how come real heli's no have flybars?

could it be the size and weight of the rotor blades on a real heli makes them not needed?

what if we weighted our blades with the flybar weights (to mimic the full-scale), would it work without the flybar (and reduce the weight by removing the flybar and mounting stuff for it)

feeling very pensive today i guess - these questions keep going through my head like rotor noise in the far off distance

if, in a single-rotor heli, rotor noise is caused by the forward moving blades going supersonic (or 'slapping the air'), producing the 'thump thump thump thump thump' waves, would a large coaxial sound like a fart?

thump thump thump thump thump thump thump thump thump thump thump thump


edge

Real helicopters do have flybars. The classic Bell-Hiller rotor system is the most notable. Undoubtedly, the most famous is the Bell UH-1 Huey. To control gyroscopic forces and asymmetric lift, the designer either uses a flybar or a rotor system with complex hinges and dampers.

Granted, many modern helicopters use a semi-rigid or fully rigid rotor system. However, such systems rquire large amounts of effort (Hydraulics) to move and complex blade and swash plate design to offset asymmetric lift via flapping and lead/lag of the blades.

The thumping you hear is not supersonic. It is a result of asymmetric lift. The blade is moving around the plane of rotation like a stripper seeing $10 bills waving in the crowd. Some designs 'almost' eliminate the whocka-whocka. The Hughes OH-6 (Loach) sounds more like an angry bumble bee than a helicopter.

neat - gotta be an engineer! thanks!

so on a rigid system, the swash would just be changing the pitch as the blades go around front to back and side to side like a real heli, but instead it, at least on our little fixed pitch cx's, is actually leaning and tilting the rotor disk instead - cool!

so much for cp on the big coaxial - too many variables - i'm sticking with the fp design of the current cx

thanks again,


edge

Cool! I just love helicopters! Wish I could pilot a real one!

been there done that stump3r! - try about 6 stock cx's per flight - just way too expensive for me - 15 grand went just like that (finger snap), and i couldn't complete

you can do the trick of flying 'through the glass' a lot cheaper - use a real-time camera like the 2.4ghz cams and fly it like a uav looking through the cam only - essentially the same thing without the big price tag

my dream is to sit in the big chair in the den and fly it round outside looking at the 'pilot view' on the big screen

i've got a video somewhere of me holding the tx, flying 'though the glass' looking at the tv which is playing the live cam picture, and the cam in the heli is looking down at me from about 20 feet up - totally cool - flew a whole batt through the glass



edge

Edge,

Got any recommendations for such 2.4 GHz "real time" systems? ALso, if I am running a 2.4 GHz TX / RX, will the video signal interfere with the operation of the Heli?

yep, it will interfere - you need an old 72mhz cx as a cam bird - avoids the problem completely (and doesn't unbind the heli unexpectedtly) - a used one will do, or just a used 72mhz 4-in-1 and tx

the 2.4ghz wireless security cam from wal-mart is what i use, and i run it right off the 2-cell lipo

see the old thread about 'putting a cam on my cx2'


edge

I was afraid of that. Oh well, I don't have any 72 MHz birds around. I got into Helis right after the CX2 really replaced the CX.

i got a cheap one from the lhs - used but with about 20 bucks of parts it flies great


edge

here ya go!

can't find the video, but here's a still of me trying to hold hover from inside the bird staring at the back of my own head

that was the same video with the awful tx/rx 'glitches' in it if i recall - tx batts went one bar low and some loudmouth trucker started flying my bird

weekend dress code lol!!!

i would really like a winder angle pilots view with a set of working instruments (alititude, heading, vario, and the green/red light visible on the panel), or some sort of telemetry package going and put them into the video image - its easy to get turned around up there, not know how high you really are, etc

uav, baby!


edge

Cool stuff! But is it like looking at two opposing mirrors?!!?!?

no, you are in the pilots seat, so left goes to the left and right goes to the right - you can't see directly behind you (just like in a real heli) - this cam cannot look around either, but an articulated camera mount (also on 2.4 ghz) would be able to - i saw one of those but way to heavy for the baby cx - will have to wait on the cp (and me learning to fly it well) for that i think

here's some footage of 'through the glass' LLF (low level) flight and blowing the leaves around - you can really feel the inputs i'm making on the sticks - lots of side to side stuff too - check out the perfectly banked turn too as i was coming around for more!!! - http://rcuvideos.com/item/4SMB8MZ12JQZBT8B - sorry about the bouncy landing but it was windy

some might need seasick pills for the side to side and a kidney belt for the landing, but i love it! and it was freeeeeeee!


edge

there are some RC heli's that have no flybars but you really add to the complexity of the system. To stabalize the rotors you need an additional 2 gyros I believe, which adds alot of weight to these small heli's. Basically the flybar is a mechanical way of keeping the blades where they should be, you can do it other ways, but they add more expense and complexity to the system not to mention weight and cost is a given. Alot of the RC ones are just to mimic the scale flying of real heli's. I have no idea though by real heli's do not use a flybar system very often. I guess that's what your realy q is?

it is raining today and i didn't get to fly - then the movers came and brought a ton of crap and filled up my flyin room downstairs so i can't fly inside anymore

now i want a micron v2 and a tent or something, and i have walkera #4 on the way instead - at least i can fix the cp for flying outside when the parts come - so much for that paycheck


a totally bummed out edge

Lol..........[sm=lol.gif] Just remember.........The bigger the tent, the more flying room ya have......lol...

What about a nearby college that might have an unused gym at night.
Or a club with a racket ball court, no one plays racket ball anymore.
Barn, silo...where there's a will there's a way.

thanks wolfpakin

i'm looking, but there's not much out here in the woods bigger than a house (i love it) - more cows than people out here

i'll find somewhere to fly , or pick up a big tent on sale at wal-mart and get a micron v2! - gosh the smaller the heli, the more expensive the kit!

tried working on my fp hovering in the living room - it was like surrounding the radd box with all kinds of instant sharp cornered heli death - great motivation but very nerve-wracking - keep it in the box or it will immediately be smashed



edge