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rmuckley
10-09-2007, 11:57 AM
We've seen that Mikado has the come out with the v-bar system and other companies are making flybarless heads. Do you think the future of this hobby is headed toward flybarless headed helis?

KamikaziRcPilot
10-09-2007, 12:50 PM
It would help to understand the pros and cons of having a flybar-less setup. What's the primary function of the paddles and what it lost or gained by removing that element?

Funky
10-09-2007, 01:24 PM
I think flybarless is the future, but not as a replacement, just another option. The new technology with the latest flybarless setups is great. Faster cyclic, more response, better flight times. I can't wait to see a kit for the 450!!

rmuckley
10-09-2007, 01:49 PM
It would be awesome! Just think of how much less time would be spent on setting up linkages!

najones
10-09-2007, 01:53 PM
Does flybarless *require* gyro stabilization on the other axis?

markb
10-09-2007, 03:29 PM
It would help to understand the pros and cons of having a flybar-less setup. What's the primary function of the paddles and what it lost or gained by removing that element?

The paddles/flybar do two main things.
1) They provide stabilization in roll and pitch by acting as a gyro. When the heli pitches or rolls (due to external forces like a gust), the flybar disc stays where it was due to its angular momentum. Then, since the flybar is spinning out of a plane parallel to the main rotor, it applies cyclic to the main rotor, such that the main rotor comes BACK to the plane of the flybar. Restoring the helis original attitude.

2) The flybar paddles provide force amplification, reducing the cyclic load on the servos. The servos/swash apply cyclic pitch to the flybar. The flybar paddles use aerodynamic forces to change the spinning plane of the flybar. This in turn changes the main rotors cyclic pitch. So, the cyclic load seen by the servos is only from the flybar, not the main rotor. The servos still have to deal with the full range of collective pitch loads, but are spared a lot of the cyclic load.

Personally, I think flybarless is going to continue to get more popular/common. I think so because electronics constantly get cheaper. Mechanics dont. Eventually, it'll be less expensive to do electronic/gyro stabilizing, than to build the flybar linkage train. And, it will be equally or more effective. And more adjustable/tunable. I'm a electronics/control systems engineer, and really know whats going on in those little electronic boxes. Its going to get better, and cheaper. Its just a matter of time.

I can envision a programmable stabilization box, that can be set up (via computer interface, or programming codes like an ESC) to act like a heading hold gyro for roll and pitch... or neutral to negative stability like we fly with now... or really jumpy, with no stabilization over straight swash to rotor coupling.

davidw
10-09-2007, 03:54 PM
10 years ago: Is brushless going to be the future??
Is flybarless going to be the future??
Once again the only things holding it back are price and weight/size of the electronics. But in the world of electronics things move fast so it shouldn't be too long.
I recently came across (the first?) rc heli designed completely for flybarless: http://www.heli-tuning.com/1000_start.html

rabidguineapig
10-09-2007, 04:46 PM
It's a bit expensive now, but in the future maybe not...?

skydude
10-09-2007, 10:48 PM
Markb

In your first paragraph you mention an external force and then state that the flybar disc stays in plane and brings the rotors back to a plane parallel to this.

So the gust displaces everything but the flybar disc?

I am curious how it has a more solid inertia than the rotor disc which gets moved.



---

JKos
10-09-2007, 11:12 PM
> So, the cyclic load seen by the servos is only from the flybar, not the main rotor.

Not so sure about that. Last I checked, my main blades have a direct input from the swashplate. The purpose of pitching the flybar is to keep it in the same plane as the main blades. If it lags, it will slow the cyclic rate. If it leads, it will increase the cyclic rate.

> I can envision a programmable stabilization box, that can be set up (via computer
> interface, or programming codes like an ESC)...

This already exists. It's called V-Bar (or V-Stabi), GyroBot, ProBar, Helicommand, AP2000i, and a few others on or near the market right now.

- John

LITHIUMSTATIC
10-09-2007, 11:50 PM
I' don't know all the whys & hows ..... all I know is the V-bar type systems are 100% the way of the future, at least on the larger helis.

Jafa
10-10-2007, 06:36 AM
> So, the cyclic load seen by the servos is only from the flybar, not the main rotor.

Not so sure about that. Last I checked, my main blades have a direct input from the swashplate.


Agreed - the servos do see load for sure


The purpose of pitching the flybar is to keep it in the same plane as the main blades


Not sure what you mean - the pitch on the paddles or the tilt of the flybar?
From your description it sounds like you mean tilt of the flybar
but the main blades never leave 90 degrees to the main shaft
(with the exception of damper compression - which is a fraction of the flybar travel)

And the flybar will never hit the main blades
because the paddles and flybar are fixed at 90 degrees to the main blades
they are miles away from each other

Jafa
10-10-2007, 06:39 AM
Yeah - I reckon V-Bar is the way of the future for sure
Very responsive but vry stable also
The electronics are able to manage both requirements
where as mechanical has a fixed reactive operation
so you have to compromise
setup for 3D (quick and maybe twitchy) or F3C (smooth and stable)

markb
10-10-2007, 08:37 AM
> So, the cyclic load seen by the servos is only from the flybar, not the main rotor.
Not so sure about that. Last I checked, my main blades have a direct input from the swashplate. The purpose of pitching the flybar is to keep it in the same plane as the main blades. If it lags, it will slow the cyclic rate. If it leads, it will increase the cyclic rate.
I stand corrected. There is a direct connection, albeit through mixing levers that provide some leverage for the servos. So the servos do see some (but not all) of the cyclic loads. If you look at the amount of cyclic produced in the main rotor directly, its much smaller than the cyclic produced in the flybar, by the same swash input. (Set the main rotor in line with fuselage, apply back stick, and look at the paddles) I believe that the flybar responds faster than the main rotor (leading it) and much of the total cyclic input to the main rotor results from the flybars deflection. The flybar responds faster, because it has a larger cyclic input, and no stiff snubbers connecting it to all the stuff hanging below! So, its free-er to deflect.

