SEN-404 April 17 2000

News and Reports 2000 - First half
SCAT Electronic News 17 April 2000 issues 404

Table of Contents

Help!!! - Lumberjack
Talon model for sale -Kreuzer
full house F1B - Linkosalo
Lightfastness Test - Jahnke
Applogy - RDT and CIAM Meeting - Tracy
Re Full House F1B - King

Author : This email address is being protected from spambots. You need JavaScript enabled to view it.

For the last four years I've been in Science Olympiad. For the last three
years they have had an event dealing with free flight. For the first two
years I was the person to beat at the state level. This year I took 3rd
place because my planes aren't performing like I want them too. I'm not
going to nationals and I'm disappointed but I'm starting for next year and
want to have ideas. I was wondering if you could help me develop a plan for
the plane that would get me a time over, at least, two minutes. I was
thinking of a canard design but I'm not sure if it will fly like I want it
too. If you could help me design a plane I would be very thankful.


PS .I'm from North Dakota.

[The last time someone wrote for Science Olympics help
they came from a middle school close to my house ! Brian
is a long way from most Free Flighters - are there
any readers out ther in ND ! or someone who would like to
help him ofsuggest a design ? Eventhough I risk to recieve the
wrath of Doug Joyce, I do not think a canard is the best way to go!]

Talon model for sale
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Hello, my name is Bob Kreutzer and I live in San Diego. I have a Jetco (
I think that was the kit manufacturer) Talon towline glider for sale. It
is BEAUTIFULLY built and 20 years old. The silkspan is deteriorated in
numerous spots, but ,it has been hanging high and dry for all these
years. It has been gracing my garage for all this time, but, I will
never use it ( it has been test glided once and is in perfect
condition). It is finished in yellow Pactra buytrate (sp?) dope on the
fuselage, and black on the wing frame. The covering is natural ( what
has'nt shrunk to the point of ripping) silkspan and butyrate clear dope.
Would you know of anybody who might be interested in such a nice model?
If so please let me know. The asking price is $100, OBO Thanks. Bob

Lightfastness Test
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I did a lightfastness test on four shades of the Design Master spray colors
from Michael's arts and crafts store. The colors I selected were Pink Glow
703 ( a flourescent), Orange 775, Glossy Black 625, and Holliday Red 714.
These colors were chosen because similar colors faired well in our
visibility study from the 1998 sympo.

Methodology: An area 5 cm x 10 cm of each color was sprayed onto a 10 cm x
20 cm piece of Rives BFK 100% rag drawing paper. This paper was chosen
because it is acid free. 1/2 of the samples were covered front and back
with illustration board to block light and restrict exposure to the air,
leaving the other half of the samples exposed. The sample sheet was hung in
the window on April 2, and checked about twice per week for two weeks.

Results: Holliday Red and Glossy Black faired very well with no appreciable
change. The orange showed some fading within what I would deem an
acceptable range. The change in the orange was perceptable after just four
days in the sun, but little change was noted afterward. The pink faired
poorly, showing a dramatic change after only four days and continuing to
fade as time went on. (Four days is the length of two weekend contests!)
It is no worse than other flourecent spray paints however. I recommend
using it on clear mylar, where it can be removed with acetone and reapplied.

I also weighed my sample to get a rough estimate of the weight gain one
could expect. The weight gain from a fairly heavy coat of these colors was
.101g / sq. dm, or about four grams for a typical F1B wing. This is lighter
than regular spray paints. A light coat would yield good color with a
smaller weight penalty. A thin mist is all that is necessary on mylar for


Applogy - RDT and CIAM Meeting
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For the consideration of an efficiency that might erode a plateau of
intransigence and acrimony I want to apologize to the CIAM AMA team for
certain selected verbage contained in paragraph 4 of my report on
Free Flight Subcommittee activity that appeared in the 29 March,'00 SEN.

Daniel J. Tracy

[Dan, it sounds like the RDT, CIAM and AMA is a sad history of mis-
communication. The proposers of the RDT had no intention to upset
the relationship that the AMA has built up with the FCC or to spoil
the flying of fellow [R/C] modellers. While the bare bones expression
of the RDT rules [and the current F1C Rules] could be read to be
disruptive, in fact the intent and development work done was
to avoid frequency conflicts and FCC issues. In the past
changes to the Free Flight rules
had not had the potential to affect others like this one did. We
do not really have in place the mechanism to add explanatory material when
submitting chnages to the AMA or to comment to the the AMA on rules
from other countries. Similarily we did not have a way for the the AMA
to express their concerns back to the Free Flight modellers and to
enter into a dialog before the CIAM meeting. These issues are exacerbated
by the short time to get ready for the CIAM Meeting.

I understand that since the CIAM meeting there has been some
fruitful discussion with the AMA Frequency commitee. Up to
this point the USA has been a
leader in the application of technology to all aspects of aeromodelling
and it is important that we keep it that way. Both for the individual
modellers and the hobby industry at all levels.

While initailly this item seemed to be of interest to a comparatively
limited number of hard core FAI competition flyers - questions in SEN
from the well known sport flyer Don Ross indicate that if the unit
can be manufatured for a reasonable price others might be
interested. ]

Re Full House F1B
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Dear Jim

I read about your endeavours with F1B trimming. As I have not done a lot of
flying recently I will leave it to others to advise you. However, for what
it is worth, most people use a VIT timing of ca 3.4 to 4.0 secs. I
found your observations on the timing of the VIW very interesting as I have
also found the same problem with my latest models.
All though I have always, in the past, left the AR and VIW in for the whole
climb, my latest two models have shown a tendency to straighten out for the
last half of the cruise for some reason. I also have had to remove the AR
and VIW but not untill about 18secs into the 50sec climb. This cured the
problem. I have tried to figure out what was going on and finally came to
the conclusion that, as the model goes to a fairly shallow climb angle, the
velocity may increase slightly. This would have the effect, due to the
speed related effects on the L rudder and the aileron effect of the VIW, of
straightening the model's flight path. Maybe when the model is still
strugling to maintain a high climb angle, the speed is quite low and this
would reduce the effect of the rudder, plus the VIW would have a strong drag
effect, tending to pull the model to the right. This is all conjecture, of
course but would be a rational explanation. I think I have actually seen the
model increase speed slightly as the model flattens out. What is not so
clear is why I have only noticed this phenomena on my latest models. The
only significant difference has been that I have reduced the motor to only 26
strands. Before that they seemed to act quite normally ??

I would be very interested to hear any other thoughts on this and the
other points you mentioned.

Good flying !!!

Peter King

full house F1B
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a few years ago I wrote my ideas of trimming F1B into web, see:

That could maybe use some update, but the basics should still be
there. HTH.


Roger Morrell