RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2059 views Post Reply
Home✈️Aircraft🚁HelicopterHelicopter Main Discussion › Flybar above or below main blades
05-23-2007 10:58 PM  13 years ago
Topic Vote0Post 1
cellexjohn

rrNovice

Lafayette, In - USA

MyPosts All Forum Topic
Flybar above or below main blades
I did a search and didn't get any useful results.

It their any advantage to having them above or below the main blades? It appears that different manufacturers just do thier own thing. I wouldn't figure it matters but was courious of others opinions.

Thanks
John
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-23-2007 11:05 PM  13 years ago
colsy

rrElite Veteran

Cambridge, UK

MyPosts All Forum Topic
Evidence of grass clipping's on the blades is more of an achievement if the flybar is over-slung.

That's about all.

colin.
Only Quote From Experience.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-23-2007 11:05 PM  13 years ago
The Old Guy

rrVeteran

UK Surrey

MyPosts All Forum Topic
None whatsoever!!!!!!!!!!!!!!!!
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-23-2007 11:10 PM  13 years ago
JeffM1999

rrApprentice

Erie, CO

MyPosts All Forum Topic
One advantage of an under-slung flybar that comes to mind is that you don't have to deal with those "hoop" links like on a raptor, and you don't have to have a really expensive head block, like the sylphide. As far as flight characteristics, I really think they fly about the same.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-23-2007 11:10 PM  13 years ago
RappyTappy

rrProfessor

Encinitas, CA

MyPosts All Forum Topic
There is no extra benefit from having the flybar above or below the rotorhead.Still buyin' and flyin' then crashing and cryin'
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-23-2007 11:17 PM  13 years ago
bmw

rrApprentice

Lake Zurich U.S.A.

MyPosts All Forum Topic
You really don't need a fly bar either.Runway? what runway??
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-24-2007 12:59 AM  13 years ago
Rockohaulic

rrElite Veteran

Canyon Country, CA, USA, 3rd Rock from the Sun

MyPosts All Forum Topic
You guys tell me - another advantage to an underslung flybar is that the main blades are a bit further away from the boom, so less chances of a horrific boom strike while flying...Saturday morning I flew my helicopter in my pajamas
How it got in my pajamas I'll never know
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 01:11 AM  13 years ago
mcfast

rrKey Veteran

Quebec Quebec Canada

MyPosts All Forum Topic
I like the underslung flybar, looks better manically.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 01:13 AM  13 years ago
Portblock

rrVeteran

Van Nuys, CA

MyPosts All Forum Topic
less chance of biting your fingers on an underslung when you try to palm the top of the head when is spooling down. I said less chance, becouse some people just shouldnt do it either way.The voices in my head can beat up the voices in your head.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-24-2007 05:47 AM  13 years ago
Danny Calderone

rrKey Veteran

South Jersey

MyPosts All Forum Topic
💎Sustaining Member
I have always found that the underslung flybars fly more stable in fast forward flight while just as aggressive in 3d, I prefer them.Signature
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 11:40 AM  13 years ago
ChristianM

rrVeteran

Oslo, Norway

MyPosts All Forum Topic
I have always found that the underslung flybars fly more stable in fast forward flight while just as aggressive in 3d, I prefer them.
This has to do with the flybar mixing ration (or Bell-Hiller ratio) and it is not a function of weather it is over or under-slung. If your experience is with a Raptor then I agree that it can be a bit unstable in forward flight especially with light paddles but it is the 1:1 mixing ratio that is the issue and not that the flybar is located above the main blades.

Christian
Burn fuel, be happy
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 02:26 PM  13 years ago
Danny Calderone

rrKey Veteran

South Jersey

MyPosts All Forum Topic
💎Sustaining Member
I must respectfully disagree. Although the bell hiller mixing at 1:1 is certainly "AN" issue it is not "THE" issue. If I set the mixing ratio to 1:1 on an adjustable head w/ an underslung flybar(such as the knight 3d) the heli is still inherently more stable in fast forward flight.

It is due to the flybar not being left out in the open air where in fff it can and does flex upward on the leading edge when in close to level flight (same as feeding in up elevator) which is when the heli will "porpoise".

