Unlike conventional quadcopter motors, which mounted in parallel to vertical axis,
In this particular implementation 50mm EDF engines are inclined 10-15 degree toward vertical axis.
This create self stabilizing feature, that helps flight controller to recover aircraft from bank, caused by external forces, more efficiently.

50mm Electric Ducted Fan (EDF) Engine Designed for QF2611 (2000-6000Kv) motor.
It’s sold with propeller. 3D printed propellers just shatter.

Duct exhaust requires partial support, see attached Cura SupportBlocker screenshots.

Printed on Ender-5 and Ender-7.

Video available at: https://youtu.be/GlALweRM2ao