Radio Control: Sport and Aerobatics
DO YOU LIKE to trim out a new airplane? I don't. Rather than have the kind of airplane about which the designer reports, "It flew right off the drawing board," I mostly seem to have the other kind. As I sat trying to puzzle out what to do to sort out all the idiosyncrasies of my newest airplane, I decided to make all the hassles partly pay for themselves by writing about them in this column. This will not be a complete "how to trim your new airplane" article, but rather an explanation of some things to try in order to get out of your miseries a bit easier. The first thing I noticed about this airplane was that it was nose-heavy. I had to use enormous elevator deflections to loop it, so I was ready when I landed it. Sure enough, I ran out of Up elevator just before touchdown. This is typical of a nose-heavy airplane. Fortunately the small amount of vertical sink didn't hurt anything.
Radio Control: Sport and Aerobatics
SERVO TESTER strikes again! Ten years ago when I offered to send a schematic of a nice servo tester to anyone who sent me a SASE, I got several hundred responses. When I made the same offer twice during the past few months, I didn't expect to receive more than a couple of hundred requests. However, my daily mail has been including 10 to 15 letters (with a SASE) asking for the schematic! That's great. It is a good piece of equipment that is inexpensive and easy to build. A couple of the early requesters have asked how to calibrate the dial. Most servos use a 1.5 millisecond centering pulse, and tester-builders can use a good (new or lightly used) servo to calibrate the dial pointer to 1.5 milliseconds. Most radio systems will vary the pulse by 0.5 milliseconds for full throw (normally 45º of servo rotation) in either direction.
Radio Control: Sport and Aerobatics
SEVERAL years back, the FAI rules group deleted the scoring of takeoff and landing. Since then the quality of takeoffs and landings by most FAI pilots has been uniformly poor. I seldom missed the chance to harass FAI pilots, suggesting that they should attend remedial takeoff and landing school. It was with considerable glee that I greeted the announcement that FAI pilots would again be judged for takeoff and landing in 1988. They were about to get their comeuppances. Then I got hold of a notice that Ron Chidgey (who is chairman of the FAI's CIAM F3A Subcommittee) sent to all U.S. clubs. The subject was F3A rules clarifications which were to be effective January 1, 1988.
Radio Control: Sport and Aerobatics
PERIODICALLY I read in aircraft design articles about how to "prevent" control surface flutter. In most cases the suggestions are good ideas to use in delaying the onset of the phenomenon, but few actually work in preventing flutter. Before I get into the subject further, there are a few things which need to be clarified. First, in the classical sense, what modelers usually call control surface flutter isn't flutter at all but control surface buzz. Flutter engineers reserve the word "flutter" to describe oscillatory, self-sustaining motion of aircraft components which involves the interaction of two or more modes of component motion. Control surface buzz involves only one mode of aircraft component motion. Big deal, right?
