Here is an interesting little 1/4A free-flight model. The round
wing planform is unique enough, but what I really like is the s-curved
airfoil formed into the balsa sheet wing. Designing and test flying
these kinds of models with unusual construction techniques often
takes a lot of time and effort by the designer. It is really good
old seat-of-the-pants aircraft development. Whether it be flying
Snoopy dog houses, witches on broomsticks, or flying saucers, there
is always someone out there willing to put the work into making
those kinds of models fly.
Website visitor Lieven Merckx, of France, was kind enough to
send me these photos of the 'Flying Sorcerer' that recently he built.
Depron corrugated plastic was substituted for the original balsa
wing. The heavier weight of Depron necessitated more counterweight
ahead of the center of gravity, so Lieven made good practical use
of it by adding a wheel.
At the bottom of the page are a couple close-up photos and a
video of the first flights. Notice
how each flight improved as Lieven made trim adjustments. Free flight
is the one realm of model aviation that requires a good working
knowledge of aerodynamic in order to achieve a good combination
of powered and unpowered flight. He noted that these flights were
made 45 years after the article's appearance in the September 1970
edition of American Aircraft Modeler.
Do you believe in flying saucers? Now you can -this one's
for real, an 020 free flight.
Jack Headley Photos by Author
AFTER some years of study, the Air Force apparently has decided
that flying saucers really don't exist. Perhaps they should have
paid more attention to Southern California before making up their
minds, because flying saucers have been seen there for quite a while.
Of course, these saucers are not too big and don't fly too long,
so possibly the Air Force can be excused.
These UFO's are in reality models, the latest version being the
Flying Sorcerer. Earlier models were powered by various-sized engines,
including one Jetex-powered version. Then there was the model known
as the Flying Pizza because of an unfortunate color scheme composed
mainly of yellow and red!
Before beginning construction, it is especially important to
study how the various pieces are cut from sheet wood. The following
materials are needed: 2 pieces of 3/32 x 4 x 36" balsa; 1 piece
1/4 x 2 x 18" balsa; 1 piece 1/8 x 1 x 1" plywood; 1 piece 1 x 2"
gauze; and 4, No.2 x 3/8" wood screws.
Take the two sheets of 3/32" balsa and select the harder. This
is the sheet to use for the front and back pieces of the wing and
for the fins. To get the shapes correct, put the wood under the
plans and , with a pin, prick through the outline of the shape onto
the wood. Next, using a ballpoint pen, join the marks. Mark all
the pieces before beginning to cut the balsa.
When assembling the few parts involved, fuselage
and rudders hold wing's curved airfoil. Use lots of glue and pins
at these joints.
When everything is laid out and all the various pieces have been
fitted onto the sheet stock, cut out the pieces with a single-edged
razor blade. Check these pieces with those shown in the photo to
make sure all the required ones have been cut.
Pin down the plans on a flat board, cover with wax paper, and cement
together the four balsa pieces to make the circular wing. While
this is drying, the engine mounting can be fixed to the fuselage.
Cement the small blocks of balsa to the nose of the body (these
blocks can be built up from scrap pieces of 1/4" sheet if no block
balsa is handy). When the blocks are dry, sand the nose pieces flat
and cement on the 1/8" ply engine mount. It is best to leave this
to dry overnight.
When both assemblies are thoroughly dry, the wing can be cemented
to the body. It's a good idea to draw, with a ballpoint pen, the
three lines on the top of the wing. They indicate where the wing
is placed on the body and where the fins are located. The fins can
be attached now, making certain they are lined up straight before
the cement dries. Next, add the remaining pieces of 1/4" sheet for
the canopy. Suddenly, it's almost finished!
Let everything dry before going over all the edges with sandpaper.
The final task is to cement a strip of ordinary gauze bandage to
the firewall and around the nose block. This reinforces the engine
mount. Use wood screws to mount the engine.
Simple markings made with paint, decals, and
marking pens turn it into a USAF-type plane. Model must be painted
for fuel protection.
Give the completed model one coat of clear dope and, after this
dries, sand lightly and put on one more coat of clear. Sand again,
then put on the color dope. Do this very lightly; too much weight
will reduce the model's performance. The prototype was sprayed silver
and a few decals added to dress it up. The markings also can be
applied with colored felt pens.
Check the balance when the model is completed. If it does not
balance at the point shown on the plans, add a little modeling clay
at either the front or back until it does. Then try a few hand launches
into some long grass. A nice smooth glide is required. If it dives
too fast, bend the back of the wing up a little. If it stalls, bend
the back of the wing down. When it seems about right, attempt a
power flight with the engine at low power and the propeller on backwards.
If the model climbs to the right, everything is fine; if it flies
straight or to the left, put a small washer under each engine mounting
screw on the left side. This will make the engine point a little
to the right and should make the model climb properly. Glide can
be trimmed finally by small adjustments to the back of the wing.
After a few flights at low power, try putting the propeller on
the correct way and opening up the engine a little more. The model's
performance is excellent, so don't forget to attach your name and
address. They may be needed!
<click for larger version>
The AMA Plans Service offers a full-size
version of many of the plans show here at a very reasonable cost. They will scale the plans any size for you. It is always
best to buy printed plans because my scanner versions often have distortions that can cause parts to fit poorly. Purchasing
plans also help to support the operation of the Academy of Model
Aeronautics - the #1 advocate for model aviation throughout the world. If the AMA no longer has this plan on file, I
will be glad to send you my higher resolution version.