On Keith's comment, I know that the "two connectors per line" rule was in there much more recently than 1972, in fact, when this thread came up, I thought it was probably still there in the general rules somewhere, and am surprised it is not. Present or no, as the author of the current stunt rule, I think it obviates any such rule even if it is still in there somewhere. What would happen if someone found a conflict and protested it, I don't know.
I would not recommend line extenders as a general trimming tool for a variety of safety and mass properties reasons, but as found here, it's not obviously fatal.
Comment regarding 2. above:
eParrot XL flies the entire pattern on the extended lines. I have actually extended the original lines (58.5') three times.
The initial lap time was 5.12 seconds. After adding about one foot, the lap time was 5.23 seconds. After adding another foot: 5.33 seconds.
Then, I extended the lines for the third time, reaching the lap time of 5.45 seconds.
5.45 seconds per horizontal lap and the ability to fly the entire pattern quite well and like in a slow-motion is only possible when the counter-rotating propellers are used.
My second model (MPBee) is powered by a single motor-single propeller configuration and cannot fly the entire pattern well when the lap time is 5.45 seconds.
When the lap time for MPBee is 5.25-5.3 seconds, the model can fly the entire pattern very well.
So a completely different airplane with (whether you know it or not) different trim and power setup flies differently and has different requirements? Why do you think it is about the counter-rotating rather than, say, different pitch and governor response - or the different everything else?
For example, your experiment might have completely different results if you move the rudder setting 1/32" - making your single-prop setup better and your counter-rotating setup worse. Fly both for a few full seasons (say, 500 flights each), optimizing both in a large range of conditions, THEN you can compare them and come to a reasonable conclusion - which is nonetheless still ambiguous because of the differences in the airframes that you are not controlling for and not considering.
That what I previously meant by "uncontrolled experiment" - definitive conclusions are EXTREMELY DIFFICULT to extract from what we do because of the many uncontrolled variables, and are certainly not possible given a few stabs looking for only the effect you expect and ignoring the far more important (and for the most part, unknown and nearly unknowable) other factor. In this case, two completely different airplanes of different design which you would certainly EXPECT to be wildly different.
I know you will be once again incensed by this comment, and I certainly intend no malice, but I am trying to point out you are jumping to conclusions and you have not at all shown anything definitive about your preferred feature - which almost certainly *does* have some significant benefit and everyone acknowledges would be "better" as a general proposition and considered only for it's angular momentum characteristics.
My conclusion: there is no point to check only the horizontal flight lap time - the entire pattern must be flown in various wind and turbulence conditions.
That is unquestionably true. There are far too many people trying to read all sorts of things in to the few things they happen to be able to measure, rather than using the measurements to inform their knowledge of *all the other things that are more important that they can't measure*. Typical examples are screwing the needle in and out trying to hit that magic RPM someone told them about, or, as you note, trying to hit a particular lap time that they "like".
Brett
Topic: Lines extension (Read 1908 times)