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<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=420240401-20112004>All
right Dean!!! Important "Safety tip" from someone who's wise to marketing's
little tricks... This is what happens when "bean counters" override the careful
work of skilled Engineers! (Bad day at work).</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=420240401-20112004>
<P><FONT size=2>John Pavlick<BR><A href="http://www.idseng.com/"
target=_blank>http://www.idseng.com</A><BR> </FONT>
</P></SPAN></FONT></DIV>
<BLOCKQUOTE dir=ltr
style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">
<DIV align=left class=OutlookMessageHeader dir=ltr><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>Dean
Pappas<BR><B>Sent:</B> Friday, November 19, 2004 1:52 PM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> RE: Futaba radio
question<BR><BR></DIV></FONT>
<DIV><SPAN class=828125118-19112004><FONT color=#0000ff face=Arial size=2>The
Banshee kit had the tail shortened to make the fuse sides fit in thew kit box.
Get a set of real plans from Flying Models, and your Banshee will be like
Joisey jim's.</FONT></SPAN></DIV>
<DIV> </DIV>
<P><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV align=left class=OutlookMessageHeader dir=ltr><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>Bob Richards<BR><B>Sent:</B> Friday, November 19, 2004 1:36
PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> Re: Futaba radio
question<BR><BR></FONT></DIV>
<DIV>The whole idea of "linear" control throw depends on the entire system.
Yes, the pushrod moves straight-line while the servo is circular, thereby
the pushrod will move further per degree of servo travel around neutral.
However, the same thing happens in reverse at the control surface, the
control arm moves in a circular arc. So, if the distance from the hinge line
to the clevis pin is the same distance as the clevis-to-servo wheel
centerline, then the control surface should move the same degrees as the
servo. Linear.</DIV>
<DIV> </DIV>
<DIV>I had toyed with the idea of using a pulley mounted on the servo, to
get rid of the non-linear response on the pull-pull cables. I even thought
about making the pulley elliptical in shape, to build-in expo in the
linkage. That would make the center resolution better. Never got around to
trying it, but seemed like a good idea to me.</DIV>
<DIV> </DIV>
<DIV>Troy is right-on when he talks about maximizing the servo travel to get
the most resolution from the system. This is something I wrote
about in the <A href="http://www.toprudder.com/hobbies/fut7uap.pdf">K-factor
article</A> I wrote way back when.</DIV>
<DIV> </DIV>
<DIV>I'm not entirely sure the lift is proportional to the angle of attack.
I suspect there is a lift curve, obviously there has to be since at some
point the wing will stall, but how linear it is around neutral, I don't
know. And this also depends on how linear the lift of the stab/elevator is
with the change in elevator position. I remember back in the days before
expo, some pattern planes (Banshee) had a diamond airfoil section on the
stab, supposedly this made it less sensitive around neutral.</DIV>
<DIV> </DIV>
<DIV>BTW, I still have a Banshee kit, NIB, circa 1970?. Wicked looking
plane.</DIV>
<DIV> </DIV>
<DIV>Bob Richards.</DIV>
<DIV><BR><BR><B><I>"J.Oddino" <joddino@socal.rr.com></I></B>
wrote:</DIV>
<BLOCKQUOTE class=replbq
style="BORDER-LEFT: #1010ff 2px solid; MARGIN-LEFT: 5px; PADDING-LEFT: 5px">My
theory on "linear":<BR>Consider the pitch plane. We want to do a loop. We
need to change the lift.<BR>Lift is proportional to the wing's angle of
attack.<BR>1) We want to change the wing's ANGLE of attack in order to
change the lift.<BR>2) We do this by changing the deflection ANGLE of the
elevator.<BR>3) The angle of the elevator is proportional to the ANGLE of
the servo<BR>output arm.<BR>Therefore the change in lift is proportional
to the change in angle of the<BR>servo arm not the change in linear
distance of the pushrod.<BR><BR>Regards, Jim<BR><BR>----- Original Message
----- <BR>From: "Troy A. Newman" <TROY_NEWMAN@MSN.COM><BR>To:
<DISCUSSION@NSRCA.ORG><BR>Sent: Friday, November 19, 2004 6:46
AM<BR>Subject: Re: Futaba radio question<BR><BR><BR>> Negative expo on
Futaba is softer neutral<BR>><BR>> .................<BR>> and
Positive expo on JR is softer neutral<BR>><BR>> It takes about
20-30% expo just to get the surface to throw linear. The<BR>> reason is
the servo is in a rotational output vs. the pushrod which is a<BR>>
linear output. If you use large servo arms and have the connection
further<BR>> out on the servo wheel this gets minimized some...but you
sacrifice<BR>> resolution of your servos because now you have to dial
back you rates too<BR>> far to get the actual travel you want. I don't
fly my D/R or my flying<BR>rates<BR>> back below about 75%. The reason
is you sacrifice the precision of the<BR>> servo. I try to maximize my
ATV values and keep the max out of the servo<BR>and<BR>> TX resolution
as possible.<BR>><BR>> To this end you will need about 30% expo just
to get a linear output to<BR>the<BR>> surface. I tend to run 40%-50%
expo on Ailerons, about 40% expo on the<BR>> elevator and about 60-70%
expo on the rudder in my normal flying rates.<BR>><BR>> I would
caution against high expo values like 60-100% you will get a
hump<BR>in<BR>> there and it will drive you nuts. Main thing you see is
the roll rates<BR>don't<BR>> stay constant...They start slow speed up
and then finish slow. The reason<BR>is<BR>> you are moving the stick so
far before the surface responds.<BR>><BR>> Another note that may be
significant to some. I fly one rate or Flight<BR>mode<BR>> all the
time. I have a upline snap rate (aileron +10%, elevator +10%,<BR>>
rudder -10% on the rates), this is only used for upline snaps where
energy<BR>> management is critical. And I have a spin mode or condition
where the<BR>> elevator rate is higher by 20-30% travel. This is until
the break into the<BR>> spin...then the spin is done on the flying
rate. The spin mode has more<BR>expo<BR>> on the elevator to give the
same feel for flying as the normal flying<BR>rate.<BR>> All other rates
stay the same in the spin mode.<BR>><BR>> All snaps (save the
uplines), rolling loops, circles and maneuvers are<BR>done<BR>> on the
same rates. By the way these rate are all on the same switch
and<BR>its<BR>> easy to prepare for the upline snap. or spin
entry...<BR>><BR>> I think that if I could get used to the higher
aileron rate I could fly<BR>the<BR>> upline snaps without a switch for
these.<BR>><BR>> Hope this helps.<BR>><BR>> Troy
Newman<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>