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<DIV><FONT face=Arial size=2>Troy,</FONT></DIV>
<DIV><FONT face=Arial size=2> Responses are
below.</FONT></DIV>
<DIV><FONT face=Arial size=2> So far my impressions from the
feedback I have received are : </FONT></DIV>
<DIV><FONT face=Arial size=2>TE may be too rounded and pointy</FONT></DIV>
<DIV><FONT face=Arial size=2>I may be expecting too much w/o the higher (45%)
expo.</FONT></DIV>
<DIV><FONT face=Arial size=2> My basis of comparison is the
Prophecy that I normally fly in Intermediate. Compared to the Meridian it
seems to lock in on the roll axis better and not have the twitchiness around
neutral (expo is 26%). </FONT></DIV>
<DIV><FONT face=Arial size=2>One thing about the Meridian is that it weighs ~
9.5 lbs due to having a YS 91 AC up fromt rather than a 2 stroke. This was
a double whammy since the YS makes it nose heavy and I had to add tail
weight. Going to a 2 stroke would reduce weigh by 1/2 to 1 pound.
Still, a lead sled doesn't usually have roll twitch problems.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks,</FONT></DIV>
<DIV><FONT face=Arial size=2>Paul</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=troy_newman@msn.com href="mailto:troy_newman@msn.com">Troy A.
Newman</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> Monday, December 05, 2005 2:08
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Excess Aileron sensitivity
around neutral</DIV>
<DIV><BR></DIV>
<DIV>
<DIV><FONT face=Arial size=2>Paul,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Everything looks Ok so far....What deflections
are you using with those 100% ATV values....?Both ailerons Up and down
please? <FONT face=Impact>15 degrees up and down</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As for the TE being too sharp if it is 1/8" is
fine. Getting down to less than 1/16th is getting too thin. Its a little
sharper than many of the newer models have but it is OK...The sharp TE will
tend to hunt. It will also be more of a problem with servo pot wear. It
can also feel a little touchy at Neutral as Del mentioned because you are over
shooting hand eye stuff as the servo hunts center. The result can be that
you feel like the wings can never stay level, and you keep over
shooting. This can give the feel of touchy right off neutral. I
really think this is not the issue at hand 1/8" is common out there today, not
the best but not the worst either. <FONT face=Impact>1/8 " thick with
1/16 " radius at the TE end. Tapers from 1/2 inch at wing down to 1/8 "
at end over a 2" width.</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>9252's should be fine and not have the blow back
problem. Good torque at 92oz... a little fast than most guys are using at
0.14sec...but this is good as long as you have a good linkage setup. I
have never run those servos but I know Futaba digital servos are pretty good.
It is very close to the servo I'm using...9411SA at like 82oz of torque and
0.15sec..But I'm also running a little higher voltage than the 4.8V spec so
I'm probably up close to what you have. Maybe slightly less torque like 89-90
or something.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We need to make sure you have good mechanical
advantage of stuff. Pushrod at 90 degs to the servo arm and all that is good
too....Stiff linkages (CF rods) is also good <FONT face=Impact>MA
: 25 mm control horn 15 mm servo arm.</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>But the Next Questions:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Distance from hinge line to the aileron horn
clevis pivot point? Just slide a thin metal or plastic ruler down in the hinge
line and measure up to the pivot point. Just need a rough idea on the
number...within 1/8" to 1/4" is fine for this measurement. <FONT
face=Impact>30 mm</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Distance from Servo wheel connection point to the
center of the servo wheel? Try to get with a 1/16" of so. <FONT
face=Impact>15 mm</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What servo wheels are you using? Futaba so you
have the black plastic ones right or aftermarket (dubro,
aluminum?)</FONT></DIV>
<DIV><FONT face=Arial size=2>If you are using the Futaba plastic horns these
are OK but which one are you using the (X, star, or the round wheel-big one or
the small one that comes installed on the servo?) Reason I ask is Servo arm
flex...Sometimes the servo arms can flex and this can act a little spongy on
the ailerons... Again at a higher speed it could be different than a lower
speed. I understand that you are not have a speed sensitivity issue but the
hotness feel at neutral is seeming to change at low speeds right? <FONT
face=Impact>The futaba X arm is being used. The sensitivity is not
related to speed, twichy at all speeds.</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Differential setting in the radio? <FONT
face=Impact>None</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>One more thing. Because the servo wheel is
