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This item is discontinued. GREAT PLANES SHOESTRING ARF 
Airplane Type: ARF Sport Scale COMPLETED MODEL CHEERS - Very complete kit; extremely quick and easy to assemble; compact and easy to transport; agile and spirited flight performance. JEERS - Fuel tank mounted solidly to formers; canopy didn't fit well onto the cockpit. "The Cleveland Air Races prior to WWII were a big thing for aviation enthusiasts. After the War, a new class of racers was started called Goodyear Racers, or as we called them when I was a kid...Midgets." Those were the words of Bryan Kreimendahl, son of Shoestring racer designer and builder, Rodney Kreimendahl, about how his Dad and other Lockheed Aircraft employees got into Goodyear racing back in the early 1950's. The Shoestring was named by Bryan's mother, since the entire project was financed on just that. Since it was a rather small plane with a wingspan of just over 19', it would seem to be a fine project for modeling in 1/4 scale, and that's just what Great Planes Model Mfg. Co. did. The Shoestring ARF is an Almost Ready to Fly IMAA legal mid-wing monoplane that can be powered by relatively small engines, and guided with inexpensive 4-ch radios. The assembly manual says it has a 61.5" span, the box says 60.5", and mine was 61 3/4." The model comes precovered in red and yellow MonoKote, while the original Shoestring was painted in red and chartreuse. What, no chartreuse MonoKote? The Shoestring ARF is a very complete kit, supplying just about all the basic materials needed to complete the model in less than 20 hours. The colorful box contained the fuselage and wing panels, the tail surfaces, a fiberglass cowl and wheel pants set, painted plastic cockpit and canopy, a plastic spinner, painted aluminum main gear legs, wheels, tail wheel and bracket, fuel tank, adjustable engine mount, all the necessary hardware including control linkages and hinges, and a 24 page manual. What, no fuel line? Using the inventory sheet in the manual, I determined that everything intended was present. Since my wife was babysitting at my daughter's house, I had a whole day to assemble the model. I started at 7 a.m. by unpacking and inventorying the box. The cockpit cover had been damaged during shipping, so I called Great Planes for a replacement. It arrived in just three days. After using my covering iron and heat gun to remove a few wrinkles from the covering, I was ready to begin assembly. First came preparing and joining the wing panels. Each appears to be built from balsa ribs, spars, and sheeting, with a hardwood dihedral brace and joiner. The ailerons are solid balsa with lightening holes bored through each, and hinged with CA type hinges glued with thin ZAP. Then the aileron servos and linkages were installed, and Great Planes even thought to install a piece of string in each panel to pull the servo wire through the exit hole. I fabricated a set of aileron extension leads, since the leads on my servos were about 1" too short to reach the exits. The hardwood dihedral brace fit the wing slots just fine, and I used Pacer 30 minute epoxy mixed with milled fiberglass to hold the piece in place. The panels were then joined with a bit more epoxy on the root ribs. I removed a little of the center covering, and applied a layer of glass cloth using thin ZAP (more on this later). After connecting the two aileron leads together, the wing was fitted to the fuselage, and the wing bolt plate was installed. The horizontal stabilizer and fin were added to the fuselage, and the control surfaces hinged in place. Little or no sanding was required to get the stab level with the wing. The tailwheel bracket is the typical half-hinge with a bent wire arrangement found on many planes this size. It places a load directly on the rudder, but I decided to use it anyway. Any weight savings will just add to the flight performance. The painted fiberglass wheel pants are mounted on the formed and pre-painted landing gear legs using plywood plates, bolt-on axles, and several small wood screws. The wheels supplied are probably large enough to be used on some grass runways, but their foam construction makes it necessary to keep the plane off the floor during storage, or the soft tires will develop flat spots. While waiting for the replacement cockpit, I skipped ahead to the engine installation. The supplied adjustable engine mount fit the pre installed blind nuts in the firewall perfectly. This was nice, because the instructions say the user has to do all that. Not so! After much deliberation on which engine to use, I finally chose a Saito .91 4C. The deciding factor that finally swayed me was the fact that I just happened to have one sitting on the shelf. I reversed the carburetor so that the needle valve would stick out the top of the cowl, with the throttle linkage at bottom. The painted fiberglass cowl was installed after cutting a large clearance hole for the cylinder head. A standard .60 size 2C engine would fit just fine, but even then I suspect that the exhaust system would need a large hole. Wooden blocks were added to the firewall to secure the cowl in place with servo screws. The Shoestring ARF comes with a fuel tank that appears to be about 14 oz. Aluminum tubes are provided for the clunk and vent lines, but the supplied clunk hose appears way too small to pick up enough fuel. I used Du-Bro medium fuel line to plumb the entire fuel system. The fuel tank is also a bit lower than I'd like, but muffler pressure should keep the fuel flowing. The level of the tank appears fine for a .60 size 2C, though. The formers are perfectly shaped for the fuel tank, but no room is left for any padding. This may or may not be the right way to install the tank, but I'll check back after I run the engine. Holes for the glow plug access, needle valve, and fuel line were also cut into the cowl. Then I installed the servos and control rods, followed by the throttle linkage. The three servos mount in a plywood servo tray, and I added two