Hard to catch, but maybe someone can find a video that shows the flybar plane as hard cyclic is applied?

Markb
In your first paragraph you mention an external force and then state that the flybar disc stays in plane and brings the rotors back to a plane parallel to this.
So the gust displaces everything but the flybar disc?
I am curious how it has a more solid inertia than the rotor disc which gets moved.
--- Yes. Thats exactly what I think happens. The rotor disc has collective applied all the time. The flybar does not. When a gust hits the main rotor, it produces differential lift, meaning the blade advancing through the gust generates more lift than the blade retreating with the gust. This differential lift creates the change in attitude of the main rotor. However, the flybar has no collective pitch, so it has no lift at all, and no differential lift. So, the flybars plane of rotation does not change...the seesaw allows it to sit there in its original plane. The instant the main rotor starts to move, the flybar starts causes cyclic input to it, which returns the main rotor to the original position (mostly) .


I can envision a programmable stabilization box, that can be set up (via computer interface, or programming codes like an ESC)...
This already exists. It's called V-Bar (or V-Stabi), GyroBot, ProBar, Helicommand, AP2000i, and a few others on or near the market right now.
- John
I didn't know that. VERY cool.

JKos
10-10-2007, 02:37 PM
> Not sure what you mean - the pitch on the paddles or the tilt of the flybar?

I mean the tilt of the flybar.

> but the main blades never leave 90 degrees to the main shaft

Correct. Basically, the paddles must be pitched in order to create a force (lift) which forces the flybar plane of rotation to follow the plane of rotation of the main blades. If the paddles didn't get pitched (or were simply replaced by weights) the heli would be extremely sluggish because the flybar would always be fighting the cyclic inputs.

> maybe someone can find a video that shows the flybar plane as hard cyclic is applied?

That would be great.

- John

EricW
11-06-2007, 02:06 PM
I voted yes, cause it works very well and it's exclusive.
Like ABS on a car, first optional and exclusive, now it's common and only exclusive cars have a switch to toggle it on or off ;).

Eric

BOOGIE
11-06-2007, 06:49 PM
Its not the future for me its the standard I will never go back to fybars! Its faster to build has more power and flys better. V-Bar all the way!

Kinger
11-06-2007, 11:09 PM
Flybarless may be the way of the future, but just like the electric heli's until the price comes down the masses won't convert for a while.

stevehonn
11-07-2007, 06:42 PM
The extra agility a flybarless setup brings is nice but for me the main advantage is removing the drag of a flybar & paddles. I've seen figures of around 20% of power is used just to spin the flybar and was a little sceptical, that was until I tried it with my Logo 500, the improvement in collective response is simply amazing and if you don't need to use all the power you will get longer flight times on electric helis.

int2str
11-07-2007, 06:55 PM
Yes, I think it's the future.

Flybarless setups are much less complicated, require less parts and are more easily tuned in software. As soon as the mass producers can produce V-Bars etc. for cheap and integrate them, flybarless will be the norm IMHO.

BruceW
11-07-2007, 06:55 PM
Uggg, I was going to be happy getting a Logo 5003D with a flybar until I read this thread.:YeaBaby:

I've been looking at going flybarless but the price is still too step for me to justify. With the savings I'll just get another battery pack. Overall I agree with others here that it will become more common in the future and the electronics will get cheaper. Right now I think the feedback control loop codes are only known by a few but will be more common knowledge later and that will drive prices down along with more specialized hardware that gets cheaper in bulk.

NTM
11-08-2007, 02:21 AM
Uggg, I was going to be happy getting a Logo 5003D with a flybar until I read this thread.:YeaBaby:

I've been looking at going flybarless but the price is still too step for me to justify. With the savings I'll just get another battery pack. Overall I agree with others here that it will become more common in the future and the electronics will get cheaper. Right now I think the feedback control loop codes are only known by a few but will be more common knowledge later and that will drive prices down along with more specialized hardware that gets cheaper in bulk.


If you factor in the extra runtime the v-bar gives you out of every pack, it may actually put you in the air for more time compared to buying another pack !

I was hesitant to lay down that kind of cash too, but I can honestly say going with the v-bar for my 6003d is easily the best money I've spent since I started this hobby. No bull ! Money very well spent !

Ticidytoc
11-08-2007, 03:00 AM
Once you knock off the price of the 611 you dont need to buy, a longer flight time, less mess on the head to replace after a crash. flybars, links, cage, $20-25 carbon paddles.....

Just think of all the money you will save. :wink:

And man, does it look sexy! :bad

BruceW
11-08-2007, 03:10 AM
Your not helping my justification.;)

The only problem is I want to have about 2-3 batteries so I can fly in the morning before work or at lunch. Even with the savings on power with no flybar I won't get as many flights in if I only have one battery.

Also, I just picked up a Spartan DS760 gyro for the Logo when it comes in although I'll probably try it out on my Trex450 first. But... I could always sell it if I change my mind.

How stable is your flybarless Logo600 when its close to the ground? I've heard others saying that its twitchy but I assume that can be adjusted via software.

BruceW
11-08-2007, 03:15 AM
And man, does it look sexy! :bad

I also really like the air popping sound those blades make in a v-bar config.