SEN 688 - 2 Apr 2002
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- Category: Archive 2002
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SCAT Electronic News 2 April 2002 issue 688
Table of Contents
=================
F1P - Flapper ? - Schlosberg
Mylar films - Stevens
Cold Rubber - Matthews
CIAM Meeting in Lausanne, Switzerland - Bogie
THIS WEEKEND ->> San Valeers Annual - Thorkildsen
More F1P Comments - Loribecki
VD prop - Joyner
Super Maxed - Woodhouse
Polypaper - Woodhouse
Reid Simpson's MP JET .06 Engines for SALE - the other Simpson
Nos. rules! - Brooks
hobby poxie clear epoxie paint. - Wilkinson
F1P - Flapper ?
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Well, we have a new junior power class, pulled out of the sleeve by
Sandy Pimenoff at the CAIM meeting under the guise of an emergency
rule change. The fixed lifting surfaces and the span limits clearly show
the influence of Ivan Horejsi, and these ideas date back to a USA
non-tech proposal submitted in '94.
It is surprising that an emergency clause was used to rectify a situation
that has been known for at least a year - since the last junior world
championship. A better approach would have been to float a request
for proposals, with the requirement that a demonstration model be built
and flown.
What we ended up is a model that will be slightly smaller than a Nordic -
31.73 dm2 or 491.8" (assuming a stab area of 13.3%) and a loading of
8.82 gr/dm2 (73.5% of a Nordic or Wakefield loading). This is a large
and heavy model! In fact, the better 1 cc motors would manage to drag
such a model in a shallow climb up to about 50 meters in ten seconds.
That's high enough to make the three minute max in reasonably neutral
air. F1P falls squarely into the slow power regime. In the States, the
AMA .06" powered models are much smaller and nimbler!
A better approach, In my opinion, would have been to opt for a 1.5 cc
motor (.09"). The model would clearly have a much better power/climbing
performance, which, in my mind, is the primary reason why people fly
power in the first place. So why would junior fly a lethargic or "non-sexy"
event while Nordics have bunts, and Wake flied might still have a
reasonable juice left with 30 gram motors?
The other issue is the definition of the class requiring aerodynamic
surfaces to remain fixed in flight, "except for changes in camber or
incidence". Taking the incidence changes first, will this allow the models
to bunt at the end of the climb by changing the stab's incidence? At least,
my impression was that that the intension was to have a model with fixed
lifting surfaces.
The "change in camber" of aerodynamic surfaces is probably an elliptical
way to allow auto rudders. But this could also be interpreted as opening
the door to flappers, which are technically difficult and may curtailing
the wing's induced drag during the climb, and reducing its glide sink rate.
It is doubtful if this was the intent.
The last two points needs clarifications. The engine's size should be
debated as it has the potential of making or breaking the new event.
Aram Schlosberg
Mylar films
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Easter morning. 2002
Say guys, is there some way I can ask your many modelers for help is
locating a new source for mylar or other polyester films suitable for
model airplane use. I can use the following sizes; .000025, .000125,
.00025, .0005 inches thickness. I would like to get some of these
in clear and silver both, and it would be nice if they were heat
sealable on one side only and of course some heat shrinkage would be
nice. This is normally used for covering stabs, rudders etc. More
recently I have been supplying a lot of the .00025 and .0005 to the R/C
electric flyers. The only thing I have been able to buy in the past year
or so has been .0005 silver and I have maybe 200 pounds of that in
stock.
My problem is that I can not seem to connect with a good dependable
supplier, I spend between $2000 and $5000 per year on Mylar and that is
not enough to keep up the interest of the normal plastic film
converters. I can not buy direct from Dupont because they need an order
of about $5000 of each size before they will deal with me. The model
airplane usage will allow me to buy perhaps 100 pounds per year of most
sizes. I have my own slitter and roller and can deal with most anything
but the hit and miss suppliers are driving me crazy. So help out here,
where can I buy Mylar ?
Curt Stevens
Model Research Labs
25108 Marguerite #160
Mission Viejo, CA 92692
FAX (949) 248-1074
e-mail; This email address is being protected from spambots. You need JavaScript enabled to view it.
or curtstevens!@cox.net=20
Cold Rubber
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SCAT user wrote:
> Effect of Rubber Temp. (Peter King)
> ===================================
> Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
>
> It was interesting to see the problems associated with the 30gm motors when
> flying in low temperatures at the Scandinavian Comp. I ran some cases in
> the simulation program and the effect was not that marked, using the normal
> conversion factors for effect of temp.
