For Openers
Learning New Tricks
The old saying that "You can't teach an old dog new tricks," unlike Murphy's immutable law that "anything that can go wrong will go wrong," doesn't hold water. If it did, we would not be X-ing out occasional comments which soothingly express surprise that "the old man" actually flies airplanes. Presuming that you are here to relax with this monthly garage sale, and that the profundities can wait, we are reminded of kids who dared the "old man" to go near the water, then were speechless when he swam out to the raft after them. To be a modeler is to be forever young.
For an "old dog" we certainly are learning new tricks—so fast, in fact, that we aren't sure what is going on. Perhaps it comes from asking questions. It's surprising how much other people know, isn't it? This is why we are having so much fun with MA. When an editor takes to asking questions of experts all over the land, in all phases of modeling, and publishes their answers in the form of articles, he finds that his own narrowly held notions can be a governor that limits rpm, whereas the input of many minds is a shot of ether right down the carb throat.
Muffler Pressure
Our favorite article this month is John Kilsdonk's "The Mystery of Muffler Pressure." We had a ridiculous amount of engine-run problems last year—and saw many other guys fighting the same battles. You are well aware of the constant articles and comments about fuel tank location. If you don't run pressure, the compromise needle setting often does not adequately handle the rich/lean variations. One has only to visualize an engine fuel system in horizontal and vertical positions to marvel that with such vast differences in fuel head and variations in "draw," the engine manages to run at all. The competition experts who must have engine consistency and reliability—FF, CL, RC—use pressure. Perhaps the "plumbing" dismays us, or we've heard too many old wives' tales from inept people.
In that old cabin RC job we've been flying, we had a Veco 19 and a slant tank with too long a draw for climb attitudes. A helper was tweaking the needle while we held the ship nose high, and one could feel the hot flecks of carbon that spelled engine trouble. Bill Hershberger, a pioneer pylon flier, said nothing, but held the vent tube line behind the muffler. The engine richened and ran beautifully. Bill muttered something about pressure always helping. Now if that tiny pressure helped that much, even a forward-facing vent line might have beneficial ram effect to add a speck of pressure. Apparently almost anything will make a difference—we think even an open system with a line to the muffler tap is some improvement. Of course, the system should be a closed one.
Muffler pressure, like water from your faucet, is there for the taking. Many mufflers come with the tap, or a place for it to be drilled and tapped. We know a National's winner who merely sticks a piece of brass tubing into a hole in the muffler—at the right place, of course—and seals the joint with high-temperature liquid silicone rubber.
Who would be a good man to tell us the facts of muffler pressure life? We phoned "Big John" Kilsdonk, a long-time great in CL racing who knows engines like the back of his hand. Besides, John was getting into RC Pylon. What he had to say will be found on page 18. You'll even find a table of pressures for scads of engine/muffler setups—he ran all those tests before he'd surrender the copy.
Ours is a sport flier's approach—the simplest and cheapest. Actual muffler pressure is much lower than case pressure, it is constant (not being timed), and it is not present when you are starting the engine by hand. There are marvelous pumps and things for those who would use them—but muffler pressure for the sport flier is free and easy.
Be smart, be happy; if engine problems spoil anticipated weekends, there is something you can do about it: go muffler pressure.
The Jetster
The biggest achievement in this issue—and in many a moon—is Dick Sarpolus' magnificent Jetster. For F.O., it really began about 1950 when, as editor of MAN, a Philadelphian named Purcell submitted, out of the blue, a Half-A ducted fan F-86. Strange things give editors ulcers. Would this "thing" work? Did we dare publish it? Thank goodness we went into it. It was the first, in America at least.
Over the years many people struggled to advance the art. But with the rather recent exception of Bob Violett and Scozzi with his fan, ducted fans for RC flew like logs. The Violett airplane is scale jet—and fast. And we know Bob to be a top man in Pylon with engines that really wind up. Bob Kress, a prominent aeronautical engineer with Grumman and a modeler, developed a simple ducted-fan powerplant for the sport flier that is now kitted by Midwest. And we know that John Maloney at World Engines is cooking up something with ducted-fan power units designed by Duane Johnson, a McDonnell-Douglas engineer. Johnson has given impressive demonstrations.
Kress's theoretical articles were promised to RCM—they were tops. Seeking a design, we badgered Bob and Nick Zirolli—who designs and flies anything—and Duane Johnson. Duane's rather advanced twin-engined F-15 was promised to Jim Sunday. We knew Dick Sarpolus to be a capable designer, a thinker, and an active flier with a leaning to the way-out—like canard sailplanes (published in Flying Models). Dick took the plunge.
We had hoped for a spectacular scale-like enclosed jet, but after seeing the tremendous flight results gained by Dick's approach, we were rhapsodic. The Jetster is lovely. It flies beautifully, doing pattern maneuvers with ease. You can handle it. That it has the punch is evident from its impressive knife-edge. Dick saw this concept as an effective, fun way of getting into jets—a big need now. So we send Dick clippings of exotic future fighters with notes saying, "Do you dare...?"
