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<DIV><FONT face=Arial size=2>Just make sure the cow isn't mad ;-)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Aimer</FONT></DIV>
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<DIV><FONT face=Arial size=2></FONT><BR></DIV>
<DIV><FONT face=Arial size=2>Hmmm... lets see! Ahhh
one cow divided by two horsies equal..... one magic carpet!!! I
think I got it Amir thanks!</FONT></DIV>
<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=amirneshati@earthlink.net
href="mailto:amirneshati@earthlink.net">Amir Neshati</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> Tuesday, November 25, 2003 3:13
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: CTE</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Wayne, if I'm envisioning your set up
correctly, the bellcrank is taking the changes in CTE
there.</FONT></DIV>
<DIV><FONT face=Arial size=2>Without the bellcrank, running a straight shot
pushrod will still cause changes in trim....</FONT></DIV>
<DIV><FONT face=Arial size=2>I'm sure you Texans are at least </FONT><FONT
face=Arial size=2>as smart as us camel jockies to figure this one out
;-)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Amir</FONT></DIV>
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<DIV><FONT face=Arial size=2></FONT><FONT face=Arial
size=2></FONT><BR></DIV>
<DIV><FONT face=Arial size=2>I am running an MK bellcrank and c.f.
pushrod in my carbon fiber/coremat fuse Aries. Titanium ends
and ball links hooking it all up except for the control horn I used Du-bro
nylon clevis. I don't remember but maybe a flight or two that
I had to change the elevator trim even a click. Not only is the c.f
fuse dimensionally stable but I have no formers in it outside of the two
rails for the rudder and elevator servo. I have replaced the nylon
control horns once due to wear (MK ballbearing clevis would eliminate this
problem) but other then that it has worked fine and with hardly any
trim problems</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Wayne G.</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=amirneshati@earthlink.net
href="mailto:amirneshati@earthlink.net">Amir Neshati</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> Tuesday, November 25, 2003
2:18 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: CTE</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Both sides of a the cable will expand or
contract the same, so the trim will still not change due to different
CTEs</FONT></DIV>
<DIV><FONT face=Arial size=2>They may </FONT><FONT face=Arial size=2>get
tighter or looser, but still no trim change.....I flew a few hundred
flights on a glass fuse. with a carbon</FONT></DIV>
<DIV><FONT face=Arial size=2>pushrod, had the trim sensitivity set to
20% and would take as much as 6 of these little clicks to trim
each flight.</FONT></DIV>
<DIV><FONT face=Arial size=2>As it got warmer, the problem I encountered
was that I would take off, on the trim pass the plane would head for the
ground,</FONT></DIV>
<DIV><FONT face=Arial size=2>so I would start adding the up
trims....about a minute in the flight the fuselage would cool and now
the fuselage would</FONT></DIV>
<DIV><FONT face=Arial size=2>contract a bit, so comes in a click or two
of down trim now, but noticed the rudder pull-pull would never
change trim with</FONT></DIV>
<DIV><FONT face=Arial size=2>any changes in temps ..so, I gave
pull-pull a try on the elev. and after 400 flights in temps. ranging
from 50 to 100 degrees</FONT></DIV>
<DIV><FONT face=Arial size=2>it still worked great. I tightened the
cables only one time after the first day or two of flying and didn't
touch them again.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The only thing I can see here is that due
changes in air density (the CTE for those tiny molecules of
air)</FONT></DIV>
<DIV><FONT face=Arial size=2>a tiny bit of elevator change may be
experienced, and one may change the trim by a tiny click and be
done.</FONT></DIV>
<DIV><FONT face=Arial size=2>Where as with a pushrod, I had to change
elev. trim by 4~6 clicks at first, then after a minute or so into the
flight</FONT></DIV>
<DIV><FONT face=Arial size=2>as the fuselage temps. stabilized due to
the cooling air flowing over it, would have to re-trim
again...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I weighed a carbon pushrod once that was
ready to install and weighed around 1.5 ounces and I believe the
</FONT></DIV>
<DIV><FONT face=Arial size=2>40 lbs. coated fishing line stuff
weighed only a few grams...Kevlar would probably weigh only a couple of
grams.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Have fun,</FONT></DIV>
<DIV><FONT face=Arial size=2>Amir</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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<DIV><FONT face=Arial size=2></FONT><BR></DIV>Sorry to disagree here,
but it would appear that the conclusion being drawn by the respondants
is that the pushrod expansion and contraction is the major cause of
the problem. Not so, in my experience! Going to pull-pull cables,
whether they be steel or kevlar thread will not get rid of the
elevator trim change under consideration here.The coefficient of
thermal expansion between the cables, which is very small, and the
balsa in the fuse, which is significantly greater(glass too) will
generate a differential of sufficient magnitude that the "devil" will
still attack you when you least expect it. <BR>The best solution that
I have observed is to put the servos in the stabs. Short of this, I
have been using servos mounted just at the L.E. of the stab and using
a very short pushrod(approx. 6"). My current thinking is that I will
still mount the servo in the same area and go with cables.Very light
and direct. As regards Kevlar, I currently have a pattern practise
ship that I do almost all of my flying with that has kevlar on the
rudder and it has two years of mucho sequences to it's credit with no
apparent wear or abrasions to the thread. At this point in time I have
still not acquired the necessary intestinal fortitude to use kevlar on
the elevator. <BR>Georgie
<P>Amir Neshati wrote:
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<FONT face=Arial><FONT size=-1>Pull-pull will eliminate the trim
change...</FONT></FONT> <FONT face=Arial><FONT
size=-1>Amir</FONT></FONT>
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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=natpenton@centurytel.net
href="mailto:natpenton@centurytel.net">Nat Penton</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, November 24,
2003 7:24 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> CTE</DIV> <FONT
face=Arial><FONT size=-1>Gray what is the CTI for balsa ? I have
carbon push rods / balsa fuse and my elev trim moves around
considerably. I suppose it is because of humidity variation
between the shop and outdoors ?? The pushrods are 50"
long.
NatPenton</FONT></FONT> </BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>