Re: Re: Curved Wing Tips and Vertical Stab

From: Bill Gowen <b.gowen_at_earthlink.net>
Date: Thu, 9 Aug 2007 16:52:34 -0400

My F1M, LPP, and OPP all have flat wings with tip plates. They are all very stable. All these models have low aspect ratios. I haven't tried this configuration lately on higher aspect ratio models like F1L and EZB. A number of years ago I built an F1L with tip plates but it had all the problems you described. Starting around 2000, all of my SO designs except LittleSquare had flat wings with tip plates and they flew well. I didn't try it with LittleSquare because of the higher aspect ratio of the wing compared with earlier models.

----- Original Message -----
  From: calgoddard
  To: Indoor_Construction_at_yahoogroups.com
  Sent: Thursday, August 09, 2007 4:23 PM
  Subject: [Indoor_Construction] Re: Curved Wing Tips and Vertical Stab


  Thanks Bill.

  I can always count on you for some good input.

  Here is another question.

  I have seen some competitors try to max lifting area of the main
  wing (under max span and chord limitations) by not having any wing
  tip dihedral, or any dihedral at all for that matter.

  They have a flat main wing (except for the airfoil ribs of course)
  and they have vertical tip plates. See Double Trouble for example by
  Brent Sanborn I believe.

  I tried this a few times, and the planes suffered from occasional
  inherent instability problems (slide slip and/or spiral down). Once
  I got one of these models to fly really, really well, but on only
  one flight. It couldn't be duplicated.

  I found that a main wing with outboard wing tip dihedral sections
  seems the most stable, and that, oddly, the angle of these doesn't
  make much difference as long as it was at least 30 degrees.

  Your thoughts?



   

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Received on Thu Aug 09 2007 - 13:54:19 CEST