Flybar assisted helicopter control.

A flybar, also called a stabilizer bar (which might be more appropriate). uses the natural resistance to changes in orientation of a rotating object (a gyroscope) and change the pitch/angle of attack of the rotor blades with it. This acts similarly as moving the cyclic (roll/pitch control), but doing so only when the helicopter is rotating. This makes the helicopter resist angular movement (rotation), increasing stability greatly.

Even though this can be achieved with electronic/wire assistance via a speedometer (angular sensor, as can be seen here) changing the cyclic position, The flybar has some advantages if it uses paddles. These are small wings/blades which change angle of attack (by use of cyclic) and tilt the flybar while it’s moving. They decrease load (thus vibrations) by changing the cyclic indirectly (instead of the swashplate doing it), decrease the load on it (force it has to resist).

They also provide advantages during lateral flight (moving forward/backwards and sideways) as they will tilt the flybar offsetting the cyclic, helping cancel out dyssymetry of lift (one blade producing more lift then the other because of different speed). There is some direct control to the blades though, two levers mix the movement of the flybar with that of the swashplate.

This allows semi-direct cyclical control and direct collective control. These levers create a mechanical advantage which further decreases swashplate load.There are other positions in which the levers can be placed.

The helicopter in the video has them hinged at the flybar. This induces precession (a ever increasing oscillation) of the flybar. To stop this, two hydraulics dampen its movement (the black ropes are hydraulics).

The helicopter shown in the video uses a semi-rigid rotor. The flybar can be used on Rigid, semi-rigid and fully articulated rotors or any design.

Advantages of a flybar over direct control (swashplate directly changes blade angle of attack):

  • Increased lateral flight stability.
  • Decreased swashplate load.
  • Increased hover stability.

The disadvantages are:

  • Increased construction complexity.
  • Increased duplication failure using advanced duplicator. (It gets “dupe raped” very easily, so proper duplication is hard to achieve. It can be successfully duplicated using TB’s duplicator).

This is this last of the three types of rotor systems I set out to replicate in 2008 (semi-rigid, fully articulated, flybar stabilization). It has been close to two years from when I set out this goal, I have achieved it. This is thanks to great amounts of perseverance and dedication, for to my knowledge I am the only person to replicate helicopter flight so simply and smoothly using only the fin tool. I hope the reader can appreciate the work I have put into these designs and can glimpse my emotions towards it. I also thank those who have followed my work since 07’ and seen it’s evolution, thank you for sticking with me.

Most of this would have not come to pass as soon if it not were for the efforts of Twitch. For it is he who designed the swashplate I have used throughout most of my development. My eternal gratitude and best wishes towards you. :slight_smile:

I will continue to improve these designs in any way I can along with some other aircraft before I write a tutorial for all this.

Sexy, as always.


epic shit

You and your helicopters. :allears:

The same fugly helicopter body :v:

but it looks like it works great though

I love these threads, they’re the definition of informative.


You’re not funny.

Pretty cool, you and your helicopter magic.

Epic. This one is semi rigid though isn’t it? Have you tried it with a fully articulated format?

Does this mean you will be making other stuff now?

Ok. I have a challange. Flybar fully articulated powered by an engine. Good luck.

Also, I would be very happy if you could give me an engine tutorial, as I intend to take my oldschool derigable wip as realistic as posdible. The aurora was 100% realistic except the propeller shaft was angForced as apposed to engined, as I can’t seem to top a fail 1 cylinder thruster engine

Hell, I can teach you to make an engine. Why didn’t you just ask me?

oh lol. K. asks

@ Xro: Yes.