SEN 857 - 27 Feb 2004

SCAT Electronic news 27 February 2004 issue 857


Table of Contents
=================
Looking for Noam & Roni Weissman - Summersby
Texas Cup Announcement - Simpson
Tai Chi and discus dynamics - Skykieng
F/F DLG - Biggles
Re:Low Tech trimming - Lipori
Experiments with Zitdt EEM - Ivers
ffdlg - Barker
Maryland Farm Site - Shailor

Looking for Noam & Roni Weissman
================================
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Can anyone help me making contact with Noam & Roni Weissman. They made =
Audio Tachometer in 1992.
Roy Summersby.
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Texas Cup Announcement
======================
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Hi Roger, would you please include this Texas Cup Competition announcement
and 2004 rules on SEN

Thanks, Reid Simpson

TEXAS CUP COMPETITION ANNOUNCEMENT

To all Free Flighters;

You are all invited to participate in one or more of our Central Texas
competitions this year and compete for the Texas Cup awards.

We fly the three major FAI events (F1A,B,C) and the three mini FAI events
(F1G,H,J ) at three of the contests.
F1P will be flown at two of the contests. We also fly a mix of AMA events at
all four of the contests.


2004 Rules Update - February 24, 2004

This letter is to provide you with the 2004 rules for the Texas Cup point
championship competitions.

The only change to this years competitions is to add the NFFS 2004 One
design event model, Toshie Matsuda's Zero, to the Starduster-X event. See
section 7 of this letter for the rules and information on the availability
of a Zero kit.

The Starduster-X competition has proven to be so popular nationwide that
NFFS has decided to hold that event again this year at the Nats along with
the Zero model. We are following suit since we also have seen the popularity
of this event.

________________________________________________________________________

TEXAS CUP COMPETITION 2004

The purpose of the Texas Cup Competition is to foster the development of
flyers and models, and to experience the joy of friendly competition in the
4 central Texas contests. This competition encourages flyers to attend
multiple contests each year in order to win. To this end the following
rules have been formulated.

1. Points are accumulated in these 4 Texas contests.
Spring Cup (Seguin) - April 2004
Tri-City Contest (Seguin) - June 2004
Cloud Climbers Contest (Beaumont Ranch) June 2004
Autumn Cup (Seguin) - Nov 2004

2. Overall Point champions will be awarded in the following categories:
Gas
Glider
Rubber
NFFS One design event (Starduster-X and Zero)
P30
Jr/Sr overall Points

The Starduster-X/Zero and P30 events have been singled out
as individual event championships to encourage newcomers to build and
compete in two simple events. Kits are available for both events. The points
accumulated in these events will also be counted towards the Gas and Rubber
Championships awards.

3. Awards - High Point Championship Perpetual Plaques will be awarded at the

April 2005 Spring Cup Banquet.

4. Gas Champion - Points can be accumulated by flying and placing in any Gas
powered event at any of the 4 contests in any of the following events.
AMA Gas (all 4 contests)
Nostalgia Gas (Tri-City and Cloud Climbers contests)
FAI Gas (all contests except Tri-City)
NFFS Design Starduster-X/Zero (all 4 contests)

5. Glider champion - Points can be accumulated by flying and placing in any
Glider event at any of the 4 contests, in any of the following events.
FAI Glider (all 4 contests)
Hand Launch Glider (Tri-City and Cloud Climbers contests)
Catapult Glider (Tri-City and Cloud Climbers contests)

6. Rubber champion - Points can be accumulated by flying and placing in any
Rubber event at any of the 4 contests, in any of the following events.
FAI Rubber
F1B (All contests except Tri-City)
F1G (all 4 contests)
Unlimited Rubber (Cloud Climbers contest)
P30 (all 4 contests)

7. NFFS One design event Starduster-X/Zero Champion
The Star Duster-X/Zero event has been chosen as an
individual Championship event, due to the simplicity of the models, the
design restriction as kitted makes these models ideal beginners gas event.

