SEN 736 - 5 Sep 2002
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SCAT Electronic News 5 September 2002 issue 736
Table of Contents
==================
Re: Books for sale. - Scott
Goldberg wings - Curth
Answer to Lee R Hines - Beschasny
covering - Robertson
Super MaX - Hinson
Dueation column - Kluiber
dribbling on about bunting and such - Skykeing
... more Poitou 2002 - Salzer <<<=== Featured Article === >>
More on Bunts. - Van Wallene
Round wingtips, the last word - Andresen
Past issues - Bernard the Bout
Light weight ticker - Woodhouse
Tilka Kit where
Re: Books for sale.
====================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Peter Scott has two, new copies of "The Pioneers of Model Aviation In
Australia" by John Marquette for sale. $20 (Aust) each plus postage.
Anyone interested can contact him on This email address is being protected from spambots. You need JavaScript enabled to view it. or telephone
Australia (02) 9624 1262.
Goldberg wings
==============
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Has anyone checked Carl Goldberg's wings? Ellipses have pointed tips, we
used to fill them out to get more area while still looking elliptical. I
do not have any plans to check. R. J. Hoffman (Ziac publication "Model Ae
ronautics made Painless") told us elliptical wing tips were the most effi
cient, so we used them.
To determine curved wing area draw an ellipse over the plan and use the 0
.8754 times chord times span for that portion and calculate actual wing a
rea by using squares, triangles, etc to add or subtract area to/from the
elliptical portion.
Otto Curth (with the Chicago Aeronuts since 1938)
Answer to Lee R Hines
======================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
I love how Lee is seing the question. Absolutely agree with his point of vi
ew at curved surfases area.
About Super Max: TIME made must COUNT! Let's go to 270 seconds first round F
1A. Just no playing with rules!. In the case of overweight let's say it is ove
rweight! In the case of overarea let's call it OVERAREA.Nothing else! Which bon
us?
With respect,
Vasily.
covering
========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
I have misplaced the SCAT issue which had the name and address of
someone selling colored 0.0005 plastic covering. Could you reprint the
name and address again.
Thanks,
Tony Robertson
Super Max
==========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
from traveling long distances just to miss the first max, on a field
that I do not fly regularly on. The whole idea of better equpment
available to everyone and consistant quality rubber was to grow the
number of flyers. We have done that. I think everyone should have a
chance to max out and be in the flyoff. That is what has kept me in the
team program for the last 30 years. I have flown in the MaxMen on a
number of occasions. I have made the flyoff, and also been a timer in
the flyoffs. I have been a timer at the World Champs twice. I do not see
where the problem is. All that is required is for ALL the flyers to get
off their back side and get a watch and help out. I would hate to see
F1B go back to the way it was in the 70's and early 80's where only a
very few were able to win all the time. We do not need another sport
like tennis, ruled constantly by about 4 or 5 participants.
As a Contest Director, I will think long and hard about being the CD of
a contest that imposes the Super Max.
Rex Hinson
Dueation column
===============
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
My first responce to the memo regarding the cutback of the Duration column in
Model Aviation was, I suppose, the typical FF'er's "Here we go again -
everybody picking on us" knee jerk sort of reaction. Tim's comments on his
conversation with Bob Hunt shoulc give us cause to step back and see what
actually develops. To those who immediately start a 'time for a change'
campaign, I would remind them that the ANA site in Muncie is the ONE and ONLY
FF SITE for many of us in the Midwest. There's a lot of acres for corn and
beans if you don't need it for FF.......
Thermals
Rudy Kluiber
dribbling on about bunting and such
===================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Hi, all.
Mr. Barker sez:
>The one point I did want to
> mention is that the 55 degree climb angle mentioned in Martin Simon's
> book is not really relevant. It probably forms a useful exercise for
> students but as it relates to airplanes in straight flight with no
> change of incidence settings between gliding flight and high powered
> climbing flight it is not applicable to modern airplanes with moving
> surfaces and usually turning as well. Incidentally the angle is not
> exactly 55 - it changes with L/D ratio. For example 49.8 at L/D 6, 53
> at L/D 15.