rotational it will impart a little reverse expo around neutral. The linear
distance traveled by the linkage is different for the first 1-2 deg off
neutral than it is the last 1-2 degs at the ends of the stick travel. This
means that on most setups you need to run about 25-35% expo just to get the
thing back to linear output. Common Expo values like 45% like you have sound
like a bunch but in reality you are only getting a little soft at center. I
will also say that the expo function between radios is different not just
between JR-Futaba but I have found a different feel between Futaba 8uap and
9Z, and JR 10X and 8103. The 9303 and 10X by JR seem to be very close if not
identical if that matters. Moral of this story a blatant statement that you
need 45% expo or 60% is tough to confirm in all applications. I have found as
the expo creeps up around 70-80% you start to get a knee kick in inflection
point in the curve...but again it depends on so many other things. I would say
currently you are 45% this is not excessive. This is not light expo
either....But maybe increasing up to say 55% would smooth it out a bit better
for you. Small little tweaks can sometimes make a huge difference in feel. You
wouldn't think 5% would make a huge difference...but the subtle difference is
the comfort level you might need. But the amount of expo you need is a
function of lots of things...</FONT></DIV>
<DIV><FONT face=Arial size=2>So lets look at actual deflections of the
ailerons as well as servo horn and control horn lengths.</FONT></DIV>
<DIV><FONT face=Impact size=2>Interesting, Initally I ran 25% expo and the
plane was twichy. Since I increased it to 45% it has settled down a
lot. In light of your comments, this may be a cockpit problem
!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We'll get it figured out. I never owned a
Meridian, but I flew a couple helping guys trim them out. It should be fine.
Piorun designed some good models...Rick Allison was in on many of those
designs too and he knows the ins and outs as well.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>have patience with the process. A little check
out here and there will give us some data that we can work with. Since I'm not
there to help you fly the thing looking into various aspects can help us
eliminate things one at a time.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Troy Newman</FONT></DIV></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=paul.horan@sbcglobal.net
href="mailto:paul.horan@sbcglobal.net">paul</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> Monday, December 05, 2005 9:10
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Excess Aileron sensitivity
around neutral</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2> Oops, when I said the
ailerons were OK at full throttle I meant to describe that the aileron
authority was not excessive, not that the excessive sensitivity is speed or
throttle related - it is not. Sorry I was not more
specific.</FONT></DIV>
<DIV><FONT face=Arial size=2> Some more
details:</FONT></DIV>
<DIV><FONT face=Arial size=2>* Servos are two digital 9252s, should be
plenty of torque and have excellent resolution around neutral - no pot
problems.</FONT></DIV>
<DIV><FONT face=Arial size=2>* Linkage is carbon fiber rod and no
slop.</FONT></DIV>
<DIV><FONT face=Arial size=2>* Expo is - 45% to reduce the twich.
ATV is 100 % high rate 90% low 75% (normally high would be 100% but is
dialed down while working this problem).</FONT></DIV>
<DIV><FONT face=Arial size=2>* Airframe - no loose covering, clevis pin is
over hinge line at neutral, servo arm and control horn are 90 degrees at
neutral (control geometry). CG is rearward but not tail heavy - pitch
is not twichy. </FONT></DIV>
<DIV><FONT face=Arial size=2>* have not measured wing and
stab incidence angles.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>*** one thing that Del mentioned - Aileron
trailing edge (and wing) taper to a very sharp radius ~ 3/32 to 1/8
inch.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks,</FONT></DIV>
<DIV><FONT face=Arial size=2>Paul</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=paul.horan@sbcglobal.net
href="mailto:paul.horan@sbcglobal.net">paul</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> Sunday, December 04, 2005 5:26
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Excess Aileron sensitivity
around neutral</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2> I have a Meridian with a
frustrating characteristic, the ailerons are excessively sensitive around
neutral.</FONT></DIV>
<DIV><FONT face=Arial size=2>I'm the second owner of this plane but the
first owner said he had the same problem. Aileron authority at full
throttle is not excessive - in fact it slightly on the mild
side. </FONT></DIV>
<DIV><FONT face=Arial size=2>Any ideas ?</FONT></DIV>
<DIV><FONT face=Arial size=2>Thanks,</FONT></DIV>
<DIV><FONT face=Arial size=2>Paul</FONT></DIV>
<DIV><FONT face=Arial size=2>NSRCA
3606</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>