SEN-466 Sept. 7 2000
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News and Reports 2000 - second half
SCAT Electronic News 7 September 2000 issue 466
Table of contents
=================
Canadian Cup Results - Schlosberg
FAI GYPSY RICHARD L WOOD - Wood
Re "Any new technology is undistinguishable from MAGIC" - Chaussebourg
Best source for Icarex!!! - Davis
RE timekeeping and Martin Dilly's comments in issue 465.. - Morgan
More on covering materials - Van wallene
F1E (Magnet Steered Gliders) References and Web Sites - Thornbery
Editorial Convention
====================
In SEN as the editor I reserve the right to make editorial comments.
These typically follow a message from some one else and are
enclosed in square brackets [like this]. It might happen that with some
non English character sets that are displayed as some other character.
Sometimes I write articles myself, typically these are not signed.
Canadian Cup Results
====================
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Roger,
These are the results from the first Canadian World Cup, based on the work
sheet sent out by Leslie Farkas, the contest's CD.
F1A 1 2 3 4 5 6 7 8 9 10 11 12
1. G MacKenzie* CAD 180 180 180 180 180 130 180 180 180 180 180 180 2110
2. T Boiaddjev* CAD 180 180 180 180 164 180 147 180 180 180 180 180 2181+213
3. K Kumakko FIN 180 180 180 180 180 180 180 180 180 101 180 180 2181+201
4. A Nuttgens GER 180 180 180 174 158 180 165 128 180 180 180 180 2066
5. C Lenartowcz* CAD 180 180 180 180 148 142 180 180 180 180 145 180 2055
6. P Allnutt CAD 180 180 180 180 120 180 180 180 180 173 171 149 2053
7. J Horack CAD 180 180 180 118 180 120 120 180 180 180 180 180 1978
8. A Schlosberg USA 180 180 149 180 138 180 180 180 119 180 137 129 1932
9. L Hines USA 180 163 180 066 158 172 147 119 180 180 180 174 1879
10. P Brun USA 180 180 180 167 152 180 166 066 180 091 117 180 1839
11. J Abad SPN 180 172 170 127 118 180 180 180 057 087 180 165 1796
12. C Markos USA 167 074 156 164 180 177 140 087 0 180 159 180 1664
13. M McMahon CAD 141 180 101 180 180 129 086 153 180 088 0 0 1418
14. T Tzvetkov USA 180 142 180 043 180 180 147 087 118 0 0 0 1257
full scores 12 9 8 5 2 1 1 1 1 0 =
F1B 1 2 3 4 5 6 7 8 9 10 11 12
1. C Acerley* CAD 180 180 180 180 180 167 180 153 180 175 180 180 2115
2. L Horack* CAD 180 180 180 180 180 180 113 178 180 180 180 180 2091
3. J Brooks* CAD 180 180 170 180 180 167 180 180 180 180 180 144 2101
4. J McGlashan CAD 180 180 180 180 180 180 180 180 105 180 180 154 2059
5. D Rowsell CAD 180 071 180 180 180 098 180 180 0 0 0 0 1249
6. T Ioerger USA 180 0 180 0 0 0 0 0 0 0 0 0 360
full scores 6 4 3 3 3 2 1 1 0
F1C 1 2 3 4 5 6 7 8 9 10 11 12
1. F Schlachta* CAD 180 180 0 180 180 180 180 180 180 180 180 180 1980+180
2. B Gutai USA 180 180 0 180 180 180 180 180 180 180 180 180 1980+142
3. R Sifleet USA 180 180 0 170 148 180 180 180 180 179 180 180 1900
4. E Conden* CAD 180 180 0 180 180 180 180 180 0 0 0 0 1260
5. D Sugden* CAD 159 160 0 153 148 180 180 180 0 0 0 0 1160
6. S Arambasic CAD 180 168 0 150 180 0 159 0 0 0 0 0 787
7. A Kirilinko USA 180 180 0 0 0 0 0 0 0 =0 0 0 360
full scores 6 5 - 3 3 3 3 3 2 2 2 2
*2001 Canadian Team
FAI GYPSY RICHARD L WOOD
========================
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Hi Roger,
I would like to publicly thank Hugh Jones of WNYFFS for the beautiful plaque
that christend me as an "FAI Gypsy". He presented it to honor my quest to
attend the maximum possible number of Americas Cup events this year( 24
POSSIBLE AMERICAS CUP CONTESTS).
