/ stitching slings from webbing by hand
hi, did any of you ever make slings (from webbing, sewn by hand), or has any info on it? thanks, pit
A sling costs from about 3 quid. Why on earth would you want to?
And, if you really must, tie a tape knot.
Dude, assuming that you are asking for use in a climbing context as you've posted in Rocktalk, if youneed to ask this, there is no earthly reason you should even be attempting it. As Oceanrower says, buy them for peanuts from Decathelon if money is tight, or buy Nylon tape and knot then with a tape knot - plenty of info on the web about that. I would be unhappy even if you'd said you would be doing it on a sewing machine, but by hand? Forget it - Darwin award waiting to happen.
In the early 80s my mates mum made him a sit harness out of a Datson seat belt. She hand sewed it and it looked lethal. My mate trusted it and used it until abbing off a crag the stitching started to burst.
Lucky he didn't fall on it!
Never seen those Camp Pentagons before. Anyone used them?
May be some people have but they wouldn’t be able to respond to your post.
A friend of mine sewed some up on an industrial sewing machine and I tested a few of them for him, they were fine. (We'd acquired some reels of free webbing and he was an experienced sewer). If you don't know what you're doing as other's have said I'd just buy ready sewn ones or knot them.
Back in the day I made quite a reasonable sit harnesss using knotted seat belt webbing, a steel belt buckle and a maillon rapide, more comfortable than a Whillans!!!
"Why on earth would you want to?"
why on earth would someone wanna climb?, thats why.
"In the early 80s my mates mum made him a sit harness out of a Datson seat belt."
we use seat-belts from cars all the time in canyoneering down here in spain. great stuff, & free.
"Back in the day I made quite a reasonable sit harnesss using knotted seat belt webbing.."
the link that connects the leg-loops of my harness to the belay-loop broke twice (wear and tear) - easy fix with a piece of webbing.
From a technical standpoint, sewing slings by hand, you I am sure could get something that will hold some load. But unless you have an Industrial sewing machine, the results are going to at very best highly variable. You've not actually answered the valid question as to why you would want to do this.
That should be:
> "Why on earth would you want to?"
> why on earth would someone wanna plummet to a grisly death followed by a flapping streamer that used to be a home made sling?, thats why.
I have made slings using a bar tacking machine before and they looked good and were quite strong enough with a static load. However, they failed at dramatically different dynamic loads, enough to make me think that I would leave it to those who knew what they are doing for the sake of a few quid.
> In the early 80s my mates mum made him a sit harness out of a Datson seat belt. >
A mate of mine, also in the 80's, couldn't afford a harness, just a waist belt so he hand sewd his own legloops using fishing line.
Tell that to the kids these days (when they're bleating on about how tough it is) and they wouldn't believe you
I hand sewed my first harness with webbing I got from the army surplus store...
So one of the bits of your harness which the rope is tied to is made out of some unspecified webbing which is presumably held together by some DIY stitching. That’s just crazy! I appreciate that a new harness might be a lot of money for some people but what price do you put on your own life?
> "Why on earth would you want to?"
> why on earth would someone wanna climb?, thats why.
Hmm. So you can only climb if you make your own sling out of hand stitched webbing?
Barking. Absolutely barking. I'll take some of what you've been having, please!
I made leg loops to go with a second hand very old Troll climber's belt as my first harness! The leg loops were old car seatbelt sewn on my mum's sewing machine. Fortunately I survived long enough with that to later find a cheap JRat harness in a bargain bin in Birmingham Snow and Rock. Then I just lent the home made one to friends!
God what did you do to your enemies ;)
Amazingly some of those people, who used the home made leg loops, from my 6th form Wednesday afternoon activity sessions - where we decided top roping at Worcestershire's premier cliff using our chemistry teacher's elderly 11 mm rope that he sold to me for a fiver would be our activity - are still my friends 25+ years on!
Well I'm not going to ask why you want to do it, it seems like a reasonable thing to be asking. Whether its a reasonable thing to actually do depends what use you intend to put the sling to.
