HOME          FORUM          ARTICLES          REVIEWS          TIPS          HOW TO's          LINKS





Flybarless RC Helicopters

December 11th, 2008 · 1 Comment ·

Flybarless helicopters have been out for a little while now and are becoming more affordable and more popular than ever before.

flybarless RC helicopter

So what’s a flybarless RC helicopter you ask?

Simple answer: A helicopter without a flybar.

Instead of a traditional flybar, flybarless RC helicopters use as series of gyros and software controlled mixers to take angular momentum measurements and replicate the feel, control and stability of a traditional flybar without the extra parts (more on this in a sec).

Sometimes called a virtual flybar system, the rotor heads on flybarless RC helicopters are much simpler than flybared rotor heads and have a few less parts. For example, flybarless head designs don’t have the flybar, cage, mixing arms, carrier, washout and paddles.

flybarless RC helicopter
(Flybarless rotor head)

flybared RC helicopter
(Flybared rotor head)

Do you even need a flybar anyways?

While it is possible to fly an RC helicopter without a flybar or a flybarless system – scale pilots have been doing it for years – it’s not something that is easy to do or is recommended.

The purpose of the flybar is to do three things:

  1. Provide gyroscopic stabilization. When a RC helicopter moves due to an external force like wind, the flybar resists these forces due to its angular momentum. Since the flybar is spinning out of a plane parallel to the main rotor, it applies cyclic adjustment to the main rotor so that the main rotor comes back to the plane of the flybar keeping the helicopter level.

  2. The flybar paddles also provide force amplification that reduces the cyclic load on the servos. When a cyclic swash movement is applied to the flybar, the flybar paddles use aerodynamic forces to change the spinning plane of the flybar which changes the main rotors cyclic pitch. This means that the cyclic load seen by the servos is only from the flybar, not the main blades which means a lot less wear on your servos (though the servos still have to deal with the full range of collective pitch loads).

  3. And lastly the flybar compensates for the pitch up effect of a RC helicopter in fast forward flight. In fast forward flight, the advancing paddle creates a slight tilting of the flybar, which acts as a slight elevator down command which eliminates the pitching up effect which is created because of the extra lift caused by the advancing blade.

So, without a flybar or electronic virtual flybarless system, the controls will be hyper sensitive making the heli difficult to control and you’d have pitching problems. Scale pilots who have done it have successfully usually have very slow moving helicopters with small cyclic inputs. A lot of them also use multi-bladed rotor heads which offer more gyroscopic stability that traditional two bladed rotor heads which inherently make the helicopter a lot more stable.

Also, without a flybar or flybarless system, you can’t do any type of 3D and will experience pitching problems in forward flight.

There’s a ton of upsides of a flybarless system which is in part why they’re so popular. For example, flybarless systems can be set up so it will pretty much over hands off when there’s no wind. And because there’s less parts, no flybar or paddles, there’s less weight and less drag which translates to more power and faster cyclic inputs.

The only real downside is that flybarless systems are a little more expensive than a non flybarless system, but depending on the tail gyro you’re using and the flybarless system you choose, the difference might not be that big.

For example, before I went flybarless on one of my larger heli’s, I used the Futaba’s GY611 tail gyro. The price difference between the GY611 and a flybarless system like Mikado’s VBar that includes the tail gyro (which is better than the GY611 in my opinion) is just a couple of hundred dollars extra and the benefits are well worth it.

Prices are also coming way down and one day, flybarless heli’s may be cheaper than flybared ones because the electronics are getting cheaper and mechanics are getting more expensive.

Another minor downside is that flybarless helicopters are bit more complicated to setup than a flybared RC helicopter, but, because there are so many setup options, the performance is insanely tunable to suit any flying style.

Daniel Jetschin Logo 600 3D Flybarless RC Helicopter

Pros Of Flybarless

  • Increased flight time
  • Increased power
  • Increased maneuverability
  • Less weight, less drag, less vibration
  • Crashes are cheaper (less parts)
  • More customizable to flying style
  • Looks better
  • Sounds sweeter :)

Cons Of Flybarless

  • More expensive to purchase
  • More complicated to set up
  • More servo load means servos can wear out faster

Flybarless RC helicopters have a slightly different feel than flybared RC helicopters… they feel more quick and precise like an extension of your hands. If you’re a newbie pilot though, at first you may find that a flybarless RC helicopter can be slightly more sensitive and jerky because they’re quicker to react and every movement is almost instant (this of course depends on how you set it up) and more noticeable. In the hands of a skilled pilot though, they’re very smooth and precise machines

How Do Flybarless RC Helicopters Work

Flybarless systems replace the flybar and instead using the flybar as a mechanical gyro, use electronic gyros and a mxing control software. The sensor unit must include at least two gyros, one for pitch and one for roll. Some also include a third gyro for the tail rotor.

