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<DIV><FONT face=Arial size=2>Courtesy of Buddy, I've placed (with his
permission) his summary of the "trimming" issues. Probably many of you
share my view that his summary was one of the most on-target, concise statements
I've read about trimming in a VERY long time, if ever!!! Posted here for
your reference:</FONT></DIV>
<DIV><FONT face=Arial size=2><A
href="http://www.rcaerobats.net/trim_chart.htm">http://www.rcaerobats.net/trim_chart.htm</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks, Buddy!</FONT></DIV>
<DIV><BR>Bob Pastorello, Oklahoma<BR>NSRCA 199, AMA 46373<BR><A
href="mailto:rcaerobob@cox.net">rcaerobob@cox.net</A><BR><A
href="http://www.rcaerobats.net">www.rcaerobats.net</A></DIV>
<DIV> </DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=BUDDYonRC@aol.com
href="mailto:BUDDYonRC@aol.com">BUDDYonRC@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, March 30, 2004 1:08
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Trimming Help</DIV>
<DIV><BR></DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial
color=#8000ff size=2 FAMILY="SANSSERIF" PTSIZE="9">Paul<BR>I am no
aerodynamics expert, but I have learned some basic's over the years that work
for me.<BR>1. The wing must have a positive angle of attack to create
lift.<BR>2. the stabilizer and elevators steer the pitch attitude of the
airplane resulting in more or less lift.<BR>3. Balance can change the angle of
attack which will change the pitch attitude.<BR>4. Aileron's up or down will
change the pitch attitude .<BR>5. Up or down thrust will change the pitch
attitude.<BR>Therefore:<BR>A. Increasing the positive wing incidence will
cause the airplane to climb, which will require down trim to achieve level
flight.<BR>B. Likewise adding tail weight will cause the airplane to climb and
require down trim to achieve level flight.<BR>C. Added weight does not alter
the vertical down line BUT elevator trim added to maintain level flight
because of the added weight will effect the down line. Tail weight will
require down trim which will steer the airplane more to the belly in a down
line, and added nose weight will require up trim which will steer the airplane
to the canopy.<BR>D. In the vertical up line elevator trim and the engine
thrust line will effect the vertical and/or yaw direction <BR>All
of the above will effect the knife edge flight of the model.<BR>Combinations
of adjustments to any or all of the above trim items done at the same time
will leave you confused and frustrated.<BR>Most models will require some
mixing to achieve near perfect lines in all flight attitudes in order to
minimize / eliminate control inputs by the pilot to maintain a perfect
course.<BR>I have yet to see the perfect airplane should such an animal exist,
but I keep looking and building since I truly believe that nothing is
impossible.<BR>When trimming an airplane make a written log of every change no
matter how small so you don't have to start over when changes are not
correct.<BR>Buddy</FONT> </FONT></BLOCKQUOTE></BODY></HTML>