Oh John, that's no fun...........(just kidding & thanks for the additional info)
Now for my $.02, well, maybe $.03
OK, I'll start this off, and this post will deal with mainly "
Line Measurement". One of the most questionable parts of this process, for me, has been coming up with a reasonable, and fairly accurate estimate, as to the amount of bulk line needed, once I have decided to build a specific line set, for instance, 90# x 100'. It's obvious, if we are making a 100' line set that the individual lines have got to be longer that 100', to begin with. We've got to add "
a little extra", to that 100', to compensate for the line used in the sleeved loops, knots, etc. I have always wondered about that "little extra", and pondered if there was a way, to determine that amount, with some bit of accuracy, not only to determine the amount of bulk line to purchase, but to give me a definite "cut length", prior to making my lines. Sometimes, or most times in my case, that "best guess", has ended up producing sets that were several inches longer, or several inches shorter, than expected. Not that this is tremendously important, especially if you are mainly flying alone, but still, I would like to have a starting point, that I could somewhat depend on. So, I thought it would be interesting to hear all "
the different processes & procedures, that different people use to make up their line sets". Line measurement is only one of those procedures.
As for me, my process begins by
pre-stretching the raw line. Many people, have many different ways of doing this, (
maybe someone will chime in and elaborate on that topic later), but basically, it just involves stretching the raw spectra line, until most of the "creep", or gradual elongation, has been removed. That's a feel thing, and again, maybe someone else will elaborate on that. Once the pre-stretching is done, then it's time for the line measurement part, plus that "little extra" that I mentioned, earlier. I'll get back to that later.
Now, before I begin to
measure the spectra line, I'll assume that pre-stretching has already take place, by whatever method deemed appropriate. With this being said, my first step is to clamp or secure, one end of the spectra line to an immovable object, which in my case, is the front edge, of a stationary bench in my workshop. Then I walk the line directly out through my garage door, continuing down my drive way, where I have permanent marks on the edge of the concrete, measured precisely, from the front of my workbench, beginning at 50', and then at 10' intervals, on out to 120 feet. Once at the appropriate mark (in this case 100 feet), I measure, or add-on, "that little extra" length, that I mentioned earlier, and then I place a kite stake "firmly" in the ground, at that exact point. I then carry the line around the kite stake, and back to the front of my workbench, where I pull the line fairly snug, just to remove any obvious slack. Then I temporarily secure this second end to the front of the workbench. At this point, from the bench, out to the kite stake, and back to the workbench, I have exactly two "cut lengths", roughly measured.
NOTE: if you are making a quad set, before doing anything else, you may want to repeat this process by making another complete pass with the line, from the initial starting point (workbench), back out to the kite stake, and back to the beginning. This will give you the two additional lines, for the quad set.
Now, to
equalize the (2 or 4) lines, I release the lines from the front of the workbench, and gently pull on them (pulling against the kite stake), individually and/or together, until each line hangs exactly as the adjacent line, both under tension, and when allowed to sag. Once I am satisfied that all of the lines are equalized, I once again clamp them all together, to the front of my workbench, where I make a mark across the lines, with a Sharpie pen. This will be my final cut mark(s) for each line. Now, I go back out to the kite stake, pull it out of the ground, and with the line(s) still running around the stake, I step back just a little, to take up any slack, again checking to see that all of the lines remain equal, both under tension and when allowed to sag. Assuming that everything looks good, and all lines are still equal, I mark the line again, exactly at the back center of the kite stake, dividing the line(s) into two equal segments. At this point, I
cut the line(s) cleanly, for the first time, and lightly fuse the cut ends (if you don't have a hot knife, a match or lighter will do). Then I go back to the work bench, where I cut & fuse the (2 or 4) lines at the Sharpie marks. Now I have (2 or 4) equally matched lines, ready to be sleeved, which if all goes well, will end up equal in length, and at the desired finished length, +/- an inch (maybe two), but very close. Again, that finished length, is determined by that "little extra", that I added on during in the initial measuring process, as well as how the sleeving is measured, knotted, and looped.
NOTE: For the finished lines to come out equal, the sleeving material must be precisely cut & fused to the exact same lengths. Each end of each line must then be sleeved, knotted, and looped identically, from loop to loop and from line to line, with the only variation being possibly, sleeve color, for desired ID purposes.
