Line Length Idea

[Dick Pacini]

I have an idea that may save a few dimes and be an aid to trimming a new airplane.

Most serious C/L enthusiasts change line length to achieve lap times and/or alter flight characteristics a bit.

I suggest cutting up some old lines into 2 sections each of 1, 2 and 3 feet.  Fit the ends with thimbles and wrap.

This assortment would allow line length changes from 1 to 6 feet.  These extensions would be inserted at the handle end to minimize wind resistance from the extra thimble ends and connectors.

My thought was that this would allow determination of correct line length for a new model, so the exact length could be purchased or made up to suit, or used in those situations where you thought "If only my lines were a couple of feet longer," and none were readily available.

Ok, flame away!

[minnesotamodeler]

Actually, seems like a good concept to me. No flames from here.

[Trostle]

That is sort of a neat sounding idea for adjusting to find a desired line length in the trimming process of your model.

HOWEVER----

You cannot fly at a contest with line extensions as proposed.  From the Control Line Gerneral rules, Paragraph 5:

"No more than two connectors may be used per line."

If you are flying an airplane with such extenstions, not even at a contest and the accident was in no way related to the "line extensions" and there is an accident, there could be a problem with insurance.

Keith

[Alan Hahn]

I think for AMA insurance, all you need to do is to satisfy that you followed the AMA CL safety code, which means you did a pull test and followed the line diameter.

The rule book is for competition, and not necessarily for general flying (except for the reference in the safety code to the pull test requirements in the rule book).

However this is my opinion and it doesn't hurt to check up to be sure. Of course extra thimbles and line wraps add up to extra failure points.

I have thought of the same idea for trimming purposes. If you do it, I would do it on the handle side, since you wouldn't have any drag issues with the extra thimbles that you might have if you put the extensions on the wing side.

In the end, I would then cut a new set to match the length that worked the best.

[minnesotamodeler]

My thought was that this would allow determination of correct line length for a new model, so the exact length could be purchased or made up to suit, or used in those situations where you thought "If only my lines were a couple of feet longer," and none were readily available.

Ok, flame away!

Dick's last paragraph kinda touches on both those scenarios, after determining optimal length then "the exact length could be purchased or made up to suit..."--not actually used in contests.   A good idea.
 
But then, "OR...used in those situations (competition?) where you thought 'if only my lines were a couple of feet longer'...".  Maybe not such a good idea.

Still seems to me to be a very useful tool at the practice field.

[Richard Grogan]

Sounds like a great tool for dialing in your PA ship, and replacing them with custom length lines when finished.

[Scott Hartford]

It sounds like a good idea to me!

[W.D. Roland]

Good idea Dick.

I have been planing on doing a similar thing with a U-reely even though its offset and heavy.

I think that line length can be adjusted during flight and allow faster comparisons.
Will try a static/loaded/length change test first.

once lengths are found for each airplane will make them from bulk.

Have not looked in the rules but just wondering if changing length during a competition flight(U-Reely) is legal???
Long for the low altitude stuff and short for overhead?
Just a brain storm that might explode from lightning!

David
51336

[jim gilmore]

Personally I'd use them with one added at each end so as to notr have them catch each other. do the down line on the inbd end  and the up line on the outbd side. Just to reduce the risk of the extra clips getting hung up on the other set of clips.

[Paul Smith]

As Keith says, there is a rule in the CL General Section about only two clips per line.   But this is a Contest rule, not a safety code issue.

If you can make a set of lines with two clips and four terminations (counting leadouts, lines, and handle), you could make a setup with four, six, or ten terminations and/or clips and be no less safe.

The only sense I could ever see behind the "two clip" rule was to preclude sneaking out some line length in a speed event.

On the practical side, back in the olden days some of the younger modelers tried to salvage broken lines by reterminating them and clipping the pieces together.  In every case, the mass and drag of the extra connections (while it did not break) was unacceptable for any enjoyable flying.