HAVING received word of a new personal light
plane in the low-price field incorporating features only found in more
expensive aircraft, we made a trip to Teterboro airport in New Jersey to
have a look-see. One glance at the trim little silver-and-red ship
standing in the hangar aroused our interest immediately.
The clean design, with its plywood fuselage and retractable tricycle
landing gear, gives this single-place ship plenty of eye appeal. A
Lycoming engine furnishes the power and the low drag of the Mooney gives
it a maximum speed of 138 mph and a rate of climb of 1,300 ft. per minute.
According to Mooney Aircraft, Inc., the manufacturers, its take-off and
climb over an obstacle are superior by a large margin to that of any
personal airplane available today in its horsepower class.
From a model builder's standpoint, Mooney lends itself very nicely to
construction. Scaled at one inch to the foot, right from the factory
blue-prints, we came up with the ideal size for our OK Cub and found that
scale wheels and canopy, usually a bugaboo in a scale model, could be
purchased with little trouble at any hobby shop. At first glance the
canopy looked like a problem, but after trying a few different sizes, the
portion needed was cut from a standard five-inch bubble.
As for construction, select a very soft block of balsa l-¾" x 2" "x 17".
This forms the lower half of the fuselage, so trace the side view onto the
block and carve to shape. Do the same with the top view. Carve to the
outside shape, being careful not to dent or nick the sharp edges at the
top corners of the block. When satisfied with the carving operation,
proceed to hollow out the inside. Work toward a wall thickness of
approximately ?" except where the wing joins the fuselage and forward to
the nose. At the wing junction leave it about ½" thick, tapering gradually
forward to ⅛" at the nose.
Next add the V-shaped block at the tall that forms the stabilizer
mount. At this point you will have to install the bellcrank and the rest
of the control system. After the top shell is added, you can't get to the
innards. The stabilizer is cut from ⅛" sheet of light-weight balsa and
sanded to a streamlined airfoil. Cut off the portion that acts as the
elevators, round the cut edges of both stabilizer and elevators, and
re-assemble with cloth hinges. Two control horns must be used as shown to
get tree movement of the elevators.
The push rod is-made in three sections. Make certain that the two short
ends that form the "V" are identical in length. Use about .040" wire for
these parts and bend a small loop at the end of the push rod just large
enough to engage the loops at the ends of the "V" pieces. This connection
should be loose enough to allow free movement of all three pieces but not
so loose that uneven elevator travel results. Cut a hole on each side of
the tail cone so that the push rods pass through to the control horns
without rubbing. Install the entire control system and horizontal tail.
Add a balsa strip at the point shown to act as a guide to prevent any side
movement of the main push rod. This is very important so don't forget to
add it at this time.
Cut the three formers to shape and cement them in their proper
locations. The turtle deck is cut from 1/20" sheet balsa using the pattern
provided. By wetting the outside of the sheet and applying clear dope to
the inside, pre-bend the sheet in your hands until the sheet assumes the
curve needed. By using plenty of cement and pins and following the above
suggestions, you should have little difficulty joining the sheet to the
fuselage.
Add the rudder, which is cut from a sheet of
⅛" stock. The space
around the rudder where the turtle deck ends should be filled in with
scrap balsa. Use 1/20" sheet to fill in the space below the canopy between
formers #l and #t2 as shown. The firewall is cut from 1/16" plywood. You
will probably have to use the cut-and-try method to arrive at the shape
necessary for a good tight fit, and rather than remove a little from the
plywood, cut a groove into the balsa where necessary. Do not cement the
firewall in place yet.
Cut the fuselage away for the cylinder head and the crankshaft, and
hold the engine in place. Mark the mounting hole locations and remove the
firewall. Drill the holes, mount the nose wheel strut, using plenty of
cement, and bind with thread. Don't forget to drill a ¼" hole through the
firewall for the neoprene fuel line. Now cement the unit in place and
check, holding the engine in place, for a zero line of thrust. The engine
can be bolted in place now or added later, after the model is painted. Cut
the head off a 3-48 machine screw and cement and bind it in place
vertically to the rear of the firewall as shown. This screw should be just
long enough to protrude through the top half of the cowl with the nut in
place. This serves to hold the removable cowl top in place.
Now carefully sand the entire fuselage, removing any irregularities
where the turtle deck meets the lower half. At this point the fuselage and
tail surfaces are given a coat of filler and again sanded smooth.
BUILD the wing in two halves, allowing the leading edge to extend one
inch on each half as shown. Sheet the leading edge and capstrip the ribs
with 1/20" soft sheet balsa on the top surface only.
Next cut out the dihedral gusset and main landing gear mount from 1/16"
plywood. Cut a slot across the bottom of the fuselage so the gusset fits
snugly and flush with the bottom of the fuselage. Cement and bind the main
gear to the plywood as shown. Now cement the plywood into the fuselage to
receive the one-inch extension of the leading edge so that they too will
fit flush.
Although the ship has quite a bit of dihedral, note that the center
section is straight across the bottom at the trailing edge. To gain this
appearance, we used a piece of the tapered trailing edge stock 2" long
also recessed into the bottom of the fuselage. Now join the two halves to
the fuselage and don't spare the cement. With the wheels in place you
should have 4⅛" dihedral from the ground line to the wing tips. When the
wing is firmly cemented in place, cut the leading edge away at the
dihedral joint until it is flat across the bottom edge. Using 1/20" balsa,
sheet the center section both top and bottom as shown. Cover the bottom of
the wing with lightweight Silkspan from the third rib out to the tips
before applying the balsa sheet.
Now using the patterns, cut out the wing fillets 1/20" sheet for the
two main fillets and light Bristol board for the others. A real super job
with rivet detail and all can be done if light shim brass is used instead
of the Bristol. It can be cut easily with scissors and the rivet detail
can be applied by simply pressing a small blunt nail against it from the
underside. Just apply enough pressure to form the rivet head but not
enough to puncture the brass.
Cover the top of the wing and add some of the scale details such as
scoops, inspection plates, hatch slides, etc. Dope the inside of the
cockpit and engine cowl, using a bright red fuel-proof dope. Add the
instrument panel and the bubble canopy.
As stated previously, the entire ship is painted silver with bright red
trim. Tester's silver "Hep" was used. To get a smooth finish with silver
without using a spray gun has been a problem until recently. If you have
had the same trouble, follow these simple instructions: First brush on a
good coat of the silver. When dry, spray on a very thin coat with an
ordinary Flit gun. This thin coat is perfect for removing the brush marks
and streaks that always seem to spoil a silver paint job. Remember to keep
this last coat very thin so that it comes out of the gun in a fine mist.
A simple, way to mask the bubble while spraying is to wet a piece of
Silkspan and lay it on the bubble. The soggy Silkspan will stick firmly
enough and prevent any spray from sneaking under it. The aileron and flap
lines go on with a ruling pen and India ink.
The Mooney emblem on the fin is finished in the following colors: Red
"M" with blue outline; white ellipse with red outline; wings blue in front
portion with blue outline around white rear portion. |