mjosparky 4 #26 August 31, 2006 QuoteQuoteBut...but...I want to know! Ditto. The more I know, the better. Well it looks like Mick had to clean the bathroom. When you are joining two pieces of like material together the joint should have enough inches of stitching to equal the strength of the material being joined. When joining 2 pieces of Type VIII webbing with 5 cord (40 lb.) at 5 SPI you need a minimum of 22.5 inches of stitching to equal the strength of the webbing. (4500 lb.) If you make a 3 inch 4 point or W W pattern you will get 27 inches of stitching which gives you more then the required stitches overall for the joint. 5 X 40 X 27 = 5400 pounds If you were using Type VII webbing, 6500 lb., you would go to a 4” pattern, which would give you 36 inches of stitching. 5 X 40 X 36 = 7200 pounds By wrapping the joint with a piece of something like Type 12 or Type IV you reinforce the joint against the load force being applied in a non-sheer or peel motion. I hope this help more than confuses.My idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
bob.dino 1 #27 August 31, 2006 Yup, makes sense. Hopefully Mick isn't having too many problems with the bathroom. Quote Share this post Link to post Share on other sites
riggermick 7 #28 August 31, 2006 QuoteYup, makes sense. Hopefully Mick isn't having too many problems with the bathroom. Just missing the bowl now and then!! Actually I had to go to work 1/2 way through the discussion What Sparky said basiclly sums it up, it all comes under the heading of "joint efficency". I do find it interesting that the 4 point had no box around it (if I read the photo's correctly), the box not only adds additional stiching and thus joint strength it also provides another barrier to runaway shearing action by retarding/ impeding the inital load force during deceleration. A full confluence wrap of T4 3" and a 4 point box stitch is the best way to construct an upper harness junction involving canopy release hardware. All bets are off if the thread is substandard. I'm going to go out on a limb here but I am willing to bet the thread used in the harness construction is going to be untraceable as no TSO/ ISO process was in place (I'm guessing here based on what I saw in Russia in 1996). Mick. Quote Share this post Link to post Share on other sites
Jeffrey 1 #29 August 31, 2006 Just for grins, I decided to mock this up and play a little tug of war with a 50 lb. weight and one 6’ drop. The load on the junctions was taken in peel just as a reserve risers may load on a diagonal due to an undesirable body position at deployment. This is not the first time I have seen this type of damage. If I had a very old spool of 5 cord laying around I would have compared it as well. I’m sure the results would have been just as predictable. The top mockup has the box across the top of the 4 point stitch pattern with a type 12 confluence wrap and 5.5 SPI. The bottom mockup has no box across the top of the 4 point with a 3” type 4 confluence wrap and 5.5 SPI. Guess it s pretty obvious why we left that box stitch in when the RW1’s and RW7 came out. Jeff Quote Share this post Link to post Share on other sites
mjosparky 4 #30 August 31, 2006 It looks like you tested both methods on the same drop. For the test to be valid you would need to test each one separately. That way you know that the given load was taken by just the one joint. jmoMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
JerryBaumchen 1,354 #31 August 31, 2006 Hi Sparky, One caveat to your calculations: back when I was a young rigger (yes, Sparky; just after they discovered dirt) and doing some very crude harness designing, an old rigger out here on the west coast by the name of Eddie Brown helped/taught me a lot. He always said to reduce your calculations by 15% because of thread damage as it goes through the sewing machine. I always have and I always will. I use the assumption that the thread is the cheapest item in a rig. Jerry PS) A nice explanation; there is hope for you. Quote Share this post Link to post Share on other sites
rigger_john 0 #32 August 31, 2006 I was told 20% by my examiner, I wonder if there is a correct figure, maybe it depends on a lot ov varibles, machine speed, needle size, age of thread._________________________________________ Nullius in Verba Quote Share this post Link to post Share on other sites
riggermick 7 #33 August 31, 2006 QuoteIt looks like you tested both methods on the same drop. For the test to be valid you would need to test each one separately. That way you know that the given load was taken by just the one joint. jmo Even if they were done together it still validates the point about the "box" pattern. All things being equal the load would have been shared by both joints, this is scary as it means aprox 1/2 the force used was required to seperate the joint. Mick. Quote Share this post Link to post Share on other sites
