This Is Why RC Helicopters Have Flybars


Why Do RC Helicopters Have Flybars

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Flybars are a critical component of RC Helicopters. As technology changes and flybars begin to become more and more obsolete in the world of RC Helicopter flying, their contribution to the flying process has to be replaced by components such as 3-axis gyro systems in Flybarless helicopters.

Why do RC Helicopters have flybars? RC Helicopters have flybars to keep the helicopter stable while it is in the air. In helicopters with mechanical flybars, these help keep strain off the servos that are housed in the rotor system of the RC Helicopter.

In this guide to flybars, we will explain in further detail how they work and talk about the differences between flybar and flybarless RC helicopters. We will also answer the question: Are there any advantages to going with RC Helicopters that have flybars?

Why RC Helicopters Have Flybars

Stability

The flybar is the component of an RC Helicopter situated above the blade. Once the rotor speeds up and the helicopter takes to the air, the flybar keeps the RC helicopter stable.

Most modern RC helicopters fly with flybarless stability systems. They have gyros that keep the helicopter stable via electronics.

For those of you flying RC helicopters with flybar systems in place, you will notice that the flybar system does a perfectly adequate job of keeping the chopper stable while it is in the air.

Keep the Servos from Getting Overworked

The servos on the RC helicopter are the components that convert the commands from your receiver or flight control system into physical movements.

Within the system is the swashplate, which is responsible for controlling the cyclic and collective blade pitch of the RC Helicopter.

In a flybar RC helicopter, the flybar itself is able to take some of the pressure off the swashplate servo by helping to control the movement of the motor blades.

An RC helicopter without the traditional flybar system in place has to be manufactured in such a way that the servos in the helicopter are able to adequately perform the task of controlling the physical movements of the helicopter, as is described in further detail in this article which appeared in Model Airplane News.

How Flybars Work

There is a paddle at each end of the flybar. The paddles on the end of the flybar are constantly working against each other while the helicopter’s rotary unit is in motion.

As one paddle rises upwards, the other will rise downwards. This motion, described in further detail here, allows the entire helicopter to lean to the side, which has the paddle experiencing the lesser lift versus the other paddle.

This is how the helicopter alters direction in a longitudinal fashion.

How Can I Tell If the Flybar on MY RC Helicopter Is Broken?

If the flybar on your RC helicopter becomes broken somehow, you will probably be able to tell immediately by the way your helicopter is flying.

The flybar directly affects the pitch of the helicopter. The pitch is the angle the main rotor blades take while they are spinning. Being able to achieve correct pitch is important for many of the movements the helicopter will take as you control it.

  • An RC helicopter with a broken flybar may not be able to take off at all.
  • If it is able to successfully take off, you may notice it dipping uncontrollably to one side.
  • If the flybar has become bent in some way that is not immediately noticeable, you may first notice the helicopter not responding very well to your movements on the dial of your transmitter.

What is Flybar Mixing?

You may have heard of the “flybar mixing ratio” on RC Helicopters without even knowing what these terms mean. Here we will briefly discuss the three types of flybar mixing.

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Flybar mixing ratios alter the way in which the RC helicopter is able to move through the air.

Bell Control System: the stabilizer bar used in this set-up is basically just a weighted flybar without any paddles on the end. The rotor head is providing gyroscopic stability in the Bell Control System. There is a mixing arm on the weighted flybar that takes input directly from the swashplate, which is translating the flight control information into motions of the main rotor blades.

Hiller Control System: The difference with this setup versus the Bell Control System is that now after the input is sent from swashplate to the flybar, there are main motor grips attached to the flybar. The tilting flybar will force the motor grips to follow the same circular path as the flybar. This system results in increased maneuverability but also lag in controls.

Bell-Hiller System: This control system can be considered the best of both worlds. This system allows users to adjust the amount of influence they want the flybar to have over the main blades on the helicopter.

Do All RC Helicopters Have Flybars?

No, there is a relatively recent development of the flybarless, or FBL, RC helicopter on the market. While it was nearly impossible to fly without a flybar in the past, new technology has helped with some of the downsides.

