cub.pdf

NATIONALS

FLYING SCALE

WINNER

A good flying scale job should

be easy to build and fly. This

Cub model has got everything.

BY ROGER HAMMER

PLANS BY PAUL PLECAN

FLYING scale models have always been

popular, especially among beginners, since they

look so much like their prototypes. If one should

look at the list of entries at the National meet,

however, he would undoubtedly think that flying

scale model builders are few and far between.

Such is really not the case. Many model builders

who attend the Nationals each year have built

and flown flying scale models, yet they seem to

forget that particular type when building their

ships for participation in the annual brawl.

Why? The answer is simple. A model builder

thinks that he has to have something more or

less exceptional if he is to place among the

"big-name" builders, so he thinks of a very clean

design that will take a lot of time to build. In

doing so, he does the reverse of what he should

do. The correct way of going about this flying

scale business is to choose a simple, easy--

to-build and easy-to-fly model, and to make it

strong. The strength is very important if the

model is to stand up under all the abuse a flying

scale model is subjected to when testing and

flying under adverse conditions. The Taylor Cub

(the 1937 Cub, then manufactured by Taylor),

while not as clean as some military designs,

makes up for this by its strength, which is almost

unbelievable. The square fuselage construction

allows as much strength as in a cabin type

fuselage of the same size, permitting the use of

a powerful motor for top performance.

If you have intended building a flying scale

model for a forthcoming contest, consider the

Taylor Cub. Its fine performance in almost every

flying scale meet entered, and proven stability

when built as

The original Cub model had to be packed in a

small model box, therefore, the wing and wing

struts were made so that they could be removed

at will. This is not necessary if you have the

room to stow away a three-foot model in your car

or model box. After you have read the building

instructions and looked over the details on the

plans, you should try to remember to use heavy

balsa in the front of the model and medium balsa

in the tail surfaces, so that the model will not be

as tail-heavy as the original. Since the model has

to weigh at least 5-1/8 ounces, it is best to put

some of the weight into the fuselage and landing

gear structure.

The main fuselage structure should be made

first, by building both sides of the fuselage right

over the fuselage side view drawing. While the

sides are drying, the cross braces should be cut

to double the length shown in the top view, as

only the right half of the fuselage is shown. Since

the bottom of the fuselage is perfectly flat behind

the landing gear, the cross pieces should be

inserted in place after the two sides of the

fuselage have been pinned down to a drawing

similar to the top view drawing. The rear cross

braces should be cemented in place first, and

after nearly the whole fuselage is complete, the

front part should be cracked slightly ahead of the

landing gear portion, and cemented.

Note that the sides "toe in" quite sharply here, so

reinforce this part with a few extra coats of

cement. When applying formers F1 and F2 to the

top of the fuselage, note that F2 is slanted

forward. After the fuselage frame has dried and

the stringers behind the wing portion have been

added, the front should be covered with 1/32"

sheet. Do not forget to cover the fuselage bottom

up to the part where the rear landing gear strut

meets the fuselage. In making the landing gear

strut fittings, use wire about .049" in diameter

and brass or aluminum tubing that fits snugly.

After the small lengths of tubing have been

cemented to the fuselage, they should be

reinforced by cementing small staples in place.

Remember that the celluloid in the side windows

should be cemented inside the cabin, after the

balsa has been color-doped.

In making the landing gear strut, the following

method should be used: Bend the V-shaped part

fist, and bend in the upper ends. Insert these

upper ends into the short lengths of tubing on the

fuselage, and build up a triangle of balsa to fit

inside the strut. After cementing well, the strut

should be covered with silk. Balloon-type wheels

should be used for maximum shock-absorbing

qualities, but the landing gear can take any

shocks by using the rubber band spreader in the

center. The band should consist of about five

small loops of 1/32” rubber inserted in the

hooked end of each axle bar and passed through

the V strut that has its ends cemented to the side

fuselage longerons. The axle bar should be bent

at the tip to retain the wheel, but a neater

appearance can he had by soldering a washer in

place. An ordinary bushing is cemented or

soldered in place on the other side of the wheel.

The nose block should be carved out of a small

hard balsa block, and the cylinder details added.

The cylinders are merely 5/16” dowels wrapped

with thread, and the cylinder head is 1/16" sheet

balsa cut to the shape shown in the side view of

the fuselage and covered with lengths of thread

arranged horizontally. The engine, gas gauge,

and air intake tube should be added only after

the fuselage has been doped.

The details are all black, and should be

cemented in place after they have been

color-doped. The nose plug should be a snug fit

so that it doesn't drop out of place in flight due to

a slack motor. The rubber tensioner may or may

not be used, according to the weight of the

finished model. If the model is too light when

weighed with the motor, prop and all the parts

assembled, a tensioner device should be added

so that a longer motor can be used to bring the

model up to weight rule. No instructions will be

given concerning the construction of the tail

surfaces, as they are of simple flat construction,

utilizing 1/8" sheet outlines and 1/8" by 1/16” ribs

and spars. Most of the wing is given full size, and

all that is necessary to complete it is to cut the

plan at the proper place and separate the two

parts until the space between the innermost ribs

of each section is 9". This space should be

divided into six spaces of 1-1/2" each,

completing the layout of the entire left wing

panel. Note that the end of the wing spar is

tapered, allowing the tip portion to be built at a

slight dihedral angle.

If it is not necessary to remove the wing when

transporting the model, the wing can be

cemented in place permanently and the wing

struts cemented in place also. If the wing is to be

made removable, the wing struts should have a

tubing and wire arrangement whereby they may

be slipped into place for flying and slid off when

the model is ready to be packed away. The

motor should not have any slack if the model

comes up to weight rule when assembled, as a

tight motor has much more power than a loose

one. If the model is too light, the rubber tensioner

device should be used. On the original, it was

necessary to add 8" of slack rubber to bring it up

to weight rule. A small amount of clay was

placed in the nose also, as the wing could not be

moved for adjustments. A motor consisting of

sixteen strands of 1/8" should give this model

enough pep to get it upstairs in a hurry. A

freewheeling of the Garami type should be used

to extend the glide to the best angle possible.

The Cub should be adjusted to fly in right circles

under power and in the glide. Well your model is

finished, so-happy landings!

Scanned From April 1940

Air Trails

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