Jeffrey 1 #34 August 31, 2006 Mick, Thanks for pointing that out. That’s all I intended to do in the first place and why I called it a little tug of war, just for grins. This was only a little 25 min. test to highlight the first obvious flaw in that system you previously pointed out in this thread. Sparky, Had I intended put some real numbers on it, I would drawn up test program and the drops would not have been in my office and taken far longer than 25 min. to only find out what we learned over 25 years ago. Jeff Quote Share this post Link to post Share on other sites
alexey 6 #35 September 5, 2006 And, here is a new example of the work from same company - size correction of Racer http://www.skycentre.net/index.php?showtopic=2231&st=0 Smart construction Lexa Quote Share this post Link to post Share on other sites
riggerrob 643 #36 September 5, 2006 QuoteAnd, here is a new example of the work from same company - size correction of Racer http://www.skycentre.net/index.php?showtopic=2231&st=0 Smart construction >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Those stitch patterns look cute - sort of like old Soviet military surplus harnesses - and "busy", but the chest and hip joints are so small that they don't have enough stitches to be very strong.Good thing that chest strap is wrapped around the MLW. I am not quite sure why they bothered with that bottom confluence wrap ... Rigging Innovations just uses a row of E-thread zig-zag stitching. Quote Share this post Link to post Share on other sites
RiggerLee 61 #37 September 5, 2006 I have no idea what they are saying so I'm trying to understand the pic. Does the front riser come down and wrap around the hip ring and go back up and terminate before it goes through the main 4 point? Does the rear turn back up to become the loop for the RW-1? Where is the diaganal from the back? LeeLee lee@velocitysportswear.com www.velocitysportswear.com Quote Share this post Link to post Share on other sites
alexey 6 #38 September 5, 2006 Ok, I'll try to explane. That rigger was asked to shorten MLW. So, he remove chest strap, and cut some lenth from inside layer of MLW. (so make MLW shorter) Then he made new cheststrap and "confluence wrap" above hip ring. So, the front reserve riser go thry 3-ring, down to the hip ring, then do up and termanate just above chest strap. And back reserve riser is just sewed by main stitch pattern. But - after installation on chesrstrap and low confluence wrap the pocket for reserve handle became so small, that reserve hanle always fall out. After two-out because of that, jumper give that system to different rigger, he opened mudflaps and was schoked...Lexa Quote Share this post Link to post Share on other sites
RIGGER 0 #39 September 5, 2006 Who is controling the riggers & rigging system in your country ? Safe Rigging !!! Quote Share this post Link to post Share on other sites
teason 0 #40 September 6, 2006 The main error in the harness lies in the lower confluence just above the hip ring not under the mud flap. Type XVII is far too small and requires a four point stitch over type VIII. The termination under the mud flap isn't the problem, it's the poor confluence at the ring. ... well that and the chest strap is the backwardsI would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites
alexey 6 #41 September 6, 2006 QuoteWho is controling the riggers & rigging system in your country ? Nobody Fun, yeLexa Quote Share this post Link to post Share on other sites
skydiverek 63 #42 September 6, 2006 Quoteand the chest strap is the backwards Just like all Racers . Quote Share this post Link to post Share on other sites
riggermick 7 #43 September 6, 2006 QuoteQuoteAnd, here is a new example of the work from same company - size correction of Racer http://www.skycentre.net/index.php?showtopic=2231&st=0 Smart construction >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Those stitch patterns look cute - sort of like old Soviet military surplus harnesses - and "busy", but the chest and hip joints are so small that they don't have enough stitches to be very strong.Good thing that chest strap is wrapped around the MLW. I am not quite sure why they bothered with that bottom confluence wrap ... Rigging Innovations just uses a row of E-thread zig-zag stitching. Rob, Looking at the pic's it's a good thing that the lower confluence is there. If I'm seeing it correctly, all of the structural stitching on the main lift webs amounts to two small three points and 3/8 " of the upper 4 points that catch the very tip of the MLW turn back. It would tear the webbing to shreads if heavily loaded with out the two three points below it. Excluding the afore mentioned 3/8 " of stitching catching the MLW turn back (useless under load), the two three points (30 spi x 40 lb = 1200 + 40 spi x 40 lb = 1600 lb) =2800 lb total. Below the webbing strength, but above the hardware limit although, not by much it is not a good scenario, there is ZERO over build in this harness!! The weak point is the single layer of T 7 left below the upper 4 point. One can only hope this "rigger" got his thread from a different scource than the stuff used in the other harness we have been discussing. Yikes!! Mick. Quote Share this post Link to post Share on other sites
