Here's a quick rework of my helicopter, inspired by the post I found (see below). I redesigned the toroidal rotor with additional rotor blades.
https://www.printables.com/de/model/394700-toroidal-rotor-4-strong-flying-propeller
Have fun!
Original Version:
https://www.printables.com/model/227852-strong-flying-propeller-pull-copter-no-supports
The author marked this model as their own original creation.