Where as being in the rotor wash stabilizes the flybar with a constant pressure on the paddles. This problem is further compounded by the long and somewhat thin (3mm) flybar of the raptor. If you were to install a 4 or 5mm flybar in the raptor or shorten it the heli would fly much improved in fff.
Signature
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 02:41 PM  13 years ago
ChristianM

rrVeteran

Oslo, Norway

MyPosts All Forum Topic
It is due to the flybar not being left out in the open air where in fff it can and does flex upward on the leading edge when in close to level flight (same as feeding in up elevator) which is when the heli will "porpoise".
Where as being in the rotor wash stabilizes the flybar with a constant pressure on the paddles.
I understand your train of thought here but I don't agree with it. If this was the case then the Raptor would become more stable when you do FFF inverted since the paddles are now in the rotor wash. Likewise the Knight 3D would become less stable during inverted flight. Clearly this is not the case (at lest in my experience) so the issue has to due with something other than the location of the flybar. I will contend that the mixing ratio, flybar stiffness and paddles weight are the main factors here.

Christian
Burn fuel, be happy
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 04:13 PM  13 years ago
cellexjohn

rrNovice

Lafayette, In - USA

MyPosts All Forum Topic
Thanks for all the replys. Interesting info.

The reason I was asking the question is that I am moving to a .50 and the 2 heli's Im looking at the .50 EVO or the .50 Raptor. I know this is like Ford vs Chevy but those are the 2 I am interested in.

Thanks again,
John
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-24-2007 09:55 PM  13 years ago
Danny Calderone

rrKey Veteran

South Jersey

MyPosts All Forum Topic
💎Sustaining Member
I can tell you for sure that my raptors are more stable in inverted fff confirming the theory in my mind at least. lol. Hey bud, you cant go wrong with either of them, I just prefer the raptor over the hirobo 100:1............now if you wanted an eccpm bird w/ g10 frames and all the possible upgrades for a great price, go with the compass knight 50 3d. hands down the best flying 50 I have ever flown.Signature
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-25-2007 01:40 AM  13 years ago
kangarooster

rrApprentice

Orlando Fl-USA

MyPosts All Forum Topic
I think you get the best stability when the flybar and rotor are the same plane.

Linkage geometry is easier also.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-25-2007 11:13 PM  13 years ago
RAK402

rrElite Veteran

Alhambra, CA

MyPosts All Forum Topic
All of them used to be overslung. I think Hirobo may have been the first, or one of the first to put the flybar underneath. We all thought the underslung was really cool (this is about 25 years ago).

Bottom line-it makes no difference. The person who stated that the mixing ratios were what detemines flight characteristics wins (along with damping, flapping arrangement, blade mass, blade chord, blade center of gravity (both span-wise and chord-wise), blade airfoil, flybar length, paddle weight, paddle area, paddle airfoil, RPM, etc). All of these are more important than whether the flybar is up on top or underslung.

Add to that the fact than when you take a helicopter with an underslung flybar and flip it upside down, it is now an overslung flybar (and vis-versa) and you will find that it flies exactly the same as it does when it is upright.

The only possible advantage to an overslung flybar was mentioned on another forum, and that was that it could bring the blade disc closer to the center of gravity of the helicopter.

As someone else mentioned, the underslung flybar allows shorter, more direct, linkages.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-25-2007 11:37 PM  13 years ago
EvoFlight50

rrApprentice

Southbury, CT

MyPosts All Forum Topic
Don't go through all the hastle you're going through to figure out what heli to get, just get the Hirobo and call it a day!
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-26-2007 12:08 AM  13 years ago
Danny Calderone

rrKey Veteran

South Jersey

MyPosts All Forum Topic
💎Sustaining Member
hey, I say take whatever advise and theory you like and run wth it, but there is no question that they fly differently. Good luck with your new heli!!! whichever one you chose!!Signature
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2007 03:18 AM  13 years ago
kangarooster

rrApprentice

Orlando Fl-USA

MyPosts All Forum Topic
So if it is overslung you pinch the sticks and if it is underslung you thumb the sticks
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2059 views Post Reply
Home✈️Aircraft🚁HelicopterHelicopter Main Discussion › Flybar above or below main blades
Print TOPIC

 12  Topic Subscribe

Saturday, January 16 - 8:58 am - Copyright © 2000-2021 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online