riggermick 7 #44 September 6, 2006 QuoteThe main error in the harness lies in the lower confluence just above the hip ring not under the mud flap. Type XVII is far too small and requires a four point stitch over type VIII. The termination under the mud flap isn't the problem, it's the poor confluence at the ring. ... well that and the chest strap is the backwards Couldn't DISSagree more, see my post to Rob one post back. I't explains my reasoning. Mick. Quote Share this post Link to post Share on other sites
rigger_john 0 #45 September 6, 2006 QuoteThe weak point is the single layer of T 7 left below the upper 4 point. Ok Mick I'm lost! Do you mean the single Layer of Type 13?_________________________________________ Nullius in Verba Quote Share this post Link to post Share on other sites
riggermick 7 #46 September 6, 2006 QuoteQuoteThe weak point is the single layer Shit, you're right it is T 13!! It's early here on the west coast, gimmie a break. But the weak point is still there when compared to the overall design. Harness webbing has a tendency to fail at the ends of stitch patterns when loaded to destruction. My bad about the T7/ T13 thing, yawn. Mick Quote Share this post Link to post Share on other sites rigger_john 0 #47 September 6, 2006 In that case I agree with you. I just thought my eyesight was going John_________________________________________ Nullius in Verba Quote Share this post Link to post Share on other sites riggerrob 643 #48 September 6, 2006 QuoteOk, I'll try to explain. That rigger was asked to shorten MLW. So, he remove chest strap, and cut some length from inside layer of MLW. (so make MLW shorter) Then he made new cheststrap and "confluence wrap" above hip ring. So, the front reserve riser go through 3-ring, down to the hip ring, then do up and terminate just above chest strap. And back reserve riser is just sewed by main stitch pattern. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> In comparison, if you mailed your Flexon or Talon ('94, 2, 3, FS, etc.) or Voodoo back to Rigging Innovations for the same harness re-size, they would cut out the old MLW and discard it. Then they would pull fresh Type 7 webbing off the roll, mark it on a production template and sew it onto the old harness. The new webbing would start at the front reserve connector link, go down through - through the slot in the 3-Ring - through the hip (or chest) ring, then back up to the rear reserve connector link .... sort of an over-grown set of reserve risers. By using one piece of webbing and wrapping it around the hip ring, you vastly reduce the importance/dependence upon stitching. Quote Share this post Link to post Share on other sites teason 0 #49 September 6, 2006 QuoteQuoteand the chest strap is the backwards Just like all Racers . Actually, the one in the pic is the right way for other rigs but backwards for a racer which is backwards to all the others which means the right direction is the wrong direction. That means if he put it on right, it would be the wrong way round for other gear but he put it on wrong because he thought it should go the right way and ... uh .... ....What the hell am I talking about?!?I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites teason 0 #50 September 6, 2006 Quote In comparison, if you mailed your Flexon or Talon ('94, 2, 3, FS, etc.) or Voodoo back to Rigging Innovations for the same harness re-size, they would cut out the old MLW and discard it. Then they would pull fresh Type 7 webbing off the roll, mark it on a production template and sew it onto the old harness. The new webbing would start at the front reserve connector link, go down through - through the slot in the 3-Ring - through the hip (or chest) ring, then back up to the rear reserve connector link .... sort of an over-grown set of reserve risers. True enough but the mod that was done was not that far off the mark, it just simply showed a lack of understanding on the concept of joint efficiency when the lower confluence was done incorrectly and went unnoticed because of the assumtion that the webbing continued in through the three ring and upwards. You can't blame the rigger for different design process of the original manufacturer. Racers and Talons are different animals. What is in question is not the rigger's desire to do take short cuts but his/her lack of understanding of design and the basic rigging concept of joint efficiency. The lack of understanding could be the route of the failure on the student gear.I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites Prev 1 2 3 Next Page 2 of 3 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 Go To Topic Listing
rigger_john 0 #47 September 6, 2006 In that case I agree with you. I just thought my eyesight was going John_________________________________________ Nullius in Verba Quote Share this post Link to post Share on other sites
