SCAT Electronic News January 24 1999
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SCAT Electronic News January 24 1999
Table of Contents
=================
America's Cup Calendar Update - FAI Invitational Dates
Preliminary Info on Australias bid for the 2001 World Championships.
FAI propsals - George X
Stuff from Hermann
More on Dihederal
F1B rules
Certifiable F1C Timer ?!
What's this about F1C ? -Daryl.L.Perkins
looking for help
German proposal for Junior rules and F1B rules
America's Cup Calendar Update - FAI Invitational Dates
======================================================
Roger,
The AMA International Aeromodeling Center at Muncie has been reserved for
Aug 21 and 22 by the Chicago Aeronuts as our traditional date for the FAI
Invitational Contest...the one you were at last year. I am the CD (Mitch
Post has been dead for about 2-3 years now) and the sponsorship has shifted
from the Illinois MAC and Bong Eagles to the Chicago Aeronuts. We will have
the mini-events as well as the big events.Two other Aeronuts contests will
be held at the field on the same weekend, our Fall Oldtimers Contest and
the Midwestern States Championships.
The calendar lists the NY champs on the same weekend....but apparently
their site is still not secured. Please put our listing in the calendar.
Chuck Markos
655 Carlisle Av
Deerfield, IL 60015
ph 847-982-7681
eMail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Thanks
Preliminary Info on Australias bid for the 2001 World Championships.
=====================================================================
From: "Bill East"
Roger,
We are currently preparing a proposal for the 2001 World
Championships to be tabled at the forthcoming CIAM meeting
in March. The proposal was moved forward due to Ian Kaynes'
discussion in a previous SCAT Newsletter.
Details for the Australian proposal will be outlined fully
next month and a Web Page will be available hopefully within
the next 4 days, I will send the web page location data as
soon as it's available. At this stage April 2001 is the
preferred time of the year with the location being Wagga or
Dubbo - Dubbo being the strongest chance at the moment due
to the Wagga fields possible use by the Navy for Land
Antennas. The field at Dubbo is about 4km x 5km in size with
excellent retrieval areas including a road around its
perimeter. At this time of the year the field will be
grassy. The weather at this time of the year is usually
excellent being Autumn with mild temperatures and light
winds. Quite a few modellers including Eugene have flown on
this field in the Australian Free Flight Championships last
year.
Accommodation is being examined with the view towards
dormitory style such as the college at Goulburn.
Europeans, British and American modellers will be able to
take advantage of the savings due to our international
dollar value which is currently
$1 AUS = 54p UK and 62cents US. These savings alone
constitute value for money thus reducing the cost of the
travellers trip by almost half.
We will be looking into a reduction in Airfares with
National carriers including the waver of any freight costs
for Model Box transportation.
We will have a contest before the Championships - probably
the AFFS which is a World Cup event.
I hope this small amount of information will be of help, of
course at this stage things are still in the planning stage
and may change slightly but rest assured this will be a
World Championships that will be fondly remembered for many
years.
Please distribute this information to all concerned, My door
is always open to questions you or any person wishes to ask.
All questions will be answered honestly based on
information current at the time. As mentioned before a
Special Web Page is to be uploaded shortly that will contain
information as it comes to hand.
Thermals
Bill East and Alan Edwards
World Championship Proposal Co-Ordinators
This email address is being protected from spambots. You need JavaScript enabled to view it.
FAI propsals
============
From: This email address is being protected from spambots. You need JavaScript enabled to view it.
[this was in response to a question to George Xenakis if the proposed
FAI FF rules changes had be distributed yet. George Xenakis is on
the CIAM FF Subcomittee and has been involved with the FAI process for many
years]
Roger,
Nothing yet. Talked to AMA and they said no agenda is available yet. We may
not get one before the March meeting because of delays caused by the move of
FAI to Switzerland.
If anyone has info on agenda items, they should send them to Scat and opinions
should be sent to Dan Tracy who has replaced Waterman and will be going to the
meeting.
George X.
Stuff from Hermann
==================
Roger,
Southwest Regionals:
John Nystedt has the SWR info and if he survives his allergies,
should put together a fine report.
RULES:
Guess some of my comments (like ROG) sounded quite retro.
One concern I have is the unintended consequences of rules changes that
result in the opposite result to the intended result. One example
is the 1 gram rule in F1D which resulted in fat chord 65 cm models
that barely fit in 90 cm boxes. Does anyone think to remove the wt
limit? No. Proposals are for 55 cm and 1.2 gram which would make models
10' long.
