January 2014

Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.

Issue link: http://experimenter.epubxp.com/i/247918

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Page 12 of 38

parts. Basically, what we wanted was something that fit our style of flying better than the standard Cub." Frank said a Super Cub fit his needs well, but most of his flying is alone; and he wanted something that was good on fuel so he could aford more time in the air. As he put it, "It's not so much about going cross-country as it is enjoying slow flight, so that's why the Lil' Cub has a removable rear seat with no rear controls and uses a smaller engine than most." Not having an engineering background or anyone close who could do the analysis, Frank used the time-honored method of see-what-others-have-done-and-adapt-it. "We studied lots of small plane designs and the tests completed by Jerry Burr and others," said Frank. "Basically, we followed the general parameters of a Piper Cub J-3, PA-11, and Super Cub. To keep things organized, we used the "list method": One notebook kept the list of goals; another kept conceptual hand drawings, test results, and trim parameter changes." Of course, as is almost always the case with a one-of experimental design, getting the airplane flying was just the first step. From that point on, refining the airplane was a nonstop series of changes where ideas were tried, found wanting, and so another was tried. Frank said, "The build has been evolving based on the initial flying results. From there we modified the fuselage, tested and modified the flaps three times, modified the droopy aileron system a couple times, and we tried several sets of tires and installed a carbon tail tank. "One of the best modifications to the Piper design was dropping the firewall and moving the small instrument panel out against the firewall. This allowed the Lexan windshield to The flaps go all the way down to 70 degrees and the ailerons droop at the same time. At maximum deflection, the ailerons are down 22 degrees. extend much further than stock and allowed the windshield to be bent from flat-stock Lexan with no compound bends." The engine for the Lil' Cub is the tried-and-true Continental C-85-12, with a few modifications aimed at squeezing a little more power out of it without reducing its legendary reliability. Frank explained those changes: "It has been stroked using an O-200 crank, and the jugs have been ported and polished, both of which generally yield only a little more power but increase efciency. The same thing could be said of the balanced rotating assembly. It makes everything smoother, but the 10-to-1 pistons EAA Experimenter 13

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