Free Flight and CL
To you free flight guys who have been so patient, we have good news. After much give and take with many experts—that they should publish themselves—we have a great lineup of things in the works, beginning with Jim Morris' veteran, high-performance Toothpicks (page 50). Ralph Prey has interviewed many of the top fliers about their adjustment methods and boiled down a mountain of material into a just-out-of-this-world two-parter, beginning next month. It presents things many of us never heard of and organizes a first-rate briefing in a way never done before—to our knowledge. In it you will find ten basic trim set-ups used by the experts, how each works, and what adjustment combinations work in which situations. Jim Newman, a fine illustrator who did so many nice things for Midwest, is now in business for himself, and one of his first big projects was to reinforce Prey's fine copy with illustrations we'll always remember. This is the tip of the iceberg.
Meanwhile, we are struggling for a good CL program—those guys felt slighted, too! Everyone does! Watch for some nice designs, Rush on Combat, etc. There has been a rumor (No. 909) that MA is cutting down on CL! How do these things get started? Come on guys, pitch in. Join the good fight for the sake of your own kind. If free flighters can do it, so can you.
Typically, one guy asks, "Are you crazy enough to publish such-and-such?" F.O. is crazy enough to publish anything that advances the art and gives us all enjoyment, whatever our prime interest. We are suckers for bright, good ideas—progress is the name of the game. And we are fidgety about always getting the very best airplanes. Don't be timid about writing—it is easy. We are here to help you. Just ask!
Bob Meuser and Quarter-Scale Projects
Bob Meuser, the spokesman for the "cottage industry" in free flight, is another working scientist with a dilettante's taste for flying ideas that sail to glory—like records. His copy will give you a lift on a rainy Sunday. Puzzled by our excursion into RC Quarter Scale, Bob announces, tongue in cheek, that he is building a quarter-scale Gee Bee in which he will lie prone and look out the nacelle. "Simply doesn't dig us," he sez. (We are a free-flighter, in his eyes.)
So we've told him to scale up his favorite Manhattan to nine feet—he can't twist all that rubber—and it would smart him to death if he lay prone in the cavernous fuselage, so add an engine and a radio, and he would dig our lightweight General Aristocrat. We figure that prop drives and Quadras, etc., draw the line that separates the men from the boys, so we are walking the sunny side of the street with rubber and free flight techniques. Can't be done? You'll see... we hope.
To give you some idea of what this thing is like, see the pic of a mock-up of the entire nose, which we had to make to figure out how it would hang together. The mock-up really paid off—try it before you get lost in your monster project.
Meanwhile, the data research is nearing the South Pole. Warren Shipp's old instructor, who owned one of these things, is alive and kicking down in Florida, and, oh joy, he was the company test pilot! Our flying buddies call up and ask, "Is this the Aristocrat Archives?" And what we have done is nothing compared with what the scale experts go through. If you want a cram course, try a quarter-scale design of your own. Everybody worries about your ability. You get snowed with hints and tips, and a zillion things you never heard before.
You must jig the sides when you put in cross pieces. We should wet the bent longerons while they are held by the jig blocks nailed to the bench—that relieves the "tensions." They say the good scale guys blow a water mist on the bends and let the frames set for three days before taking them up. You must use epoxy. Don't use epoxy for cross pieces—white glue is better. On and on. What a riot. Where in the heck have we been all these years?
Small Pleasures and Tools
Little things please us. Like Futaba's corner grommets for mounting servos. Or Sigment—which we found so handy on the field for quick drying, and for its ability to stick a metal tab on a wing, or a big butyrate-sheet windshield, or a canopy, to the fuselage. Kraft's model builder's clamps, Williams Brothers old-timer wheels. And so on. But the thing that really brightened up our workshop gymnastics—though it is hardly a little thing, physically speaking—is the Dremel Moto-Shop. This is a true plug; Dremel doesn't advertise in MA, and, if you must know, we bought the thing. How we managed to live all these years without a decent jigsaw we'll never know.
Once we had a Synchro jig saw—are they still around? It was really a vibrator that hummed and nibbled its way ever so gently, and slowly, through the thinnest ply. We've hacked endless cockeyed parts with a coping saw. Frankly, we were crazy. That picture of the nose mock-up—never had considered making it without this saw. It went together like magic. All those guys with their Dremel equipment made us feel put down—like some goofy new golf club or tricky tennis racket, or a Mercedes-Benz. So we are here to tell you that you only live once, and you might just as well go first class with equipment that really speeds up your building, and makes the difficult seem simple. And the sanding disk. Oh, endless hours of sanding with blocks and boards. Like life in the Dark Ages. If you don't have one of these things, save your pennies. That saw is, to us, as a milking machine is to a farmer.
The "plug" is on the house.
Letters Page Policy
One of the more enjoyable features in any magazine is the Letters page. Model Aviation receives many letters and, as stated at the top of that page, publishes those of general interest—as far as space permits. Published letters relate only to the subject matter of the popular section of the magazine forwarded to the AMA News page. If a reader wishes to write about association matters, he should address AMA Headquarters, not the editor. Occasionally, someone may feel that such a letter "must" be printed in Letters to the Editor. Although few such misunderstandings have occurred, it appeared advisable, nonetheless, to clarify the policy of the Letters page. "Letters" is intended to be pleasant, and the editor believes you prefer it be restricted to modeling subjects.
Transcribed from original scans by AI. Minor OCR errors may remain.
