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Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

807.0. "Flaperons vs. ail. & flaps" by WRASSE::FRIEDRICHS (Where's the snow??) Wed Dec 21 1988 08:21

    As many of you know, I am building a C-45 from Tom T.'s plans.
    
    I have decided to also use this as my first plane with flaps.  My
    question here though, is what are people's experience with flaps
    and ailerons versus flaperons.  I am thinking of using the dubro
    v-tail mixer to combine the 2 servos.  Has anyone else used this
    setup??
    
    My alternative setup would be to cut the control surface in half.
    If I do this, are there any suggestions as to how much of the surface
    should be flap and how much aileron.  It should be noted here that
    the control surface is not a constant width, it gets narrower towards
    the wingtip.  Should I make the cord of the surface greater or should
    I increase the throws??
    
    Thanks for any suggestions!
    jeff
T.RTitleUserPersonal
Name		DateLines
807.1FLAPERONS TABOOPNO::CASEYATHE DESERT RAT (I-RC-AV8)Wed Dec 21 1988 13:0217
    Jeff,
    
    I'd definitely advise _against_ the use of flaperons on this bird
    (or most any other scale subject for that matter).  Why?  Because
    deflecting both ailerons down has the effect of producing wash-"IN",
    the very thing you can least afford when low and slow; the tips
    will stall first and snap you into the turf in a heartbeat.  The
    C-45, I'm told by an authoratative source, was snap-prone in real
    life so it follows the model will emulate this behavior and some
    wash-"OUT" might be adviseable to counter this tendancy but NEVER
    wash-"IN"!!!  You'd just be begging for it, I'm afraid.    

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)
807.2VTMADE::SOUTIEREWed Dec 21 1988 13:444
    Jeff,  on my Chipmunk the ailerons are 17" and the flaps are 7"or
    9".....just to give you an idea.
    
    Ken
807.3I'd go with _Flaps_WMOIS::JORGENSENWed Dec 21 1988 14:0314
Flapperons...  I would have to vote against them for effectiveness.  I have an
Airtronics 7sp with all the necessary mixers for a two servo set up, and they 
proved very ineffective;  with a substantial reduction in the effectiveness  
of the ailerons.  Hence, it made landings a bit tricky.  In addition, with 
a mechanical linkage, I suspect that when you trim the plane out, you will 
run into problems with your flapperon trim?!?!

It all amounted to complications, and I'd have to say the effective flaps that
I've seen have been traditional flaps - my _guess_ is that you want about 
1/3 of you wing control surfaces to serve as your flaps.  
    
    
/Brian
807.4SA1794::TENEROWICZTWed Dec 21 1988 14:139
    
    Al, I'd heard of the C45 stall problems  but the model isn't using
    a scale airfoil. Far from it. I've opted for a 15% thick wing with
    a semisemetrical airfoil at 9% above and 6% below the airfoils center
    line. This isreally a forgiving airfoil. I will cut a little wash
    out into the cores. Perhaps 3/16 of an inch in each tip.
    
    
    Tom
807.6WRASSE::FRIEDRICHSWhere's the snow??Thu Dec 22 1988 12:127
    Flaps and Ailerons it is then!  Thanks..
    
    This should really make the C-45 fly neat...
    
    cheers,
    jeff