[NSRCA-discussion] Fwd: RE: Design Question

J N Hiller jnhiller at earthlink.net
Tue Nov 10 14:54:12 AKST 2009


Hi Tom.
"have a read of his (Bryan's) article". Where can I find this? I am very
interested.
Jim

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Koenig, Tom
Sent: Tuesday, November 10, 2009 1:13 PM
To: 'General pattern discussion'
Subject: Re: [NSRCA-discussion] Fwd: RE: Design Question

Hi Jim and all,

Jim.....enjoy those long winters, have a hot cup of coffee....and realy, I
mean really, think about what Bryan tells you. It is a brain twister and can
be confusing. But...he is right in everything he tells you. I realise there
are people out there who do not agree with Bryan, and that is fine, but my
advice is to have a read of his article-if only for interest.

If I had the time, and my ability to express myself were better-I would try
to explain some of my design ideas. But I simply suck at that-hence my
initial response, just go for it.

Another genius to ask(besides Bryan) would be Nat Penton...he will also make
your head spin! A very learn'ed man indeed.

Draw a line on a sheet of paper as your Datum, mark out 2 meters and go for
it. Better still, use some CAD package.

PS. Make it pretty-or you wont want to fly it!! Also-keep us informed how
you are going. I certainly am interested in your project, maybe others are
too.

Tom




-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of
shinden1 at cox.net
Sent: Wednesday, 11 November 2009 7:48 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Fwd: RE: Design Question

Ok
Bryan
---- shinden1 at cox.net wrote:
>
> > From: "J N Hiller" <jnhiller at earthlink.net>
> > To: <shinden1 at cox.net>
> > Subject: RE: [NSRCA-discussion] Design Question
> > Date: Tue, 10 Nov 2009 09:51:44 -0800
> >
> > Bryan, I find it hard to believe that vertical wing placement doesn't
affect pitch trim. The wing especially a thick one contributes significantly
to total drag and any offset between the center of drag and center of thrust
would create a rotational moment that would need to be balanced with H-stab
/ elevator trim. Maybe it's insignificant compared to other factors. This is
what I'm trying to understand.
> > Yes CG is a significant contributor. I've been able to change vertical
pitch by changing the CG and wing incidence, forcing a H-stab / elevator
trim change. CG placement is a whole different issue as is weight in the
extremities such as wing tips, nose and tail.
> > Thanks.
> > I'm really interested in this aspect of pattern, good thing, winters are
long here.
> > Jim
> >
> > -----Original Message-----
> > From: shinden1 at cox.net [mailto:shinden1 at cox.net]
> > Sent: Monday, November 09, 2009 7:14 PM
> > To: General pattern discussion
> > Cc: J N Hiller
> > Subject: Re: [NSRCA-discussion] Design Question
> >
> > Hi Jim
> > The vertical wing placement has no effect on pitch trim,,NONE !
> > what does is,the incidence and C/g. Don`t even worry about it.
> > However it will effect  Dihedra you will need to move the wing after the
test flights. or rebuild a new one with the right dihedral or, Mix it out.
> > Rudder angles ,sweep, or position ,has a tiny effect ,so little it`s not
worth worrying about .draw something that looks good.
> > Just build your airplane and adjust to what it does not do well.
> > your not going to hit it on the first try,but the effort will be worth
the Learning and enjoyment, in a self designed model.
> > There are so many dynamics involved in designing your first airplane
> > you cant possibly think of them all on the first attempt.
> > just  have fun and build a light pretty model.
> > Bryan
> > ---- J N Hiller <jnhiller at earthlink.net> wrote:
> > > Thanks Lance. I don't want to stray too far from proven relationships
but
> > > understand there are many variables rendering each design different.
> > > I presently have the wing located 1/2" below a centerline through the
H-stab
> > > and engine centerline. The stab is about 1/2" above the tail tube
centerline
> > > and positioned about 1/4 the height of the V-stab.
> > > Both the wing and stab will be adjustable and previsions are included
for
> > > changing thrust angles. Tweaking these angles should effectively
change the
> > > flying height of the tail but the wing offset remains about the same.
> > > Other than changing the vertical center of drag what are the pros and
cons
> > > associated with positioning the wing higher or lower. I'm thinking the
> > > vertical center of drag relative to the thrust line can contribute
> > > significantly to pitch trim. Is it a major influence?
> > > Before beginning to cut parts it occurred to me that the design /
> > > construction detail offers considerable leeway in vertical wing
placement,
> > > maybe as much as an inch higher or lower from the -1/2 presently
planned and
> > > changing the wing location later will require major surgery.
> > > I guess what I'm really looking for is more understanding of the
effect
> > > vertical wing placement has on pitch trim. I guess I asked the wrong
> > > question. Any thoughts on this will be helpful.
> > > Thanks
> > > Jim
> > >
> > > -----Original Message-----
> > > From: nsrca-discussion-bounces at lists.nsrca.org
> > > [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of
> > > patterndude at tx.rr.com
> > > Sent: Monday, November 09, 2009 2:38 PM
> > > To: General pattern discussion
> > > Subject: Re: [NSRCA-discussion] Design Question
> > >
> > > That's all?  There a number of design issues we face in pattern where
> > > there's little documentation readily available. This is one, KE flight
is
> > > another, wing incidence and engine thrustline effects in 4 axis flight
is
> > > another. The more I think about it the more I think of.
> > >   There's no one answer and anything between the chordline and
thrustline
> > > can be made to work by changing rudder shape and incidence. I settled
on a
> > > quarter inch above the chordline and then adjusted the rudder to allow
a
> > > trim incidence near zero so inverted flight is more effortless.
> > >
> > > Lance
> > > AeroSlave
> > > Sent via BlackBerry by AT&T
> > >
> > > -----Original Message-----
> > > From: "J N Hiller" <jnhiller at earthlink.net>
> > > Date: Mon, 9 Nov 2009 09:36:13
> > > To: NSRCA Mailing List<nsrca-discussion at lists.nsrca.org>
> > > Subject: [NSRCA-discussion] Design Question
> > >
> > > Hello all.
> > > Here's a topic for discussion that I'm personally very interested in
and may
> > > be of interest to others.
> > > I'm working up a new pattern design and would appreciate comments
regarding
> > > the vertical placement of the wing and thrust line relative to the
stab
> > > centerline.
> > > I not only would like to know what the vertical offset is on modern
pattern
> > > designs but how the vertical location affects flight trim, and why?
> > > Thanks all.
> > > Jim Hiller
> > >
> > >
> > >
> > > _______________________________________________
> > > NSRCA-discussion mailing list
> > > NSRCA-discussion at lists.nsrca.org
> > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
> > > _______________________________________________
> > > NSRCA-discussion mailing list
> > > NSRCA-discussion at lists.nsrca.org
> > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
> > >
> > > _______________________________________________
> > > NSRCA-discussion mailing list
> > > NSRCA-discussion at lists.nsrca.org
> > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
> >
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

************************************************************************
*PLEASE NOTE* This email and any attachments may
be confidential. If received in error, please delete all
copies and advise the sender. The reproduction or
dissemination of this email or its attachments is
prohibited without the consent of the sender.

WARNING RE VIRUSES: Our computer systems sweep
outgoing email to guard against viruses, but no warranty
is given that this email or its attachments are virus free.
Before opening or using attachments, please check for
viruses. Our liability is limited to the re-supply of any
affected attachments.

Any views expressed in this message are those of the
individual sender, except where the sender expressly,
and with authority, states them to be the views of the
organisation.
************************************************************************
_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion



More information about the NSRCA-discussion mailing list