Nov 13, 2012, 12:51 PM
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sigma main having tension knot malfunctions
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Hi
in the past year or so my dz has had 6 malfunctions due to tension/pressure knots (3/4 way up lines) on a sigma 370 main
-the first 2 happened within 6 weeks of each other, we (Tm's) discussed packing technique with packers, in refference to line tension and line stowing. - no mals happened for about 6 weeks, on the 3rd we thought it was possible it was due to the line set as the lines where due for a reline - we didnt have another malfunction for about 4 or 5 months - the last 3 have happened within the last 2 months
- all different packers packed the malfunctions one of which was the dzso - all on the that sigma 370 alone, other sigma canopys havnt had issues with
Nov 13, 2012, 1:35 PM
Post #3 of 6
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Re: [Frankie84] sigma main having tension knot malfunctions
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Dacron lines?
Untwist the control lines, when they start to twist up the cascade flattens out and will grab the C/D cascade in front of it during opening. It gets MUCH worse as the lines age. 3 of my 4 tandem chops were due to this.
Nov 13, 2012, 2:08 PM
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Re: [AggieDave] sigma main having tension knot malfunctions
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we had a huge problem with tension knots also. even on newly replaced line sets. the issue was with the brakelines especially, i emailed UPT at the time and there was a fix that you could do. you have 2 brake lines, the primary and secondary breaks. the fingertrap where the brake lines cascades where the excact same lenght making a lot of bulk there. if you adjust that fingertrap on the secondary brake line, IE make it shorter so that they are off set from the primary lines, that will help matters considerably. although a new lineset should have that correction already built into them.as someone else mentioned make sure the line twist are taking out on the brakelines every couple repacks. i know its a pain in the bud but it does help and reduces cutaways. we had something like 25-30 of them in a year. but we have knocked that right down these days. hope that helps rodger
Nov 15, 2012, 3:34 PM
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Re: [Frankie84] sigma main having tension knot malfunctions
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I can say that on almost 5000 Sigma 340 or 370 dacron or Vectran, you can eliminate a lot of those only by making sure that the trap door is not to long. Ask Mark Procos about us at Voltige2001 dz and ever since we keep the kill line long enough, we never had this kind of mal .They did a bulletin about the length that you should have and believe me, line stretch make a big difference. As soon as you feel yourself in a too long trap door, you get a chance to get tension knots, happen more on old lines as well. We reline our canopies every season. Hoping that helps to solve your problems
