SCAT Electronic news June 3 1998
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- Category: Archive 1998
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SCAT Electronic news June 3 1998
Correspondence
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AMA personnel wanted to go to McDonalds, not me. But being the adaptive guy I
occasionally am, I went along for the ride.
Waterman
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Subject : RE: scat meeting in Bishop
Sure would like to come, infact I told Bob White I was planning to , but
beings the last two chemo's failed I must start a Hi-Dose this Wed.. I
sure enjoy receiveing the E-Mails, they keep me going, thanks. Ed
Another approach
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Subject : Re: On proposed changes to rules of FAI
I would like to contribute further thoughts to this interesting discussion. In
other sports in which I have a good understanding of, particularly Formula 1
racing, the problem of rules is as acute as the one we are confronting in
free-flight. It has become almost a wasted exercise to introduce a new set of
rules to " equalize" the competition and makes costs smaller in car racing, as
the more astute teams always find ways of making up for the
assumed restriction in power or tyre performance. I think that F1 racing
is a salutary lesson in the futility of banning progress. The possibility
of achieving the ultimate performance within the set of original rules
is what has been driving free flight for the last 60 years or so and
should not be restricted both for the sake of the
sport itself and for the extreme difficulty of policing such rules. It is also
agreed by most discussers that the price paid for the refinement
of performance is the enhanced cost and the exclusive dedication that
the sport requires. These two items detract people, who find the
competition too demanding and expensive, hence the dwindling numbers
of FF flyers, magazines, shops catering for.
My suggestion in this sense is to use the same idea employed elsewhere
when peo ple with different ability wish to compete in the same event,
that is to introduce a handicap system, that will allow the flyers with
less sophisticated equipment to compete in equal terms with the high-tech
fellows. Let us take the case of Wakefield, F1B. A penalty in time
could be given for using particular items of high cost or difficulty of
construction. Let us say: composite material (carbon/kevlar) for the
wings 3 seconds, fuselage 2 seconds. Movable surfaces AR, VIT, wing
jeigglers, 3 seconds each. Variable pitch propeller 3 seconds.
Continuous pre-programmed electronic timer 3 seconds. Thus a straight
balsa and tissue, fixed surface F1B would qualify for a max with
163 seconds, a fully equipped F1B will require the 180 seconds. For the
fly-offs, the handicap is pro rata the normal flight, thus for the 4
minute fly off the handicap would be 17*4/3=22.7 seconds ,
the simple model going to the next 5 minute round if it can fly 240-22.7=218.3
seconds, and so on. The system is simple to implement, the CD can adjudicate
easily the handicap to each model at the beginning of the contest and the final
computations are not beyond a few minutes with a hand calculator. If the more
advanced contestant feels that there is an advantage in technology, there are
no restrictions in that sense to hamper progress, yet newcomers can compete
with some chance of success.
There are additional benefits to this scheme: it will force a review of
the "real" advantages of mechanical and material trickery and perhaps bring
new insights on different ways of trimming F1B models, as Bob White and
Jean Wantzenriether have proposed for so long.
The handicap in F1A and F1C models could be as easily determined.
It is importa nt that if such a system is implemented, a right
balance be struck so that the simple model is not penalized by too small
a handicap on one hand, nor is the state of the art model handicapped
out of sight. In my mind, the progress due to the new developments
is indeed very real, but has made F1B (and the
other categories too) too specialized and costly.
Sergio Montes
Hobart, Tasmania, Australia.
Mike would to see ..
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Subject : Re: SCAT Electronic News - May 25 1998
Roger
I really enjoy the SCAT news reports and always find the discussions
lively and sometimes useful to a new FAI flyer. As a new FAI guy the
hardest part I believe to attracting new flyers is the collecting of
useable information to contruct the models and learn to fly them. Most
FAI designs have minimal dimentions (93 plan book) and zero information
on construction techniques for those of us that have never done it
before. Those of us that are not engineers but are visual learners
struggle with multiple phone calls to those that might help us and then
have trouble putting the phone conversation into practice. I must say
that most FAI modelers really try to help and Ron Mc Burrnet has been my
personal savior, showing me the way, but we live about 4hrs from one
another so the ablity to get together for a " I know what you said, but
show me" session, is limited. I think more published technique and
systems articles, photos, and working three view drawings would help
taking us "newbies" thru the basics of each class so the light bulb will
go on more quickly. Most conversations and articles assume the listener
or reader will know or understand details known to all FAI modelers, but
not to us new guys, so the details of three position rudder mechanisms,
flood off systems, multi-function timer set-ups, even wing wire
installations and alignment etc. can become daunting until you figure it
out or some benevolent sole walks you through the process. After
building my first D box wing, the second one turned out much better, but
the process had way to much "re-invent the wheel" for information that
could be readily availeable to new comers. My opinion, but I now think I
could mentor others to try FAI, saving them many of my mistakes.
