al05r 2 #1 Posted June 9, 2019 (edited) Hi all. So my rigger just installed a new Vectran 400 line set on my JFX87. Jumped it and all appears normal, however when packing I noticed the stitching on the cascades end about 1cm lower than the point where the cascade emerges from the "outer" line. Of course I brought it to his attention, and while he didn't have a particular reason for doing so, he also didn't think there is any issue with this method. I also showed it to the other rigger on the DZ, his preferred method is to finish the stitch right at the cascade mark. Again, he had no particular reason for doing so, other than copying what the manufacturer did. He also pointed out that he only has experience with PD linesets, and the method for NZA may well be different. Looking at some Youtube videos, I found other riggers claiming this can create friction and increased wear on the outer line due to friction. I'll give NZA a call tomorrow (Monday), but in the meantime I'm wondering what the riggers on here think. Is this a major issue that will significantly reduce the life of my lineset? Is the cure just putting another stitch on higher up, or would one need to unpick the existing ones first? Edited June 9, 2019 by al05r Quote Share this post Link to post Share on other sites
Deyan 36 #2 June 9, 2019 If the rest is fine ( stitch quality,thread size....etc) 1 cm lower than the start of the cascade is not a problem. That's how at least one major manufacturer lets them out of the factory floor. Quote Share this post Link to post Share on other sites
al05r 2 #3 June 10, 2019 Cool, thanks for the info Quote Share this post Link to post Share on other sites
al05r 2 #4 June 11, 2019 Just to add for anyone looking at this in the future, the response from NZA was "Don't worry, it will not increase wear". Just being a bit too paranoid I guess... Quote Share this post Link to post Share on other sites
wolfriverjoe 1,523 #5 June 11, 2019 7 hours ago, al05r said: Just to add for anyone looking at this in the future, the response from NZA was "Don't worry, it will not increase wear". Just being a bit too paranoid I guess... Meh. You saw something that looked 'funny', so you asked. As it turns out, it was nothing to worry about. What if it had been a mistake? Being concerned about those lines on that canopy isn't 'paranoid', IMO. Quote Share this post Link to post Share on other sites
riggerrob 643 #6 June 12, 2019 Tolerance - between the finger trap and first stitch is "minus zero or plus a half inch." Too close and the separate lines will tear stitches. Too far and most people do not notice. The primary function of the stitch is to hold lines in alignment until the finger trap is loaded. Almost any stitch will hold thing sin alignment. Once the finger trap is loaded, it will lock in place. Quote Share this post Link to post Share on other sites
mark 107 #7 June 13, 2019 2 hours ago, riggerrob said: Tolerance - between the finger trap and first stitch is "minus zero or plus a half inch." Too close and the separate lines will tear stitches. I'm not sure this correct. Before there were fingertraps, ParaFlite just bartacked one piece of flat-braided dacron B/D cascade directly on top of a piece of flat-braided dacron A/B line. MC4/MC5 (CT6 for Canadians like riggerrob!) were made like that too. I don't recall any issues with the bartack stitches breaking. Quote Share this post Link to post Share on other sites
al05r 2 #8 June 13, 2019 5 hours ago, mark said: [...] bartacked one piece of flat-braided dacron B/D cascade directly on top of a piece of flat-braided dacron A/B line. [...] I guess the key words are "bartacked" and "dacron" though ... these lines are too thin for that. Quote Share this post Link to post Share on other sites
mark 107 #9 June 13, 2019 12 hours ago, al05r said: I guess the key words are "bartacked" and "dacron" though ... these lines are too thin for that. Doesn't matter how thin the lines are. The spreading force is concentrated at exactly the point where the cascade joins the continuous line, and it doesn't seem to matter much whether the lines are held together by carriers in the outer line or by the very last stitch in the bartack. Quote Share this post Link to post Share on other sites
RiggerLee 61 #10 June 13, 2019 All the canopies that I can think of that were made that way were lined with the wide flat dacron. You could really sew the hell out of it. It was also harder to fingertrap with that tighter weave. I doubt it was as strong as a proper fingertrap. I think you would have needed about twice the stitching that they had in it to get to the same percent of strength that you can get with a finger trap, at least with a modern loser weave line. Lee Quote Share this post Link to post Share on other sites
RiggerLee 61 #11 June 13, 2019 I might also point out that there is no force spreading, pealing them apart till the slider descends bellow the cascade. By then you are past the worst of the opening shock. All the real force is in straight shear. Lee Quote Share this post Link to post Share on other sites
