Free Flight Sport-2011/11

132 MODEL AVIATION
Also included in this column:
• Bill Schmidt’s MiG-15
• Drapery ring motor bearings
• Karl’s Stringless Wonder
• Dave Mitchell’s Half-Wake
[[email protected]]
Free Flight Sport Gene Smith
Doug Beardsworth’s Diels Bf 109
IN MY SEPTEMBER column, I featured
Doug Beardsworth’s Spitfire. This column
features his Diels Bf 109 Emil. It was
constructed from the Dave Diels kit which
is based on Doug McHard’s excellent plan
in Flying Scale Models of WWII.
Doug wanted something slightly
different, so he chose the desert
camouflage scheme used by
Jagdgeschwader 27 (JG 27) during the
North African Campaign. The colors were
sprayed using the plasticized nitrate dope
base, with Floquil model railroad colors
blended in. The finish added
approximately 2 grams of weight to the
Emil.
The kit decals were used for the
crosses. The JG 27 Afrika decals were
from a Techmod Decals set made for a
1/24-scale plastic model of a Bf 109 G. The
fuel marking triangles and fuel filler caps
from that set were also used. There are not
many decals offered for 1/24-scale plastic
kits, but those available can provide nice
authentic markings.
After flying the Bf 109 at the 2008
Flying Aces Club (FAC) Nats, Doug
picked up several tips that helped his
building and flying. One was to change the
motor peg location. The following winter
he moved the motor peg forward by a full
2 inches. The same motor length was used
but with more braided turns to prevent
slack.
This resulted in two improvements. He
was able to remove 2 grams of lead ballast
from the nose and eliminate the fouling of
the motor against the formers as it
unwound in the narrow rear part of the
fuselage. Those two changes helped the
Emil go.
If one planned to fly using a 15% motor
(a rubber motor weighing no more than
15% of the model’s empty weight is
required in some FAC events), the peg
could be moved forward to a point above
the wing’s TE and still have plenty of
hook-to-peg distance to manage that motor
length.
Doug found that two loops of 3/32 for a
model of this size and weight will fit nicely
into a 5- or 5½-inch hook-to-peg length.
With more radical repositioning of the peg,
one should be able to remove another gram
or so of nose weight.
With the gear down and dirty, this will
never be good for long flights, but the
model flies pretty consistently for 30 to 35
seconds. It is set up with typical trim
settings for a left-hand pattern—more
washout in the right tip than the left, left
rudder, and finally left- and downthrust to
suit the power.
Power has been two loops of 3/32 FAI
Super Sport. The empty weight of Doug’s
Emil is now at 26 grams. If one used
chalked tissue instead of paint, built light
aft of the CG, left off the landing gear, and
used a forward motor peg, this kit could
come in at the 20-gram range.
The propeller is made from three blades
of Peck-Polymers 6-inch propellers. The
blades were thinned considerably by
scraping them with a sharp, single-edged
razor blade held vertical to the long axis of
the propeller. They were separated at the
center, leaving a 120° portion of the plastic
bearing attached to each blade.
Right: Karl Geis photographed his
Stringless Wonder. The kit is simple to
build, flies great, and is one of his favorites.
This beautiful MiG-15 is built from Dave Livesay’s
design. Bill Schmidt photo.
This Messerschmitt Bf 109 with desert
camouflage was built from a Dave Diels
kit. Doug Beardsworth photo.
of 1/8-inch braided rubber and an 8-inch
propeller. The propeller was removed for
the picture. This design is a challenge to
trim for flight, but it can fly well.
November 2011 133
The blades were glued to a plywood
backplate for the spinner. A brass tube
with a ramp-type freewheel was used for
the spinner bearing. Doug reinforced the
joint of the three blades with small
patches of 0.5-ounce fiberglass cloth
and CA glued the blades to the brass
bearing and the plywood backplate.
Doug believes the real magic for the
durability of this propeller has been the
thinning of the blades. He can fly it over
relatively short grass without breaking
the propeller.
Doug rates Dave Diels’ kit as superb,
with lightweight wood and great 1940sera
decals. If Doug were to build the
model again, he would make the
changes noted. This model has good
duration potential. He would love to do
another one in early Battle of Britain
colors and enter it in FAC World War II
Combat.
The Diels Bf 109 kit is currently out
of production, but Dave still sells the
plans and may have some parts. He can
sometimes be persuaded to make a run
of a kit if there is enough interest.
Contact Dave for information.
