Since first starting with
control line model sin the late 1960s, I always intended to build a multi-engine
model of some sort, but didn't get around to it until around 2016 when I began
construction on a
Douglas DC-3 (maiden flight occurred in 2023). With the
plethora of ready-to-fly (RTF) and almost RTF (ARF) models on the market today at
very reasonable prices, there is no real good excuse for not doing it; so I'll have
to stick with my bad excuses. But I digress. This simple twin "Wee-38" Lightning
which appeared in the December 1959 issue of American Modeler magazine,
uses a pair of Cox .020 or .049 engines and solid balsa components. You could electrify
the model with equivalent brushless motors, ESCs, and a LiPo battery pack. It
would be nice if a series of ESCs would be marketed for twin motors, since
unlike with brushed motors, only one brushless motor can be connected to the ESC
output. The P-38 Lightning makes one of the nicer looking profile scale
subjects because of the twin tail booms and short fuselage. Wee-38
By Harry E. HarpsNow even us poor folks can afford to fly a twin-engine
control line plane and talk about piloting pleasure...!
There's something about the appearance--at a flying circle-of a twin-engined,
U/Control plane that will draw the attention of the most jaded enthusiast. Perhaps
the crowd gathers to watch the technique used to get and keep both motors going,
or maybe they congregate to absorb the music of two engines snarling in unison.
Whatever the reason - attraction and appeal are certainly there.
Sooner or later every fan of this round-about
sport has an urge to try his hand with a dual motored ukie. A profile model satisfies
the need for an easily constructed plane that is strong enough to withstand hard
landings. Given a careful application of sandpaper, filler and dope finish, details
and proper insignia, a good looking, scale-like appearance will result.
Power available determines size, which brings up the next problem. What power
should be used? A pair of oh-forty-nines is a logical choice, since their output
would equal that obtained from a single motor in the .074 to .09 range. Yet, the
Cox .020 Pee Wee is intriguing and a power-packed gem. There seems to be quite a
few in circulation. Who hasn't bought one just for kicks? Best of all, their small
backplate simplifies the mounting arrangement. Out of this cogitation came the tiny
P-38 Lightning.
First just a word about flight before we wade into construction. Flight handling
characteristics do not differ from those of an ordinary ½A ukie. Line pull is certainly
as great with the twenty-eight foot, nylon lines, and breezy days call for more
cautious flying as usual.
Building data on full size plans.
WEE-38 BILL OF MATERIALS
All sizes are in "inches" and material is "balsa" unless otherwise noted. One
1/32 x 2 x 3 for landing gear caver doors; (1) 1/16 x 3 x 8 for fins and stabilizer;
(1) 1/16 x 5/8 x 2 1/4 plywood for landing gear reinforcement patches; (1) 1/8 x
7/8 x 2 1/4 plywood for firewalls; (1) 3/16 x3 x 36 for wing, fuselage
and tall booms.
1/16 music wire for landing gear; .020 music wire for tall skids; .015 music
wire for leadouts; 1/32 music wire for pushrod; (2) 1" sponge wheels, (1) 3/4" sponge
wheel for landing gear; (8) 3/8" long 2-56 bolts for mounting motors; (2) 1" long
3-48 prop mounting bolts; (2) 1" prop spinners; (2) 3/8 oz. capacity fuel tanks;
(2) 4.4" D by 2.5" P props.
Misc: small bellcrank; alum. tubing; solder lugs; cloth hinges; gauze; filler;
clear and colored dope; fuel proofer; Pee Wee motors; lines; fuel and accessories.
Wee-38 Lightning Plans <click
for larger version>
Notice:
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.
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Model Airplane Plans.
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