I'm interested to know in general terns about sewing webbing. My trusty 'do everything' rucksack strap has come detached from the lower fixing point on the bag - a nylon (I assume) triangle to spread the load from the bottom of the strap to the bag. What it really needs is some nifty sewing skills rather than the bodge of rope loop I have right now.
> I'm interested to know in general terns about sewing webbing.
I can recommend upholstery thread for sewing webbing (for rucksack repairs etc. -- re: slings I have no expertise, only a deep sense of dread).
I did some similar things using my wife's Bernina sewing machine in buttonhole mode (where the needle alternates between left and right and the cloth feed is purely manual), e.g. fixing a second ice axe loop to old Macpac rucksack.
Does not look particularly neat, but works. I also replaced the horribly weak webbing loops on my LS Katanas with some old quickdraw slings, but by hand as I did not have a upholsterer's or saddlers sewing machine at hand.
Reattaching your rucksack strap sounds straightforward, give it a try!
Don't use cotton thread as it will rot. Use heavy duty nylon thread (not polyester). Do not sew by hand if you're planning to use it in a context where failure would risk injury. Use an industrial sewing machine and sew one band across and pull test that. The result of the pull test will tell you approximately how many bands you need to sew across to get to 25kN pull strength. Pull test your resulting product to failure, throw it away, and buy a sewn sling instead.
I've fixed several rucksack straps with novice stitching using the correct thread and none have failed again.
> Reattaching your rucksack strap sounds straightforward, give it a try!
Negotiating the use of MrsD's pride and joy sewing machine will not be straightforward !!
Hand or machine sewing ?
It was for me, but exactly once...
Hand back stitched. With some ad lib on top.
I had to replace a strap after someone dropped a flake on my bag (2m long, 2-3 inches thick and a foot wide), If you cut the stitching at the top of the little pocket where the strap is sewn in you can easily slide in the replacement, then stitch it in the shape of a large rectangle along the length of the strap before adding diagonal reinforcements as you feel necessary, pretty easy to do by hand. I did mine about 3.5 years ago and it's not fallen apart yet.
Could do! Fairly sure you'd load them just the once though............
> Negotiating the use of MrsD's pride and joy sewing machine will not be straightforward !!
Then get her to do it!
"But unless you have an Industrial sewing machine, the results are going to at very best highly variable. "
industrial means: more stitches, tighter packing...¿ if you consider how, f.e., a belay-loop is stitched: the material (thread) of stitching is clearly much less (´inferior´) than the actual material (webbing) thats joined. thus: i assume the function of the thread is to ´glue´ the webbing together -- would like to know the physics behind that... and: if , to stick with the example of the belay-loop, it is stress-tested, what gives first, the webbing or the stitching¿
"You've not actually answered the valid question as to why you would want to do this."
out of curiosity (for a start)
"But unless you have an Industrial sewing machine, the results are going to at very best highly variable. You've not actually answered the valid question as to why you would want to do this."
this aint about money (money is boring... thats why a lot of climbing is so boring... too much money in and around it) - its about knowledge (which is exciting... like climbing itself)
"Amazingly some of those people, who used the home made leg loops (...) are still my friends 25+ years on!"
the leg-loops have little function (beside comfort)... (as said earlier, they failed twice on my while falling).... the waist-belt is the knackpunkt
"My trusty 'do everything' rucksack strap has come detached from the lower fixing point on the bag"
(the duct-tape of threads etc - i use it for fixing clothes, shoes, gear...)
I have 2, (I didn't make them) they currently hang from my loft hatch and attach to my axes for pull up training. NOW the worrying thing is they came off my hang glider in the 2000's and were used to attached the harness to the glider. Only years latter when I got into climbing did I look back on then and think, Hmmmmm!
Well OK, thereare several reasons you want an industrial machine - bear with me - webbing is not my field of expertise, metal is more my thing but:
webbing is thick - an industrial machine has a lot more power, uses heavy duty needles and is simply more capable. Most are water cooled so that the needle doesn't overheat when you're doing lots of bar tacks.
