[SPAM] Re: No fixed tips?

[Mike Hester]

Interesting thread. Predictable responses too, in some cases.

Well, here's my 2 cents. I've had the opportunity to play with this for a while now, and I simply don't think it matters that much. The plane I'm currently flying has the ailerons cut all the way through the tips, with small counterbalances. This is the best snapping plane I have ever flown. It's so predictable it's ridiculous. The wings are light, and the tips are smaller than most as well. Matt is right on about wing weight, it will affect snap dampening MUCH more than your aileron cut out.

I did notice some VERY SLIGHT aileron centering issues lately, but didn't notice at all until about 800 flights. This plane is all wood, so maybe that has some bearing as well, servos have never been an issue thus far. I think 800+ flights is acceptable.

I simply don't believe it's an important design criteria at all. Not under the current patterns anyway. If you like tips, then use the tips. If you like them cut through the tips, do them that way. If you're burning up servos, you have other issues than whether or not your aileron is cut through the tip. Look elsewhere for a solution.

Or just do whatever everyone else does =)

-Mike

  ----- Original Message ----- 
  From: Rcmaster199 at aol.com 
  To: discussion at nsrca.org 
  Sent: Sunday, January 30, 2005 2:24 PM
  Subject: [SPAM] Re: No fixed tips?


  I have done it both ways and notice virtually identical performance as long as the aileron areas (as a percentage and planform) are unchanged. What I have found stops the snap accurately and repeatably is a light wing. Have not required servo pots in either type after 100's of flights. Don't know why some are losing servos after a few flights, but do know what works for me.

  Commercial jets flying at 600 mph and models flying at 100mph, don't have much in common.

  MattK

  In a message dated 1/30/2005 12:30:22 PM Eastern Standard Time, pattern4u at comcast.net writes:
    The current theory is that the ailerons all the way out to the tips, stop the snap more accurately.

    Eric.
      ----- Original Message ----- 
      From: Bill Glaze 
      To: discussion at nsrca.org 
      Sent: Sunday, January 30, 2005 11:33 AM
      Subject: Re: No fixed tips?


      Again, with the full-size:  Notice that such luminaries as Boeing, Douglas, et.al don't run their ailerons to the tips, but instead stop short?    As Troy and Doug have stated, the wingtip vortices generated are the reason.  I had a long discussion with Dick Hanson about this, and he stated that "it didn't make any difference on our models."  Well, from what Troy has discovered about aileron pots, it seems it DOES make a difference.
      Bill Glaze

      Troy A. Newman wrote:

        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 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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