Now, as I have referred to, several times previously, should you want that set of lines to end up at a specific finished length, that's where the "
little extra", comes into play. That's what got me to thinking about this whole process, in the first place, and after all this deep thought, discussion, and burning up of good brain cells, as well as agonizing (not really) over the whole situation, I suppose that it all comes back to the one big question,
"Does a few inches either way, really matter?". IMHO, the answer to that is "NO", as has been stated elsewhere in this forum several times. What is much more important here, is that the lines that you make, are consistent and equal to each other. However, being somewhat of a perfectionist, occasionally I get hung up on the calculations, and the precision of those calculations, and that's all that the remaining part of this post, is really about. So, I did some actual trials, and I did some simple calculations, and I came up with, for lack of a better term, a pretty decent planning tool, so far as determining, the raw line needed, to yield a predetermined finished length. I also put together a few charts, for my own use, that have worked quite well, and provide me with a quick, and pretty accurate reference point, however, the forum doesn't like Excel Spreadsheets, so I'll spare you those. But, as for predetermining, that rough "Cut Length", there is really nothing magic about it. It's just simple math, and being consistent with what you do, from loop to loop and from line to line . So far, my trials have yielded finished lines, within +/- 1", or less, of the specified, or desired finished length, and here's all there is to it,
(and yes, it's quite simple, but bare with me, I'm trying to explain this for someone that's never done it).
So to come up with a very close, "rough cut length", that will yield a "specific finished length", try this:
Take "
the desired finished length", add "
one (1) length of sleeving", then add
3 inches, then add another
3 inches, and this gives you a rough "
Cut Length", for the raw line. See, that's pretty simple, add one length of sleeving plus 6 inches, for each line, and so far, and it has worked out perfect for me, BUT for this to work, again, you have to use "evenly cut" sleeving, and you'll need to knot that sleeving precisely the same, on every loop, and somewhat close to the method that I describe below, however, I'm sure it will come out very close, no matter what your preferred method of knotting may be. Just be consistent.
This is how I
sleeve and
knot: (see photos below) First of all, after pulling my line through the sleeving material, I allow the line to extend about 1/2" out the terminal end of the sleeving. Then I tie an overhand knot, in the sleeving, about 1/4" from the terminal end of the sleeving, leaving the 1/2" of line protruding. Then I hold to that knot, and firmly pull the sleeving back down the line, away from the knot, so that it becomes tightly stretched, over the spectra line. Then, when I'm sure that there is no slack and nothing loose, I tie a second overhand knot, about 1/4" from the other end of the sleeving. Now, with the sleeving secured on the line, I bring those two knots together, to form the
loop, and proceed to tie, two (2) overhand knots, in the doubled sleeving, just above the previous knots. Try to tie these knots smoothly, with no line roll-overs, which will help to prevent, the spectra line from creeping, or slipping through the sleeving under stress. Now, do this precisely, on each end (or do it with your preferred method), and your finished line, should end up very close to your desired finished length.
Bottom-line: My goal was simply to come up with something, that would indeed, "get me close, very close", to a designated line length, should that be desired or become important, plus, I normally order my line, by the foot, in bulk, according to whatever length set, I plan on making. This being the case, it's always good to be close, although, vendors usually do put a little extra on the spools, just to be sure, but still, my chart enables me to quickly reference the total length of line to order, for whatever sets I may be planning to make. I suppose, short of buying one of the 3000 yard spools, and not worrying about waste, it's more of a planning & ordering tool, than anything else.
Here's a quick example: Assume you want to make a 100 foot line set, and assume that your sleeving is 15" long (can be any length). Here's how I would calculate the rough "cut length".............
100 feet (1200") + 15 inches + 3" + 3" =
1221 inches (or)
101.75 feet (or)
101' 9" which is the initial
100 feet, plus 21 inches (that's the little extra)
NOTE: the +3" and +3", is for the knots, etc, made in each loop, on each end of each line, and that, along with the one length of sleeving, ends up being that "little extra", that seems to make things work out right, in the end.
Examples of some popular line lengths, when using
15" sleeving, so you just
add 21" to the "desired finished length", per line !
For
120 foot finished lines – cut the raw lines 121.75 feet or 121 feet 9 inches (or)
120 feet, plus 21 inches
For
100 foot finished lines – cut the raw lines 101.75 feet or 101 feet 9 inches (or)
100 feet, plus 21 inches
For
85 foot finsihed lines - cut the raw lines 86.75 feet or 86 feet 9 inches (or)
85 feet, plus 21 inches
For
80 foot finished lines – cut the raw lines 81.75 feet or 81 feet 9 inches (or)
80 feet, plus 21 inches
For
75 foot finsihed lines - cut the raw lines 76.75 feet or 76 feet 9 inches (or)
75 feet, plus 21 inches
For
50 foot finished lines – cut the raw lines 51.75 feet or 51 feet 9 inches (or)
50 feet, plus 21 inches
For
30 foot finished lines – cut the raw lines 31.75 feet or 31 feet 9 inches (or)
30 feet, plus 21 inches
For
25 foot finished lines - cut the raw lines 26.75 feet or 26 feet 9 inches (or)
25 feet, plus 21 inches
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