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Airplanes and Rockets visitor
Steven S. wrote to ask that I scan the article for the
Quarter Pint and
So-Long free flight models
that appeared in the April 1972 American Aircraft Modeler. The Quarter Pint, a basic
free flight nitro model, gets its name (partly) from using a 1/4A engine (Cox .020).
Here is Steve's completed Quarter Pint. Per his letter: "As a teenager I bought
many issues of AAM. I built 'Quarter Pint' from the April 1972 issue and 'So-Long'
from the June 1972 issue.
 Every so often I try and find any
info on the magazine or plans so I could build them again nearly 42 years later.
What a treat to find your website and see the covers of those magazines. I remember
them like it was yesterday. I want to build these two planes again. I remember in
high school enlarging the planes using an overhead projector for Quarter Pint, I
couldn't wait to order the plans but did order the planes for So Long. Of course
I had the tank full and seemed the engine ran forever. I still have the engine from
from QP after all these years but So Long lived up to its name and flew away never
to be seen again on its first flight."
"I finished Quarter Pint with "Coverlite" by Coverite, a heat shrink dope &
tissue substitute, works very well. Modeled by my lovely wife Jocelyn. I will install
the correct engine (a Cox Pee Wee .020) I won eBay soon as it arrives (here it is). Fun little project. "
See more photos of Steve's Quarter
Pint below, as well as his Bee-Tween,
Ace Whizard, Simple
Citabria, Simple Duster,
Quarter Pint,
So-Long, and
Ace Pacer models..
For the Tenderfoot:
Quarter Pint
No matter how you launch this shrunken old-timer, it gets into a right spiral
climb followed by a long easy glide.
By Paul Denson.
 While looking for ideas for a sport plane, I
recently ran across the article "Famous Free Flights" in the 1964 American Modeler
Annual-a concise history book, full of ideas for sport free flight. I first considered
Goldberg's "Zipper," but the thought of covering those elliptical wings with tissue
caused me to turn pale. Then I saw Lou Garami's "Half Pint;" and those lines punched
my aesthetic button. Using what I could see from the small side view, I made the
original drawings for Quarter Pint. Since it uses a 1/4A engine, what name could
be more appropriate than Quarter Pint? However, considering the proposed change
from the English to the Metric system, I thought I might call it .125 Liters (1/4
pint in the Metric system), but someone might have thought I was talking about the
displacement of a foreign sports car.
Quarter Pint is not intended to be an exact replica of "Half Pint." It was originally
designed as an RC single-channel RO, but I found cramming all that gear into a plane
this small to be quite a headache. After watching it fly, I was glad I decided to
eliminate the RC gear and make it free flight.
I started with a side view of the fuselage and made it square rather than diamond
shape for ease of construction. By rummaging through the extra wings that always
seem to survive the crashes, I found the top wing of a bipe that had been built
some time previously. This gave me the dimensions for the pylon; from there. it
just naturally fell together.
Big air wheels are 2" in diameter. Balsa equivalents could be
made if desired (as these provide low-down drag needed). Don't substitute smaller
or thinner wheels.
This is Steve S.'s present day ¼ Pint sporting a Cox PeeWee
.020 and balloon wheels, like the original.
A hypodermic syringe is useful for putting about one cc. of fuel into the tank.
Crank it up using a 4D-2.5P Cox .02 prop and fling it away in any direction-into
the wind is usually best. It flies straight out about 30 to 40 ft., gains speed,
then climbs up as if it is going to loop. On top of the loop, it rolls out into
a steep right-hand turn and climbs until it runs out of fuel. At this point, it
makes a transition to a large left-hand circle and floats flat-out much like a Nordic
glider. I have never used a dethermalizer, because the motor run has been so
short that it never gets high enough to catch a thermal. (I know, famous last words.
I heard of a fellow who lost a plane OOS at 35 min. on a test glide!) The fuselage
could be left uncovered just above-the stab and the top longerons used as it stop
for a pop-up stab dethermalizer.
Construction
The construction is straightforward and should pose no problems even to the beginner.
The wing is built flat in one piece, leaving the two center ribs unglued. Put the
bottom sheeting down first and build on it. The leading edge, spar and trailing
edge can be cut in half, beveled slightly, and one tip elevated three in. Glue the
wing halves together using a piece of 3/8 x 1/16 ply laminated to the spar to make
a strong dihedral joint. Cover the top of the wing with 1/16th sheet balsa, and
add the wing tips made from soft 1/2" balsa. It is now ready to be sanded and covered.
The rudders and stab are cut from appropriate thickness of sheet balsa, sanded,
assembled and covered with tissue.
The fuselage is made over the plans in the standard manner. Be sure to insert
the blind mounting nuts for the engine before sandwiching the landing gear wire
between the firewall and former No. 1. Former No. 1 is drilled with 1/16th holes
and the landing gear wire is sewn to it with heavy thread or soft wire. When sandwiching
these two pieces together, use two-part epoxy glue. After finishing the 1/8th square
construction of the fuselage, fill in between formers I, 2, 3 and 4 with 1/16th
sheet balsa on the sides and the bottom. The pylon is laminated from three pieces
of 1/16th medium hard balsa and is glued in place between formers 2 and 4. It is
braced by filling in on each side with 1/16th sheet. All of the fuselage is covered
with Jap tissue and given three or four coats of hot fuel proof dope.
If the plane is tail heavy when test gliding, put shims under the trailing edge
of the wing; if nose heavy, put shims under the leading edge. Even though it test
glides flat, put down thrust in the engine or it will loop under power and get you
from the rear before you can get out of the way. To make thrust washers for your
planes, go to any plastics dealer and buy a foot or so of 1/4" Teflon rod. Drill
the proper size hole in the end of the rod, then slice your own washers to the thickness
desired. It makes fine bearings too. Fly it to the right with right thrust under
power, and make it turn to the left when gliding by bending the trailing edge of
the rudders.
This is a fine small field flyer. Many times I have caught Quarter Pint without
moving more than three or four steps from where it was launched.
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Quarter Pint should be a challenge and a real success with the
Tenderfoot modeler.
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Steve S.'s Completed Quarter Pint done up to look like the original
- nice job! Clever photo at same angle as original.
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<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.
Try my Scale Calculator for
Model Airplane Plans.
Posted December 11, 2010
January 9, 2011 Update:
The Quarter Pint is complete! An authentic Cox .020 engine will be installed
once it arrives.
Here is the result of Steve's handiwork!
Will he dare to fly it?
Covered and trimmed underside
January 1, 2011 Update:
Steve was kind enough to send some photos of his Quarter Pint while under construction.
It looks just the like plans! Kinda cool, eh?
All framed up.
 
Fuselage and empennage framework
A close-up of the framing
An overhead view
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