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:
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.
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.
Quarter Pint should be a challenge and a real success with the Tenderfoot modeler.
Steve S.'s Completed Quarter Pint done up to look like the original - nice job! Clever photo at same angle as original.
<click for larger version>
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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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