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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

231.0. "Help on Piece-O-Cake..." by STEREO::DINATALE () Tue Jul 28 1987 11:22

    I have completed my Piece-of-Cake and am in the process of trying
    to trim the plane. The original instructions that showed the trim 
    and balance procedures were destroyed.
    
    The information that I need is:
    
    	The balance point, it glides ok but seems to be tail heavy.
    			The placement of gear from the engine is the
    			batt, rec.(vertical), servos. All electronics
    			are as far forward as they can be.
    
     	Maximum flight weight. To much for the engine??
    
    The flight characteristics seem to be very unstable. All control
    surfaces are at minimum throw and wings are flat and level.
    Any infomation or hints that you have on the plane would be greatly
    appreciated.
    
    Richard
T.RTitleUserPersonal
Name		DateLines
231.1MJOVAX::BENSONTue Jul 28 1987 12:1911
    Two observations:
    
    1) Tail heavy will prove to be very unstable (better to err nose
    heavy).
    
    2) "Wings flat & level"- Shouldn't there be quite a bit of dihedral
    on that bird?  That will lend much to the stability as well.
    
    One Summation:
    
    1) GET AN INSTRUCTOR !!!
231.2SPKALI::THOMASTue Jul 28 1987 13:2013
    
    	I am assuming that you don't know where the CG is supposed to
    be.  Measure the cord of the wing. 
    
    	Cord is at the fuse,  cord = distance from leading edge to trailing
    edge.
    
    	The balance point should be from 25% to 30% of the cord measurement
    from the leading edge of the wing.  If the plane show to be tail
    heavy and you can't move any of the gear any more forward the ann
    nose weight.
    
    						Tom
231.3Raise the front of the wingAKOV01::CAVANAGHWe don't need no stinkin badges!Tue Jul 28 1987 15:1810
  Also add a 1/16 - 1/8 shim under the leading edge of the wing.  I was told
by Dan Snow (a POC owner) that it is necessary for proper flight.  I did it
on mine and it works.
  Do you have the proper dihedral?
  Also note that the max speed for this plane is about 7 mph.  Any kind of
stiff breeze is going to make flying very interesting.  Mine likes to fly
backwards!


  Jim C
231.4I'll try itSTEREO::DINATALETue Jul 28 1987 16:2312
    The POC (as it has been called) has the proper dihedral. What I
    meant by flat was the incedence (?) between the main and tail. The 
    few times I had it out there was almost zero wind. 
    
    I'll calculate and check for the correct CG.

    Also will install the shim ASAP and see what happens. Umm.. what will
    happen anyway? Why?
    
    Anyone knows how much it should weigh??
231.5I have the plansAKOV01::CAVANAGHWe don't need no stinkin badges!Tue Jul 28 1987 16:3712
    Actually, Richard, why don't I send you my copy of the plans for your
reference?  As long as you return them when you are done I don't mind.  I
can have them in the mail first thing in the AM.  
    After thinking about it for a while, I remember having to add several
onces of lead to the nose to balance it.  I will weigh mine tonight and let
you know what the total weight comes out to be.
  By the way, mine never had a 'great' flight due to a bad motor.  I have 
just installed a new Black Widow and have not tested it yet.


 Jim C
231.6I'm not sure why, but it works.29901::SNOWMon Aug 03 1987 21:4321
    
    Richard,
    	I don't understand the areodynamic theory behind increasing
    the angle of attack on the wing, (Tom, can you explain this?) but
    anyway, when I did the first test glides on mine, it was indicating
    nose heavy, i.e. glide angle was steep and down. I rechecked the
    balance point and it was right on. I then asked my instructor, and
    he suggested raising the leading edge of the wing a 1/16th of an
    inch. This levelled out the glide path. As far as your plane exhibiting
    unstable characteristics, what do you mean. The high dihedral wing
    will cause the plane to roll quite rapidly when rudder is applied,
    and you quite often will get a very wobbly looking flight path when
    making several rapid control inputs.
    
    Jim is right about how the plane handles the wind. It doesn't. I
    have flown mine in winds of 15-20 mph, and it is really interesting.
    
    Hope this helps a little.
    
    Dan
231.72 CENTS WORTHSVCRUS::EVERSMon Aug 03 1987 22:4610
    
       I've flown my piece-o-cake in a 10 mile hour wind and as long
    as you keep it heading into the wind it will just sit there in
    mid air.But anyway the piece-o-cake is not designed to climb any
    more then 25 degrees at one time.It takes a while to get it to
    200 feet or more unless you take the motor off and shoot it up
    on a high start.Well that's my 2 cents worth.
    
                                     KEEP'EM FLYING
                                     JERRY
231.8SPKALI::THOMASTue Aug 04 1987 08:1315
    Increased angle of attack increases lift. To a point. Increasing
    the angle of attack for normal flight will also increase the
    possibilities of a stall. 
    
    Q: What is the cord of the wing and how far back do thy tell you
    to put the CG? Also how much does the plane weigh?
    
    To increase a sailplanes penetration into the wing you add ballist
    at the CG. I saw many sailplanes in CXO that had tubes built right
    into the wings on the CG for the purpose of adding ballist. I flew
    in a 20 mph wing east of CXO with almost two lbs. of ballist one
    day.
    
    
    						Tom