Don't think that's the case. According to Martin the approximate angle
holds true -- and we are talking about high-powered auto-equipped airplanes.
If you recall, Martin discusses the advantages of using auto-equipment
including variable cambered wings. I disagreed with him over sticking with
the shallow climb angle .... But that is a different story.
When was looking into discus launching I found a great site out of New
Zealand run by a gentleman with the last name of Kaiser (Wilhelm? um, nah.)
I inquired about climb angles and such. He had it all graphed out. I told
him about my ongoing disagreement with Martin over the power ship trajectory
and he was kind enough to do a great mathematical analysis. Of course it
merely supported the now common use of vertical climb for ships sporting a
certain minimum excess of thrust over weight... like multiples. I passed
the results on to Martin. Unfortunately, I lost Kaiser's URL, etc. a couple
of computer crashes ago. I'm still working out using a discus throwing
motion, so....one of these days, weeks years......
Now another author comments:
>Thinking further, it could be proposed that the most
> energy efficient climb would be truly ballistic with a
> single tail setting after pitch up but I don't see
> anyone trying this. I guess the closest is Van
> Wallene/Limberger.
I was trying to get somewhat that idea across. It should not be truly
ballistic in the cannon ball sense of not using the wing for lift. I don't
know why the stab should have a single setting however.
> a) Anyone know why RC HLG's don't climb vertically
> after the discus launch but at maybe only 60 degrees ?
Well, sure! The glider decelerating passes through that
thrust/inertia/weight realm that so fascinates Martin Simon.The most
efficient way to bunt is for the free climb angle to rely more and more on
lift from the wing to maximize altitude/time as speed drops off. That means
the angle lessens as the thrust (inertia power) decreases. That not only
milks out the most altitude but it takes LONGER to get there; so you are at
least as high -- if not higher -- and you have a few more nano seconds
already on your stop watch when the ship starts its glide proper. (But there
is a really good and probable chance that I don't really know what the hell
I'm talking about.)
(In flying a HLG the best height I can get is by using the wing going up.
Its a no-brainer. But maybe that's only because my body isn't designed for a
vertical launch.)
One thing I should clarify is that I never suggested a 55 degree climb
angle under tow. There is no meaningful limitation of power in that phase.
The 70 plus degrees mentioned in the ancient symposium sounds right. Come to
think about it I believe the same author did an analysis of flappers and
folders. As I remember he estimated the duration advantage of a folder as
something like 18% ... of course that is a gross underestimation... a proper
folder should be, well, at least three or four hundred percent better,
minimumum. Yeah, sure, that sounds about right.
Skypsycho
... more Poitou 2002
====================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Hello Roger,
the following text ("plain" copy) looks better as a .pdf (attached)
because of the pictures.
Should you want the original word-doc, or the pics in higher
resolution, drop us a note!
Regards
Veronika (+ Klaus) Salzer
A 25 year old fairy tale
Beyond seven hills, beyond seven seas, where the sand flows and the
water runs a small church is sitting on a hillock since the dawn of time.
In the valley are fields, food giver for thousands of people, but also
fields just now being trodden by sportsmen.
A country, surrounded by water, the dynamic Atlantic, the smooth
Mediterranean, a country of wine, of cognac, of beautiful flowers in
front of the houses, a country of small romantic bakeries always
exuding the smell of fresh bread and pastries, even on a Sunday, a
country of marvelous people with good hearts, professional minds and a
friendly laugh.
An area called Poitou. Even little Julies manage time functions,
Aureliens already get airplanes in their cribs, which they chase even
before they chase girls. Little schoolgirls not only compute
mathematical formulae, but also calculate faultlessly the flight times
of the sportsmen and manage a perfect information system.
The best lady on F1B-day, 16-year-old Lea, fills the "void" between
her easily flown rounds with twittering words of the heart. Always
with a smile, never nervous, no technical problems, quite masterful,
on a first-name basis with the thermals. "Little" prince Vladimir
takes over from king Igor - both get their highest goal, the fly-off.
