Im trying to make a helicopter and i have some questions about the design?

Question

how do helicopters turn?

i need to make a rotor thing what can i make it out of and

how?

can i used rudder like things on the back to steer instead of a tail rotor?

Answer 1

Before you try to make your own, I suggest buying a radio-controlled helicopter and learning to fly it (though you will almost certainly crash it).  They're very complicated machines, and you'll need to study one up close to have any chance at building one.

As for replacing the tail rotor with a rudder, this will not work.  Without a restoring torque on the tail, the main rotor will cause the helicopter to spin violently, leading to loss of control and a crash.  A rudder could supply this restoring torque when the helicopter is traveling at speed, but when it's hovering (which it does every time you take off and land), the rudder provides no force whatsoever.  If you tried to fly such a design, I guarantee it would crash almost immediately.