Starduster-X will be flown with the established 2003
one-event rules.
Motor - Cox TD .049, or the Cox TD .051
Motor Run - 9 seconds for 1st 3 flights and
then 6 seconds for all fly off flights. (Note: Beginning Gas flyers can be
given an additional 2 second motor run, at the discretion of the CD)

The Toshi Matsuda's Zero will be flown with the established
2004 one event Nostalgia criteria rules including engine selection.
Motor Run - 9 seconds for 1st 3 flights and
then 6 seconds for all fly off flights. (Note: Beginning Gas flyers can be
given an additional 2 second motor run, at the discretion of the CD)
The Starduster-X Kit is still available, Contact:
Allen Heinrick, (760) 948-6334
Aerodyne Models
17244 Darwin, Bldg H
Hesperia, CA 92345
The Starduster _X tank mount (CM110), called for in the
plans is still available. Contact:
K. K. Fags (201) 664-2606
236 Thayers St.
River-Vale, NJ 07675

The Zero kit is available from BMJR for $37.65 plus $5 postage
BMJR Model, Products, PO Box 1210, Sharpes FL 32959-1210.
A short kit is also available for $25 plus $5 postage.
Zero plans are available from Jim O'Reilly for $7 plus $1 postage
Jim O'Reilly, 4760 N. Battin, Bel Aire KS 67220

8. Points - Points are awarded for placing 1st thru 5th place in each event
as follows:
1st Place 25 Points
2nd Place 20 Points
3rd Place 15 Points
4th Place 10 Points
5th Place 5 Points

9. Bonus Points - Bonus points are awarded to the 1st thru 5th place
finishers as follows. When more than 5 competitors are entered in an event,
1 point will be awarded for each competitor over 5. For example, if there
were 7 competitors, each of the first 5 place finishers would receive 2
bonus points. (Note: for bonus points to be awarded, a contestant must make
an official flight to be counted as an entry in that event)

10. Ties - All ties in each event must be settled by the end of that
contest. Ties for the Overall Championships at the end of the competition
will be broken based on number of 1st places each contestant has won in the
competitions. And if necessary 2nd places, followed by 3rds, 4ths and 5ths
until the tie is broken.

11. Scoring - Results of all events from each contest must be forwarded to
Reid Simpson showing all entries in each event and their placing. As well as
showing Junior and Senior entries.

12. Texas Cup Committee

Reid Simpson Faust Parker
115 Trailridge Dr. 103 Blue Willow
Athens, TX 75751 Houston, TX 77042
(903) 677-8525 Hm (713) 266-2961
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Tai Chi and discus dynamics
===========================
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Since my good MMM buddy Jerry Murphy doesn't lie very often it might be true
that it is possible to discus launch a conventional HLG. I only wish this
tiny and nearly ancient 12th Dan of the Black Belt of Tai Chi swirling could
fill us in on the fine points of his remarkable technique.

For me it has been a bust.

Some years ago I was trying to figure out ways to defeat the aging process
and regain some velocity in my HLG launch. Since I had played around
throwing the discus in my youth I tried incorporating a pirouette style
whirligig that climaxed with a conventional baseball-type launch. It was
very successful ... but only in its side effect of eliciting peals of
laughter and thigh slapping amongst heartless spectators. But that wasn't
quite what I was looking for, and frankly it was quite painful having to
assume a sheepish grin after every launch. And furthermore there were the
consequences of tripping over my feet.....and then there was the sticky
matter of control compounded by trying to locate the model when I was face
down in the dirt.

But about every fourth attempt it did show promise in that everything flowed
together and full power was delivered before the glider left my finger tip.
I imagine it got about 30% higher....which meant that I was still 30% lower
than the young studs.

