Old-Timers - 2011/04

134 MODEL AVIATION
TWIN-PUSHER RUBBER designs dominated early modeling
competition. Later, Vernon Boehle and others showed that singlemotor,
rubber-powered airplanes could also be competitive.
In the early quest for performance, little attempt was made to
copy full-scale aircraft. Then, as gasoline power became practical,
more models began to sport a scalelike appearance, including cabins
and windows in their design.
Pylon models appeared in the late 1930s and immediately did
well in FF competition. They featured a wing mounted above the
engine thrustline, atop a streamlined pylon support. Pylon aircraft
aren’t intended to resemble full-scale aircraft, and that fact bothers
some Old-Timer (OT) aficionados who much prefer “cabin” models.
However, as a kid in a rural area, my first acquaintance with
models was through an article in Popular Mechanics that featured
mostly photos of Pylon models. So I like ’em.
FF trimming experts credit the superior flying qualities of Pylons
to the effects of propwash against the side of the pylon, plus other
characteristics. I like
to think that I
understand while
they’re reciting it,
but I’d have a hard
time explaining it to
others after they
were finished.
My simplified
take on the design is
that the fuselage is
similar to a
pendulum hanging
below the wing,
making it more
stable in glide—
especially as an FF
model. And because
the early gasoline
engines often
performed with
erratic power output,
pylons helped
maximize climb rate.
If engine power
drops during climb,
the aircraft reduces
its angle of attack
instead of stalling
and simply climbs at
a slower rate that is
appropriate to
reduced power.
Conversely, if power
suddenly increases,
that low-mounted
engine rotates the
model to a higher
angle of attack for
steeper climb.
The Cleveland
Model Company
kitted the Playboy
series of Pylon
models. Joe Elgin
Left: Ladislav Kulhavy
presents his beautifully
constructed Falcon
at a SAM Chapter
122 contest in
the Slovak
Republic. Lubomir
Hrncar photo.
Above: This is how a Playboy looks. (The model, that is—
not launcher Alan Douglas.) Mark Venter took this photo at
last year’s New Zealand Nationals.
From twin pushers to Pylon models
Old-Timers Bob Angel | [email protected]
Also included in this column:
• Cleveland, Joe Elgin, and
Playboys
• The art of soldering
• Drilling propellers
• International SAM
• Vintage glory days
• Model Builder magazine
Above: Gino Gazzea launches his 1949
Astrale glider at a SAM Chapter 2001
meet in Rieti, Italy. Sergio Montez put
the author in touch with photographer
Eros Cavallaro for this nice shot.
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April 2011 135
worked for Cleveland for a couple of years
and designed/drafted the Playboy Senior,
the follow-up Playboy Junior, the Baby
Playboy, and other of the company’s
designs.
Thousands of Playboys have been built
throughout the years. They have always
been successful in their particular class of
competition.
Few modelers knew the Cleveland
designers’ names in the early days,
because owner Ed Pachasa didn’t allow
them to sign or identify their artwork. Joe
always regretted that fact.
But in later years, most OT modelers
have become well aware of the man who
designed the Playboys. Joe was treated as a
celebrity at Society of Antique Modelers
(SAM) Championships, and he was often
invited to autograph Playboy wings.
As a concession to those aeromodelers
who prefer Cabin models, Joe was asked to
design a Cabin version of the Playboy. He
did so by adding a few outlines to the basic
pylon plans. The builder was left to work
out the fine construction details, which
most OT modelers can do successfully.
Joe Elgin was born in 1920 and was
raised in Cleveland, Ohio. It was more
than a coincidence of residence that landed
him a job with the model company; he was
a successful competition modeler, both
before and after his stint with the firm.
Along with engine-powered flying, he did
well in international Rubber competition.
During World War II Joe was a
navigator on a B-17, surviving 19
missions. His bomber was eventually shot
down, and he spent a couple of years as a
prisoner of war. While imprisoned, Joe
built flying models with the few materials
available, using lots of ingenuity. He
passed away in 2002 at the age of 82.
Soldering is one of the skills that many
OT modelers need—especially those who
use spark-ignition engines. Think of it as
an art form.
Some people produce clean, neat,
shiny, compact joints, while others
produce lumpy, dull blobs. I don’t claim to
be a member of either camp in order to
comment.
Nicer-looking joints generally perform
better, with fewer intermittent problems or
complete failures. Numerous articles are
published about soldering, so I’ll limit this
discussion to a few pet items I haven’t
seen mentioned elsewhere.
