Single Rotor Gyrocopter w/ Weight-shift Control

[Rotor Rooter]

pancho,

Thanks for the information, particularly when you mention the use of pitch to adjust yaw.

[Intermeshing configuration] In my opinion it is far superior to the coaxial rotor system, but still very complex. KAMANs are also known for their sluggish response.

I totally agree. Perhaps the appreciation of lateral symmetry comes from the background in fixed wing aircraft.


Dave

[flugtek]

It gets into shemantics about how hang gliders control vs a gyrocopter.

They are both really changing the lift vector/center of gravity relationship.

[Gyro_Kai]

Eventually, yes. So do all other aircraft. But how they achieve it is quite different. A fixed wing reduces lift on one and increases lift of the other wing, thus creating a resultant sum lift which is not perpendicular to the wing-plane and therefore does not go through the CoG. The gyroplane changes the aoa of the revolving blades, therefore, again, creating a difference in lift between both sides.
A trike, however, has equal lift on both sides, but moves the weight out of the lift vector.
This results in quite a lot of differences in behaviour.

Kai.

[Sita]

The balance between lifting surfaces,wings or rotors, needs to be controlled.The result will be the same if this is done by reducing airfoil lift capacity or by "adding" weight on that particular side.
There are the factors of drag -power and time requirements obviously which makes lift capacity chance more attractive I guess.

Basically I guess that every flying machine is controlled by "weight shift" in the broadest sence of the word...................I could be VERY wrong though LOL !!

Cita

[birdy]

A coaxial with extremely rigid rotors can have a much smaller gap because the out-of-plane flexure is the limiting concern.
If single rotors arent alowed to flap [ tweeter] wen forward flight is approached, control will be lost.
If counter rotating rotors arent allowed to teeter, there will be extream stress on the structure between them.
If you want to 'force' these unteetered rotors into a different plain, your control structure will need to be 'stress proofed' just as much, but will still be under stress. [ impossibly heavy]
If you 'cyclicly fly' the rotors into their new plain, you have a much greater mechanical advantage.


Every heavier than air craft [cept rockets] is weight shift control. [ you control the direction of the lift force in relation to the center of weight/gravity.]
The term weight shift means just that, you shift the crafts weight in relation to the lifting parts force. This destabilises the lifting surface, and it tilts to the 'heavy' side.
In rotor craft its the same, you shift the lift force [ RTV] and the craft follows.
If the lift force is directly opposing gravity, nothing will change. Move the RTV, and the craft will follow.

[birdy]

The use of undersling is to minimize the vibration in the rotor by attempting to keep the rotor's center of mass on the centerline of the mast.

The use of undersling is to minimize vibration by keepn the rotors center of LIFT in line with the TEETER axis.

[C. Beaty]

External gyroscopic force is cancelled in the case of counter rotating rigid rotors. Internally, between rotors, stresses are as expected.

The various flying platforms generally used CR rigid rotors and were adequately controlled by weight shift. Lift dysentery in forward flight also cancels.

[EI-GYRO]

Whatever about the weight-shift/cyclic debate, that airframe is either
a Hafner Rotachute, or a very close derivation.

If you cross a Rotachute with a FA330, you get an early Bensen.

[C. Beaty]

And however these machines are controlled, whether Cierva’s first, controlled by tilting the airframe with elevators and ailerons, or Bensen’s first, controlled with an overhead stick tilting the rotor spindle via a spherical roller bearing; all are a variation of cyclic pitch control.

It is otherwise impossible to tilt a rotor against its own inertia. Flap hinges make cyclic pitch control possible.

[Sita]

Originally Posted by C. Beaty

And however these machines are controlled, whether Cierva’s first, controlled by tilting the airframe with elevators and ailerons, or Bensen’s first, controlled with an overhead stick tilting the rotor spindle via a spherical roller bearing; all are a variation of cyclic pitch control.

It is otherwise impossible to tilt a rotor against its own inertia. Flap hinges make cyclic pitch control possible.

I guess we could also state that all are a variation of weight shift....kinda like the chicken/egg debate LOL !!


Cita

[kolibri282]

This report seems to cover some sort of c.g. shift control
http://www.rotaryforum.com/forum/sho...074#post492074