A couple of years ago I thought about trying a true discus type launch using
arm extended. I took a preshaped sheet of 4"X 36" balsa and stuck it on an
old fiberglass Nordic boom. I was surprised about how high it got. I even
adjusted it to go up into a loop. (It was not meant to glide and there was
no dihedral. There was a nice alfalfa field to cushion the crashes)

I blabbed this top secret finding to a friend but he quickly pricked my
bubble by telling me about the sensational performance of RC DHLG. Ummm. So
I got on the internet.

However what could be accomplished using zero dihedral didn't seem to carry
over to a conventional HLG. The classic combination of high dihedral and
minimal vertical fin seemed to cause a problem ....that would be from the
induced yaw induced by the spinning launch. Perhaps I was merely clumsy but
trying sidearmed launches found conventional glider's flipping over and
tumbling. This had me convinced that normal gliders were a no-go...until
Murph came back bearing his tall tails from Japan.

Murph didn't mention the additional tail area on the Japanese HLG until now.
That modification would help the situation in the launch (but might cause
problems in a thermal.) I'm not sure how the wing peg figures on the RC
planes. It may be merely structural or perhaps acts as a pivot to allow
cleaner tracking of the plane around the circumference. With a lighter FF
HLG I can see the solid grip on the wing tip either contributing to the yaw
problem or presenting the ship at the desirable angle. It will take a lot of
experience before discovering just what "english" to add to the Japanese
approach.

Further thoughts. The C.G. location of the RC ships are forward (30%?)
compared to the usual 50% of the FF. The centrifugal moment would angle the
noses of the RC ships outward. If this is an important distinction then
perhaps some sweepback on the FF versions would be helpful.

I find the whole subject rather stimulating since it opens up a virtual
ground floor opportunity to de-flower a virgin facet of Free Flight. (that
doesn't sound quite right)

Skyhigh


(Murph writes)

Last year I was in Japan on a business trip and I attended a YSF contest
with my friend Yasuo Yoshioka.
At this meet I saw people flying very traditional looking HLGs with a
discus launch technique.
One flyer was a small man in his 70's and he was able to obtain launch
altitudes with this launch that was on a par with the best of the
traditional flyers back home. I looked at his model and there were no
moving parts, no peg on the LH wing tip, nothing out of the ordinary.
The only thing slightly different was the larger than normal sub rudder.

I wish I could have taken a video of his launch, but that wasn't
available to me.

The model was launched from the LH wing tip in a slight ( < 20degrees)
nose up attitude. It climbed in a LH spiral which opened up to a RH
glide.

Murph




F/F DLG
=======
Martyn Cowley



Roger,

* For SEN



Re: Free Discus
===========

Hey Phil,

* Czech out this excellent modeler's website, illustrating several
configurations of F/F DLG, click on "598" and "599" which details
DLG's 1, 2 and 3, with high-tech carbon bits and pop-up wing DT etc.
I have tried contacting him without response, so perhaps we need a
Czech Mate to interpret and write to him ?

http://www.tmrmodel.cz/graphito.htm

- Biggles




Re:Low Tech trimming
====================
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----- Original Message ----- Low Tech Trimming
=================
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All freewheeling props tend to turn the aeroplane to the right on the glide.
On the 'Achilles' the effect
is so bad that left rudder is needed to stop a right spiral. Under power
the left rudder causes the thing to cavort all over the sky. This can be
cured by adding right sidethrust. The trouble is that the sidethrust
increases the right turn o1Gn the glide - back where I started. After wasting
a lot of time trying to balance side thrust and rudder I tried the
unthinkable - I trimmed the beast to go left on the climb. Result, a
smooth, fast climb. Regards John Barker - England

John,

There may be a small inherent right force due to the freewheeling prop
(gyroscopic, slipstream on the rudder or whatever.) There is another force,
which is probably more significant, and difficult to diagnose (at least for
me,) caused by right thrust on a freewheeler: Any right thrust used to trim
the climb, translates into a left force in the glide, as the air is now
pushing the prop rather than the prop pulling the airplane.
Not familiar with the "Achilles," Where is the rudder located, top or
bottom? Bottom rudders usually have a strong right tendency in the burst.