It seems to me that Peter's results do not reflect the losses due to temperatur
e that are
actually seen with rubber motors. One of the symposiums had the results of actu
al testing
of rubber at various temperatures (was it by Fred Pearce?). The effect was very
pronounced. Perhaps Peter's temperature variables are not sufficient?
Tony Mathews
CIAM Meeting in Lausanne, Switzerland
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Dan Tracy gave a very complete rundown (SEN 686) at the meetings, both F1
subcommittee and the Bureau. I would like to mention that the definition of
the towline glider flag is for F1A and F1H. F1G does not use it.
The new class F1P has been developed for Junior use replacing F1J which has
become a bit unsafe for Junior class handling and flying. F1J remains for
Senior class flyers.
Bill Bogart
F1 Subcommittee member
San Valeers Annual
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Roger,
Did you get a e mail of our flyer for the upcoming San
Valeers contest on April 6 & 7th at Lost Hills from
Terry Kerger?
I just read your latest electronic news and did not
see it in there. I would sure like to see it in the
SCAT electronic news to help with notifying everyone.
If he didn't send it to you I can tell you what the
events are on each day.
F1A,B,C are on Saturday.
1/4A,1/2A,B,& C gas modern, slow gas and 1/2A
nostalgia are on Saturday also.
F1J,H,& G are on Sunday.
A/B/C nostalgia combined, A,D gas modern, Mulvihill,
HL glider are also on Sunday.
P-30 and Catapult glider can be flown on either day
but must be finished on the day started.
Junior events are catapult glider, hl glider,p-30 &
1/2A gas.
Hope everyone comes out to Lost HIlls that weekend for
a fun contest.
Thermals,
Terry Thorkildsen
More F1P Comments
=================
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As I thought more about this subject, more questions came up.
A problem that soon crops up is our (US) method of selecting the junior
team. Presently the F1J juniors fly against the older flyers to get the
required flight time. Now we have a new class that is totally
incompatable with F1J. 10 second engine runs and 3 minute maxes. Will we
have another class at every contest just for the two or three that will
compete nationwide? The logistics on this are more complex then what we
have now. If this is how it is going to be, then I guess that John and
Austin will stand a really good chance of repeating for the 2004 team.
Will we really see any increase in participation? Special models with
specific requirements do not increase flyer count. The present rules let
everyone with a 1/2A able to compete and we still didn't have many
modellers. Look at 1/2A participation at the NATS. We had one flyer in
Jr and only a few more in Senior. Plus, why did'nt every junior and
senior fly F1J since they already had the machine for the class? Making
a big airplane that won't fly in another class (except A Gas, but that
is still 7 seconds and 2 minutes) doesn't seem to solve the problem. WE
NEED TO GET MORE JUNIORS JUST TO FLY FREE FLIGHT!! This has been the
problem the last 10-15 years.
My son loves the high tech, high power models. He really enjoys flying
F1C. He likes the sound, speed, feeling of power (too much drag racing
in him!). Kids now adays (I sound old now) like to buy it, fly it, chase
it, instant gratification. I never thought I would say this, but F1J
allows buying a plane and being competitive and maybe it isn't a bad
thing. Is money a problem? I feel that most kids that fly are sons and
daughters of modellers. Because of this, many times the money is
available. I cannot speak for foreign modellers, but from what I see
here in the US it is true.
Can we solve the problem with a new class? Nope, but we can get more
kids involved. It takes a combination of parents, grandparents, and
mentors. Not easy, but it can be done. It takes time, patience, and
training. We all started somewhere. Maybe we need more advertising.
Problem is we are always out in the boonies and noone knows we are
there. When kids see the stuff fly, then they get enthused. Maybe we are
one of the best kept secrets in the world. When was the last time your
club asked a Boy Scout or church group out to the field to see us fly. I
know I never have, but when you get fathers and sons together, they may
click and see the sport for what it does. A static demonstration doesn't
accomplish this.
Well, enough of solving the world's problems. I still feel like a rookie
in this class, but we did jump in with both feet and we are running.
Finally, I would like to thank SCAT for making this forum what it is.
The time and money you guys put in makes this a better sport!!
John & John Lorbiecki
VD prop
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Roger:
Hope you enjoyed your trip to NZ. Sounds like the Russians have found the
place.
Saw the mention in today's SEN of Krebtov's VD prop (we may need to come up
with a better acronymn). Any additional info available? Photos?
Years ago Marjan Klenovsek sent me some drawings from a Soviet magazine of
two different VD front ends. Both were very incricate looking, and seemed a
bit on the heavy side. Is Krebtov sliding the blade as Perryman did some 30
years ago (his was spring-loaded and dependend on centrifugal force to
"throw" the blades to a higher diameter). The indoor F1D approach changes
the axis of the blade relative to the hub and seems impractical with an
F1B's higher loads.