Thanks for all you do with this newsletter and your promotion of FAI
freeflight.
Mike Roberts
Subject : Do Electronics Optimize our Models?
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What do computers do? They faithfully execute a series of instructions
and present information for the programmer to use elsewhere, bugs and all.
Programming:
A series of calculations to determine:
Wing area and stab area
Mean aerodynamic chord
Tail Volume
Frontal area
and so forth
How is it done?
Use fingers to count
Use a simple calculator
Use a slide rule
Learn Fortran, Basic, Pascal, or C++ to calculate the climb height
Ask someone to do it for you
F1A at launch:
Intelligence is built into the system to pitch up the model after line
re lease. The same system knows when to pitch down to level flight
(hopefully) after making an increase in height beyond 50 meters line
length. In order to optimize the bunt height, precise knowledge into
the aerodynamics of the model and its moments of inertia (mass properties)
must be known as well as line release model airspeed and line tension.
Only guesses can be made that allow computer simulations to determine
the height at lev el flight. Imprecision comes in releasing the line,
and is hard to repeat any more than an athlete running a 9.5 second
100 meters time after time. Even electronics cannot optimize this maneuver.
There is too much that is unknown.
In F1B, the imponderables are:
output torque versus turns for the temperature
aerodynamics and mass properties
stab, wings, and rudder settings along the climb
blade pitch changes
speed and elevation of launch
mass properties
design
Computer simulations could tell how to match stab setting with torque,
based on the above imponderables.
F1C - Is there any way up but vertical? When the thrust is greater than
the weight, no. They got that figured out. They also learned to coast after
the motor shut off before bunting. I think the bunt maneuver is much
h too quick for optimizing the height gained.
What are their imponderables?
optimized prop pitch and diameter
optimized wing span and area
variable pitch with speed
mass properties
design
With all these unknowns, just how is electronics going to 'optimize' the
ship? Optimization is none other than what we have been doing since
Leonardo designed the first model airplane.
By and large, the bulk of the people who do not want these improvements a
re those who are uncomfortable with the new fangled stuff. I spent 47 years
in aerodynamics and found that there were those who could not give up
the slide rule for a computer. Instead they became managers. It was only
after the kids learned computer programming in school that the step was
already taken. Some learned along the way and the others rejected the
computer. Now we see those who do not spend the money on retrieval radios
s because of the 'cost.' A few years ago, I was editor of the NFFS Symposium
for several years. In one of the articles, The Brothers Cahill and
their Clodhoppers, there was mention of many flyaways since the DT had not
been developed. What the retrieval radio does, for the seemingly high
cost, is get the model back. In this benefit, the modeller does not have
to build a replacement ship and take the time for finding best settings.
This saves huge time and cost, and allows the flyer to make one-time
purchases of built parts or whole ships.
In the final analysis, and regardless of the configuration of the model and
its workings, it is up to the flyer to build the intelligence and settings
into the model with persistent trimming to get the best out of the ship.
The desire to excel is what drives improvement in the sport. When
the skill and maxing out gets to be the general case with a majority of the
flyers, then changes in the rules arise to keep the contest at the World
Championship level down to a one day contest, that is, unless the competitors
want more flying, then the cost of presenting the contest increases.
Denying improvements of whatever nature only stultifies and frustrates
the more competitive modelers.
Has anyone suggested going to five minute rounds since we are all used to
using binoculars? That alone will slow down the huge flyoffs. Maxing out
is not the real answer. It is getting the highest score that does it
every time, whatever the number is.
Bill Bogart
Comment from Bill Gibbons
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I was talking to Bill at the Big Al's Shoot out and his proposal
was to incease the max time to 195 seconds. Similar idea to
Bill Bogarts last suggestion.
.........................
Roger Morrell
