Free Flight Sport - 2004/06

146 MODEL AVIATION
IN THE LAST 10 years a variety of small electric motors have
been introduced that are just right for small FF models. HiLine and
Kenway offer several motor/battery/propeller combinations that
make it easy to get started.
Several years ago I saw a picture of one of the Guillow’s 900-
series kits that had been converted to electric using the HiLine
Micro 4 motor system. I had the 905 kit, which was the Mustang, so
I gave it a try. It was a nice flier—at least until it flew into a nearby
creek. In retrospect, the Mustang was not the ideal choice. Because
of its relatively long nose, the motor’s weight required that I place
the two-cell battery as far back in the fuselage as it would go.
I recently decided to try another of the Guillow’s series 900 kits:
the Skyraider. Dave Rees told me that this model would balance
with the two 50 mAh batteries just behind the wing. This proved to
be true. The Skyraider went 30 feet high and flew roughly 45
seconds on its first flight. I built the model basically per the plans
using the kit wood. I did delay gluing in some of the top formers
until the motor, switch, charge jack, and battery were installed.
I installed the Micro 4 by cutting a hole the size of the motor in
the front former. I pushed the motor far enough forward that the
propeller would clear the plastic cowl ring. I also angled it for 3° of
downthrust and 3° of right thrust. I used medium cyanoacrylate glue
to secure the motor. Take care, because a drop of cyanoacrylate in
the wrong place could ruin the motor.
Another modification was to put an extra center strip in the fin
Gene Smith, 1401 N. Husband St., Stillwater OK 74075; E-mail: [email protected]
FREE FLIGHT SPORT
The Monsoon Clipper is a little-known Jimmie Allen model. Build
one and be the center of attention at the field.
Bob Schlosberg’s Cleveland Viking looks gas powered, but the
engine cylinder is for looks only; it has electric power.
Ferrell Papic’s neat Hawker Sea Hawk uses a 3-gram RC unit to
reverse the motor as an effective dethermalizer.
Lucas Carlson shows good launch technique with his Blue Ridge
Special. His first version was lost out of sight.
06sig5QXD 3/24/04 11:47 am Page 146
and stabilizer so that the elevator and rudder could be made
adjustable. Floral wire or the wire from a twist tie make a good
hinge. As it turned out, the elevator needed no adjustment and the
fin adjustment was too sensitive. If I were to build another (I have
the Trojan and Typhoon kits), I would make a small adjustable
rudder tab instead of hinging the entire rudder.
The plans show a large amount of dihedral. This is very
important. It looks a little funny but is critical for easy trimming of
the model.
The kit-supplied tissue has little or no wet strength, so I attached
it dry using a glue stick. I then shrunk it using a mist of water
followed by a heat gun. Wet and shrink both sides of the wing or
tail surfaces at the same time to avoid causing warps.
I cut out some of the paper lettering and markings and applied
them to the model. I used light gray acrylic paint to cover the white
plastic cowl and the canopy framing. The final finish was a couple
light coats of Krylon Crystal Clear spray.
Flying starts with a preflight check in the shop. My Skyraider
balanced at the front top wing spar. This was slightly forward, but
it’s better to have the CG a little far forward than too far back. I
elected to leave it there, and that has worked well for the first
flights.
Sighting the wings, I found a little washin of the right wing (the
trailing edge of the wing was lower than the leading edge). The left
wing was flat. Electrics are notorious for high initial torque. This
would tend to make the model roll left. Left torque coupled with
washin of the right wing would have been a recipe for disaster. The
first flight would have been a quick left roll into the ground.
Pulling out my trusty heat gun, I alternated heat between the top
and bottom of each wing, twisting a trace of washout into the left
wing and 1⁄16 inch of washout into the right wing. This allowed the
left wing to have a bit more lift than the right wing and counteract
the motor’s torque.
