<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Message</TITLE>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2800.1476" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Seems to me if the servo arm and the control horn
are the same length you get a degree of control surface movement for every
degree of servo movement. However this is not the usual linkage
configuration.</FONT></DIV>
<DIV><FONT face=Arial size=2>Jim</FONT></DIV>
<BLOCKQUOTE dir=ltr
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=jonlowe@aol.com href="mailto:jonlowe@aol.com">Jon Lowe</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> Thursday, February 10, 2005 8:17
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Notes to Self 3</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2><SPAN class=393020416-10022005>What he is saying
is this: As the servo arm rotates from 90 degrees, the effective length
of the servo arm gets shorter, meaning that for each incremental degree
of rotation of the servo arm from 90 degrees, you get less incremental
movement of the pushrod. Therefore the control is inherently more
sensitive around neutral than it is at the ends of the servo throw, assuming
linearity in the rest of the system. Expo can be used to counter this
natural tendency.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=393020416-10022005></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=393020416-10022005>HOWEVER, the
effective length of the surface control horn also gets shorter as the surface
moves from neutral, increasing movement with each incremental movement of the
pushrod. So it is a race between decreasing effectiveness of
the servo output arm vs. increasing effectiveness of the control horn.
Then you get into non-linearity of the aerodynamic surface effectiveness
itself as it moves from neutral, and you can get confused real quick.
You are dealing with several areas of non-linearity, and trying to compromise
between them all.</SPAN></FONT></DIV>
<DIV><SPAN lang=en-us><FONT face=Arial size=2></FONT></SPAN> </DIV>
<DIV><SPAN lang=en-us><FONT face=Arial size=2>Jon Lowe</FONT></SPAN>
<BR></DIV>
<P>
<DIV></DIV><FONT face=Tahoma size=2><FONT face=Arial></FONT>-----Original
Message-----<BR><B>From:</B> discussion-request@nsrca.org
[mailto:discussion-request@nsrca.org] <B>On Behalf Of </B>Tim
Taylor<BR><B>Sent:</B> Thursday, February 10, 2005 8:28 AM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> Re: [SPAM] Re: Notes to Self
3<BR><BR></FONT>
<P></P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV><FONT face=Arial size=2>Troy let me get this straight in my mind, You
said</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>"The reason is the servo wheel is round and its
Y axis distance changes for each degree of travel as the servo rotates
around the back side."</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Now It took me a few readings and some
pondering to understand what you said. It doesn't matter what type arm you
use,correct so far? What I take this to mean is as the servo arm moves the
point at which the servo is connected to the driving rod and the center arm
screw is at it's farthest point at 90 degrees to the servo case (assuming
the servo case is 90 degrees to the hinge line) as it moves forward or
backwards the distance between the pivot points decreases with each
degree of rotation. Correct?</FONT></DIV>
<BLOCKQUOTE dir=ltr
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=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> Friday, February 11, 2005 11:05
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [SPAM] Re: Notes to Self
3</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>8103, 9303 and 10X expo are the same Positive
is softer and Negative is harder feel. I'm writing an article for the KF
right now that talks about Expo and how to use it. When to use it. And the
effects of it. Sometimes a reverse expo (faster response) at center can be
of benefit. We have played with this in snaps and found that it has some
promise...Lots of regular expo on the ailerons and rudder and reverse expo
on the elevator...The result is the model will pitch harder on entry
before the rotations.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Another thing depending on the radio it takes
20-30% expo just to get the output to be linear. The reason is the servo
wheel is round and its Y axis distance changes for each degree of travel
as the servo rotates around the back side.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This is March KF stuff so I won't elaborate
here but I have some data to back up my words. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Troy</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE dir=ltr
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=tncbrown@charter.net href="mailto:tncbrown@charter.net">T&C
Brown</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> Wednesday, February 09, 2005
8:42 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Notes to Self 3</DIV>
<DIV><BR></DIV>
<DIV><FONT size=2>That is odd Tim. I wonder why JR decided after
all these years to change from a pos. setting to a neg. for a
"softer feel". I'm a firm believer in "If it ain't broke, don't
fix it" </FONT></DIV>
<DIV><FONT size=2>I made the same mistake a few years back when I
switched from a Futaba 7UAP to a JR 8103 and inadvertently put neg. expo
in the 8103. Talk about pucker factor for a few
minutes.</FONT><FONT size=2> </FONT></DIV>
<DIV><FONT size=2>Maybe Fu-tuh-boo-boo is rubbing off on JR!