When butt-joining two stranded wires
end to end, a couple of methods are
usually described: laying the bare ends
parallel to each other or laying them
parallel and then twisting one or both
around each other. I prefer a more compact
joint, which is also more efficient at
minimizing current loss.
I strip, clean, and prep the wires by
dipping the ends in an electronicscompatible,
nonacid liquid flux. Then, if
necessary, I splay the wires a bit before
pushing them straight together, so that the
individual strands are interlaced. The
resulting soldered joint is much more
compact, and that is especially noticeable
beneath heat-shrink tubing.
Soldering articles instruct you to heat
the workpiece to be soldered to
temperature and then apply solder to the
item—not the iron. That’s sound advice,
but sometimes it doesn’t work.
You’ll encounter situations in which
there isn’t quite enough contact area
between iron and workpiece to achieve a
melting temperature. In that case, almost
all you can do is use a small blob of solder
on the iron as a heat conductor to start the
process.
The trick here is to feed just enough
solder to the iron or workpiece while
judging when you have a sufficiently hot
joint. Remember that it’s an art form.
I’ve heard that manufacturers that still
require hand-soldering often prefer women
workers. That’s because the women they
hire are trainable; most males are positive
that they already know how to solder.
Drilling propellers for large engine shafts
is another thing we all know how to do, right?
But as usual, there’s a right and a wrong way.
Dick Fischer wrote the following about the
popular OT McCoy engine:
“I learned something interesting about
APC props which I’ll pass along.
“I was concerned about drilling out a
prop for the McCoy 60. The hole diameter
needs to be large at 7/16 inch. I called APC
Tech Services to ask how big the hole
could safely be. The guy said that 7/16 inch
would be OK structurally, but I should be
aware of how the props are balanced.
“An APC prop has a boss on the back
side of the hub, and the hole in the front is
a little crude. The boss in back is
‘precision molded’ and provides the
centering on the shaft. The front hole may
be uneven.
“So if you drill out the prop large
enough to obliterate the boss in the back,
which 7/16 will do, then you should first
carefully locate the center of the boss and
be sure to maintain that center. And
whatever you do, don’t begin drilling or
run a prop reamer through from the
front.”
I’ll add a bit to Dick’s and the APC
technician’s story. The blades on APC
propellers project forward beyond the
mounting surface for the front propeller
washer.
Therefore, you can’t merely lay the
propeller on its face on a drill press table
and drill accurately. You need to place a
small piece of wood (having parallel top
and bottom surfaces) supporting that front
washer mounting surface, to avoid a
wobbly drilling job.
A stepped reamer used from the back
would be best, but propeller reamers are
seldom that large. I prefer replacing the
McCoy .60 drive parts with a Fox
propeller extension set (part 6545); that
leaves a much healthier propeller, having
only a 3/8-inch hole.
But the Fox drive spool needs a 1/16-
inch-wide slot filed inside with a tiny file
to fit the McCoy drive key. I use an old
automobile point file. The aluminum spool
is easy to file.
SAM International: SAM was founded in
the US. But the idea has such universal
appeal that there are approximately 35
international chapters. The photos in this
column are from outside the US.
Each year there is a Euro Champs, which
moves from country to country. This year’s
venue will be San Marino, Italy, and the
contest will take place June 22-26.
“Glory days” is the theme for a
noncompetition fun-fly that will be held at
the Old Julian Airport in Julian, North
Carolina, on May 21-22. Any model that
was designed, built, or had plans published
on or before 1976 is invited—along with
their owners, of course.
Vintage RC, CL, and FF will be
featured. The approximately 100-acre site
will have two or three CL grass circles,
along with an all-grass runway and a 60 x
30-foot asphalt takeoff ramp.
The announcement came from CD Bob
Harris, who reported that organizers were
still in the planning stages as of December
2010. Today’s activities are tomorrow’s
history, so you might want to attend this
inaugural event. Keep watching for
updates via the AMA “Contest Calendar”
and the sources listing.
Model Builder magazine, which is now
out of print, has been transcribed in its
entirety as a two-DVD set. Roland Friestad
has copied every issue from cover to cover
(approximately 35,000 pages) and is
selling the indexed set for $75 postpaid.
This is an amazing amount of history
and construction expertise in its most
compact form. MA
Sources:
Propeller extension sets:
Fox Manufacturing
(479) 646- 1656
www.foxmanufacturing.com
Vintage Glory Days:
Bob Harris, CD
[email protected]
Old Julian Airport
www.oldjulianairport.com
2011 Euro Champs:
www.antiquemodeler.com
Roland Friestad
(309) 342-7474
Society of Antique Modelers
www.antiquemodeler.org
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