April 2001 109
cybeR-Flying ReviSiTed: I received some good
feedback on the January 2000 column feature about
practicing racing flight using the Great Planes flight
simulator.
Alert reader Jim Skolmowski of Toledo, Ohio writes:
“Thanks for the advice on setting up a racing machine. My
sons and I have been cyber-flying to get ready for next year’s
round of club contests. We do the SuperTigre .40 engine thing
at Toledo Weak Signals.”
Jim reminded me that Great Planes offers an “Add-Ons”
CD-ROM with additional airplanes and fields to try. I
purposely didn’t mention that, because the pylon course
included was less than satisfactory.
However, Jim managed to get around the problems. I’ll turn
the description over to him.
“Give this a try. Select the Canyon Pylons as your field.
Under ‘Options,’ where you select background features such as
buildings, etc., select ‘Pylon short course.’ I find this works
best for my purposes.
“By now you are saying, ‘Yes, I know, but you have to fly
from the right of pylon 3.’ Not true! Taxi out between pylons
2 and 3 and near the cross-runway. Point your zoomer toward
pylon 1. Hit the F4 key (only once) at this point and take off.
“At first, until you take off, the view will appear as though
you are in the cockpit. However, once you hit the gas you will
find that your position is now between pylons 2 and 3 with
your aircraft zooming away.
“You have to experiment with the positioning a bit before
hitting F4 to get yourself where you like to be. Now crash that
thing or hit the space bar, and you will find that on your next
takeoff, you are still positioned between the pylons but taking
off from the runway to the right. You remain positioned
between the pylons until you exit out from the session.”
Duane Gall, 1267 S. Beeler Ct., Denver CO 80231; E-mail: [email protected]
RADIO CONTROL PYLON RACING
Stu McAfee (L) fires up the Stiletto while Chip Hyde holds.
Lou Rodriquez and Gary Schmidt make last-minute adjustments.
“If you can hear this, put in your earplugs.”
Nobuyuki Chujo’s model with birdlike wing and tail, working
retracts. Mabo Amano photos from F3D Team Trials.
Thanks, Jim!
When I tried Jim’s method, I learned
that the screen image would shimmy or
appear “scrambled” when I hit the F4
key, but would immediately smooth out
once the simulated airplane started
moving forward.
I don’t know if that’s unique to my
computer, but don’t be alarmed if it
happens on yours.
The Skinny on Hinges. I’ll continue
with another letter. Denny Wann, aka
Speedy Gonzales, writes, “What kind of
hinges do you recommend for flying at
200 mph?”
After choking down the urge to say,
“Thank you for thinking I have ever
gotten anything to go 200 mph,” I was
able to collect my wits enough to pen the
following response.
For hinges on high-speed airplanes,
the “skin hinges” on modern composite
Quickies and Quarter 40s are ideal.
These are where the fiberglass skin on
one side of the premolded surface acts as
a hinge, and the skin on the other side is
cut away to allow free movement.
The resulting slot is usually covered
by a strip of Mylar™ tape that is
adhered to the back side of the slot and
tucked under the skin at the front edge.
This allows air to flow smoothly over
the slot, rather than burbling up into it
and causing drag.
With or without the cover over the
slot, skin hinging seals the hinge line so
air can’t get through it—not only
reducing most of the drag, but greatly
reducing the tendency of the surface to
flutter at high speed.
The premolded airplanes use at least
two-ounce glass cloth for the skin—
usually more.
You can duplicate this on a built-up
airplane by laying up a strip of two- to
four-ounce glass cloth and epoxy resin
on one side of the surface, and cutting
away enough of the wood on the other
side to allow it to swing back and forth
the necessary amount—10-15° on most
airplanes.
Those who use MonoKote® or similar
iron-on coverings can apply the covering
directly over the smooth side of the hinge
(i.e., the top if you’re talking about
ailerons or elevators), making the hinge
line all but invisible.
If you’d rather use conventional
hinges, space them closely—say,
roughly every three inches. The flexible
plastic kind, especially the ones with a
frosty coating that adheres well with
cyanoacrylate glue, are the best.
When you’re finished installing the
hinges, bend the movable part of the
surface as far as you can one way and
bridge the hinge gap with clear vinyl
tape. Then slowly bring the surface back
to neutral, while working the tape into
the gap with your fingernail.
My preference for tail surfaces is to
make my own prehinged balsa stock,
then cut the tail feathers from the stock.
It’s simple; laminate two layers of light
balsa with a layer of two-ounce glass
cloth, and epoxy resin between them.