Seems like there was a Meuser piece in one of the old Sympos on VD--but he
seemed to suggest that the change in diameter needed to be significant ie
30" going to 20" for cruise.
Also increasing the diameter will increase the pitch, if the blade angle
remains constant.
Thanks,
Louis
[Louis
Off the cuff I think that the diameter change was 28mm. Krebtov also
had a hub with both variable diameter and pitch. For sure
he did not use that one in the contest and I'm not sure about
the one with just the variable diameter.
]
Super Maxed
============
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Well I said it didn't I! So let's see sense and bin it before it does real
lasting damage. 12,000 miles to down under for that! NO! It ain't worth
the candle!
Michael J. Woodhouse, Norwich, UKFree Flight Supplies now has secure
internet credit card facilities.Free Flight Supplies is now Rapier powered!
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Web site: http://www.freeflightsupplies.co.uk
on 29/3/02 6:27 am, SCAT user at This email address is being protected from spambots. You need JavaScript enabled to view it. wrote:
> Comments
>
> Two excellent events run by Rob Wallace and Chris Murphy respectively. The
> turnout was a bit lower than last time, probably because of the World
> Champs being in the USA.
>
> One event - F1B in Kotuku cup turned like the FFSC intended with their
> super max. One one person who made the 5 min super max in F1B max
> the event so not flyoff was required. Note that Malkin who made the super
> dropped one second. As with the other event I've flown in the USA -
> the SCAT Annual that included the Super Max - the universal consenus amongst
> the contestants was disappointment and disillustionment.
>
> Those with simpler models that could not make the super max were bummed
> from the beginning. Those with the peformance models that made the super
> max but dropped later felt as if they had been ripped off. [applogies
> to those unfamilar with the coloqual expressions !]
Polypaper
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Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
The supply will continue, I have been selling for sometime with material
via Klaus. We (Klaus the mfgs, and myself) have got things sorted. I have
supplies on their way to me in sufficient quantity. A question: it would be
simpler to sell in half width rolls (50cm) is this a good idea? if so I
will explore how to get the rolls cut in half.
Michael J Woodhouse, Norwich, UK
Free Flight Supplies now has secure internet credit card facilities.
All mail to: -
web site: -
on 27/3/02 8:51 am, SCAT user at This email address is being protected from spambots. You need JavaScript enabled to view it. wrote:
Reid Simpson's MP JET .06 Engines for SALE
==========================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Right after Reid input the advertisement for the engines, he lost his
emailing capability. Anyone who emailed him regarding the engines
should email me at This email address is being protected from spambots. You need JavaScript enabled to view it. as Reid will be without email
until April 8th at the earliest.
Roger Simpson
Nos. rules!
===========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
I've found some good motors thanks to SEN and the helpful guys who follow =
it. I decided to build the T Bird in a variety of sizes. (any model that =
climbs to the left must be good!) In an article in NFFS about the T Bird, =
the designer suggested additional top wing spars, at 33% " and one in =
front" (of that). His drawing shows 2 spars, one at 33, and another at =
what looks like 20%. Don't the NOS. rules limit additional spars to no =
further forward than 33% of the wing, if the original had no turbulation =
spars?
I saw a picture of a fairly large T Bird with Monocote. Would this be =
stiff enough?
C class Nos. planes seem to vary in size from 650 (Jays Bird) to 800 =
(Spacer) sq. in. What would be a good size for CAT lll T Birds in B and C =
sizes? Could the same size plane work for a .29, and a .35?
hobby poxie clear epoxie paint.
===============================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
roger.
do you or maby some body else out there know where i
can get some hobby poxie clear epoxie paint.
i have tried several hobby shops and no luck.
thx don.
My email address and $EN
========================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Roger,
Please change my email address
from: This email address is being protected from spambots. You need JavaScript enabled to view it.
to: This email address is being protected from spambots. You need JavaScript enabled to view it.
Thanks,
Elmer Nelson
Phoenix
Question: How can we make a contribution to the upkeep of SEN?
EEN
[Elmer
Firstly this is a good example of how to tell me that your e-mail
address has changed. .. I do not normally publish the address.
Secondly you can give me money at any event I attend
or send a check made out to Roger Morrell
to
1916 B Gates Ave
Redondo Beach, CA 90278
typically people donate what they would for a print publications.
Note that SEN is produced to support FAI Free Flight. We do
not solicit contributions. ]
...................
Roger Morrell