This is the year for Bf 109s and MiG-
15s. One of the photos shows Bill
Schmidt’s version of Dave Livesay’s
1992 MiG-15 design. The model spans
20 inches, is covered with Polyspan
Lite, and finished with nitrate dope. The
rubber-powered model uses four strands
Howard Littman was kind enough to
send a useful tip for those who like small,
rubber-powered models. He has been using
¼-inch plastic drapery tieback rings for
Dave Mitchell’s Half-Wake stands out in its bright
chartreuse Easy Built tissue. The laser-cut kit is available
from Easy Built models. Mitchell photo.
The U-shaped motor hook with
an O-ring is simpler to bend and
faster to hook up than a reverse
S-hook. Howard Littman photo.
Dave generated this neat
paper “decal” for his
model using computer
graphics. Mitchell photo.
Howard has flown two models with this
setup and it seems trouble-free. This setup
is what Howard will use from now on,
when he doesn’t use a GizmoGeezer front
end.
Karl Geis sent me some pictures of his
Stringless Wonder built from a Peck-
Polymers kit. It looks like a cross between
a small kite and a flying wing. It is simple
to build and flies well so you might want
to pick up a few kits for yourself and your
grandkids.
The Peck line was purchased by A2Z
Corp., which is now producing the kits
with laser cutting and excellent wood. You
can find most of your favorite Peck-
Polymers kits at A2Z.
Many years ago Northrop sponsored a
flying wing contest. The Stringless
Wonder won the event once or twice
before being disqualified because it was
“not really a flying wing.”
There is a new FAC event for half-size
Wakefield models built and flown from
1937 through 1953. These models have
roughly 50 square inches of wing area—
slightly larger than an Embryo.
Dave Mitchell built his eye-catching
Half-Wake from an Easy Built kit. For the
initial test flights he used four strands of
1/8 x 25 inches to turn a Peck propeller.
Dave’s model required a lot of negative
stabilizer incidence (roughly 3/16 inch) and
1/32 inch of more positive wing incidence
than shown on the plans.
With the wing in the forwardmost
position, the model balanced at
approximately 45% of the wing chord. The
day of initial tests there was too much drift
for full power, but the Half-Wake attained
good altitude on limited winds. The glide
was respectable but not great. That may
have been because of drag from the
decalage.
Dave discovered it was very important
to have the stabilizer/rudder assembly
keyed in position. Initially, the model flew
erratically, often resulting in a steep right
spiral dive under power. Dave keyed the
stabilizer, which prevented the rudder
from getting out of alignment. Rules for
the Half-Wake event are on the FAC
website.
If you live in the Dayton, Ohio, area,
check out the McCook Field FAC
Squadron. It is an active group that holds
several contests each year, both at home
and at the AMA flying site in Muncie,
Indiana.
Take a look at Hobby Specialties. It
specializes in hard-to-find items for the
Scale, Sport, and Duration Free Flight
modeler, including inexpensive viscous
DTs, quality balsa-strip wood, carved
balsa propellers, and fine-spoked wheels.
The items are produced by an aeromodeler
for aeromodelers.
Bob Langelius Sr. has reintroduced
several of the old Blue Ridge Models kits
including the Square Eagle, a simple-tobuild,
but great-flying P-30. The new kits
are laser cut. Contact Bob at Pal Model
Products for pricing. MA
Sources:
Diels Engineering, Inc.
[email protected]
www.dielsengineeringinc.com
Flying Aces Club
Half-Size Wakefield
www.flyingacesclub.com/halfsized
wake.pdf
McCook Field FAC Squadron
[email protected]
www.mccookfieldfac.com
Hobby Specialties
[email protected]
www.hobbyspecialties.com/index.php
Pal Model Products
32 Clinton St.
White Plains NY 10603
[email protected]
A2Z Corp
(877) 754-7465
www.a2zcorp.us
bearings on the motor peg end of his
motors for years. These rings provide all
the benefits of a bobbin, but are much
simpler and easier to get the peg through
when changing motors. Howard tried
using them at the front end, but they
climbed a conventional propeller hook.
They work with a Z-bend hook but it is
bulky in a tight nose and is a trick to bend
properly. The first one Howard bent from
the instructions in the article looked
beautiful, but was left-handed. (Been
there, done that!)
One of the Blacksheep members, Matt
Payne, turned his engineer’s eye to the
problem and decided that the simplest
solution was best. He bent an elongated
hook that was the same width as the
drapery ring. With the ring hooked into it,
a simple universal joint is formed and
that’s it—almost. As the motor went
slack, the ring would move forward and
pop out of the hook. Matt solved that
problem by braiding the motor to avoid
slack.
Howard found another solution for
those who don’t braid their motors or for
those who like the “belt-and-suspenders”
approach. He bent a detent into the hook,
roughly a ring’s width from the back of
the hook. The ring snaps into place when
the motor is hooked and will not come out
when the motor goes slack.