wing tip shape

[Rcmaster199 at aol.com]

Lance, the rounded leading edge of the control surface was practiced way  
back in the golden (stone?) age of model aviation, when the hinge material was  
plain thread. Believe it or not, the control surfaces were literaly sewen into  
the wing or stab or fin. Surface actuation essentially allowed the surface to 
 "roll", ie- it did not pivot about a single axis as present set-ups do
 
Yor observation is correct: a rounded edge hinged with present hinges, will  
tend to bind.
 
MattK
 
In a message dated 11/25/2004 12:47:09 AM Eastern Standard Time,  
patterndude at comcast.net writes:

Please  someone explain this rounded control surface thing to me.  If we use  
a CA hinge and but the aileron to the wing, then the only way the surface  
can move is if it has a beveled point.  A rounded interface will bind  unless 
the aileron has a gap to begin with.  However, if all we are  saying is to 
round the part of the bevel that blends into the aileron,  then I get it.

Confused again....
--Lance

----- Original  Message ----- 
From: "John Pavlick" <jpavlick at idseng.com>
To:  <discussion at nsrca.org>
Sent: Wednesday, November 24, 2004 8:38  PM
Subject: RE: wing tip shape


> Hey, That's how they are on  my Super Kaos Jr. Not exactly 45 degrees, but
> the outboard 3" is  tapers toward the tip. If you do this by sanding the
> bottom edge of  the aileron at the tip, you also add a little washout to 
> help
>  prevent tip stalls. Not sure if it's enough to make a difference but I  can
> land this plane nose high without any surprises. Someone mentioned  
> rounding
> the leading edge of control surfaces rather than  beveling them - I've 
> always
> done this unless the surface is  really thick (like a barn-door aileron). 
> In
> the 1st U.S. R/C  Flight School training manual (the red one) the idea of
> control  surfaces with round leading edges that are slightly thicker than 
>  the
> fixed surface is discussed. They claim it reduces flutter (without  sealing
> the gaps) and makes the control response less speed sensitive.  Has anyone
> tried this? It would be interesting to hear if it works on  pattern planes.
>
> John Pavlick
>  http://www.idseng.com
>
>
>> -----Original  Message-----
>> From: discussion-request at nsrca.org
>>  [mailto:discussion-request at nsrca.org]On Behalf Of John Ferrell
>>  Sent: Wednesday, November 24, 2004 5:43 PM
>> To:  discussion at nsrca.org
>> Subject: Re: wing tip  shape
>>
>>
>> If you carry the aileron all the way  to the tip it is good
>> medicine to clip
>> the trailing  outboard corner at 45 degrees to help suppress any
>> tendency  to
>> flutter. It is common practice on combat  models.
>>
>> John Ferrell
>> My Competition is not  my enemy!
>> http://DixieNC.US


 
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