Bob




Experiments with Zitdt EEM
==========================
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Roger,

I would like to accept your invitation to re-submit messages that were
not published.

The subject message is below (slightly re-written)

Dick Ivers


Subject: Experiments with Zitdt EEM


Dear Fellow FF's,

The zit EEM is an electronic electromagnet module originally designed as
an actuator unit for model rocket recovery. I recently purchased two of
them to try out as FF DT actuators. The bench tests and flight test
experiments I've done may be of some interest to FF's.

The EEM's are made in Slovakia by Jan Zitnan, but distributed here in
the US by Kevin Kuczek. The design and manufacture of these devices is
very high quality. They weigh 1 gram each and cost $18. My only
complaint is that the attachment hooks could be a little more heavy
duty.

The spec sheet for the device says that maximum tension force allowed on
the hook is 10 grams. This number is much too low for most FF
applications. However, I have bench tested the part with up to 200 grams
force and it worked perfectly, using a 1.5 volt alkaline battery. I
think the force could have gone even higher but I ran out of range with
my spring scale. Also, I have an EEM flying in a FF Electric Power model
which my son flew at King Orange. It DT'd perfectly every time. The stab
hold-down tension force was about 120 grams. There is a small extension
spring in the DT line to make the line more stretchy.

The EEM's work a little differently than you might think. During flight
the release lever is held by a cleverly designed mechanical latch. The
device is actuated (released) by an electrical pulse to the coil. I use
a 50 ms, 5 volt pulse. Thus, the EEM is not using any battery power
during flight and only a tiny amount on release. The pulse is derived
from an electronic timer in the model. The timer drives a mosfet to
pulse the EEM for DT release.

The zitdt site is www.zitdt.com

Dick Ivers



ffdlg
=====
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In response to Phil Ball in SEN 855
Phil, I do believe you about your cg position. Also I do not any longer, on
CLGs, 'select a cg position and trim around it'. I can understand your
mistake because the last time we talked about it, in January, you were a bit
distracted. If you remember I was in the unusual position of leading you in
the CLG competition. Of course you fouled things up by finding some lucky
lift, maxing the last flight, and beating me by thirteen seconds!

Seriously, I did mention this matter of cg position in my talk on CLGs at
last November's Free Flight Forum. I should like to quote a bit of the
paper because it redounds to the credit of SEN as well as explaining my
thinking. Early in 2003 I thought that my gliders were not climbing as well
as they should and asked in SEN for advice. Amongst a lot of replies (off
line!) there was consensus on three things: the glider must be light, not
too big, and have little incidence difference between wing and tail. On the
first two I was in line with recommendations so I looked at incidence
difference and how I had arrived at what I used. The following is a quote
from the paper:

'"All the gliders I had looked at had a CG around 50% and sometimes ahead of
that. I used a similar CG position and then adjusted incidence to get the
slowest glide, or in other words the highest lift coefficient (for best
sinking speed). This procedure is so common in free flight trimming that we
almost take it as a law that a forward CG must have a big incidence
difference and a rearward CG little difference. This is true if one wants
to fly at maximum lift coefficient but it is not obligatory. It is
perfectly possible to fly with a forward CG and little incidence difference
if a lower CL is accepted and this is the trim that catapult gliders adopt.
When I reduced my longitudinal dihedral my major climb problem disappeared."

John Barker - England




Maryland Farm Site
==================
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Does anybody have information about the flying site in Ingleside Maryland?
There is a contest there on May 1-2.
Can I park a motorhome there?
Also, don't forget about the 55th Annual Inter-City meet that is going to be
held May 15 and 16 at the AMA field in Muncie.
It is earlier this year, but we expect to get it back on track for 2005 and
have it once again in late June.
There is also an FAI qualifier the Friday before, May 14. No rounds, no
entry fee.
Hope to see you all there!
Regards,
Bill Shailor

...................
Roger Morrell