Small-Field Flying - 2012/02

Also included in this column:
• Small-field Pitts
• Another Pat Tritle classic
• RC Micro World
• Reader thoughts on scaling-up
Comet designs
item. It has evolved since that first model,
and has become the heart of many smallfield/
indoor projects.
For many, the choice of an AR6400
series brick system is for an indoor flier.
That trend is seeing a bit of a shift.
Although the early RTF models using the
system were probably best flown indoors,
the manufacturers are offering more models
that can be flown outdoors. The AR6400
has been refined to create a broad
application environment for smaller
models.
The revolution of the AR6400 series
brick system has made the world of design
and build-your-own small-field models
much richer. The AR6400 has inspired
other manufacturers to develop compatible
offerings that work well for indoor models,
The SPeKTRUM AR6400 Series:
Indoors or out in the wild blue? When the
ParkZone Cessna RTF model was
introduced, the world of smaller RC model
airplanes was forever changed. That neat
little package included the early Spektrum
micro-brick receiver.
It was not long before the enterprising
builder began to extract the Cessna receiver
and power system for scratch-built or
converted lightweight FF models.
Thankfully, Spektrum began selling the
receiver/ESC/servo brick as a stand-alone
Paul Bradley | bradleyp@Small-Field Flying ix.netcom.com
The Spektrum AR6400 brick receiver revisited
but are also great for the smaller, outdoor
model aircraft. Just to wet your whistle a
bit, let me share some projects from two of
the regular contributors to this column.
I will begin with a nice model developed
by Gordon Johnson. I previously shared
with you his lightweight structure approach
in the February 2011 edition of the column.
He has developed an outdoor small-field
Pitts. It is a profile foam model with some
nice refinements. A Spektrum-compatible
receiver from Deltang, available from Bob
Selman Designs (see the “Sources” listing),
controls his creation. The receiver is
compatible with the ParkZone servos used
with the AR6400.
Gordon’s Pitts has a wingspan of 19
inches. The wings are wire-cut foam from
Indoor model wizard Gordon Johnson’s 19-
inch Pitts is for outdoor flying.
John’s model is a good example of how the Spektrum
AR6400 receiver brick can be used for scratch-built
outdoor models.
The brains of Gordon’s Pitts are
supplied by a Deltang DSM2-
compatible receiver and ParkZone
servos.
John Krouse delights us this month with
a small-field climb-and-glide model.
February 2012 89
02sig3.QXD_00MSTRPG.QXD 12/16/11 1:54 PM Page 89Flyingfoam.com. The wings are a
departure from the more typical flat-plate
type we see on so many small, profile
foam models. These wings have a Clark
Y profile, which contributes to the
model’s flying performance and provides
more strength.
Along with the Deltang receiver and
ParkZone servos, Gordon used a Mighty
Midget brushless motor that is driven by
a two-cell 250 mAh LiPo battery pack.
The all-up flying weight is 91 grams, and
Gordon reports that the model is a great,
outdoor small-field flyer.
To take this discussion in a different
direction, let’s look at a model from John
Krouse. John has developed a fine, smallfield
climb-and-glide model. His aircraft
powers up to a comfortable altitude when
the motor is shut down and flight gliding
commences. This is a great way to enjoy
some thermal hunting within the confines
of your small-field venue.
The model is all balsa and features a
26-inch span, single-surface wing. All
controls of John’s model are handled by
an AR6400 brick system. The built-in
ESC controls a 7mm Super Slick
brushed motor that is coupled with a
Gary Jones 4:1 gear drive turning a
GWS 5030 propeller. The source for all
of the equipment is BSD. The energy
source is a single 160 mAh LiPo cell.
Total flying weight is 48 grams.
John says the model is stable,
responsive, and fun to fly. He notes that
the fun factor is really pushed up after
the power is cut and you encounter a
passing thermal.
These are two great, small-field
models that give us a look at what is
possible with the AR6400 and related
systems for outdoor models.
I would like to address general-aviation
aircraft and small-field Scale models. I
have been fortunate to share some
general-aviation-based Scale models that
are perfect for the small-field flyers. The
designs of the full-scale airplanes tend to
translate into great model airplanes.
A good friend to small-field flying,
Pat Tritle, has created some general
aviation aircraft-based model airplane
kits. I am happy to report that he has
added a new one to his lineup. I have
included a photo of the model series
170.
That general-aviation aircraft is a real
classic and is one near and dear to many
full-scale airplane owners and pilots. As
is typical of a Pat Tritle design, it is light
for its size. At 1:8-scale, it falls into the
larger side of the small-field spectrum.
The wingspan is slightly less than 54
inches, but it has a flying weight of only
23 ounces. Once again, we have that
wonderful combination of a light, but
larger size, model.
Control functions include throttle,
rudder, elevator, ailerons, and flaps—acomplete control package. Power for
Pat’s prototype model comes from a
Suppo 2217 (950 Kv) brushless motor
turning an APC 10 x 5 electric propeller.
Two 2,000 mAh LiPo cells comprise the
battery pack.
Pat notes that flying qualities of the
model are excellent, with good response to
the flaps. He says that it is a stable, docile
flyer, but is responsive and positive on the
controls. Short kits are available. Nice
work, Pat. See the “Sources” listing for
Pat’s Custom Models.
There is a great plans resource for smallfield
flyers. I have often written about
online resource, RC Micro World
(RCMW). That publication was started by
the late—and significant—contributor to
this hobby, John Worth.
John passed away in late 2011 and will
be missed. Fortunately, he made
arrangements to keep RCMW operating by
transferring operations to Roland Friestad.
As a result, this valuable resource can
continue into the future.
I wanted to mention RCMW because it
has been going through some delivery
changes. Roland has been working through
some online issues that are now resolved.
This is a first-class publication for those of
us who like to include smaller models in
our hangars.
A nice feature of RCMW is you can
now view all issues for free. However,
there is an annual subscription fee to
access full-size plans.
I have included a couple of photos of
Bob Aberle’s 200-square-inch Anderson
Pylon. Full-size plans for that model, and
many others that are perfect small-field
flyers, are available for download with a
paid subscription. See the “Sources” listing
for contact information.
I want to share the specifications for
Bob’s Anderson Pylon model. The model
has been reduced from the original 1937
90-inch span to 36 inches, yielding a wing
area of 200 square inches. It has a flying
weight of 7 ounces. Power comes from an
eFlite Park 250 brushless motor driven by
a two-cell 800 mAh LiPo battery pack.
I want to revisit Comet designs as scaledup
small-field flyers. Before closing, I
would like to share some feedback I
received about my October 2011 column.
Reader Al Hieger liked Pat Tritle’s
scaled-up Comet Gull II. He said there are
other models in the lineup of classic Comet
designs that would be good candidates for
similar treatment. He mentioned Sparky
and Phantom Fury, for example. I can
vouch for those designs. Pat Tritle has a
55-inch short kit available for the Sparky. I
have also seen the Phantom Fury done in a
similar size range.
Al is right on the money when he says
the old Comet designs make great RC
small-field flyers when scaled up. Perhaps
this could be a project for one of you to
take on and share with the rest of us.
I guess this is a wrap for now. Don’t be
bashful about sharing your latest project.
My contact information is in the “Sources”
listing. MA