Old-Timers - 2011/06

126 MODEL AVIATION
A Southwest Regionals report
Old-Timers Bob Angel | [email protected]
Also included in this column:
• Scaling plans
• Escapements
• Making small wooden
wheels Dick Nelson preps his FF Powerhouse. That white plastic stand
pivots, allowing a model to be stored nose-down as it weathervanes
into the wind. Caley Ann Hand photo.
Steve Moskal’s patriotic Brooklyn Dodger won the electric Limited
Motor Run event at the 2010 Southwest Regionals. The Dodger is
one of Sal Taibi’s best-known designs. Doug Klassen photograph.
Fred Foster and friends fly in close formation as they help
him locate his RC-1, which was lost in the sun for a moment.
Fred won the Southwest Regionals Texaco event.
I ATTENDED THIS year’s Southwest
Regionals, which is held in Eloy, Arizona,
each January. The FF and RC sides of the
expansive field are thoughtfully separated by
almost a half mile, for safety. The FF venue
sees higher attendance because it incorporates
several modern events along with Society of
Antique Modelers (SAM) Old-Timers (OT).
The RC site is strictly SAM OT RC.
I was busy flying and timing OT RC, so I
spanned the gap only once, to observe the FF
action and attend the open-air swap meet. The
swap meet is similar to a flea market, with no
charges to the seller or buyer. The sellers
provide their own setup and tables.
The swap meet is a good place to pick up
hard-to-find kits, plans, engines, and other OT
supplies. I came back with another engine that
I couldn’t do without.
• FF with RC assist
• US Free Flight
Championships
• Flying Aces Club
06sig4.QXD_00MSTRPG.QXD 4/20/11 4:46 PM Page 126
A highlight on the RC side is the
Saturday-evening outdoor social hour,
featuring a campfire, barbecue cookout, and
self-provided musical entertainment. Dick
Griswold, the late SAM western-region vice
president, hosted the gathering for years.
This year his widow, Ann Maly,
generously stepped in to fill the void, with
lots of help from friends. We enjoyed ideal
weather and some great desert sunsets.
Caley Ann Hand took many pictures,
including the one shown of Dick Nelson’s
Powerhouse. But she’s also an enthusiastic
modeler, who entered F1G—one of the FAI
events.
She was one of five in a field of 12
competitors who completed five max flights
to put herself in the flyoff. Caley said that she
surprised herself as well as the others by
winning the event.
Al Lidberg, who has managed the
Southwest Regionals for several years, has a
great website with complete results of all
classes and a large album of excellent
photographs. There are reports not only of
this year’s events, but also of each contest
from the last 10 years. The address is in the
“Sources” listing.
Scaling published model designs to different
sizes was done often in the early days. The
main reason was that engines were relatively
expensive and prized possessions.
Few aeromodelers owned them, and those
who did usually had just one. In some cases a
model club jointly owned an engine that was
swapped in and out of various models that
individuals built. So published plans were
often enlarged or reduced to fit the power
plant on hand.
If you double the wingspan of an airplane,
the wing area increases by squares to four
times the original. Wing area is the more
important dimension to consider when
scaling; as it increases, the required
horsepower goes up even faster. But that’s
another subject.
We use a simple formula to arrive at the
wingspan and other dimensions needed to
change to the wing area selected. The formula
produces what’s called the “scale factor.”
This can be used as a multiplier to arrive at
the new span, along with any other
dimensions of the new-size model.
You start with the wing area (in square
inches) of the plans to be scaled and with the
new wing area you’ve chosen. To get the
scale factor, you divide the square root of the
desired area by the square root of the area of
the original plans.
If you’re scaling the original size larger,
the scale factor will be a number greater than
one. If you’re shrinking the size, the number
will be a decimal smaller than one.
In either case, you can multiply the
wingspan and every other dimension to arrive
at the new size. But few of us are into
drafting, so you can take the original plans to
a good copy shop to get them shrunk or
enlarged to the desired wingspan.
Escapements were used for flight control in
June 2011 127
BMJR Model Products
• Original Design by: Jerry Stoloff, 1944
• 46" wingspan, 307 sq" wing area
• For 1/2A or Electric Texaco
• Original design by JASCO, 1952
• 32" wingspan, 170 sq” wing area
• For 1/2A Early Nostalgia
Box 1210 • Sharpes, FL 32959-1210
321-537-1159 • www.BMJRModels.com
$9200
+ postage
Send $2.00 for 2011 22 page catalog or go to www.bmjrmodels.com
STREAK SWAMI
$3600
+ postage
the early days of RC, before servos came into
use. Raymond Tinley of Mt. Prospect,
Illinois, sent me a package and a brief
description of escapements, including a CD
with four photos of an escapement
demonstrator he built. Since this column has
a three-photo limit, I’ll forgo the pictures and
give you a brief description.
Model escapements operate similar to
those in mechanical clocks, watches, and
other timepieces. But a wound-up rubber
band, rather than a heavier spring, is normally
used for power.
A radio pulse activates a relay
(electromagnet), which trips a rotary
mechanism to advance one notch for each
pulse. Every notch moves a control in a
different direction. The whole thing operates
in a loop, finally cycling back to neutral.
Simple escapements operated only the
rudder, full right, full left and back to neutral.
But later, more sophisticated versions
operated multiple controls. Raymond
describes his mock-up demonstrator as
follows.
“Probably most of the R/C’ers today have
never heard of or seen an escapement, so I
thought it would be interesting to show how
they worked. The planes we used them on
would pretty much fly themselves, so all we
were doing was to get them back without
running after them.
