SkydiveMonkey 0 #1 December 31, 2001 After how many jumps is it advisable to reline a sabre (it's a 170 loaded at 1.2 if that makes a difference). I like my women like I like my coffee - hot and with a spoon in Quote Share this post Link to post Share on other sites riggerrob 643 #2 December 31, 2001 Lightly loaded canopies - like your Sabre at 1.2 - can go as long as 600 jumps between relines, but performance suffers if you wait that long.Heavily loaded canopies (2 pounds per square foot) need to be relined as often as every 200 hundred jumps if you want to medal in blade running competitions.Tandem canopies, like SET 400s lose flare power and they start opening weird with more than 300 jumps on a line set. Quote Share this post Link to post Share on other sites skybytch 273 #3 January 1, 2002 What Rob said, but it depends on line type too. 550 microline needs to be replaced more often than 825 microline which needs to be replaced more often than dacron (the thick stuff). Vectran is tougher to tell when to reline cuz it doesn't show wear like dacron or microline does.If you're noticing that your canopy isn't flying like it used to, have your rigger check the line trim against the mfrs. specs. Microline stretches and the canopy can go "out of trim" long before the lines start showing wear.pull and flare,lisa Quote Share this post Link to post Share on other sites alan 1 #4 January 1, 2002 Vectran is not as abrasion resistant as Spectra and will show considerable wear after 200 or so jumps but it is much more resistant to heat and will stay in trim longer. Where you jump also affects line wear, so 100 jumps in some sandy, dusty DZ in AZ may result in considerably more wear than a nice grassy DZ in PA. Spectra typically does not go out of trim as a result of stretching, but shrinks from the heat generated by the friction from the slider grommets coming down and from the friction from the elongation and contraction of the fibers themselves during openings. The outboard "A" and "D" lines, and the brake lines usually show the most wear and shrinkage. The manufacturer of your canopy will be happy to provide the correct trim tolerances if your rigger doesn't already have them. They are sometimes included in the owners manual of the canopy. Have a competent rigger check the trim and if it is out of the manufacturers recommended tolerances, have it re-lined.Because Spectra lines shrink slowly over a period of several hundred jumps, the change in performance it effects on the canopy is subtle and often goes unnoticed. The jumper slowly adjusts and compensates. This is bad and I suspect it is, in many cases, a substantial factor in the performance characteristics that are attributed to canopies, ie., it flares bad, opens hard, snivels too long, etc.. Many people give out opinions on the performance of a canopy and don't even realize that it may be badly out of trim, thus giving false impressions.So, bottom line..... your Spectra lines may need to be replaced after "around" 300 jumps because they will most likely be getting out of trim. Vectran lines may need replacing "around" 300 jumps because they are worn, even though they will most likely still be in trim. alan Quote Share this post Link to post Share on other sites skybytch 273 #5 January 1, 2002 Doh! Thanks for clearing up my errors there, alan {smile]pull and flare,lisa Quote Share this post Link to post Share on other sites Aviatrr 0 #6 January 1, 2002 Alan, what are the recommended reline times for HMA lines? I recently got a canopy with HMA(loaded around 1.6) and have heard various ideas about when it should be relined.. It's only got 20 jumps on it right now, so it's not an issue for now.....but I'm not sure how easy it will be to tell when these lines are wearing out.. Spectra is easy.. Vectran is not......how 'bout HMA? My canopy has 346lb continuous HMA lines.. Mike Quote Share this post Link to post Share on other sites cobaltdan 0 #7 January 2, 2002 hma and vectran are both aramids. vectran is just a trade name...as far as when to reline, simply learn how to measure your lines and do so every once in a while.to check you lines:1) get a line dimension chart from the canopy manufacturer2) stretch out a tape measure on the floor and nail the start to the floor, leaving the nail sticking up3) put you links on the nail, and measure 2 lines at a time, (same lines one left and one right)4) measure all lines and record on paper, try to use even force when tensioning the lines.5) subtract out the length of the link and compare your chart with the factory specs.simple, should take you about 10 mins.note: uneven dimensional change is an indication for reline on lines such as spectra,aramid based lines will not appreciably change dimension, and will: develop micro filament fractures, and uv fiber strength degradation that are both difficult or impossible to tell by a simple inspection. best senario for these lines to to treat them very well and religiously change then based on the # of jumps recommended by the manufacturer.sincerely,danatair Quote Share this post Link to post Share on other sites alan 1 #8 January 2, 2002 Mike, sorry for the delay in responding. I've been busy with the Holidays and all and wanted to get some additional info as well. I talked to Chris Martin at Precision and he will be sending me some technical information soon and I will post it when I get it. Until then, here is what I can tell you. Your canopy is probably "mostly" 346# HMA and you should plan on replacing them after about 800 jumps. These lines have been in field use for several years now on the Nitro with line sets lasting over 1200 jumps. I don't think we will see a repeat of what we saw with Vectran lines where many people were surprised to see how fast they "wore out".There are considerable differences between HMA lines and other arimids. Kevlar, for example is an arimid that was used for suspension lines at one time. Its use has faded as other fibers