(BG)</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>T-Bone</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<BLOCKQUOTE dir=ltr
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=twtaylor@ftc-i.net href="mailto:twtaylor@ftc-i.net">Tim
Taylor</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> Wednesday, February 09,
2005 12:18 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Notes to Self
3</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>That's the whole point in the story Ron,
I ASSUMED I was right and didn't NEED to RTFB and could have screwed
up big time. I've been flying JR radios for years but always a PCM10
of some sort, this 9303 is a new radio for me. What I did was
get in a hurry, I wanted to fly and trim this airplane and didn't
do what I should have done first. I hope my not so comical errors will
help someone else from making the same mistake I did.</FONT></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=vanputte@cox.net href="mailto:vanputte@cox.net">Ron Van
Putte</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> Wednesday, February 09,
2005 12:01 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Notes to Self
3</DIV>
<DIV><BR></DIV><BR>On Feb 9, 2005, at 8:28 AM, Tim Taylor
wrote:<BR><BR>
<BLOCKQUOTE><?fontfamily><?param Arial><?smaller>As our Continuing
story unfolds........<?/smaller><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?smaller>Timmy
T is looking out of the shop door and sees that the weather is
just perfect for some trim
flights<?/smaller><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?smaller>So
we pack up the trailer and go for some trim flights. Recalling
the last flights all control throws too sensitive so
I dial in less rates on low and put high rates to what low
was before. Ok time to dial in some Expo on all surfaces, pop up
the screen on the 9303 and dial in 30%. Ok time to fly. Airplane
seems pretty stable now but the controls feel a bit "Twitchy" hmmm
no problem continue the flight land and have a look. Ok maybe I
didn't get enough expo dialed in so add some more. Next flight
about the same but the controls seem a bit more "twicthy" hmmm
something's not right here. Ok times up for flying for today pack
up and head home. On the way home I get to thinking about the last
flight and how the airplane changed the "feel" after I added the
expo. Ok I get to wondering where the heck did I put the book for
this new radio, Ok lets review the book on page A20 is the expo
directions, it states "NOTE: Use only positive percentages unless
there is a distinct need to do otherwise". Hmmmmmm that don't
sound right! Turn the transmitter on and look at the expo I've got
dialed into the radio,
*&%^$*&#)(#&%^%)@(_*&_(^# Everything is done
to the NEGATIVE !!!!!! No damn wonder! So "Note to self" today's
lesson is READ THE FRIGGIN BOOK
!!!!!!!!!<?/smaller><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?smaller>Ok
while I'm at it lets program a little down elevator trim at
low idle, I wonder what page that is on in the
book.................. "Fade to Black as Timmy T reaches for the
book."<?/smaller><?/fontfamily><BR></BLOCKQUOTE><BR>My guess is that
he's using a JR radio, because negative exponential is what you want
on a Futaba transmitter to soften the control response. That's why
well-meaning people at the field need to find out what brand of
transmitter the guy being counseled has before telling him how to
change the expo. <BR><BR>I had a similar situation when I was
helping a novice trim out his airplane. After I flew a trim flight
for him, I told him he needed 50 - 60% exponential on elevator and
aileron. I asked him if he knew how to do that and he said that he
did. The airplane was a handful on the subsequent flight, because he
put in the wrong expo!<BR><BR>Ron Van
Putte<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>