Since there is no mechanical flybar to keep things smoothly, the functions it serves for the helicopter have to be made up somehow.

This comes in the form of software and a remote-control system. Many purists don’t like the extra complication that comes with FBL and don’t like the “feel” of flying without a flybar. Still, as technology advances, perhaps the RC helicopter world will get closer to finding a way to have the best of both worlds.

What Are the Differences Between Flybar and Flybarless RC Helicopters?

Stabilization

Stability is maintained in flybar RC helicopters via a series of paddles on the flybar while flybarless (FBL) helicopters owe their stability to the flybarless gyro system.

What the flybarless gyro systems generally bring to the table is a more innovative or more modernized approach to flying. Take, for example, this 3- axis gyro system in which flight is set up through a PC or Control Panel.

FBL gyro systems such as the one just mentioned can even be set by Android phones using bluetooth technology.

Flybar systems are known to come in at lower costs than flybarless systems, but the set-up of flybar stability systems takes up more time due to all the moving pieces.

Still, it could be argued that a flybar system is simpler since it doesn’t require the programming that the modern flybarless systems require.

Gyro

Another component of flybar RC helicopters that you won’t see on flybarless helicopters is the gyro that controls the tail of the helicopter. This is the only gyro component on a flybar RC helicopter.

Installing the head lock gyro on flybar RC helicopters involves using your transmitter to ensure that all the moving pieces are in place correctly. The process of installing a head lock gyro on flybar RC helicopters is explained in further detail in the video below.

Conversely, flybarless RC helicopters have 3 different gyros incorporated within the system, all built into one box. Control of the system is performed solely by electronics.

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Crash Damage Potential

There is a greater potential for crash damage for flybar RC helicopters than there is for the flybarless RC helicopters. This is because flybar helicopters have more moving parts in their stability systems than flybarless systems.

The individual flybar helicopter parts may be cheaper than the gyro you buy for your flybarless system, but if you do happen to run into issues with the system, you will likely have to buy more parts than you would with a flybarless system.

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Flybarless RC helicopters are also often considered to be easier to maneuver than their flybar counterparts.

Tuning Requirements

Flybar RC helicopters have more stringent tuning requirements than flybarless RC helicopters. This is because you have to ensure that all the separate components of the stability system on RC helicopters with flybars are correctly in place.

Tuning a flybar RC helicopter involves manually checking on components such as:

  • The rudder trim to make sure that it is in the right position
  • Check that the rudder has no subtrim
  • Check the travel adjustment
  • The paddles on the flybar to make sure that you have the desired rotation
  • The blades to make sure that they are giving you the desired trackability

Tuning flybarless RC helicopters is simpler than tuning flybar systems because adjustments can be made digitally.

Are There Any Advantages to Going with Flybar RC Helicopters?

Response Time

The servo is the component of the RC helicopter that translates the electrical commands from the user’s flight control system into physical movement. If you have chosen a flybarless RC helicopter over one with a flybar, you will need to consider the increased demands when it comes to servo performance.

Here’s why response time is affected:

Fast response times are of the essence for flybarless helicopter servos because you are expecting the same heading that controls the gyro for the tail rotor to also control the other cyclic or collective gyros on the helicopter.

Quick response times are important for the combined flybarless gyro systems to function seamlessly. The servos on a flybarless RC helicopter have to work more to make little corrections to stabilize the helicopter.

Stability corrections are a vital portion of a flybar’s contributions to the RC helicopter.

In addition to having to deal with more commands at once, helicopters manufactured to be flybarless need to be able to compensate for the lack of a “backup” component to control the stability of the craft while it is in the air

Tunability

Earlier, we mentioned that the ease of set-up can be a major selling point for flybarless RC helicopters over flybar RC helicopters. However, one benefit of the flybar set-up is the option for manual customization.

One expert on the matter brings up a good point that you can easily improve the stability of flybar RC helicopters by adding flybar weights. By adding weight to the flybar paddles, you can reduce the responsiveness of the cyclical controls, meaning that ever swift move will have a less dramatic effect on the overall stability of the helicopter.

