Several attempts at a fixed pitch coaxial helicopter have been made and I talk about the pros and Cons of this rotor choice and also general thoughts to my project.

The redback aviation website
https://www.redbackaviation.com

Amazing diy projects
https://youtube.com/@amazingdiyprojec...

also check out helished for everything RC helicopters, very entertaining guy, you will enjoy
https://www.youtube.com/@HeliShed/videos