After selecting the proverbial field of tall grass, I put a 30-
second charge on the batteries and launched the Skyraider straight
into the wind. The model climbed rapidly to approximately 15 feet,
and then it made a turn to the left and several left circles as it caught
a bit of light lift and headed downwind. Once the battery ran down,
the descent was rapid, as one would expect with this model’s high
wing loading. But that is what I wanted: a neat-looking small-field
flyer.
Bob Schlosberg powers his 36-inch-span Cleveland Viking with a
HiLine Dual Mini 6 and three 150 mAh batteries. The model
weighs 176 grams and uses a 6-inch Peck-Polymers propeller.
Although the Viking is capable of consistent two-minute flights,
Bob uses a timed charge to limit the motor run so that flights
average a minute and a half. Longer flights would probably lead to
the model’s loss since it has no DT. The model flies with a left-left
pattern. The cylinder is from a Cox .020 but is for looks only. Bob
uses a digital readout charger that is powered by his van’s 12-volt
system.
You can control the length of your motor’s run by using a
shorter charging time. This has the disadvantage of providing less
than full power at the launch. Another option is to use a motor
cutoff. HiLine sells a neat lightweight timer that can be adjusted
with a potentiometer. You can fully charge the motor but limit the
run time. Call (919) 778-6653 for information.
I received a nice note from Ferrell Papic, who has built quite a few
small electric FF models. Because the new Li-Poly batteries power
these aircraft for such long periods of time, he has equipped his 16-
inch-wingspan 1911 Cessna and 17-inchwingspan
Hawker Sea Hawk with a remotecontrol
motor cutoff and DT. The RC unit
can shut the motor off or, for DT action, put
it in reverse! Now that will bring your
model down!
For 16- and 17-inch-span models, Ferrell
likes the KP-00 3-volt motor and gearbox
with a U-80 propeller, from John Worth,
Dave Lewis, or your local hobby store.
Ferrell had a nice article in the February
2003 MA (“Cessna No. 1”) with an
exploded view drawing of an electric motor
and gearbox for 22- to 28-inch-span models
that works well on 8.4 volts with a 6-inch
GWS propeller.
The weight penalty for the remotecontrol
motor cutoff and DT is 3 grams, and
the remote-control transmitter, receiver, and
electronic speed control is only $14 at the
local hobby store.
I met Lucas Carlson and his dad John at the
Society of Antique Modelers
Championships last summer. Lucas was
having a blast flying his Blue Ridge Special
in the 100° heat. He got to visit with many
experienced modelers including George
Reich, whose Double Feature was flown in
a special event at the Champs.
Unfortunately I was unable to get an onsite
picture, but John sent me a photo of
Lucas that was taken under better weather
conditions. The Blue Ridge Special is no
longer kitted. Similar good fliers are the Sky
Bunny by Peck-Polymers and the Cloud
Buster by Guillow’s.
Little-Known Jimmie Allen Design: Be the
first kid on your block with a Monsoon
Clipper; I am told that this is actually one of
the Jimmie Allen model series. You can
obtain plans from Graham Knight in
England. E-mail him for the price and
shipping costs at [email protected].
Memories ... A friend sent me an E-mail
about some model plans that are available
on CD. I have more model plans than I
could build in another lifetime, but that is
beside the point. There are 10 CDs currently
available. They contain articles and plans
from old model magazines.
The individual CDs include topics such
as CL models, engine reviews, and FF
models. Of interest to FFers are volume #9
containing SAM Antique and Old Time FF
Gas (291 models), volume #10 containing
SAM Nostalgia FF Gas (264 models), and
the FF Rubber disc due out this month. Each
CD is $10 postpaid in the US.
I bought the Nostalgia Gas CD. Talk
about a trip down memory lane! I had to pry
myself away from the computer so I could
get back to the shop. This thing is habitforming.
Contact Thomas Wilk at 301 W.
Redwing St., Duluth MN 55803, or E-mail
[email protected] for a complete
listing.
NRG Wins at KOI: Bob Hanford’s NRG
design for Nostalgia Rubber and Nostalgia
Wakefield won both events at December’s
King Orange meet. See the April FF Sport
column for a source for plans. MA