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<DIV><FONT face=Arial>Dean,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>please send me your emaill address off line to <A
href="mailto:I_FLY_PATTERN@hotmail.com">I_FLY_PATTERN@hotmail.com</A> so we
can talk about the carbon gear that you need.. Thanks again for the help at
Pocono and I'm going to try a 13.8x10 four blade with the OS 91.. right
now I have gone from a 15x8 to a 15x11 and slowed it down some.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Scott Anderson</FONT></DIV>
<DIV><FONT face=Arial>nsrca 529</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=d.pappas@kodeos.com href="mailto:d.pappas@kodeos.com">Dean Pappas</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, July 02, 2004 10:36
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: Digital Servos vs analog
servos on Ailerons</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=903431513-02072004><FONT face=Arial color=#0000ff size=2>Hi
Don,</FONT></SPAN></DIV>
<DIV><SPAN class=903431513-02072004><FONT face=Arial color=#0000ff size=2>I am
pleased to see you confirming some of my long held statements
about aileron servos. At each step of development, when a servo with
better centering power became available, I have noticed better loop
tracking, especially in square corners. If I used a 1-piece wing, I
would consider an old fashioned linkage where lifting loads are not
carried by serv torque, at all. This has all gotten more noticeable as
ailerons have grown in size: mostly in chord. </FONT></SPAN><SPAN
class=903431513-02072004><FONT face=Arial color=#0000ff size=2>I also haven't
really seen a change in how much expo I use. As strong as rudder servos now
are, they still blow back a great deal. If you ever do tests with an
aerodynamic counterbalance on the rudder, be ready to change all your rudder
throws except for the spin! For some neat reading, try "the great rudder
experiment" at <A
href="http://www.mindspring.com/~rellis2/rcpattrn/rudder.htm">http://www.mindspring.com/~rellis2/rcpattrn/rudder.htm</A> </FONT></SPAN></DIV>
<DIV><SPAN class=903431513-02072004><FONT face=Arial color=#0000ff size=2>This
is interesting stuff.</FONT></SPAN></DIV>
<DIV><SPAN class=903431513-02072004><FONT face=Arial color=#0000ff
size=2>Regards to All,</FONT></SPAN></DIV>
<DIV><SPAN class=903431513-02072004> <FONT face=Arial
color=#0000ff size=2>Dean P.</FONT></SPAN></DIV>
<DIV><SPAN class=903431513-02072004></SPAN> </DIV>
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<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
discussion-request@nsrca.org [mailto:discussion-request@nsrca.org]<B>On
Behalf Of </B>Don Szczur<BR><B>Sent:</B> Thursday, July 01, 2004 11:51
PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> Digital Servos vs
analog servos on Ailerons<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>At the urging of Dave, I have finally switched
to digital servos on the ailerons. After flying analog servos for 25
years, it was explained to me that digital servos on the ailerons help
looping and radius of maneuvers. Here is my assessment.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The baseline servos were JR
7005. The digital servos changed to are JR 9411 servos.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Loops and lines. The first thing I
noticed was that, just as Dave mentioned, loops and loop segments are more
locked-in. The 9411 servos made the wings more stable, requiring less
effort on the maneuvers involving loop segments (most all of the
maneuvers). Analysis- why this occurs- the theory is that during
loops, wing panels generate quite a bit more lift. since the digital
servos lock, and hold center much more agressively than analog servos
(holding torque) this provides very little give in the ailerons during the
loop. Regardless, its a noted difference and clear advantage of these
servos.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Rolls and rolling segments. This part of
the analysis was quite a bit more complex. Clearly the digital servos
have more speed and resolution than the analog servos. The holding
torque and contol surface power requires that control throw be reduced to
attain the same roll rate. However, the analog servos would "blow
back" at high speed, but stay deflected at lower speeds. Incredibly,
the advantage to this is a more constant roll rate- independent of
speed. The ailerons (roll rate) would feel more the same
at low speed (like the top of an immelman, loop or vertical
line).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Snap rolls. This is what I call the
"rubber band" effect. The analog servos would deflect quite a bit
during snap rolls, requiring one to "unload" the snap (start coming out of
the ailerons before the snap is complete). Otherwise, the snap would
be over-rotated. Actually, this was not too hard to get used to, since
its a very consistent effect. With digital servos, however, there is
much less deflection and thus a more "honest" snap roll. It does snap
differently, but the exit is much cleaner (or easier to have a clean
exit).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Exponential. Here is another item of
interest. My initial perception was that I would have to add
additional expo to get the same feel for the digital servos. Since
control thow was reduced (moved in one notch on the servo arm) there was
still more roll rate at full stick deflection (since the ailerons are no
longer blowing back like the analog servos), but not as much roll around
neutral. I actually had to cut my expo in half. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>So, the overall analysis is that the
digital servos provide greater stability of flight, more consistent snap
exits and loop segments that are more locked in. Analog provide
more control roll authority at slower speed and more forgiveness with shaky
hands (the rubber band effect does dampen shaky thumbs). Conclusion-
overall benefits outweigh analog servos- favor the use of digitals.
Will stay with the 9411's.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>Don</FONT> </DIV></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>