Flybar RC Helicopters Can Have Analog Servo Systems in Place

Analog servo systems may be cheaper than digital servo systems, but if you are rolling with a flybarless RC helicopter, you may not have much of a choice in the matter.

This concern has also been voiced by experts over at Model Airplane News.

The analog servos, typically consisting of plastic parts, may not be able to handle the demands of the flybarless RC helicopters. The servos on flybarless systems must meet higher demands as control inputs on modern RC helicopters are built to elicit more abrupt responses.

Analog servo systems may not be practical in flybarless RC helicopters because of:

  • The consequences of nearing or exceeding a servo system’s torque rating: The torque rating alone shouldn’t be relied upon when choosing a servo system, the tiny plastic gears in the system will likely not be able to handle the increased workload


  • Equivalent speed specs between analog and digital systems may be misleading: Servo speed specs are to be interpreted as how fast an unloaded servo can transit through 60 degrees. However, the servos do most of their work responding to frequent small inputs from the flight control system over the course of the flight rather than being commanded back and forth from one limit to the other.

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The article ultimately concludes that although digital RC Helicopter servos are a much more practical option in most cases, you may be able to get by with the simple analog servo system if you are using a conventional flybar RC helicopter that will naturally have lower servo demands than the flybarless RC helicopters on the market today.

This also may make the conventional flybar RC helicopters a more viable option for beginners. Though they will have to contend with more moving pieces at the top than they would have with flybarless system, they may be able to avoid getting roped into having to purchase a digital servo system to meet higher demands.

Once they become more familiar with the ins and outs of RC helicopter ownership, they can look into getting a flybarless system and enjoying its conveniences.

Wave of The Future in RC Helicopter Flying- Flybarless Helicopters

Flybarless RC helicopters are becoming increasingly affordable for the average hobbyist and most, brand new RC helicopters on the market today are of the flybarless variety.

Flybar helicopters, such as the Cheerwing S107/S107G Phantom 3CH 3.5 Channel Mini RC Helicopter, are still a great choice for those just getting into the world of RC Helicopter flying because they are affordable and there is less of a learning curve required to fly without crashing constantly.

Flybarless RC helicopters are becoming increasingly popular with avid hobbyists due to:

  • Fewer Mechanical Parts at the Rotor Head: Stability is maintained in flybarless RC helicopters via the use of 3 in 1 gyro systems that remove the need for separate components to control the gyros for the tail rotor and the main rotor.

  • Tuning involves setting parameters electronically: A 3-Axis gyro system, such as this one, used in flybarless RC helicopters allows users to tune their helicopter through an 11 step set-up wizard.
    • Tuning flybar helicopters can involve a trial and error process in which you are choosing the right paddles in order to get the desired rotation rate and choosing the right blades to get the right trackability
    • Settings in flybar helicopters can be tweaked electronically
  • The Best of Both Worlds: Users have pointed out that flybarless RC Helicopters offer the best of both worlds when it comes to stability and acrobatics. You will not need to sacrifice the acrobatic potential of your helicopter for more stability since the flybarless motorless systems removes unneeded weight at the rotor head


  • No need to update flybar paddles as you become more experienced: Novice pilots of RC helicopters will heavy thick paddles that allow the helicopter to have more of a hovering capability, but as they become more confident in their flying skills they will need to make the change to paddles with a more acrobatic design


  • 3-Axis Gyro makes necessary adjustments on the fly: If you happen to be flying during windy conditions, you will not need to adjust the way you use your stick commands as the system will do some work for you to help keep the helicopter stable

In Summary

RC helicopters have flybars to keep them stable while they are in the air. Flybarless helicopters that make use of a gyro system to control stability rather than a mechanical flybar have been developed in recent years and are far easier for the average user. 

This technology allows users to make changes to system parameters on the fly, although the traditional flybar RC helicopter models may be more viable for beginners who are looking for something affordable.

Matt Robbs

I love to spend time with my wife and 3 kids. There is no better way to get them off the couch and outside than for us to grab the RC cars or boat and enjoy the sunshine!

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