The Gypsy plaque is well deserved because, so far this year I have:
Attended 15 Americas Cup contests located at eleven different contest sites
in ten different states (Texas has two sites). I have flown in 29 americas
cup events( Denver did not have mini's). In those contests I have flown
approximately 175 official contest flghts for approximately 25000 official
Americas Cup flight seconds.
I would like to thank all of the contest directors and clubs that made these
Americas Cup events available and especlially thank Brooks Goodnow and Mike
Roberts for sharing their chase vehicles with me.
So far i'm right on schedule with only 9 more possible Armericas cup contests
to attend. I think I'll make the 24 Americas cup contests this year if
nothing bad hpppens or the creek don't rise. Y'all come too!
your friend,
FAI Gypsy,
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Comment on - "Any new technology is undistinguishable from MAGIC"
===================================================================
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Many thanks for your very detailed comments about F1A timer used by
Victor STAMOV at last Euro Champs in Romania...
Unfortunatly, I am very sad to see that all these comments do not
confirm the events observed by myself and many other people during=
Victor's 1st attempt in the 3rd round...
Apparently, the delay for the unlatched hook "is set to 5 to 10 seconds
for the timer to do an alternate action" as for instance: having the
model come to a bunt action "and D/T immediatly".
As far as I can remember (many wittnesses can confirm) Victor tried to
launch his model with others which were starting their flight in a good
thermal, when, for some reason, he started to accelerate his model later
than he does usually, which put his model to a bad trajectory, finishing
flat. The line came out of the hook as it happens normally. The model
bunted, going to the ground, to recover at low altitude, fly on a normal
glide for about 5 seconds, when suddenly it dethermalized, giving a
flying time under 20 seconds.
My question is: why did Victor put his hand to his left pocket, just
before his model DTed, exactly the same way he has been seen doing it
when he used his radio DT for practice flights?
If the electronic timers are so clever to forgive the human errors, to
my opinion, they have nothing to do with Free Flight, as well as Free
Flight has nothing to do with Radio-Control.
With so sophisticated electronic devices, who is able to make the
difference between an RC DT action and a"simply magic explanation"?
I agree that Radio Control may help for trimming flights, or for helping
people to retreive free flight models, when practicing. But it is not
acceptable to use it during competition as far as it gives the
possibility to obtain an attempt with a flight shorter than 20 seconds,
after a bad launch, or an immediate DT action after an over run in F1C.
It must be noted that, at the moment, RC is allowed only in the class F1C.
In Romania, the FAI Jury concluded that it was not possible to prove
that the sequence demonstrated by Victor was "the sequence of events in
the first attempt of round 3 or to prove that radio DT was used". The
protest was rejected "because of the lack of conclusive evidence against
the competitor".
Later on, in FFN, Ian KAYNES wrote: "Victor showed me a program on his
DT setup which is invoked when the model has spent several seconds with
the hook open but the line not having come off - it recognises that
there has been some problem and produces a bunt followed by DT, fitting
the observed sequence of events on his attempt. While this is an
explanation it is not possible to prove or disprove that this is what
happened in the flight in question".
Some years ago, we banned the Builder of the model rule because it was
not possible "to prove or disprove that the flyer was the builder of the
model"...
To the argument that the 20 seconds rule could be banned, Victor said
that it could be also possible to have a special function, dropping a
part of the model, as the stabilizer...
The problem exists.
My conclusion is:
1- ban the 20 seconds rule for F1A F1B F1C F1E
2- Jettisonning of any part of the model will give a zero score for the
flight, as it is already the case for control line and RC classes.
This should be applied at least as a local rule for the coming World and
Continental Championships as well as for World Cup contests, before to
be included in the sporting code.
This is the only way to avoid any sad discussion about suspicious action
from anybody on a Free Flight field.
Victor STAMOV is one of the best F1A designer, builder and flyer, he did
not need such a publicity.
Pierre CHAUSSEBOURG.