An industrial machine of the right variety is programable, so you can accurately repeat the tacks at a known spacing, position and control the thread better.
The thread used as stated elsewhere is a heavy nylon which takes some energy to pull through.
As stated elsewhere you would do a single tack and then test to see how much that held and then multiply with a safety factor built in and then test again.
You would need to do this many times to ensure repeatable, reliable joints.
Belay loops are a bit of an anomoly as far as slings go - they often go round twice which means the stitching is more just to hold it together than anything else - although there is some strength, and of course some loops which just go round once will need the same strength requirements as a standard sling. The strength requirements are that the number of threads joining the sling have a similar strength to the sling it self. Not sure what the normal failure mode is - as I said - not really my thing.
I guess the thing is, to make your own, there are so many variable factors, hand sewing only introduces even more variables and it would just be completely random as to whether you've got it right. A machine makes the process repeatable. Could you produce a sling strong enough hand stitching? No doubt - I mean I once got a thin kevlar thread, looped it four times and could "comfortably" hang body weight from it. But that's not a good enough reason to think that I could make my own slings!
> Then get her to do it!
Do you think I haven't tried that one
reading you i am just glad i dont have one of those industrial machines flying about here ( i´d play around with it a lot .. and try to fashion whatever). but small is beautiful, and simple is smart.
that said, even tho i think stuff we use in climbing, like slings and harness, could be hand-stitched, it all boils down to: scale. a machine-made sling, f.e., can ´pack´ a certain load-factor in a much smaller product than one thats hand-made.
a belay-loop i wouldnt touch (hand-made), by which i dont mean it cannot be done, just that it would probably come out prohibitively cumbersome (but had i to rig one, i´d go for a simple screw-gate carabiner)
btw, i would like to play around some with stress-tests (without having another of those industrial machine here, anybody suggesting any means to approximately get test-results ((numbers)) in some sort of diy-rig¿).
regarding your experiments with kevlar: sounds good....keep it up! i custom-make some stuff at times, mostly from parts pulled from the trash (like enrolled/woven wire into loops etc) - and i test it with falls (with 2nd backup-rope parallel to the set-up).... and as i mentioned before, the guys i go canyoneering with are really ruthless.... with rigs.... but then, first they are spanish and secondly in canyoneering lower load-forces are at works... and since its typically a water-based activity it doesnt matter much pissing yourself in the pants, maybe.
As I said, it's really not so much that you couldn't get something to work by hand stitching, more that you'd struggle to get anything that was vaguely consistent. A machine will do the same thing thousands of times in a row and not make a mistake, a human will. So yes it has to do with scale, but even more so with consistency. You simply would never be able to make two slings the same hand stitching, no matter how good a sewer you are. So even if you did extensive testing, you could not ever guarantee that the next one you sewed would work.
With regards strength testing, you would need a load cell, preferably some sort of displacement sensor and something that can pull a load very slowly and consistently - you see people using hand operated hydraulic jacks - really not the same thing at all as a proper testing rig as the load will be applied in steps and most likely in a "jerky" way. What you want is a pump operated hydraulic jack, or a motor driven screw jack. But, all of that needs to also be super sturdy as any deflection in your set up will show up in your test data. If you have a load cell you can output the analogue signal to an A to D converter, then plug that into a digital data collation system attatched to a PC and view the results in various programmes. To get more information you also want to measure strain as stress is useful but not actually the complete picture - strain will show yield points, how in this case your stitching is breaking. You never know, you might pick that lot up on fleabay. Or I have a 10 tonne Instron testing rig which is in need of a new servo drive - yours for 5000 plus shipping.
You'd need more than just an industrial sewing machine. My friend does the quality checks for a well known climbing gear manufacturer, she has to check EVERY single sling produced, and a percentage of any batch is stressed tested to destruction. Without the correct equipment to stress test, then you would have no way of knowing how good (or not) your hand sewing was.