exhibited better overall performance. Kevlar is a _low_ modulus arimid. Vectran and HMA differ as well. You will find the HMA lines to be MUCH more resistant to abrasion while remaining very dimensionally stable. I hope this helps for now and I will post more later.alan Quote Share this post Link to post Share on other sites Aviatrr 0 #9 January 3, 2002 Quote Your canopy is probably "mostly" 346# HMA and you should plan on replacing them after about 800 jumps. These lines have been in field use for several years now on the Nitro with line sets lasting over 1200 jumps. Wow....I knew that HMA had a longer life expectancy than Vectran, but I had no idea it was that long.. It'll take me a few years to get that many jumps on the canopy, especially since I jump two separate rigs..I'm pretty sure that all the lines except for the brake lines are 346.. The brake lines are much thicker up to the point that it cascades to the 4 individual lines, then they appear to be the same as the rest of the canopys lines.. The only thing I've noticed so far that I don't like is that the rubber bands don't seem to grip the HMA lines as well as Spectra or Vectran......so I'm more careful with my line stows.. Looking forward to the technical info..Mike Quote Share this post Link to post Share on other sites GroundZero 0 #10 January 8, 2002 All Ground Zero canopies, (Xaos-21, Nitron and Synergy) use three different sizes of HMA line. The suspension lines are 160 kg. except for the outboard lines (at the Stabilribs). The outboard lines are 200 kg. strength as are the upper control lines. The lower control lines are 430 kg. strength.Mike has a important comment to note... This line is considerably smaller than any other line used for sport canopies. Attention must be given to line stows (rubber bands). Trying to stow these lines with your same large bands that were used for any other line would be equivalent to losing 100 lbs and not buying a smaller belt to hold your pants up. Use compatible components (i.e. small bands for small lines). Personally, I prefer to double wrap the stows.Sorry Alan, I have not had time to respond to your request for more technical information. Perhaps it would be easier to answer any specific questions here. I'll check back often, if anyone has any questions about HMA, let me know.Chris MartinPrecision Aerodynamics, Inc. Quote Share this post Link to post Share on other sites pchapman 279 #11 September 4, 2002 > hma and vectran are both aramids. vectran is just a trade name... I believe Vectran, which is described as a liquid crystal polymer, is NOT an aramid. The makers of the Vectran product (Celanese) say this: "Vectran fiber is a polyester-polyarylate fiber. The differences between Vectran fiber and two other high-performance fibers [...] are as follows: Vectran fiber is thermotropic, it is melt-spun, and it melts at a high temperature. Aramid fiber is lyotropic, it is solvent-spun, and it does not melt at high temperature." In any case, it is the actual differences or similarities of the two materials that matter. Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0
riggerrob 643 #2 December 31, 2001 Lightly loaded canopies - like your Sabre at 1.2 - can go as long as 600 jumps between relines, but performance suffers if you wait that long.Heavily loaded canopies (2 pounds per square foot) need to be relined as often as every 200 hundred jumps if you want to medal in blade running competitions.Tandem canopies, like SET 400s lose flare power and they start opening weird with more than 300 jumps on a line set. Quote Share this post Link to post Share on other sites
skybytch 273 #3 January 1, 2002 What Rob said, but it depends on line type too. 550 microline needs to be replaced more often than 825 microline which needs to be replaced more often than dacron (the thick stuff). Vectran is tougher to tell when to reline cuz it doesn't show wear like dacron or microline does.If you're noticing that your canopy isn't flying like it used to, have your rigger check the line trim against the mfrs. specs. Microline stretches and the canopy can go "out of trim" long before the lines start showing wear.pull and flare,lisa Quote Share this post Link to post Share on other sites
alan 1 #4 January 1, 2002 Vectran is not as abrasion resistant as Spectra and will show considerable wear after 200 or so jumps but it is much more resistant to heat and will stay in trim longer. Where you jump also affects line wear, so 100 jumps in some sandy, dusty DZ in AZ may result in considerably more wear than a nice grassy DZ in PA. Spectra typically does not go out of trim as a result of stretching, but shrinks from the heat generated by the friction from the slider grommets coming down and from the friction from the elongation and contraction of the fibers themselves during openings. The outboard "A" and "D" lines, and the brake lines usually show the most wear and shrinkage. The manufacturer of your canopy will be happy to provide the correct trim tolerances if your rigger doesn't already have them. They are sometimes included in the owners manual of the canopy. Have a competent rigger check the trim and if it is out of the manufacturers recommended tolerances, have it re-lined.Because Spectra lines shrink slowly over a period of several hundred jumps, the change in performance it effects on the canopy is subtle and often goes unnoticed. The jumper slowly adjusts and compensates. This is bad and I suspect it is, in many cases, a substantial factor in the performance characteristics that are attributed to canopies, ie., it flares bad, opens hard, snivels too long, etc.. Many people give out opinions on the performance of a canopy and don't even realize that it may be badly out of trim, thus giving false impressions.So, bottom line..... your Spectra lines may need to be replaced after "around" 300 jumps because they will most likely be getting out of trim. Vectran lines may need replacing "around" 300 jumps because they are worn, even though they will most likely still be in trim. alan Quote Share this post Link to post Share on other sites