riggerrob 643 #48 September 6, 2006 QuoteOk, I'll try to explain. That rigger was asked to shorten MLW. So, he remove chest strap, and cut some length from inside layer of MLW. (so make MLW shorter) Then he made new cheststrap and "confluence wrap" above hip ring. So, the front reserve riser go through 3-ring, down to the hip ring, then do up and terminate just above chest strap. And back reserve riser is just sewed by main stitch pattern. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> In comparison, if you mailed your Flexon or Talon ('94, 2, 3, FS, etc.) or Voodoo back to Rigging Innovations for the same harness re-size, they would cut out the old MLW and discard it. Then they would pull fresh Type 7 webbing off the roll, mark it on a production template and sew it onto the old harness. The new webbing would start at the front reserve connector link, go down through - through the slot in the 3-Ring - through the hip (or chest) ring, then back up to the rear reserve connector link .... sort of an over-grown set of reserve risers. By using one piece of webbing and wrapping it around the hip ring, you vastly reduce the importance/dependence upon stitching. Quote Share this post Link to post Share on other sites teason 0 #49 September 6, 2006 QuoteQuoteand the chest strap is the backwards Just like all Racers . Actually, the one in the pic is the right way for other rigs but backwards for a racer which is backwards to all the others which means the right direction is the wrong direction. That means if he put it on right, it would be the wrong way round for other gear but he put it on wrong because he thought it should go the right way and ... uh .... ....What the hell am I talking about?!?I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites teason 0 #50 September 6, 2006 Quote In comparison, if you mailed your Flexon or Talon ('94, 2, 3, FS, etc.) or Voodoo back to Rigging Innovations for the same harness re-size, they would cut out the old MLW and discard it. Then they would pull fresh Type 7 webbing off the roll, mark it on a production template and sew it onto the old harness. The new webbing would start at the front reserve connector link, go down through - through the slot in the 3-Ring - through the hip (or chest) ring, then back up to the rear reserve connector link .... sort of an over-grown set of reserve risers. True enough but the mod that was done was not that far off the mark, it just simply showed a lack of understanding on the concept of joint efficiency when the lower confluence was done incorrectly and went unnoticed because of the assumtion that the webbing continued in through the three ring and upwards. You can't blame the rigger for different design process of the original manufacturer. Racers and Talons are different animals. What is in question is not the rigger's desire to do take short cuts but his/her lack of understanding of design and the basic rigging concept of joint efficiency. The lack of understanding could be the route of the failure on the student gear.I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites Prev 1 2 3 Next Page 2 of 3 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
teason 0 #49 September 6, 2006 QuoteQuoteand the chest strap is the backwards Just like all Racers . Actually, the one in the pic is the right way for other rigs but backwards for a racer which is backwards to all the others which means the right direction is the wrong direction. That means if he put it on right, it would be the wrong way round for other gear but he put it on wrong because he thought it should go the right way and ... uh .... ....What the hell am I talking about?!?I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites
teason 0 #50 September 6, 2006 Quote In comparison, if you mailed your Flexon or Talon ('94, 2, 3, FS, etc.) or Voodoo back to Rigging Innovations for the same harness re-size, they would cut out the old MLW and discard it. Then they would pull fresh Type 7 webbing off the roll, mark it on a production template and sew it onto the old harness. The new webbing would start at the front reserve connector link, go down through - through the slot in the 3-Ring - through the hip (or chest) ring, then back up to the rear reserve connector link .... sort of an over-grown set of reserve risers. True enough but the mod that was done was not that far off the mark, it just simply showed a lack of understanding on the concept of joint efficiency when the lower confluence was done incorrectly and went unnoticed because of the assumtion that the webbing continued in through the three ring and upwards. You can't blame the rigger for different design process of the original manufacturer. Racers and Talons are different animals. What is in question is not the rigger's desire to do take short cuts but his/her lack of understanding of design and the basic rigging concept of joint efficiency. The lack of understanding could be the route of the failure on the student gear.I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites
