Hi All,

What do people mean when the say "live hinges" ?

Regards

Keith

Pretty sure they are talking about the hinge being part of the control surface.

Picture a piece of foam sheet, you cut it out to the entire shape, then cut from the bottom but not quite all the way through where the elevator is. Now the elevator is "hinged" but not physically separated from the stab.

Thanks Barracudahockey,

What is the benifit of this method?,apart from keeping the top of the wing smooth. ,butI thought that there was less airflow over the top of a wing than on the bottom.Is live hingeing only used on high speed planes an jets?

What material is used to maintain astrong flex point?

Anybody got any photo's / videos of how this hinge methodis done?

Regards

Keith

Information about living hinges (Barracuda got it, although it does not necessarily have to be the same material:
http://en.wikipedia.org/wiki/Living_hinge
http://engr.bd.psu.edu/pkoch/plastic...ving_hinge.htm

Here are some examples - Composite ARF uses 'skin hinges' on many of their planes (I have them on my Integral) - it makes for a seamless hinge on ONE SIDE of the airfoil (top or bottom):
http://www.rcuniverse.com/forum/m_22...tm.htm#2281568

Benefits:
-The sites above talk about the life of the hinge. I read about Comp ARF hinges before I bought the plane and could not find any/many failure reports.

-Air Flow:An advantage to these hinges could be that the high pressure zone and the low pressure zone (below and above the wing) are sealed off from each other. The high pressure air will want to move to the low pressure zone to balance out. This is why commercial airplanes use 'winglets' on the wing tips, to help keep the high pressure air from 'spilling over' the tip of the wing, which after a small chain of events results in inefficiency. It also may be an advantage in that the surface on the "top" (low pressure) side of the wing is smooth, which could result in less turbulence over the control surface and make the control more responsive. Traditional model airplane hinges allow for a gap or a discontinuous surface, where air most likely becomes turbulent and has to 'reattach' to the control surface.

Hi gaRCfield,

Thanks for the reply and links, very interesting.



keith

Joe, what is the skin they are using for the hinge??