“I use an old single channel Min-X
transmitter and receiver on 27 MHz to
operate the escapement. One pulse and hold
on the transmitter releases the rubber band
wound escapement and it stops at the first
position which moves the rudder to the right.
A second pulse and hold moves the rudder to
the left and a third pulse and hold kicks the
elevator up. No down elevator. With no pulse
from the transmitter, everything goes back to
neutral.”
Thanks, Raymond.
Those early transmitters had only a single
push button for control—no sticks. Timing of
the pulses and holds was the key to it all. As
escapements became more developed and
complex, pilots were able to do amazing
aerobatics with just that push button.
Bill Schmidt is a prolific builder and
innovator. He forwarded me a shortcut
method that he often uses to make wooden
wheels for small models.
He visits the section of home-building
supply stores, where various wooden drawer
pull knobs are displayed. By choosing
rounded knobs of the appropriate diameter,
he has only one side to shape.
Bill carefully saws off the unneeded
portions on the backside of each knob. The
screw holes are already centered, so it’s
necessary only to drill and fit small screws or
dowels to allow rounding and finishing the
second sides in a drill press or lathe.
The final step is to fit the center hole to
the proper axle size. A glued-in dowel can be
drilled out to size, or in some cases a small
piece of tubing may be installed.
“RC assist” has become an obsolete term in
the SAM rule book. Anyone who has
watched a hot RC competition model climb
out, shut down on command, and bunt over
06sig4.QXD_00MSTRPG.QXD 4/20/11 4:49 PM Page 127
128 MODEL AVIATION
into a glide can’t deny that the models are
under full RC control.
The rule book was purged of the word
“assist” sometime ago, although the word
somehow snuck back into the RC nostalgia
event. But the term could be introduced
again, because a few FF fliers have found a
sane and practical use for a simple engine
cutoff.
When a powerful FF model takes to the
air and is obviously looping out of control,
the situation rarely results in a happy
ending—let alone a max flight. With the
widespread use of 2.4 GHz radios, it’s now
possible to initiate engine cutoff under these
conditions, often saving the flier grief while
not interfering with regular RC operations.
If this simple safety measure becomes
common for FF, there will be little or no
effect on competition as long as rules void
the flight whenever RC cutoff needs to be
activated. There would be little effect even if
the flight wasn’t voided. A few purist FFers
might be horrified by the thought, but the
practice is sensible enough to prevail in some
form in the long run.
A similar step has already been taken
toward improving safety for SAM FF. A rule
was voted in last year to allow (not require)
the use of 2.4 GHz (only) radios to activate
DTs. According to one knowledgeable FF
CD, this was done solely to “reduce
excessive chases and reduce fire danger.”
That rule allows an FF model to complete
its flight uncontrolled as long as it’s not too
YS Parts and Service
www.YSengines.net
1370 Porter Drive • Minden, Nevada 89423
Tel 775-267-9252 • Fax 775-267-9690
• Bigger cylinder head for better cooling
• Three needle carburetor
• Same mounting pattern as the YS50ST
• New regulator design for ease of operation and reliability
• Proven fuel injection system for a consistent run & power
• Same mounting pattern as the FZ63S
• NEW steel lined backplate to minimize drag resulting in
better performance and increased horsepower
• NEW piston/sleeve design increases effi ciency
boost for more power
• Same mounting pattern as the FZ110S
!"#$%
& %'$()*
+,"#$%
!-'
./01
213/4567'
869/04:./4
;6</'41:4
='>3/%?
!-'!-'
./01./01
• Proven regulated fuel system for positive fuel fl ow
+,"#$%+,"#$%+,"#$%+,"#$%
• NEW larger cylinder head for better cooling
& %'$()*& %'$()*& %'$()*& %'$()*
• New regulator design for ease of operation and reliability
• Ring sealed crankshaft to increase crankcase
!"#$% !"#$% !"#$% !"#$%
Bore: 30.4 mm
Stroke: 25.8 mm
Displacement: 18.73 cc
Weight: 730 grams
Bore: 27.7 mm
Stroke: 19.0 mm
Displacement: 11.33 cc
Weight: 463 grams
Bore: 27 mm
Stroke: 26 mm
Displacement: 14.89 cc
Weight: 553 grams
Bore: 23.0 mm
Stroke: 22.0 mm
Displacement: 9.14 cc
Weight: 406 grams
windy and the airplane is staying reasonably
close to the field. But if wind and thermals
threaten to take it into the next county, it can
be safely brought down early.
Since it wouldn’t be prudent to DT with
the engine running, it would make sense to
allow early engine shutdown as part of the
process. This would be needed only if a
model were out of control. Otherwise the
engine would have quit through onboard
timer action well before DT action might
have been needed.
The 41st annual United States Free Flight
Championships is scheduled for September
23-25 at Lost Hills, California. The
“Sources” section includes websites you can
visit to learn about the airfield and the
contest.
The multitude of events each day is
separated into Modern, Nostalgia, Classic,
and Old Timer. Depending on your age and
outlook on life, the Nostalgia and Classic
events might be considered Old Timer as
well.
Ted Firster will be the CD for this event.
See “Sources” for his contact information.
Flying Aces Club President Ross Mayo
has sent out updated contacts for the
organization. See “Sources” for the
website address; go there for current
information. MA
Sources:
Southwest Regionals:
aalmps.com/swrintronu.htm
Society of Antique Modelers
www.antiquemodeler.org
Ted Firster
[email protected]
Lost Hills:
www.lhffmaa.com
United States Free Flight Championships
http://bit.ly/h6Fa8G
Flying Aces Club
www.flyingacesclub.com
06sig4.QXD_00MSTRPG.QXD 4/20/11 4:49 PM Page 128