Similar to adding wt and shortening towlines which turns the event
over to sprinters.
LIFT SLOPE:
Think it was Stuart Savage that pointed out the effect of dihedral
on lift slope in a Zaic Yearbook. The idea is that when dihedral
is added to a surface like a wing it runs at a lower angle of attack
than w/o dih. and generates less lift. The rate at which this happens is
related to the cosine of the dih angle squared. So with a flat center
and 45 deg tips, the tips will only have 70% (70.7) of the angle of
attack as the flat center. Additionally, the lift vector of the tips is
being pointed inward at 45 deg has a vertical component only 70% of
it's peak. Bottom line: dihedral in tips is better than washout
as it increases with angle of attack and is zero @ zero angle of
attack for lower drag.
Dihedral in the front surface is like a magical autopilot with no
sensors or moving parts. Doesn't matter if canard or real airplane.
Incidently, this is similar to the basis for Einstein's relativity
theory in that it's based on having the same result independent of frame
of reference.
Also helping stability is higher AR in rear surface.
I took a lot of flak for suggesting simple models of models to
verify the above but hey they can save a lot of composites.
Later,
Hermann Andresen
More on Dihedral
================
From: "Hermann Andresen
Roger,
Hard to put dihedral sketches into text. Like talking w/o hands.
One point for the non-believers is to consider a stab & rudder.
No matter how high the angle of attack the stab attains, the
rudder stays at zero degrees.
If a wing tip panel is progressively bent up to the vertical,
the angle of attack doesn't just follow the main panel up to
89deg dihedral and then suddenly drop to 0 attack when vertical.
Relationship between rate of generating lift depends on the
cosine of dihedral angle squared.
Simple gliders like Frank Zaic described in CIRCULAR AIRFLOW
can teach more about stability than all of the differential
equations ever written.
Hermann Andresen
F1B rules
=========
From: Marcel Lavoie
First of all my thanks to Anselmo Zeri for his kind comments in the Jan.
21 news letter. On the question of rubber weight allowed for F1B,
one possibility could be to fly the first five rounds with no changes
whatsoever to the present rules, then for the remaining rounds limit the
motor weight to something less. In my very limited experience of flying
with 20 grams, I believe world class flyers could find this a very
viable proposition. This would help rein in the long chases and field
problems associated with 5, 7, 9 minute fly-offs, and go a long way
to allay fears of jeopardizing the availability of the Tan rubber
source. It should not be a complicated matter to use the same model for
the fly-off rounds, though some people might want to use a model
specifically built around the 20 gram motor (or some other figure under
40 gram). See my letter dated Jan.18 th.
Note - I wonder if anyone has had a close look at the center-fold of the
October 1986 Aeromodeller in which I presented a new way to
use the NACA ordinate tables to draw airfoils? I'd be interested to
"hear" any comments on this.
Marcel Lavoie
[comments ...
While I do not consider myself to be an expert F1B flyer, I compete
frequently. An proposal that involves changing the weight of the
will almost certainly require differently trimmed models for the different
weights. With the current rules a poor motor will not only
cause a bad climb but may make the model go off pattern during the
the climb. One cannot require that a person continue with the
same model as it may get lost or damaged and anyway people
now change the model for other reasons related to weather or
personal whim.
It will also place more reliance of rubber testing and the selection of
motors. This will help the expert modeller and make it harder for
the beginner or causual flyer.
A modern F1B with 35 grams of rubber will do between 3 and 7 minutes
in dead air depending on the skill of the flyer. Very few contests
are flown in dead air, so the long fly off flight are the result
of thermal activity. While reducing the rubber will effect fly off
results, even in thermal conditions it will not really make much
difference when significant thermal activity is present.
We already have a class, F1G that has reduced performance
so if people have a restricted area to fly in why don't they
fly it ?
RMM]
Certifiable F1C Timer ?!
=========================
From: Rodman A Mogle
Roger,
YOU'RE BACK - A VOID IN MY LIFE HAS BEEN FILLED. I really missed
the SCAT News and do appreciate the fine job you have always done.
Notice of late a lot of comments on F1B rule changes, unfortunately a
subject on which I have little to contribute. I think its time to get
some dialog going on engine timing and electronics for F1C.
