Perry,
You appear to embed an assumption in your method: that is, you adjust the guide to cause an "...1/8" nose down" setting. One-eighth inch nose down measured where? Tip of the spinner? So the rhetorical question is why have you selected 1/8"?
Your 1/8" rule of thumb may work fine for a certain group of planes of standard dimensions, weights, and speeds (ie. a mid-size stunter that is average in weight and flies about 50-60 mph, or whatever geometry plane you have validated your 1/8" dimension for) but the point of the engineering here is that the actual equations can be used for a specific model, not limited to a mid-size stunter, and still be a very good starting point. The math is perfectly accessible for any builder using the website calculator.
I flew a .15 Rat with a Nelson engine once that the builder used his "rule of thumb" on. It was virtually impossible to take off without an out-of-control wingover into the circle leading to a big loop if you were lucky or had exceptionally quick feet. After the second rebuild and before the third pilot got a chance to duck a screaming Nelson with integral carbon cleaver attached, another friend ran the Line II program numbers for him and he moved the fixed-position leadouts, it became a manageable flyer, if not a world beater....
Dave
"For $3.00 using the grey one you can set the leadouts in a minute. The most accurate way possible. Hang the plane by the leadouts and put the level on the flat section of the nose, move the slider until you get 1/8 inch nose down. Quick, easy and accurate."
Topic: Line III (Read 1781 times)