[Pierre
Under normal circumstances I would not continue this discussion any further
because under such circumstances it will change no opinions,
serve no purpose or clarify anything. However my explanation as
complete as it was ! did have an over simplification that I needed to
correct.
I stated that the bunt timeout is 5 - 10 seconds. In fact the timeout
can be set at any number of whole seconds from 1 seconds up. I
stated 5 to 10 because this is what a normal sportsman does. I
understand that Victor being the aggresive flyer that he has his
set to 3 seconds.
The technical details on the TX itself.
The RDT transmitter operates at 50 MHz and has a telescoping antenna
which is about .75 meters when extended. To DT the model, one must do
the following:
1. Extend the .75 meter antenna.
2. "Arm" the transmitter by turning a small switch on top of the box.
3. Push and hold the DT button in the middle of the box to send the
signal.
It would be very difficult to do all this by putting your hand in your
pocket, especially the antenna!
The reason that the arming switch is required is that during the testing
phase I was flying the device on an F1B and picked up the TX while
keeping my eyes on the model and of course held it by the DT button
and brought the model down under power. I then suggested to Ken that
he include this safety feature.]
Best source for Icarex!!!
=========================
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Best source for Icarex!!!
Don't bother shopping around for Icarex any further as I have found the best
source with the best and fastest service, the most knowledgeable supplier,
all colors in stock, small (less than a yard) quantities available, color
chart on-line, easy on-line secure ordering, etc., etc., etc.
I don't usually get all wired up about buying materials from on-line sources
but every once in awhile I come across an on-line business that is leagues
above the rest. I spent two hours searching the web for Icarex suppliers and
I ended up with quite a list. I phoned and e-mailed most of them and after
a frustrating morning finally ended up at a site someone else on SCAT had
recommended, Hang-em-High Kite Fabrics. Not only was their pricing as good
as I was able to find but it was half the cost of a few of the places I
called. They had every color in stock, their web site is easy to use and
included the on-line color chart. I placed my entire order on-line and
included a note asking for actual samples of all the colors. You only pay
for the actual cost of the shipping and not some trumped up shipping and
handling charge. I called and spoke to Bonnie Marvin who I believe is the
honcho (honchette?) in charge and she was sharp and knowledgeable about
using it for model gliders. When the order arrived each piece of fabric was
carefully cut (none of the typical fabric store butcher cuts) and the color
swatch booklet she sent is neatly done and sewn together. Something I didn't
expect was a 3 page article she included from a past kite magazine about
adhesives and Icarex! I was a happy man that day!
You can find them at, http://citystar.com/hang-em-high/ushop/
Bookmark the site!, it is really good!
In all fairness to my other select supplier, John Clapp at FAI Model supply
also has great service for the products he sells (no Icarex though), if he
could only get a web site and secure order form as good as Hang-em-High
then................
We are about to engage in an Icarex covering orgy. If the stuff works as
well as purported then my days of using dope are over! No need to get high
when the models do it for us (ha,ha,ha, what a really stupid joke, it's the
best I can do today).
Jon Davis
Mac the Bigot.
RE timekeeping and Martin Dilly's comments in issue 465..
=========================================================
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One of the more minor difficulties that came up in the Australian 2001 W/Ch
effort was the impossibility of raising more than a very small number of
timekeepers with any experience of actually timing a free flight model. In
view of the likely problems arising from hastily trained and inexperienced
timekeepers, I made the suggestion that we come clean, admit we could not
supply timekeepers and tell teams they each have to supply one (and
preferably more) timekeeper - either from supporters or competitors flying
an event on a different day. In this way we might hope to get a suitable
number of people who knew what they were doing with a stop watch. Generally
FF flyers are good timekeepers - they understand the difficulties and have
developed the skills necessary to locate the correct model and follow it and
not be distracted. Flyers are interested in watching other models because it
helps them learn the conditions and the field. In the event (err actually
the non-event) I got a bit of flack from this suggestion but I still think
having timekeepers drawn from the ranks of FF flyers is the way to overcome
the obvious problems - especially in big contests. I know some of the open
internationals are now being run on the fly-one/time one system and the ones
I have participated in seem to have had relatively trouble free timing.
Perhaps it would be good to have one timekeeper supplied by the organizers
and one drawn from the flyers (e.g. from the team on the next pole). This
would at least help to provide two independent timekeepers.
