Design: Dihedral Recommendation

[Ted Sander]

Thanks George - FYI, I'm anticipating ending up with about 3.5 degrees of
right thrust.  I'll start with 3, and adjust from there.  Down will start at
zero, and be set as flight testing dictates.  Gas engine, big prop (20x10).
Vert. Stab/Rudder will be counterbalanced.  Planform isn't too far different
than on a Focus.

-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
Behalf Of george kennie
Sent: Saturday, May 10, 2003 9:46 PM
To: discussion at nsrca.org
Subject: Re: Design: Dihedral Recommendation

Put in 7/32" dihedral, and move the stab down an additional 1/2". Of course
we
don't know what the engine offsets are( I think I would try 2&1/2 right and
1&1/2 down).
Does that thing have a balanced rudder? If it does, you'll have adverse
couple
with what the manual calls for.
Good luck.
G.

Ted Sander wrote:

> It's flying season, and for all sorts of poor reasons, I'm just now
getting
> to boring holes for my wing tubes in my scratch built Edge 540.  While not
> pure pattern, I hope to get it to come in "pattern legal", so I can use it
> as a dual purpose intermediate plane for our few local pattern and IMAC
> contests.  Wing is 1 3/4 " below thrust line, stab 1" below.  Standard
> straight leading edge (what makes it an "Edge").  Original plan was no
> dihedral at all (centerline of tips on same plane as the root).  Now I'm
> starting to question myself.  Realizing that there are lots of things that
> contribute to roll coupling I haven't included here, anybody have rough
> guidelines on a starting place for the dihedral angle to build in, if any?
> Plane will have most of the provisions for getting it dialed in -
wing/stab
> adjusters, even a way for moving stab up or down, if needed.  Dihedral
will
> have to be built in.  If the rest of the plane proves itself out, I have
no
> issue fine tuning the design in the future by cutting new wings - but
would
> like to at least get it sort of close for this first attack.  How much
> dihedral does a Focus have, for example?  Any words of wisdom if I should
> increase or decrease it due to the effective forward taper of the wing?
> Thanks in advance for any advice.
>
> =====================================
> # To be removed from this list, send a message to
> # discussion-request at nsrca.org
> # and put leave discussion on the first line of the body.
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Ted Sander wrote:

> It's flying season, and for all sorts of poor reasons, I'm just now
getting
> to boring holes for my wing tubes in my scratch built Edge 540.  While not
> pure pattern, I hope to get it to come in "pattern legal", so I can use it
> as a dual purpose intermediate plane for our few local pattern and IMAC
> contests.  Wing is 1 3/4 " below thrust line, stab 1" below.  Standard
> straight leading edge (what makes it an "Edge").  Original plan was no
> dihedral at all (centerline of tips on same plane as the root).  Now I'm
> starting to question myself.  Realizing that there are lots of things that
> contribute to roll coupling I haven't included here, anybody have rough
> guidelines on a starting place for the dihedral angle to build in, if any?
> Plane will have most of the provisions for getting it dialed in -
wing/stab
> adjusters, even a way for moving stab up or down, if needed.  Dihedral
will
> have to be built in.  If the rest of the plane proves itself out, I have
no
> issue fine tuning the design in the future by cutting new wings - but
would
> like to at least get it sort of close for this first attack.  How much
> dihedral does a Focus have, for example?  Any words of wisdom if I should
> increase or decrease it due to the effective forward taper of the wing?
> Thanks in advance for any advice.
>
> =====================================
> # To be removed from this list, send a message to
> # discussion-request at nsrca.org
> # and put leave discussion on the first line of the body.
> #

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