Article & Plans
December 1972 American Aircraft Modeler
Website visitor Mike L. wrote to ask that I scan and post this "Snoopy" article that appeared in the December 1972 edition of American Aircraft Modeler. Mike liked the Snoopy so much that back in the 1970s he built a couple of them. Now, 40-some years later, the bug has bitten again and it's time to build another. Snoopy is a 4-channel R/C sport aerobatic trainer model with a 48" wingspan, using a .15 to .35 engine. It is all balsa and plywood construction. Mike's original Snoopys were powered by a Veco .19 and used a Kraft Sport 5 radio for guidance.|
SnoopyFun plane for owners of small, sporty cars and light, four-channel radio. Modified Headmaster makes it lively - but forgiving
The models presented in past magazine articles tend to favor the contest type airplane. The medium size weekend or sport type airplane has been somewhat forgotten. The Snoopy Trainer was designed to fill the gap for the guys who like to fly the medium size airplane for sport or relaxation on the weekends.
The Snoopy Trainer can be placed in the luggage compartment of automobiles without removing the wing which eliminates carrying extra pieces to and from the field. This design takes advantage of the small, lightweight radio sets - the frontal area of the fuselage is low in order to compensate for the thick airfoil section which is needed for smooth and forgiving characteristics. A semi-symmetrical airfoil section is used for better wind penetration, inverted flight and easier handling. The ailerons have been added for lateral stability and increase control due to the absence of dihedral in the wing. The standard two wheel landing gear is used to keep the construction and control linkages simplified. Many fliers would like to get away from the trike gear high and low wing lookalikes but still have good performance. Rough grass fields have been no detriment to the ground handling ability of the Snoopy Trainer.
No dihedral, inset ailerons, thick semi-symmetrical wing give Snoopy fine Sunday stuntabilty.
The Top Flite Headmaster kit was used as the basis for the design and modified into a not so lookalike. After the mods were made, the model looked ugly and dead. A Snoopy pilot was carved from a block of balsa and placed onto the top of the wing, the model livened up, hence the name "Snoopy Trainer." A great deal can be learned from flying this plane and it will forgive you for all but the most egregious errors.
Construction is so simple and straightforward that you can build it from the plans without reference to any explanatory text. There are a couple of points which might bring up a question in your mind, so let's see if they can be cleared up beforehand.
The fuselage is a typical "slabsider." but can be disguised. The 3/16 square longerons give an excellent gluing surface for the top and bottom sheeting; then when the box-like structure is completed, the corners can be rounded. Section A-A shows the cross section of the fuselage as it would appear at that point. The rounding of the corners can be done all the way forward on the top of the rear of the wing, and the full length of the bottom, fairing it out at the plywood where the landing gear is mounted. The corners at the top front forward fuselage hatch may be rounded as well. Spot glue the hatch in place, round off the top and then cut the hatch away when finished.
Since there will be many different engine installations suitable to the model, no specific mounting holes are shown. Drill them to fit the engine and bolt using 3-48 or 4-40 bolts and blind nuts.
The landing gear used was a Hallco No. B105-4; a Top Flite Tauri/Headmaster wire landing gear can be used with a little mounting modification. These landing gears are available in most hobby shops.
Another thing you might wonder about is the servo linkage to the control surfaces. NyRods are used due to the lack of sufficient space and, when installed per instructions, work just fine.
The wing is a modified Tauri wing or, to be more exact, a Headmaster wing. Ailerons have been added and are inset. There is no dihedral which makes the construction easier twist free by being able to build on a straight flat surface. A dowel rod glued in at the leading edge and nylon bolts used at the trailing edge hold the wing to the fuselage instead of the customary rubber band method of yesteryear. The added ailerons and absence of dihedral give more control making inverted flight easier and rolls smoother.
The fin, rudder, stabilizer, and elevator are constructed of 3/16 sheet balsa. This construction has proven very sturdy and simple. Make slots for the hinges in the fin and stabilizer trailing edges, and the leading edges of the rudder and elevator. The hinges are glued into the slots after the covering is applied, The same hinge technique is used in applying the ailerons to the wing. The fin is butt glued to the top of the fuselage, but before gluing, be sure the bottom of the fin fits snugly to the top of the fuselage, then add the 3/16 inch square fillets before gluing the fin in place. This makes it easier to shape the fillet as shown in section A-A.
When it comes to covering, it's entirely up to you. There are so many to choose from and each modeler seems to have his own choice. As for me, I have become a booster of MonoKote, using MonoKote exclusively to cover my airplanes for the last five years. MonoKote is the quickest possible way to get an airplane finished and flying. Follow the instructions supplied with the MonoKote and you can't go wrong. The lack of compound curves will make this an ideal model to cover with MonoKote if you have never used this fantastic covering material before. Epoxy glue is used to seal the edges of the MonoKote in the engine well area. This area may be colored to match the covering. MonoKote trim sheets or MonoKote markings may be added to dress up the finish. A clear polyurethane varnish may be used to seal the edges of the sticky type trimming. If decals are used, allow them to dry thoroughly before sealing the edges.
Sid Axelrod admires the flat olive green WW I MonoKoted Snoopy. Where's the Red Baron?
The prototype, as shown on the plans, has a Kraft proportional control system installed. The all-up weight of the prototype, with a Max 19 in the nose, is three and a quarter pounds. The first few test flights proved out the value of proportional control. After taxiing around a bit to gain the feel of the controls and the ground handling, the power was advanced and the Snoopy Trainer went down the runway. With a slight amount of up elevator the flight (fright) was under way. Great! The model was out of trim and the transmitter trim levers could not overcome the amount of adjustment needed, the flight had to be concluded with the flying sticks about one third the way over to maintain straight and level flight. An investigation proved the push-rod clevises had not been adjusted properly. After the proper adjustments had been made, the next flight had proved all the effort was not for naught and a good performing airplane for the weekend sport flyer was born.
The Snoopy Trainer is capable of flying with a Cox 09 or a Max 10 if kept on the light side. A 15 or a 19 engine will make the Snoopy Trainer perform quite well for you weekenders. Eat your heart out Red.
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Posted December 21, 2013