Lighter is better
When flying in smaller venues, small models are certainly better suited to them than large ones, unless the larger models are lightweight and capable of slower flying and landing speeds. There are a couple of ways to achieve slow flight with large models—flaps being one of them—but one thing that goes further than anything else in keeping the speed down is lighter wing loading.
I’ve heard it said about model airplanes that weight doesn’t matter because you can buy all of the horsepower you’ll ever need. The second half of that statement is certainly true, but where flying in small venues is concerned, slow flight is desired, and nothing else works as well as light wing loading.
For those of us who cut our teeth in Free Flight (FF), the concept of “light” is a given—and the same principle applies to RC. The beauty of this is that a lighter model doesn’t require the raw strength of a larger one, so as the airframe becomes lighter, it is even easier to keep lightweight.
Here’s why: a lighter model requires less power. A smaller motor weighs less than a big one, and can be well fed with a smaller battery. Because the model weighs less, lighter and less powerful servos will keep the airplane nicely under control.
Then there’s the landing gear. The landing gear and mounting system are among the heaviest components on any model. In the case of lighter airframes carrying smaller power and guidance systems, the landing gear assembly can be built significantly lighter and hold up well over time because the landing stresses are far less than those on a heavier model. As the aircraft becomes lighter, the required wood sizes are reduced, and the need for harder balsa or plywood is all but eliminated.
I’m sure you’ve heard the statement, “The whole is greater than the sum of all its parts.” It’s true. Few parts of a model need to stand on their own. Models that incorporate lift struts, tail-brace wires, or in the case of rigged biplanes, components, can be built significantly lighter because they don’t need to stand on their own.
Each is supported by something that, in combination, is lighter than a self-supporting platform. That includes everything, right down to the cover. The wing doesn’t need to be rigid because the covering will add rigidity not found in the structure itself.
Don’t get me wrong. There are models that are so lightweight and so fragile that they have to be handled too carefully to be practical, but after years of looking for a good balance between weight and strength, I settled on a blend of lightweight and practical. The resulting models fly beautifully in reasonable weather conditions and hold up well over time.
The thing to remember is that building light is truly a state of mind. In keeping with that, because anything added to a model must be picked up and carried by it in flight, why use bulky nylon control horns when a small plywood horn or toothpick will do the job, or use clevises where Z-bends are adequate?
When you get right down to it, there are really only three rules to follow: Light is right, thin is in, and when in doubt, copy. Stick with those three basic rules and you’ll be rewarded with some great-flying models that can be flown even in the smallest parks and fields.
Blériot Two-Seater
In that vein, Dave Salguero sent photos of his unusual 1914 Blériot two-seat airplane. The 30-inch wingspan model is set up for three-channel RC and is covered in tissue and dope with a bit of artist’s pigment added to “age” the tissue. The model is a classic example of using functional rigging not only to support the wings, but also on the uncovered fuselage frame.
Dave used struts to support the tail section. Power is supplied by an E-flite Park 180 outrunner motor, and guidance is by way of a Spektrum AR6410BL brick. Control is rudder and elevator. Dave thought the model might be too small to incorporate wing warping into the system. As an added bit of scale
Dave Salguero’s lesser-known 1914 Blériot two-seat airplane features functional wing rigging and hand-laced spoke wheels. Because of its diminutive size, Dave opted for three-channel control rather than using wing warping.
realism, Dave laced the spoke wheels by hand. Nicely done, indeed.
Miles M.2 Hawk
Next up, David Wagner checked in with his 26-inch wingspan Miles M.2 Hawk. The model was built for rubber-powered FF and is one of five aircraft built for the Spanish Civil War theme at this year’s Western Region Flying Aces (WESTFAC) VI contest, to be held in October in Buckeye, Arizona. The model is covered with tissue and painted with acrylics in David’s typical, flawless style. Well done, and good luck in Buckeye.
Jim Holston’s Designs
Jim Holston has graced us with two projects. The first is an original-design, 72-inch wingspan Fournier RF-4. The model is powered by a Turnigy 28-30 1,000 Kv outrunner motor with a 1,300 mAh 3S LiPo battery. The design features four-channel flight control, as well as retractable landing gear. Spoilers couldn’t be incorporated because the wing is
so thin that there was no room for the servos. The all-up flying weight for this beautifully detailed model is 33 ounces.
And last, but certainly not least, Jim converted an old Guillow’s Fairchild 24 FF model to three-channel RC using components from a ParkZone P-51 Mustang. The kit was basically built from stock; the only modifications are the addition of rudder and elevator hinge spars and a motor mount, and the replacement of the plastic nose cowl and wheel pants with balsa carvings.
The model is covered with tissue and dope, and Jim said it is “lots of fun to fly on calm summer evenings.” I’m not surprised that the model flies well. I’ve built a couple of the Fairchild kits for rubber FF and was never disappointed in the way the models flew.
That’s going to wrap it up for now. I want to take this opportunity to thank everyone who checked in, and to say that the response has been much greater than expected. I couldn’t get everything into just one column, but not to worry, I’ll get to it. In the meantime, do keep the good stuff coming.
SOURCES:
WESTFAC
www.westernfac.com
Spektrum
(800) 338-4639
www.spektrumrc.com
