Rigid head v's floating

[mahbouni]

Actually flapback doesn't occur in our helis because we don't have flapping hinges. Teetering occurs at a fixed point in the middle so the effect of tilting to the right is not present

Model Aircraft and Model Flying - W3MH - Home Page

[Guest]

I think your confusing other aerodynamic features. Without flapping these helis won't fly. Rigid, blades flex, teetering pivot point achieves it, fully articulated a hinge allows it. Why are you now introducing tilting to the right? This could equally be left. Next time you look at your Heli look at the skids are they level? Doubt it you have a tail rotor producing thrust so if your disc was level you would drift in that direction so lateral cyclic needs to be applied. Different rotor heads have other effects that may require cyclic. To counter this its usually done by the pilot, rigging offset or angular offset. In FFF all this bears little discussion. Read up on dissymetery of lift and retreating blade stall. Also look up L=CL1/2rhoV2s, and the effects of AofA as a result of induced flow. This might help your overall picture.

The more relevant roll you may see I was referring to was due retreating blade stall which often will occur slightly before (in our RH rotation helis) 15:00 due precession this will act just before 18:00 this slight roll then pitch up.

Im not going to follow up with any more discussion as its taking over the thread and the discussion is moving further away from actually been helpful. Feel free to PM for 101 on Aerodynamics.


MJ

Actually flapback doesn't occur in our helis because we don't have flapping hinges. Teetering occurs at a fixed point in the middle so the effect of tilting to the right is not presentModel Aircraft and Model Flying - W3MH - Home Page

[Delarado]

so what was the conclusion on this? Which head is for what? Im with the black on blacks at the moment, is the black rings on white bushes preferred for 3d?

[tomatwalden]

so what was the conclusion on this? ...

The conclusion was .... Ben changed the dampers, and promptly hit a tree!

[PorscheBoy]

"The more relevant roll you may see I was referring to was due retreating blade stall which often will occur slightly before (in our RH rotation helis) 15:00 due precession this will act just before 18:00 this slight roll then pitch up".

Does this mean as long as I fly outside of 3pm to 6pm I won't have any probs? Sorry, couldn't resist..... Obviously a lot of brains going into this, good read boys.

[Jamin_00]

Lol Tom.

I found the rigid head much better in fff. The floating head was not as stable nor precise. Infact I didnt like that head for any type of flight. The rigid head is fine at all headspeeds I run which varies from 1500 right up to 2450 for speed with Spunky and this year I think I will be pushing that even higher

[Delarado]

whats the rigid then? white on black? I dont know the combos!

[waveydavey]

Best thread for ages, excellent reading.

[waveydavey]

Feel free to PM for 101 on Aerodynamics.
MJ

How about a little thread then with the 101 on aerodynamics as the opener, I love this sort of stuff

[Andy from Sandy]

Dynamic Helicopter Aerodynamics !

I kept this link because one day I might read it. It is old but I guess helicopters today still fly by the same principles.

[Mike Sanders]

Phew.

Interesting article. Thank goodness for electronics.

[RyanW]

I have played around with the head settings as well recently. I started with the white bushing- red/black o-ring and I wasn't feeling the love. It turned out to be a FBL unit issue and not the machine, but during the diagnostic phase I changed it out for the black bushing and dual black o-rings. Once I got the FBL units sorted I started hammering on the TDR and found the black bushing set up to be just as Ben described. It just felt wierd.

While doing piro tic-tocs it visually had a very disconnected presence. It was as if the disc was doing one thing and the body of the machine was on a time delay, which is not favorable doing maneuvers like this. Once back to the white bushings with red and black o-rings it is much better. My next step is to try dual black o-rings with the white bushings, which is the preferred setup of some of the fastest TDR competitors in the world.

[Jamin_00]

I have not tried the dual blacks with the white bushes yet but will do this summer. I got enough here to try but so far the white with red and black is by far my fave for every type of flying I can do with both TDR's

[jasoncook]

Sorry to jump in on the thread does any one stock the bushes and o rings in the UK . I have googled it but not had any joy, My model is fitted with the black ones and it just feels wrong there is 15mm of play in the blade tips without forcing the blades. I need a pair of white bushes and two red O rings but its 15 Euro min postage which is a bit strong thanks Jason

[Jamin_00]

No, email Henseleit and ask them directly as this will save you on the €15 shipping cost