiPo battery.

Cube frame is 3D printed.

This project is open source:
https://github.com/remrc

Last version has an updated balancing point setting procedure.
Important! In this video you can learn how to set the balancing points:
   • Reaction wheels for beginners  

3D print files
https://www.thingiverse.com/remrc