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<DIV><SPAN class=828125118-19112004><FONT face=Arial color=#0000ff 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 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>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="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">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></BODY></HTML>