A question about the gyrocopter gimbal

Heron

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We are getting there Pete!
So "trim" moves frame, frame moves head, they don´t move together?
I was amazed first time I seen it done, pretty cool!
The action must be on the bolt, once we don´t have any input on the torque bar.
Thanks
Heron
 

Passin' Thru

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The action must be on the bolt, once we don´t have any input on the torque bar.
Heron, the trim pressures, directly or indirectly, are applied to the torque bar.
You moving your body parts around moves the frame, the frame moves the trim, the trim moves the torque bar attached to the head. :yo:
 
Last edited:

Kevin_Richey

Yamaha gyro...Oregon, USA
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300+ gyroplane, 11 airplane, 1.5 PPC, AND... a ZILLION hours of flying in my dreams!
What Vance has said, plus the conventional design places the bolts in double shear. However, given the correct engineering there are some variations on the conventional, as in the pictures below.

.
Alan: What gyros are your photos from? The heads seem to be pretty lightweight...is the one on the right a Butterfly? I haven't seen one in person, other than a Golden Butterfly, which to me was humongous.

I can't make out that shiny horizontal line up on the top portion of the rotorhead checkplate. It looks like a weld...but I can't tell.
 

Alan_Cheatham

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Alan: What gyros are your photos from?

I can't make out that shiny horizontal line up on the top portion of the rotorhead checkplate. It looks like a weld...but I can't tell.
The pictures are from some machines in Australia or Europe, I can't remember, but I don't think their production machines. Somewhere I have additional pictures, I will post if I can find them. And yes, that is a weld, in fact both machines use welding in their masts.


Heron,

The control system and gimbal bearings are not completely friction free and will transmit some frame movement to the head, especially if they are under load from airframe weight. Add to that any frame movement transfer through the trim system. Because of the "power steering" nature of rotor control (aerodynamic) it can take very little pressure to get the rotor to follow the airframe.

This is especially true of light single place machines but might be hard for you to understand if all you've flown is the Dreadnought Golden Butterfly.

.
 

Heron

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Alan
It is evident that my lack of air time makes it hard to understand better. I only flown two seaters, heavier machines. (7.5 hours as student pilot)
But I like to learn and there is an additional hurdle for me, the english language and gyro lingo, some areas still not clear to me, lazyness is the main problem.
Looking at those heads I can see the axle of transfer, mast to head, the force will act right at the center of the lower hinge, thus bringing the rotor to follow frame.
Very little coupling if any, in case of mass shifting driving.
The control rods will apply different forces when input is given, up and down, twisting the torque bar and the entire head (rotor).
With the other system, forces will be applied on both sides of the hinge, kinda "casting" it and moving the entire mast/rotor system. But I may be wrong in this theory.
thanks
Heron (slicing and dicing knowledge)
 
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