 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
victorbravo(at)sbcglobal.
Guest
|
 Posted: Tue Mar 22, 2016 12:54 pm Post subject: Addendum - Elevator/Stabilizer hinge ass'y |
 |
|
With all sincerest respect to Mr. Wainfan and any other great engineers out there who might be monitoring this discussion, the credentials and field experience of the engineer (who I asked to review the elevator attachment) are high enough for the purposes of settling any questions about the appropriateness of any particular aircraft structure.
He is a graduate of the 1950's DeHavilland Aircraft Engineering program in England (from youth apprenticeship up through engineering degree in aerostructures and metallurgy), and I believe Arnold Schwarzenegger cannot physically lift his aerospace resume' . Any further comment on his achievements or abilities would sound like an infomercial, so I will leave it at that.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 3/22/16, Stuart Harner <stuart(at)harnerfarm.net> wrote:
Subject: RE: Elevator/Stabilizer hinge ass'y
To: kolb-list(at)matronics.com
Date: Tuesday, March 22, 2016, 12:27 PM
"Stuart Harner" <stuart(at)harnerfarm.net>
Bill,
I am not an engineer but I did stay in a Holiday Inn last
night.  No, not really, but I do have a fundamental
understanding of load transmission through a structure.
First a question, and please don't be offended. Have
you had an opportunity to observe the structure of the Kolb
tail while it was being folded and then again when it is
bolted into place? I asked this because I found a
couple of things in the plans of the Firefly that I did not
understand until I was able to actually see it live. Simply
put, I had trouble visualizing it from just the plans.
One thing that I think is missing from this discussion is
the loads carried by the brace wires. I would posit that
most of the forces from the tail that are transmitted to the
boom tube are carried by the braces. These, when properly
tensioned are actually pre-loaded slightly. This puts the
tubes in compression which makes the whole thing quite
strong. It also transfers the loads from the horizontals to
the steel post of the verticals which in turn is transferred
to the boom tube via the steel ring which is bolted and/or
riveted to the tube.
Of course some loads are transferred through the hinge
points and the front hinge must be able to slide slightly as
the elevator moves through its arc of travel. Could this be
made stronger? Of course, but not without sacrificing
something else such as weight or foldability. It is actually
a very clever design and I suspect that the majority of
loads that move through the rear hinge come from the
elevator and not the stabilizer.
I would also bet that the loads carried through the hinges
is far below the shear and tension limits of properly
installed rivets.
I am actually more "freaked out" by the fact that everything
in the tail depends on that one little 3/16" bolt (Firefly)
that holds the lower braces in place. Really, the threads on
that bolt are all there is between you and falling out of
the sky. To combat this irrationality I swap out the bolt
fairly often and the nuts even more often. If it really
bothered me, I would stay on the ground.
Perhaps you could send a copy of your plans to Barnaby
Wainfan and ask for his analysis. I hear he is a really nice
guy. From reading his articles over the years I am sure he
could provide the answers you seek.
As Uncle Red used to say: "Remember, if women don't find you
handsome, they should at least find you handy"
Stuart
--
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
 |
Leland.Lam
Joined: 19 Nov 2014
Posts: 20
Location: Phoenix, AZ
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