skybytch 273 #5 January 1, 2002 Doh! Thanks for clearing up my errors there, alan {smile]pull and flare,lisa Quote Share this post Link to post Share on other sites
Aviatrr 0 #6 January 1, 2002 Alan, what are the recommended reline times for HMA lines? I recently got a canopy with HMA(loaded around 1.6) and have heard various ideas about when it should be relined.. It's only got 20 jumps on it right now, so it's not an issue for now.....but I'm not sure how easy it will be to tell when these lines are wearing out.. Spectra is easy.. Vectran is not......how 'bout HMA? My canopy has 346lb continuous HMA lines.. Mike Quote Share this post Link to post Share on other sites
cobaltdan 0 #7 January 2, 2002 hma and vectran are both aramids. vectran is just a trade name...as far as when to reline, simply learn how to measure your lines and do so every once in a while.to check you lines:1) get a line dimension chart from the canopy manufacturer2) stretch out a tape measure on the floor and nail the start to the floor, leaving the nail sticking up3) put you links on the nail, and measure 2 lines at a time, (same lines one left and one right)4) measure all lines and record on paper, try to use even force when tensioning the lines.5) subtract out the length of the link and compare your chart with the factory specs.simple, should take you about 10 mins.note: uneven dimensional change is an indication for reline on lines such as spectra,aramid based lines will not appreciably change dimension, and will: develop micro filament fractures, and uv fiber strength degradation that are both difficult or impossible to tell by a simple inspection. best senario for these lines to to treat them very well and religiously change then based on the # of jumps recommended by the manufacturer.sincerely,danatair Quote Share this post Link to post Share on other sites
alan 1 #8 January 2, 2002 Mike, sorry for the delay in responding. I've been busy with the Holidays and all and wanted to get some additional info as well. I talked to Chris Martin at Precision and he will be sending me some technical information soon and I will post it when I get it. Until then, here is what I can tell you. Your canopy is probably "mostly" 346# HMA and you should plan on replacing them after about 800 jumps. These lines have been in field use for several years now on the Nitro with line sets lasting over 1200 jumps. I don't think we will see a repeat of what we saw with Vectran lines where many people were surprised to see how fast they "wore out".There are considerable differences between HMA lines and other arimids. Kevlar, for example is an arimid that was used for suspension lines at one time. Its use has faded as other fibers exhibited better overall performance. Kevlar is a _low_ modulus arimid. Vectran and HMA differ as well. You will find the HMA lines to be MUCH more resistant to abrasion while remaining very dimensionally stable. I hope this helps for now and I will post more later.alan Quote Share this post Link to post Share on other sites
Aviatrr 0 #9 January 3, 2002 Quote Your canopy is probably "mostly" 346# HMA and you should plan on replacing them after about 800 jumps. These lines have been in field use for several years now on the Nitro with line sets lasting over 1200 jumps. Wow....I knew that HMA had a longer life expectancy than Vectran, but I had no idea it was that long.. It'll take me a few years to get that many jumps on the canopy, especially since I jump two separate rigs..I'm pretty sure that all the lines except for the brake lines are 346.. The brake lines are much thicker up to the point that it cascades to the 4 individual lines, then they appear to be the same as the rest of the canopys lines.. The only thing I've noticed so far that I don't like is that the rubber bands don't seem to grip the HMA lines as well as Spectra or Vectran......so I'm more careful with my line stows.. Looking forward to the technical info..Mike Quote Share this post Link to post Share on other sites
GroundZero 0 #10 January 8, 2002 All Ground Zero canopies, (Xaos-21, Nitron and Synergy) use three different sizes of HMA line. The suspension lines are 160 kg. except for the outboard lines (at the Stabilribs). The outboard lines are 200 kg. strength as are the upper control lines. The lower control lines are 430 kg. strength.Mike has a important comment to note... This line is considerably smaller than any other line used for sport canopies. Attention must be given to line stows (rubber bands). Trying to stow these lines with your same large bands that were used for any other line would be equivalent to losing 100 lbs and not buying a smaller belt to hold your pants up. Use compatible components (i.e. small bands for small lines). Personally, I prefer to double wrap the stows.Sorry Alan, I have not had time to respond to your request for more technical information. Perhaps it would be easier to answer any specific questions here. I'll check back often, if anyone has any questions about HMA, let me know.Chris MartinPrecision Aerodynamics, Inc. Quote Share this post Link to post Share on other sites
pchapman 279 #11 September 4, 2002 > hma and vectran are both aramids. vectran is just a trade name... I believe Vectran, which is described as a liquid crystal polymer, is NOT an aramid. The makers of the Vectran product (Celanese) say this: "Vectran fiber is a polyester-polyarylate fiber. The differences between Vectran fiber and two other high-performance fibers [...] are as follows: Vectran fiber is thermotropic, it is melt-spun, and it melts at a high temperature. Aramid fiber is lyotropic, it is solvent-spun, and it does not melt at high temperature." In any case, it is the actual differences or similarities of the two materials that matter. Quote Share this post Link to post Share on other sites
