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<DIV><SPAN class=835075914-30032004><FONT face=Arial color=#0000ff size=2>Hi
Bob,</FONT></SPAN></DIV>
<DIV><SPAN class=835075914-30032004><FONT face=Arial color=#0000ff size=2>They
are measured relative to each other, but there are two other things to consider.
The lesser of these is the thrustline, which will strogly affect the UPline. It
can be adjusted, though. The biggie is the relative height of the stab above the
wing. Picture an extreme example: you add 5 degrees of positive incidence to
both the wing and stab; now the plane flies along tail-high, with its nose down
like a huntin' dawg. It is now a different design ... some planes have the wing
and stab almost in line, and others have the stab up in air that is less
affected by the wing. Depending on stab size, CG, and tail length, different
stab-over-wing heights work, and others are not quite right. That means they
take lots of electronics to fix the knife edges, or have no sweet-spot where the
verticals are straight. </FONT></SPAN></DIV>
<DIV><SPAN class=835075914-30032004><FONT face=Arial color=#0000ff size=2>You do
realize that this opens up a large can of worms!</FONT></SPAN></DIV>
<DIV><SPAN class=835075914-30032004><FONT face=Arial color=#0000ff size=2>Hope
this helps</FONT></SPAN></DIV>
<DIV><SPAN class=835075914-30032004> <FONT face=Arial
color=#0000ff size=2>Dean P.</FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Bob Kane
[mailto:getterflash@yahoo.com]<BR><B>Sent:</B> Tuesday, March 30, 2004 8:55
AM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> RE: Trimming
Help<BR><BR></FONT></DIV>
<DIV>I have to ask . . . . . what is the difference between adding
positice incidence to the wing versus negative to the stab? Are they not
relative? <BR><BR><B><I>Dean Pappas <d.pappas@kodeos.com></I></B> wrote:
<BLOCKQUOTE class=replbq
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Hi
again Paul,<BR>Many planes trim nicely with a small amount of positive
incidence in the wing, compared to the stab.<BR>The typical amount is about
1/4 to 1/3 degree, or a little over 1/16" over the wing chord. If you have
full degree of incidence in the wing, you may have a belly-pitch in knife
edge, unless terribly nose-heavy. Now we need to ask those of you out there
with well trimmed Tai-Ji to tell us where your CG is. There's no sense in
re-inventing the wheel. Put the CG there, and adjust/shim the incidence
'till the elevator trim goes away, and let's see where we are.<BR><BR>Before
doing that, are you sure that the ailerons aren't both trailed up or down,
even a little?<BR><BR>Don't let us forget you, until this problem is
licked,<BR>Dean<BR><BR>-----Original Message-----<BR>From: David Lockhart
[mailto:DaveL322@comcast.net]<BR>Sent: Monday, March 29, 2004 11:06
AM<BR>To: discussion@nsrca.org<BR>Subject: Re: Trimming
Help<BR><BR><BR>Paul,<BR><BR>Most of the trim advice being given is based
(rightly so) on some<BR>assumptions -<BR>- the plane is straight and
true,<BR>- ail hinges are sealed,<BR>- servos are tracking evenly throughout
the range of throw (as measured by a<BR>throw meter - Budd Laser, CRC, Ivans
Gadget, etc),<BR>- all references to ail throw and ail differential refer to
actual measured<BR>throw at the aileron (as opposed to an
ATV/endpoint/differential setting in<BR>the radio).<BR><BR>Another thing I
would suggest - if possible, have another experienced<BR>pattern pilot fly
the plane and see if they find the same problem - and it<BR>gives you an
opportunity to very critcically watch the plane and evaluate<BR>without
needing to concentrate on the actual flying.<BR><BR>As Dean P said, negative
ail differential is rarely needed, but not out of<BR>the question. Most of
my planes end up with no differential, or a very<BR>slight amount of
positive differential - but I did have one that required<BR>negative
differential.<BR><BR>Good luck,<BR><BR>Dave
Lockhart<BR>DaveL322@comcast.net<BR><BR><BR><BR>----- Original Message
-----<BR>From: "Paul Lawrence" <PWL45@YAHOO.COM><BR>To:
<DISCUSSION@NSRCA.ORG><BR>Sent: Monday, March 29, 2004 8:19 AM<BR>Subject:
RE: Trimming Help<BR><BR><BR>> The plane is a Tai Ji 60. I may have found
an<BR>> incidence<BR>> problem too. I don't really know where the
reference<BR>> line is for this model and I am also still
learning<BR>> how to check incidence, but if I block up the plane<BR>>
and get the wings at 0 degrees and then check the<BR>> stab, it is
showing -1 degree of incidence. That seems<BR>>
excessive.<BR>><BR>> I'm flying Intermediate and the yaw really shows
up on<BR>> the humpty bump and full roll up on stall turn. When I<BR>>
perform the humpty bump, I pull to vertical, 1/2 roll<BR>> right and the
plane heads off to the left(belly in).<BR>> On the full roll up, the
plane heads off to the right<BR>> after rolling right.<BR>><BR>> So
far, I have received a lot of good advice and have<BR>> several things to
try. Thanks.<BR>><BR>><BR>><BR>> ><BR>> > -----Original
Message-----<BR>> > From: Paul Lawrence
[mailto:pwl45@yahoo.com]<BR>> > Sent: Sun 3/28/2004 10:33 PM<BR>>
> To: discussion@nsrca.org<BR>> > Cc:<BR>> > Subject:
Trimming Help<BR>> ><BR>> ><BR>> > After getting soundly
beat in Ocala last weekend, I<BR>> > realized that I have been getting
proverse yaw as my<BR>> > plane rolls.<BR>> > It wasn't evident
until I saw other well-trimmed<BR>> > planes flying.<BR>> > The
plane yaws in the direction of roll input and I<BR>> > have been
experimenting with a multitude of aileron<BR>> > differential settings
and can't seem to remove the<BR>> > yaw.<BR>> > With zero
differential, the plane still yaws in the<BR>> > direction of
roll.<BR>> > The trimming chart says to reduce differential in<BR>>
> this condition, but I have reduced it to zero.<BR>> > Should I
program in negative differential(doesn't<BR>> > sound good) or should
I program a litle bit of<BR>> > opposite rudder correction to offset
the proverse<BR>> > yaw?<BR>> ><BR>> > Also, does CG and
Incidence affect adverse or<BR>> > proverse yaw while rolling?<BR>>
> The plane was a little nose heavy and I have also<BR>> > been
adding tail weight to try and clean up the<BR>> > rolls, but still
can't get that yaw out of the<BR>> > rolls.<BR>> ><BR>>
><BR>> ><BR>><BR>>
=====================================<BR>> # To be removed from this
list, go to http://www.nsrca.org/discussionA.htm<BR>> and follow the
instructions.<BR>><BR><BR>=====================================<BR># To
be removed from this list, go to http://www.nsrca.org/discussionA.htm<BR>and
follow the instructions.<BR><BR>====================================# To be
removed from this list, go to http://www.nsrca.org/discussionA.htm<BR>and
follow the instructions.<BR></BLOCKQUOTE></DIV><BR><BR>Bob
Kane<BR>getterflash@yahoo.com
<P>
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