I am not a F1C competitor and my only experience at timing F1C was at
the recent Florida team selection finals. There, I really dreaded
multiple launches because of the difficulty of accurately detecting
the end of the engine run. From what I have learned from others my
difficulty is not unique nor is my experience level significantly below
that of timers at other regional and world events.
Because of my experience with electronic timers I have been asked to
consider a "CERTIFIABLE " electronic timer. It is envisioned this
certification would be similar to weighing rubber, verifying areas,
airframe weight, etc. The goal of using a certifiable timer would be the
elimination of the need to time the engine run; i.e., If you can
demonstrate it can't exceed 5 seconds on the ground, it can't exceed 5
seconds in the air! Initially I was excited about this concept (more
timer sales) but further investigation revealed several pitfalls in this
approach.
The reliability and repeatability afforded by electronic timers would
seem to make all this possible. Loops and limits designed into the timer
software would allow demonstration to the contest officials that the
timer would not permit an ENGINE TIME PERIOD beyond a specified limit (5
seconds).
I think this approach has two (at least) major pitfalls:
1. Notice in the above paragraph the phrase "engine time period" was
used; not engine run time. The current rule which includes run - down
time as part of the total engine run time would need to be eliminated If
a "certified electronic timer" is to be used in place of a human timer.
This in turn would eliminate the use of prop brakes, encourage the use
of high inertia props, and result in developments such as "soft
flood-off" and other devious means to extend the effective engine run a
few tenths of a second.
2. Although the timer software would include features to limit the
maximum engine run time, there is little that can be done to prevent a
creative mudeler (not modeler) from modifying the software subsequent to
timer certification in order to allow longer engine runs. I do not mean
to imply modelers are prone to cheat; on the contrary I believe they are
the most honest bunch of people in the world, but rules should be
designed to keep us all honest.
From the above comments one would conclude that a "certifiable timer" is
not my favorite approach to solving the F1C engine timing dilemma. I
believe a cleaner approach will utilize a engine motion sensor coupled to
an RF link to a ground based timing device. Such a system would utilize
the existing model locator transmitter used by most modelers. The
transmitter would have to be modified to accept a magnetic pulse or photo
diode input to sense the engine rotation. With this approach a continuous
series of pulses generated by the engine sensor would be transmitted to
the ground via the locator transmitter, both while the engine was running
and during the rundown phase. The ground based timing device would sense
these pulses (a receiver or scanner) and when the pulses stopped the
ground based timing device would be triggered off. With this approach the
human timer would not be confused as to when the engine stopped due to
other engines in the area which might still be running.
At the beginning of the flight the timing device (stop watch) could be
started in the normal manner by the human timer or with a suitable
electrical connection between the model timer start switch and the
down-link transmitter (assuming the use of an electronic timer).
I feel this approach would has many advantages over a certifiable timer
approach:
1. Foremost; engine stoppage is detected electrically, not by hearing -
no more human timer confusion.
2. Engine rundown time is included in the total engine run time.
3. Eliminates the sonic delay between the model and the human timer (0.4
to 0.5 seconds).
4. Little additional airborne weight. The sensor should be less than 10
grams.
5. A little technology at the receiving end would allow the flyer to
monitor engine RPM.
6. Problem - Coordination (or lack thereof) of locator transmitter
frequencies must be addressed.
7. Problem - Each human timer must have a receiver and timing device
(modified stopwatch??) provided by the flyer, the contest organization.,
who??
I hope all this starts some dialog and action toward solving this
problem. I hope we hear from the locator transmitter manufacturers, the
flyers, etc. By the way, this problem is not limited to F1C,many of the
same timing problems exist in AMA power.
[Note
Rod makes a F1C timer - see under supplies. This is an Electronic
timer that is replacment for a Seelig F1C Timer. ]
What's this about F1C ?
========================
From: "Perkins, Daryl L."
Hi Roger,
I breezed through the mail this morning and there was a Italian proposal
about F1C that Daniel from Argentina had made mention of ...."No Engine Run
Timing" This was the first that I had heard of this. How would we, the FAI
community get a hold of proposals like this one and others for that mater. I
am ignorant of most of the political aspects of our sport. Who would be the
representative for the USA in such matters as these?, so we can flood this
person with e-mail to let them know our views.
Also my Internet address has changed to: This email address is being protected from spambots. You need JavaScript enabled to view it.