The sun takes a bow with respect for the professional work of the
organizers, the wind missing in the morning makes the owners of the
too early landed models sad, as does the missing of Edith Riberolle.
"Flying fields", enhanced with the sons and daughters of flying
parents. Our children - always grateful co-organizers (pity the
missing Belgian contests), timekeepers, competitors, co-travelers and
companions, but mainly good friends who always understand our laughter
and anger, looses and wins on the field and in our lives. You watch us
from heaven, you cross your fingers for us at school, in a nursing
home, at work, even if you are no more, you are always with us all our
lives, rewarded with the highest and most valuable medals.
The little wizard works his magic and should we believe everything to
be OK up there, our models together with our ego fall down, exhaustion
sits on our bodies along with the dust of the fields, and on young
Dominik's head lands a bat when he visits the little church. He will
never forget this 12th birthday! We others can only wish that the 25
year old fairy tale "Poitou" will continue as beautiful with a golden
advice - next time try to refresh yourself more often with the good
French wine, it may help to fly more maxes!
But does it really matter? Isn't it the most wonderful thing, that
you, thanks to your "toys", stay children forever?
[The PDF form, including Photos will appear in a supplement]
More on Bunts.
=================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
I would like some minor remarks as to comparisons with HLG and F3B.
HLG:
For a sportsman it is impossible to do a vertical launch using the tip
swing technique. Steering the model to a true vertical position creates
a rather uncomfortable position, as the flyer cannot judge if the model
is ready for a bunt. A more level cruise, positions the model upwind and
ahead of the flyer making it easier to decide when to apply down
elevator for a bunt. Watching a model from its tail end during a true 90
degrees cruise, it is impossible to judge the speed.
F3B:
Here the towline tension and speed is created by reeling in towline on a
fast turning drum driven by a strong electric motor. Diving the model is
only to allow gravity do its job with the direct power of the winch
superimposed on that. The gained kinetic energy is higher compared to
just keeping the model level during tow and pulling the line (like we
do).
Discussion with one of the leading F3B flyers has shown that they try to
pull as much up elevator during tow as possible. Even wing flaps are
drooped to get more lift on the wings. Not to gain speed that is, but to
create enough line tension in order to save precious towline length (and
therefore altitude) which is reeled up the drum otherwise. This 'saved'
towline can then be used to speed up in the dive prior to launch when
putting max power on the winch.
All in all totally different launch dynamics compared to ours.
Ciao, Allard
Round wingtips, the last word
==============================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Roger,
Wow, whoda thought curved wingtips would tax the limits of the www. But it
dodges the real question as to why anyone would use round tips in this day
and age?
H
Past issues
===========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Due to the odd numbering of 733/734 issues I crashed the real 724 issue.
Can anyone send it to me?
By the way I support Mr Shailor's comment: Fly-Off is the fun part of the
contest, and it's more fun if this Fly-off is run at the end of the contest
and not in the first round . I also much appreciated Mike's comments.
Bernard
[Past and present issues are online at www.aeromodel.com/scat]
Light weight ticker
======= ===========
Jim
Try one of my mini timers. 3 functions and weigh in at 6 grams.
Michael J Woodhouse, Norwich, UK.
Free Flight Supplies now has secure internet credit card facilities.
All mail to: -
web site: -
on 5/9/02 6:20, SCAT user at This email address is being protected from spambots. You need JavaScript enabled to view it. wrote:
> F1B timers
> ==========
> Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
>
> I'd like to build a model using a timer to move the surfaces
> instead of my torque system. I need the lightest/smallest 3 function
> timer available. I've got a Starline 3 function at 14 g, but it's a bit
> big for what I want to do. Is there anything smaller at that weight or
> less?
Tilka Kit where
===============
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Sir/Madam
I have seen references on your web site to a "Tilka" kit but what would be
a source for such a kit.
Thanks if you can help.
Victor
[Victor - the Tilka kit is not made any more
but you can possibley find one - an altrnative wouldbe
the Vivchar Prima - obtainanble from FAI Model supply, Mike Woodhouse
and Mike Mulligan as well as Igor Vivchar]
-----------
..................
Roger Morrell