Vin Morgan
More on covering materials
==========================
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Dear Roger, some info for the SCAT page:
It is worthwhile to check out the kite scene every now and then. For
instance
http://www.stud.tu-muenchen.de/~michael.stegherr/dratuch.htm#Poly
There I found info on a 'new' spinaker type of material named AIRX. I
searched a bit on the net and found the originator:
http://www.bainbridgeint.com/BoatOwner/Airx.htm
Some nice info on the mystery of listed weight vs. measured (real)
weight, or why the real weight is allways higher than the listed weight
:-((
Boy was I disappointed to find out the hard way that the magic new Toray
cloth, which was sold at less than 25 g/m2, was in fact just as heavy as
the Icarex but twice as expensive...
Please note that the lightest version of AIRX (AIRX-500) has a real
weight of 30 g/m2 (the guy mentioning the stuff at the first URL
mentioned above was apparently fooled as well), comes in white only,
and is therefore lighter than Icarex and Toray.
They also claim absolute water tightness.
A propos watertightness, my point of view is that the smaller the hole,
the bigger the leak. This is caused by capillary action. In particular
where covering material touches solid surfaces like D-boxes etc. A
miniature puncture or slightly delaminated lap joint, causes the water
to be transported into the wing by capillary action.
If the wing is totally soaked with water, I always use a syringe
(smallest available i.e. used for insuline). Keep the wing nose up so
the water collects in the corners of the rib-trailing edge junctions.
Pierce the covering at the junction with the needle and suck out the
water. The hole is hardly visible and can be closed with a small drop of
any kind of lacquer.
Thermals, Allard
F1E (Magnet Steered Gliders) References and Web Sites
=====================================================
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For those seeking information about F1E magnet steered free flight gliders,
there are both web sites and published articles.
Web sites to visit include:
Gauss Lines in the UK at: http://www.hargv.demon.co.uk/
And for those who can read German (I stumble through) or want to then try
some of the computer translation software available on the Internet:
http://www.iag.uni-stuttgart.de/people/thorsten.lutz/thermiksense/
http://home.t-online.de/home/sprecher-f1e/
http://home.t-online.de/home/fsv-muehlheim/ has a 3-view of a contemporary
F1E. The design features a tongue joined wing, a feature not seen on F1A's
lately. Perhaps this better minimizes crash damage in a class which does
not pull high g's on launch and may be flying close to the ground.
My files and bookshelves thus far yielded:
"Vane Steering" by Hans Gremmer, Aeromodeller April, 1955, p 182-185.
(yes, 1955)
'Hill Soaring with Magnet Steering" by Hans Gremmer, Model Builder
February, 1977, p 44-47,79-80.
"Magnet Flying: The State of the Art" by Trevor Faulkner, Aeromodeller,
January 1982, p 22-23.
"Mehr uber Magnetmodelle" from the book "Vom Balsa-Gleiter zum
Hochleistungs-Segler" by (who else) Hans Gremmer (ISBN 3-88180-010-7) has
an entire 22 page chapter. If you know of someone with OCR software for
German, I would like to send them the image, let them convert it to text
and send it back to me. Then I could run the text through one of the web
sites with translation software to get it into rough English.
I'm sure there are some other articles but I hope others recall ones in
Free Flight News, Vol Libre, NFFS, etc. If you learn of others, please let
me know as I've (obvioulsly) been interested in the class for quite some
time. I have scanned in some of the articles but the image files are
rather large and there is a variety of image formats. If there is demand,
I might put them up on my web site. Attached is a text only document via
OCR conversion of the first half of the Jan 1982 Aeromodeller article.
Aeromodeller January 1982 page 22 text only of a two page article.
MAGNET FLYING
THE STATE OF THE ART
BY TREVOR FAULKNER
ONE OF THE MOST surprising features of any 'class of model flying is that it ne
ver seems to reach a position where improvement stops.
My feelings are that continued development is the combined result of multiple e
xperience, (a lot of people doing it)and the response to even more demanding ve
rsions of competitions such as limited motor runs, all-up-weights or rubber mot
or restrictions.