My company is trying to conform with the Internet naming standard, my old
address will be in affect for the rest of 1999, the new one works now also
so I thought I would start spreading it around. I thought what better way to
get the message out, I'll the mail @ SCAT.
Thank you,
Daryl
[Daryl
It goes like this, each country is represented at the FAI meetings by
their National Aero Club. So the person who votes for the rules changes
is the AMA president [Dave Brown]. The president is advised by the specialists
from each area. In the case of FAI Free Flight we are represented to the AMA
bu our FF Team Selection Committee. The person that is from
your district [and mine ]
is Roger Simpson. In addition the FF Team selection committe sends someone to
the FAI meeting to advise Dave Brown. From George Xenakis's message
this will be Dan Tracy. The permanent AMA offical who is responasble
these meetings is the competitions Director, Steve Kaluf.
Any National Aero Club can submit rules changes.
In addition there is the CIAM FF Sub commitee. The Chairman of this is Ian
Kaynes from the UK. There are people from many FAI FF countries.
George Xenakis from the US is on that committee.
This committee makes recomendations on rules chnages and makes sure the
World Champs etc are run properly. Members to this sub-commitee are
are not elected and althought they come from many countries
they do not vote on the final decisions.
So George is not strictly speaking 'our representative' but he does
try to present what US sportsmen think to the sub committee.
Typically what happens is that George has to comment on some proposal
with not much notice so he tries to contact people in different parts of
the country to see what they think about the issues.
This is typical in that the proposals were submitted in December
and the meeting is in March but 'we' do not know the details yet.
I think that it is responsibility of the FAI to distribute
the information.
If I'm not correct please correct me on details.. I did go the FAI
Politik school with Prof Allnutt but may not have got things straight.
Editor ]
looking for help
================
From: This email address is being protected from spambots. You need JavaScript enabled to view it.
Roger,
Also, I have been building and flying rubber power FF for 30 years, but have
absolutely no experience with towline gliders of any type. I am extremely
interested in F1H and would appreciate any direction from someone on plans,
equipment, etc. I normally don't build from other peoples plans, but would
like to shorten the learning curve somewhat. My young daughter is showing
great interest and aptitude with the catapult and rubber models we have built
together, but she has absolutely no arm for hlg's.
Any assistance would be appreciated. I know of no one locally who I can draw
on as a resource.
Thanks,
Rey Mazzocco
Evansville, IN
[reply]
Rey
Some of our regular readers .. Chuck Marcos for one, at least lives
in the same state as you. Chuck flys glider .. and other stuff too.
Maybe some one can contact you.
Look at the America's Cup Calendar for dates at Muncie.
Your daughter may want to look at the Junior program .. the chance
to represent the US in a World Champs !
Details will be posted real soon [won't they Mr Batiuk !]
German proposal for Junior rules and F1B rules
==============================================
From: "tandre"
Hello Roger,
>From the latest issue of Thermiksense I understand that the Germans have put
the following rules change proposals for the Junior Free Flight Classes to
the CIAM:
- The models may only be steerable by means of the rudder (F1A, F1B as well
as F1J). This is intended to encourage the juniors to fly with self-built
models and it makes simple models more competitive.
- Starting poles must be positioned 20 meters from each other. At the
starting position except for the team manager, timekeepers, jury members and
organizers, no one older than 18 years may be present. This is to avoid the
kind of problems which we have had at the last championships.
In another message in the same Thermiksense suggestions are made to reduce
the max. rubber weight for F1B-Junior to 25 grams because juniors can have
problems with winding a powerful 35 gram motor. This would also cut down on
the cost of flying. They also want to ban all other complex gadgets. (It is
very well possible to fly on 25 gram rubber. I have done experiments with 30
gram of the old type TAN rubber some 5 years ago and the models still reach
acceptable heights of 60-70 meters).
I do not have the exact wording of the proposals as the Germans have
forwarded them. I particularly like the idea of a 25 gram rubber,
gadget-less F1B-Junior class. We have a large junior group at my club (~15
kids, age 10 to 18) who are very much interested in all rubber classes, but
they are really scared away from the complexity of a modern Wakefield. If
this proposal is going to make it, we have a very good chance to see the
first Junior F1B flyers on our flying fields in Holland for the first time
in 25 years! I think John Clapp will like that also......
I hope you all support these proposals. Talk to your national CIAM-delegate.
With best regards,
Thedo Andre
...............................
Roger Morrell
