"Well, safety line uses one of the most advanced and sensitive controller ever build ... a man :) Unfortunately it's tricky to have something that don't interfere with copter dynamics and no time to develop it.
Any idea? i think safety, for people…"

"Nice to know!
Talking about this project, what about blade sizing? Why is lower blade smaller than upper one? Is it because of the air-flow generated by the upper one that i need a smaller one at the bottom?
Do you know about efficiency vs rotor…"

"Thank you very much!
I already found this one: http://aeroquad.info/bin/view (that seems to be the evolution)
but it is a quad rotor project and i'd like to build a tri coaxial rotor copter.
i will look better into it and come back when i bit more…"

"Hello,
I'm interested in building an UAV like this. Can someone point me to some good projects? I' looking for:
-Reading to start from (basic concepts and more)
-Technical details such as parts to use (engines, blades, controllers...)
-MATH MODEL!!!…"