In this light, it may interest readers to have some sort of resume concerning a
competition class in which the structure, weights and principles of operation
have retained their individual and original characteristics, and yet has contin
ued to improve directly in response to the demand for better performance under
very testing conditions.
The testing conditions' in question, concern those factors which had in the pas
t been considered essential to any form of slope soaring, namely reasonable lif
t, (wind-speed generated), and a good slope to take advantage of it.
Now, the focus has passed from the subject of the fliers' ability to record 5 m
inute maxes from good slopes in good to fair conditions, to a concentration on
similarly high flight times from low hills in very low wind speeds.
How is this achieved? Obviously by the production of models with extremely low
sinking speeds, low flying speeds, and dependable programmed flight-patterns to
make the most of limited lift-bands.
For the uninitiated, it must be explained that the Fl E Magnet model is steered
by a bar magnet linked either directly or indirectly to a rudder. It is launch
ed from a slope facing the prevailing wind as near as possible, and is normally
trimmed to fly fractionally above wind speed, i.e. to 'stand' or hang in the l
ift-wave above the slope. A moment's consideration will show that every heavier
-than-air model has a minimum air speed, below which it cannot be trimmed to fl
y satisfactorily. If this minimum speed is above the speed of the prevailing wi
nd, the model will (if steering a straight into-wind path) progress outwards, a
way from the launch point. Put this together with .a 5-mm. max and it can be ap
preciated how far even the slowest model will go.
Wind speed Model speed Distance mph. mph. (in 5 mins.)
8 10 293 yds
6 10 586 yds
4 10 880 yds
Note: 10 m.p.h. is an average A-2 type speed; the distance is that of the mode
l flight path. The retriever will travel rather more due to the ground contour
s ... and the last bit is always uphill!
However, if the model can be made to return to the lift zone, not only will the
distance travelled away from the launch point tend to be less, but the model w
ill reach a greater height.
Earlier techniques had been explored to produce figure-eights along the slope,
circles into wind, or to interrupt the direct
flight path by means of a circular session. Of these three alternatives, the la
tter has
proven to be the most fertile ground for experiment.
The late Mario Feruglio (Italy) produced a series of beautiful models which fea
tured programmable steering linked to a clockwork timer. As the mechanism was c
onceived and used, the only trim variable prior to D/T was the application and
subsequent freeing of the rudder.
As most of us know (sometimes to our cost), changing trim by rudder alone will
turn a satisfactory straight glide path into a lethal spiral dive unless certai
n very critical conditions are met. These may be summarized as:
(i) a modest application of rudder (i.e. large radius circle) only,
(ii) there must be no hint of under-elevation, and ideally the model must be on
the edge of the stall when flying straight,
(iii) there must be a non-critical C.G. position for instance, 35-40%, which wi
ll have allowed for a large incidence difference between wing and stab -
Feruglio's technique was as described, and gave excellent results just so long
as wind speeds were of reasonable magnitude.
But what about conditions of a more testing nature? Imagine a very light wind;
what is required? First, the model's sinking speed
must be as low as possible.
This means that the model must be light and slow-flying. (Drag increases as the
square of the speed, remember). The glide angle doesn't matter, but the sinkin
g speed does. Second, the model must be trimmed to its lowest sinking speed.
The difference between general model characteristics and the fine edge of perfo
rmance that an individual model can achieve is not always recognized. Where the
ultimate is being sought for light-wind magnet flying, we're in the realm of 1
00% C.G. positions, with incidence differences of perhaps 10. Such models are v
ery tricky to trim, & C.G. 's of 60-70% are practically more desirable, even th
ough a little less efficient.
At this level of refinement, it is impossible to apply rudder to even the stall
iest of trims and avoid a spiral dive, therefore, when a turn is initiated, the
negative incidence of the stab must be increased. This brings us into the trad
e-off situation between degree of turn and incidence change. One thing is certa
in, in order to turn, models must bank. The greater the angle of bank, the less
is the vertical lift component, (the force helping to keep the model up). Henc
e the desirability of a flat turn, and the associated large diameter circle req
uired.
No asymmetrical warps can be employed due to their prejudicial effect on the mo
del's straight flight trim.
The most interesting developments have
F1E: 5 minutes is Max!
...............
Roger Morrell
