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Building Tips and technical articles. => Building techniques => Topic started by: Keith Spriggs on December 20, 2006, 11:54:15 PM
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Bob Johnsons excellent posting about adjustable leadouts got me to wondering if I could make some from aluminum as I am more familiar with metalworking than I am with wood. Here is what I came up with,. The guides are reversable if you want more spread on the lines. The line holes are lined with polyethylene. The flat "wings" are to insert in a slot in the wing. They would have holes drilled in them and contoured to fit the wing, glued in with epoxy. I didn't have any real accurate scales to weigh them with but it appears they would be under 1/2 oz. Fun project.
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I'd work on cutting the weight down. Every 1/2 oz on the inboard tip will need 1/2 oz on the outboard tip to balance it, in addition to the usual tipweight. If it's really 1/2oz, you're net increase is 1 ounce. Plastic and plywood are lighter, and not much brute strength is needed. Epoxy board is another useful material... easy to drill/saw/mill/file, weight is between ply and aluminum. PC board is a decent source, you can etch the copper off, but it is possible to buy bare epoxyboard in various thicknesses.
A single slider, incorporating both LO guides, requires only one lock screw, less weight. Delrin is nice stuff to machine and holds a screw well, or you could press in a T-nut, helicoil or Keen-sert. Keen-serts would be wonderful, but when I bought a few, the sticker shock was awful...$6 each for 4-40's, and that was about 10 years ago. Aluminum socket head screws are available, but I'd probably just downsize to a 2-56. Be sure to smash the last few threads on the screw with diagonal wire cutters, to prevent it from doing a vanishing act. y1 Steve
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I'd work on cutting the weight down. Every 1/2 oz on the inboard tip will need 1/2 oz on the outboard tip to balance it, in addition to the usual tipweight. If it's really 1/2oz, you're net increase is 1 ounce.
Good point Steve. I tend to overbuild. I am going to contine tinkering and the next design will be built for lightness. Is there any advantage to having the guides individually adjustable? I did another one today that I posted. I think it would be lighter than the first one after the mounting bars were trimmed off to a length suitable for installation. I doubt that I will build "a better mousetrap" but it sure is fun trying.
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I *think* a concensus has been reached that dual adj. LOs are not really necessary. The *top* guys like to keep both LOs as close together as possible, it seems. Nobody would probably believe it, but at the 2004 WCs I coulda swore that one very prominent flyer had both LOs coming out the same hole! ;D
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I *think* a concensus has been reached that dual adj. LOs are not really necessary.
Thank You, I will keep tinkering with single adjustments instead of dual. I am learning every day. Three months ago I had never heard of adjustable leadouts.
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I have heeard,( certainly havent the sensitivity to know myself!) that there are gains to be made by being able to move the aft line independent with regards to specific points in specific manuevers. IE more or less tension on the up line(down line for reversed bellcranks.) As I state, I certainly havent the finesse to be able to ascertain any gain from it, just reporting what I have heard.