For 1⁄4-inch-thick tail feathers, use 1⁄8
light balsa on each side of the glass
cloth. Create the hinge line by routing a
slot in the balsa, down to the glass cloth
(stopping just short of the glass cloth);
or if you can think that far ahead and
keep all the pieces in alignment, you can
make the hinge line while laminating the
stock.
To do that, put small “crumbs” of 1⁄16
balsa between the edges of two sheets of
balsa when you do your lamination. The
crumbs act as spacers, creating a hinge line.
Cut away the crumbs, and your custom tail
stock will flex at the hinge line.
Whenever you use fiberglass cloth as
a hinge, orient the fibers on the bias; that
is, at a 45° angle in relation to the hinge
line. That way, all the fibers will
contribute to the strength of the hinge
and it will bend more easily without
fatiguing the fibers.
Return to the Planet of F3D: Last month I
promised you results of the F3D (Fédération
Aéronautique Internationale [FAI] Pylon)
Team Trials, held November 11-12, 2000 at
the Speedworld R/C Flyers site in Phoenix
AZ.
I’ve included some photos, courtesy of
Mabo Amano—the “M” of H&M Racing,
Inc. and host of a fun racing Web site:
www.superminnow.com.
There were 14 official contestants
and six “guest fliers,” consisting of the
current World Champion Chip Hyde and
members of Canadian, Japanese, and
Mexican teams.
Contest Director Stan Douglas
organized the pilots into two matrices of
two-airplane heats.
This was helpful, because it
minimized the chances of midairs
(according to FAI rules, it is not the order
of finish but the elapsed time that counts,
so head-to-head competition is
unnecessary) and gave a little extra time
between heats for those who needed it.
Most competitors did.
F3D airplanes are high-maintenance
beasts. If nothing else, the typical pit
stop consists of changing the glow plug,
cleaning and checking the pipe
connections and hold-downs, and
refueling. This requires removing the
cowl—that is, roughly 1⁄3 of the
fuselage—and reinstalling it with tape
covering all the seams before the next
flight.
Even with all this attention, there
were more than enough flameouts to go
around. Self-unscrewing glow plugs
were my bugaboo; other fliers had
melted-down pipes caused by inefficient
cooling or erratic runs caused by overor
under-compression (head spacing).
Precontest rumors had most of the
entries equipped with retractable landing
gear. However, by Friday, the second and
last practice day, the pits were a sea of
upside-down airplanes with retract bays
hastily covered with balsa and tape, and
fixed gear bolted on in place of the
retract units.
Even with the wheels up and locked,
it’s next to impossible to keep them from
peeking out during a high-gravity pylon
turn. Apparently the stopwatch showed
enough of a disadvantage from that to
overcome the drag reduction in the
straightaways, so most competitors went
back to fixed gear.
The only one who was able to use
retracts to advantage was Nobuyuki
Chujo of the Japanese team, with his
elegant lavender and white model (see
photo).
My setup, which employed backwardretracting
wheels that stayed up on
landing, finally got beaten to pieces on
the runway after approximately the fourth
round, so I also got out the wrenches and
surrendered.
The predominate aircraft designs were
the German Dago produced by Christian
Wolf (not to be confused with a Dago
Red P-51); the Pole Duster F3D produced
by Jim Katz; the good old Stiletto P-51
design, produced by Gary Hover; and
Bruce de Chastel’s radical bird-winged
Evolution.
All but one contestant used the
Nelson front-intake, rear-exhaust (FIRE)
.40, and the exception was notable.
Henry Bartle, teaming with Bruce De
Chastel and flying an Evolution powered
by the Metkemeyer (MB) FIRE from
Holland, set the fast time of the meet at
1:01.22.
The next-fastest competitor was
defending World Champion Chip Hyde,
with a Nelson FIRE-powered Stiletto at
1:01.82.
The MB has a big, square venturi
opening you could lose all your pocket
change in, and it loves rpm. Bruce De
Chastel made propellers for it that
measured seven inches in diameter and
spun at roughly 28,000 on the ground.
He promised the engine would unload
better when it was fully broken in!
The group of first-time, returning, and
veteran fliers provided an interesting mix
of results. Among the new F3D
competitors, Bob Smith placed first in the
contest, Ray Brown made second
alternate, and Darrol Cady had too many
“goose eggs” to qualify.
Among those returning from mentalhealth
breaks, Stu McAfee took second
place, Henry Bartle took third, and I
provided cannon fodder.
Veteran and former World Champion
Richard Verano was edged out by less
than four points (that is, less than four
seconds total elapsed time after 10 rounds
of flying), to rank as first alternate.
Complete results can be viewed on
Mabo Amano’s Web site. MA
110 M ODEL AVIATION