"...My friend does the quality checks for a well known climbing gear manufacturer, she has to check EVERY single sling produced..."
could you please ask your friend how many duds (rejects) they come across... in percent...., and, also, which products/items have on average a higher fail-rate... thanks a lot... hasta luego
mike, you seem to know a lot about that stuff. stupid question (example: belay-loop): why did they opt for stitching (the joints), and not, f.e., rivets etc -- stronger¿, cheaper¿ faster¿
"With regards strength testing, you would need a load cell, preferably some sort of displacement sensor and something that can pull a load very slowly and consistently ..."
... oh my god, you should see my set-up here .. i dont even have a chainsaw to ´make´ fire-wood
"... I have a 10 tonne Instron testing rig which is in need of a new servo drive - yours for 5000 plus shipping..."
... haha, thats the money i burn through in about a handful of years ... that said, i guess life itself could be seen (felt¿) as a big stress-test-rig...
If you can test your designs and reproduce the work reliably there is no technical reason why a safe sling could not be hand or machine stitched at home. There is no magic involved, the difficulty is not in attaining sufficient strength but in quantifying that strength and ensuring a sufficient repeatability of results.
The thing is though, why bother the hard work has been done and the development cost amortised, certified slings are cheap and available in a huge range of sizes and types.
> mike, you seem to know a lot about that stuff. stupid question (example: belay-loop): why did they opt for stitching (the joints), and not, f.e., rivets etc -- stronger¿, cheaper¿ faster¿
Stitching is increadibly strong, cheap and fast! That's exactly why they chose it! Plus when slings were first made the technology was basic and stitching was a reliable and easily effected solution. Why reinvent the wheel?
Academically speaking though, advising to use a tape knot isn't exactly the best solution either, as a tape knot is probably the weakest of all the knots. DMM tests showed triple fisherman's knot to be almost as strong as stitching, however in the real world these sorts of tests could not be relied on due to the nature of different types of loading, and changing configuration of the knot over time such as in rucksacks and gear bags.
Academically speaking ( ) you've linked to a test which is on Dyneema which is enormously slippy stuff. What is true for Dyneema is not necessarily true for Nylon. The topology of a waterknot will be more drastically affected by slippage than that of a triple fishermans. You can't as far as I'm aware buy Dyneema off the reel for precisely this reason, that it's extremely difficult to tie it so it doesn't come apart. And if you buy a Nylon sling and tie it with a triple fishermans you'll end up with a massive knot. A tape knot is for nylon slings more than strong enough for normal climbing duty, as long as you make sure that the ends are fixed to prevent loosening of the tails of the knot.
Fair point, could not find the one which compared Nylon and Dyneema side by side. Of course, not disputing that, the only reasoning I mention it I guess is that is surprising how many people climb, and don't actually have any understanding of how knots reduce breaking strengths in general. As long as people understand the limitations and increase in risks in what they are doing in both a static and dynamic context maybe.
I reckon the safest climbing gear to home make is probably things made from metal, but only if you know enough about metal quality, and designing things safely too.
> ...the only reasoning I mention it I guess is that is surprising how many people climb, and don't actually have any understanding of how knots reduce breaking strengths in general. As long as people understand the limitations and increase in risks...
I'm not surprised at all. While having a passable understanding of mechanics and materials makes the climbing safety net richer and more interesting I'm not sure it makes it any more effective in the real world. It's quite possible to learn a handful of simple rules and techniques which can be re-applied time and again to safely solve problems without ever really understanding why things are done as they are. It's better to understand IMO but it isn't very important.
It's not with the counter intuitive exception perhaps of joining abseil ropes properly tied knots which hurt people, it's carelessness, oversight and poor risk assessment. Risk is hard to understand, particularly under pressure.
"The thing is though, why bother the hard work has been done..."
to learn somethinkg (we all use ´stuff´, and are used by it, all the day that we have no idea how it works. i like to figure out at least a few more of them before i deck). gracias.
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