strips of hardwood on the bottom, both to provide more wood for the servo screws, and to prevent the servo tray from flexing. The elevator and rudder music wire pushrods have a plastic clevis at the control horn end, and use Fast-Links at the servo end. The receiver and 1100 mah battery were installed under the wing bolt plate, and the power switch was installed under the left wing panel. The receiver antenna was run out the top of the turtle deck back to the top of the fin. After the control throws were set up according to the instructions, I put all the parts together to check the CG. I marked the recommended point on the wing, and placed the Shoestring on my Great Planes CG Machine. After moving the battery forward a bit, the model sat perfectly balanced, requiring no extra weight at all. The model's total weight was 8 oz. more than the recommended weight of 7 lbs., but a couple of those ounces came from my little additions. At this pint I had been working on the Shoestring for about nine hours. Other than applying the supplied decals, the plane was ready for the first engine runs. I applied the decals on Sunday, but ran into a problem with the race number on the back of the fuselage. The contour of the fuselage isn't flat there, and the self stick decals would not lie down without wrinkling. Rather than put up with the wrinkles, I just left those decals off. The others, however, went on just fine. The replacement cockpit arrived in perfect condition, and was quickly epoxied to the top of the wing. Some carbon fiber look UltraCote was applied over the wing center section. This covering has the looks of carbon fiber, but only the strength of UltraCote. But it should draw some attention at the flying field. The pilot figure and the supplied instrument panel sticker were placed inside the cockpit after a coat of flat black paint was brushed onto the bare wood. The canopy was installed using Formula 560 canopy glue, but the edges of the plastic wouldn't sit level on the cockpit. I'll try a little heat to see of it will look a bit better, but I will definitely add some trim tape to try to cover the edges. I took the completed Shoestring out to the engine testing area and ran the Saito .91 4C engine, adjusting both needles to get the best performance. There was plenty of power available, and I felt confident that the Shoestring would be pulled along quite nicely. I took a day off work to test fly the Great Planes Shoestring, finding the weather absolutely perfect for the occasion. The wing was bolted into place, the fuel tank was filled, and the customary pre-flight photos were taken. After a last minute pre-flight inspection and radio range check proved that all systems were go, I flipped the Saito .91's prop, and it roared to life, requiring only a slight needle valve adjustment. I tried a few taxi tests on the runway, but the wheels and wheel pants repeatedly caused the tail to lift. I think a larger pair of wheels may be in order, but I was here to test fly, so test fly I did. Holding full up elevator, the throttle was slowly increased, and the plane accelerated briskly. It lifted off the runway in less than 50'. I then made a gently 180 degree turn, and then dialed in a few clicks of aileron and elevator trim for hands-off level flight. The Shoestring was moving along at a pretty fast clip by now, and I noticed that I had only increased the throttle to a little more than half stick! The Shoestring flew really well, performing loops, rolls, and stall turns with ease. When flown inverted, it needed only a slight amount of forward pressure on the stick. Low fast passes looked great, but I began to notice that this not-very-big airplane began to look really small at the far ends of the flying area! Several times I had to wiggle the wing just to see which way the plane was turning! Full throttle performance was just too fast for me. I guess I have more of a 20-30 mph brain! The first landing was aborted when I observed about 3/4 of the runway behind the still flying Shoestring! On my second attempt I set up a slower approach, pointed the nose towards the runway, reduced the throttle to idle, and then pretty much just watched as the plane settled gently onto the tall grass. I had to add up elevator to keep the plane from tipping over, but it came to a stop in a reasonable distance. Looking back on it, that was a very good maiden flight! I flew the Shoestring several more times that day, learning more and more about its flight characteristics with every minute. It will spin easily from a stall, using elevator to induce it, and rudder to spin it in the desired direction. It stops within half-a-turn when the controls are released, and continues level flight with no great loss of altitude. High speed pylon-type turns look really great, but then...that's what this plane was designed to do. It has the capability of flying really slow, though, and there seems to be no loss of control at slow speed. All in all, this is a fine flying airplane! To sum things up, the Great Planes Shoestring ARF is a really nice kit! It assembles quickly and easily, everything fits where it's supposed to, it weighs close to what the manufacturer claims, and it looks like a real airplane. It's small enough to pack into the back of a medium sized car, but large enough to be IMAA legal for giant scale. It doesn't need a gigantic engine to give spirited performance, wither. And it only needs a standard 4-ch radio system to fly well. I guess the only notable problem I found while flying was the small wheels snagging in the grass (I blame the guy who mows the lawn!). The other minor problems noted in the "Jeers" didn't seem to affect the flying at all, but they still should be corrected. But please don't let the few minor problems deter you from considering the Great Planes Shoestring ARF as your next project. It flies great, looks good, and I think you'd enjoy owning one. Reprinted with permission.November, 2001 R/C Report Editor: Gordon Banks
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