I’ll measure mine this afternoon, but my
memory is the trailing edge of the tab moves about 2 inches. If you think about
the geometry, the servo has 0.7 travel to an arm that is about 1 ¼ inches long.
The tab is about 4 inches at the widest point. This would give 0.7*(4/1.25) = 2.24
inch peak-peak deflection. Like I said, I’m measure it and report.
Paul Bricker
N63PB
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf
Of vtailjeff@aol.com
Sent: Wednesday, June 06, 2007
10:14 AM
To: lml@lancaironline.net
Subject: [LML] Re: IV-P Rudder
Trim
Who's airplane was this. 1" sounds like a lot of movement on an
elevator trim tab. I don't even think they travel 1" stop to stop, so how
could this be?
I’m new to the LML site but I have built
several aircraft over the years. One thing that scares me on the Lancair
is flutter. I recently found a IV elevator trim that could easily be
moved up and down as much as 1” at the trailing edge. It turned out to
the hinge that the tab was attached to was bending.
-----Original Message-----
From: Kevin Stallard
To: lml@lancaironline.net
Sent: Wed, 6 Jun 2007 8:34 am
Subject: [LML] Re: IV-P Rudder Trim
I’m not anywhere near an expert on
flutter, but isn’t flutter destructive? I mean if an airframe experiences
flutter, it doesn’t just wear out hinges, my understanding is the airframe
ceases to be an airframe at that point. I don’t recall having ever read
about any mid-flight break up of a Lancair except those that happen to wander
into a thunderstorm here and there.
Vibration is completely different and
there could be other reasons at “play” regarding the premature wearing of these
hinges. Chris Zavatson has some interesting things on hinges and
vibration, give it a read…
Bottom line, I don’t think flutter in a
Lancair is worth worrying about…
I’m new to the LML site but I have built
several aircraft over the years. One thing that scares me on the Lancair
is flutter. I recently found a IV elevator trim that could easily be
moved up and down as much as 1” at the trailing edge. It turned out to
the hinge that the tab was attached to was bending. The owner had not had
a problem with flutter but the hinge was completely worn out due to vibration
in only a couple hundred hours. Lowering the attach point on the horn
reduces the leverage and increases the movement of the tab. This will
make it too sensitive and lessen the arm needed to prevent flutter. I
don’t recommend it.
size=2
width="100%" align=center>
AOL now offers free email to everyone. Find out more
about what's free from AOL at AOL.com.