CG for Biplane and more control sensitivity

[paul]

Dean,
    Q 1 Wings don't have equal area so I better follow what you said.
    Q 2 I suppose the minimal 1/32 " extention of the Ail LE beyond the wing TE is not significant.
The roll rate at high rate (atv set to 100 % hi rate set at 90 % low rate set to 75 %) is a little hot bu useful for the Intermediate stall turn with full roll up.  I usually fly at low rate, it is set so max stick is good for the Intermediate 2 rolls.
    Weather this weekend may permit flying - right now in central Texas it is COLD - mid to upper 20s.
Thanks for the info,
Paul
  ----- Original Message ----- 
  From: Dean Pappas 
  To: discussion at nsrca.org 
  Sent: Thursday, December 08, 2005 4:27 PM
  Subject: RE: CG for Biplane and more control sensitivity


  Hi Paul,
  Question 1 Yes, but only if the two wings have equal area.

  Question 2 If you get completely (and I do mean completely) baffled by the problem, then think about a way to investigate the problem. Have you flown the plane with less throw? How fast is your maximum roll rate? Do you just have way too much roll rate available at 100% ATV?

  Dean Pappas 
  Sr. Design Engineer 
  Kodeos Communications 
  111 Corporate Blvd. 
  South Plainfield, N.J. 07080 
  (908) 222-7817 phone 
  (908) 222-2392 fax 
  d.pappas at kodeos.com 

    -----Original Message-----
    From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of paul
    Sent: Thursday, December 08, 2005 4:57 PM
    To: discussion at nsrca.org
    Subject: Re: CG for Biplane and more control sensitivity


    Dean,
        Thanks for the info on the Bipe CG.  Out of curosity, wouldn't the same result be found by independently calculating the 25% point on each wing individually and averaging them ?
        
        Regarding the ailerons - I have never looked that closely at the aileron LE.  Both wings have the same quirk - the aileron LE protrudes ~ 1/32 down near the root for about 2.5 " and about 1/32 up at the center for about 5".  
        What do you think ?

    Thanks,
    Paul

      ----- Original Message ----- 
      From: Dean Pappas 
      To: discussion at nsrca.org 
      Sent: Thursday, December 08, 2005 3:22 PM
      Subject: RE: CG for Biplane and more control sensitivity


      Hi Paul, 
      It's the wing area weighted average of the 25% (or whatever) MAC of each wing.
      If the areas are equal, it is centered between the 25% MAC of the bottom and the 25% MAC of the top. 
      If the top wing has, say, double the area of the bottom wing, then it's 2/3 of the way from the 25% MAC of the bottom to the 25% MAC of the top.

      While I am here: did the throw reduction fix your sensitivity problem?
      One other variable is hingeline shape. If the leading edges of the the ailerons protrude above the wing surface this can cause all sorts of issues.
      It wasn't likely, so I didn't bother to chime in, before.
      later,
      Dean


      Dean Pappas 
      Sr. Design Engineer 
      Kodeos Communications 
      111 Corporate Blvd. 
      South Plainfield, N.J. 07080 
      (908) 222-7817 phone 
      (908) 222-2392 fax 
      d.pappas at kodeos.com 

        -----Original Message-----
        From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of paul
        Sent: Thursday, December 08, 2005 4:00 PM
        To: discussion at nsrca.org
        Subject: CG for Biplane


            Anyone know how the calculate the CG for a Biplane ?  I expect it is 25-30% of the MAC; but, how do I calculate the MAC for a biplane ?
        Thanks,
        Paul
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.f3a.us/pipermail/nsrca-discussion/attachments/20051208/afadb458/attachment-0001.html