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HelicopterMain Discussion › underslung head
11-29-2005 12:06 PM  12 years agoPost 1
Tailspinner

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JAMAICA, NY

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Are there any advantages to an underslung head on a heli? If so,would it be worth converting to one?


.

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11-29-2005 01:24 PM  12 years agoPost 2
BarracudaHockey

rrMaster

Jacksonville FL

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If your worried about it just fly inverted.

Andy
AMA 77227
http://www.jaxrc.com

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11-29-2005 09:51 PM  12 years agoPost 3
Sticky

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Frederick MD

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I like the way underslung heads fly. My Gohbee 50 flys likes its on rails. The Raven 50 also flies great. I don't like the pitchiness of over slung heads, like the Raptor 50 or 60 (I have both). Even inverted underlungs track better. I'm going to convert my Raptor 50 to a Gohbee head.

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11-29-2005 11:39 PM  12 years agoPost 4
melsman

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Atascadero, CA

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Hi Tailspinner,

Not to be disagreeable with Sticky, but generally, overslung heads are not pitchy by their nature of being 'overslung'. The pitchiness comes from a combination of the flybar mixer ratio and the design paddles.

I think the experience Sticky is referring to has to do with the CG of the heli being further away from the center of the disk with a underslung head vs. an overslung. The pendulum effect takes over from there. The overslung head allows the disk to be closer to the CG of the heli and thus has more power over it.

If you'll note on some of the newer underslung models (the Avant and the Synergy), great effort has been made to move the CG upward in the frame to minimize the pendulum effect.

So, an underslung head generally is more stable ("flies like it's on rails"), and an overslung is generally more "quick".

Keep in mind that the underslung engineering requires penetration through the main shaft below the head (thus making it slightly weaker). An overslung flybar requires unusual linkage (such as the 'link loops' on a Raptor) to actuate the flybar, thus making the linkage more complicated and difficult to manufacture.

From a pure flying standpoint (CG location notwithstanding), there's really no descernable difference, even though some would argue that because the underslung is in the rotorwash, it is less effective. And that could be. But I've flown both and never found that to be an issue.

Frankly, I think you're fine either way you choose to go. Converting will simply give you different handling characteristics; not necessarily better ones.

You have to define the 'better' part.

Ashley

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11-29-2005 11:54 PM  12 years agoPost 5
Leif

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USA

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You forgot the "inline" design. The Kyosho Concept series had the flybar in the same plane as the mains.

leif

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11-30-2005 12:07 AM  12 years agoPost 6
FlyHuge

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Colleyville, Texas

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What is a overslung head?

Do you have photos you can post showing what this is?

Cra$h’n with a Heli good time!

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11-30-2005 12:40 AM  12 years agoPost 7
Salty

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St. Augustine

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here is the overslung R90

here is the underslung evo

Ask your Doctor if getting off your ass is right for you.

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11-30-2005 02:09 AM  12 years agoPost 8
Sticky

rrApprentice

Frederick MD

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I can't disagree with anything melsmen says however.. One point he makes are the loops on the Raptor. The links on an underslung head are much shorter and could cause what I think is a better "feel" to the controls.

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11-30-2005 07:10 AM  12 years agoPost 9
KC

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WA

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the advantages of an underslung head are few...unless you don't own a lawnmower


if there is a reason to go with one head over another, I would choose an "overslung" flybar design because they are faster to swap or repair.

youre not going to get a better flyer by shifting the flybar above or below the rotor, that part of the geometry doesnt make a difference.

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12-01-2005 05:47 AM  12 years agoPost 10
Tailspinner

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JAMAICA, NY

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Thanks for all of the replies. Since there will probably be minimal difference at this stage, I'll leave the Raptor in its current configuration. Maybe I;ll try an underslung on the next one. Thanks again.

Are you on the list?

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HelicopterMain Discussion › underslung head
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