On a flybared system the response is influenced by the paddle weight and Bell-Hiller mixing ratio. On a flybarless system, this done electronically and mixed into the control inputs which are sent to the servos giving you the same feel as having a flybar.

Because the signal is mixed by the controllers software, the flybarless electronics unit goes between the output from your receiver and your servos. They work by taking the raw output from your receiver (usually non mixed, non CCPM signal ), mixing it as a CCPM swash input and adding the feel, control and stability offered by a flybar.

Without the electronic mixing software (and a flybar) the helicopter would be hyper sensitive to control so the electronic stability software built into the mixer compensates for that.

Flybarless Systems

Most flybared helicopters can be converted to a flybarless model with just a few readily available parts and a flybarless system of some kind. There are a few different flybarless systems on the market which I’ll outline below:

Mikado VBar – First and most popular flybarless system. Includes awesome tail gyro and is setup on computer. Setup is extremely customizable, but is a little difficult at first. Street price: $450

flybarless RC helicopter vbar system

Skookum SK 360 – Budget, but good flybarless system. Requires a tail gyro and is computer setup. Street price: $280

flybarless RC helicopter skookum system

Captron Helicommand Rigid – Flybarless system and flight stabilizer. Uses triple axis gyros and an optical CCD sensor to provide a superb of hands off position holding stability. Includes tail gyro and programmable failsafe settings. Computer setup. Street price: $650

flybarless RC helicopter helicommand system

There are other systems available and there are more coming out all the time, but these are the most popular 3 as of this writing.

Should You Go Flybarless?

If you can afford it, I’d say go for it. The benefits of flybarless are overwhelming making it an easy decision and the feel of a flybarless bird in your hands is second to none.

Even though they can be a little difficult to set up, there’s enough information available online that it’s doable for almost any experienced RC helicopter pilot.

If you’re an absolute newbie to RC helicopters, you may want to start with a flybar unless there’s someone in your area who can help you with the setup of a flybarless unit.

Also, many of the flybarless systems like Mikado’s VBar have preset setting for some of the more popular RC helicopters which make it extremely easy to get started… so much so in fact, that there’s no reason not to.

If you’re still have trouble deciding, besides the increased performance and enjoyability, it’s an investment that’s going to save you money.

I don’t know about you, but when I used to crash with a flybar, it would usually wrap around and destroy the canopy and other parts of the head. With a flybarless system, not only is there no flybar to wreak havoc, but there’s less parts in general that could be destroyed, so crashes will be cheaper (just make sure that you don’t destroy the expensive electronics, so wrap them carefully and stick it in a location that offers some protection in a crash).

Trex 600N Flybarless RC Helicopter

Warning: Once you go flybarless, you won’t want to go back. And if you own more than one RC helicopter, be prepared to convert it to flybarless.

Flybarless Is The Future

Just like brushless motors, LiPo batteries and CCPM have become standard for most RC helicopters, flybarless systems are going to be taking over.

The prices are dropping making the systems more affordable than ever before and as more people experience a flybarless system, either as a spectator or a pilot, more people are going to buy one.

There will still be lots of beginner non flybarless RC helicopters, but for the serious RC helicopter pilot, flybarless RC helicopters will be taking over much of their fleet – it’s just a matter of time.

Have a question about this article or anything else RC Heli related? Ask it in our brand new RC Helicopter Forum and you'll get expert answers quick.

Popularity: 43% [?]

Share and Enjoy:
  • Digg
  • StumbleUpon
  • Technorati
  • del.icio.us
  • Slashdot
  • Netvouz
  • DZone
  • Reddit
  • Facebook
  • LinkedIn
  • Ping.fm
  • Twitter

No related posts.

Tags: RC Helicopter Articles

1 response so far ↓

You must log in to post a comment.