No fixed tips?

[Doug Cronkhite]

There may not be good data on our models, but there is literally libraries
full of data on wingtip vortices and how strong they can be. I agree with
Troy on this one too.. the vortices off our wingtips really beat up the
servos, especially under high G loads.
 
-Doug
 
 


  _____  

From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org] On
Behalf Of Bob Pastorello
Sent: Saturday, January 29, 2005 6:34 PM
To: discussion at nsrca.org
Subject: Re: No fixed tips?


I have to agree about the "boxed in" setups being somewhat smoother, and
having less wear and tear on the servos.
    And ARF-ers'  *are* doing it... both the Arresti I flew, and this
Icepoint have tips on ALL control surfaces.  And I don't think they would do
that if there wasn't at least a "belief" that they were needed.
 
Doubt that there's good scientific data about this on our models...but sure
a lot of anecdotal evidence to support having tips installed!

Bob Pastorello
NSRCA 199  AMA 46373
rcaerobob at cox.net
www.rcaerobats.net
 
 

----- Original Message ----- 
From: Troy A.  <mailto:troy_newman at msn.com> Newman 
To: discussion at nsrca.org 
Sent: Saturday, January 29, 2005 8:26 PM
Subject: Re: No fixed tips?

They don't fly the same....and the aileron thru the tip thing wears out
servo pots faster. I flew a model this past summer and it went thru aileron
servo pots in 50 flights. I normally get well over 100-125 flights. And this
was a wood model so the vibration was better damped than a composite fuse.
 
Wing tips have lots of turbulence coming off of them...then stick a aileron
in this turbulence. NOPE not the best from an engineering standpoint. 
 
The answer guys and manufacturers give is it snaps better. My answer is
design a good wing and it will snap better. Copy a good wing and it will
snap better.  The ailerons become more effective with the area at the
tip....but I don't feel it helps flight performance. Aileron thru the tip is
much easier and faster to build than a boxed in version. on the ARFy stuff
its cheaper...this is the biggest reason I think its done.
 
As for elevators without tips there are no references. And the same things
apply
 
All my models have them boxed and will have them boxed in.
 
Troy

----- Original Message ----- 
From: Tim  <mailto:twtaylor at ftc-i.net> Taylor 
To: discussion at nsrca.org 
Sent: Saturday, January 29, 2005 7:46 AM
Subject: No fixed tips?

No fixed tips at the end of the wing/stab seems to be the rage. Any real
reason for this? I really don't care for this very much as it makes it
harder to make sure your trim is right and the elev half's meet.

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