You wish to have a "giant scale" size autogiro, nothing wrong
with that but these things are different from airplanes and proper
arrangements are a real necessity.
Secondly. in a real large size rotor component strength will get
very important, the force that the airstream places on the rotor
is almost unbelieveable.
So it is important that the rotor blades, blade hanger and rotor
head have ample strength, also the attachmrnt to the pylon.
If you would skimp you would surely loose.
You need to scale up a really proven Giro, one that has had all
the mysteries solved.
An excellent subject would be "Giro V" details in the 2/2000 RCM
This one is now flying with a 5 ft. rotor so it is not a toy.
There also is a simplistic rotor head in the 10/2000 RCM that
probably would be sturdy enough
For some time Giros tended to be smallish, recently we have seen examples of "bigger flys better". thus encouragement to go
even larger, tempted to do that
If you get serious and have questions, just ask, should be able
Hal deBolt firstname.lastname@example.org