Author Topic: How much redressing makes a new knot?  (Read 14352 times)

Mobius

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How much redressing makes a new knot?
« on: May 12, 2015, 11:41:23 AM »
The two photo's below are the front and back of well known tiable in the bight (TIB) knot in a redressed form. What is it?  8)

I like the near symmetry it displays. I doubt it is 'new', though I could not find it on the site. It is not Post Eye Tiable (PET) and I suspect it might be jam prone. So maybe not that useful as an end loop even if it does look nice to my eyes.

Cheers,

mobius

[Edit: After playing around with the displayed version of knot some more I don't think it will jam even though the original (well known) form of the knot is supposed to be prone to jamming]

[Edit 2: Some really nice shots of the loop were removed from later in this thread, added another poor quality one here, which will have to do for now]
« Last Edit: May 17, 2015, 04:24:29 AM by mobius »

Mobius

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Re: How much redressing makes a new knot?
« Reply #1 on: May 13, 2015, 10:12:58 AM »
If anyone is wondering where my pictured knot came from, it was simply a redressed Butterfly Loop configured by repositioning the loops that usually encircle the eye and turning them into collars. There is a bit more juggling than that, however not too much more in my opinion. You could further dress the knot by making sure the legs were crossed, which might be a good idea.

I noticed this thread http://igkt.net/sm/index.php?topic=3811.msg22517#msg22517 and thought that anyone who likes using the Butterfly Loop as an end loop might like the version I have shown. I think now that the knot will not jam (the back of the knot can be separated fairly easily after load I believe).

If this Butterfly Loop version is different/interesting enough to warrant a title then 'Collared Butterfly Loop' might be a good descriptive name.

Cheers,

mobius

Mobius

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Re: How much redressing makes a new knot?
« Reply #2 on: May 13, 2015, 11:53:54 AM »
   Your original question is a very difficult one... We have not yet defined what a "knot" is, so how could we do the same for a "new" knot ?
    Knots that are topologically identical, may be geometrically very different, have different structures and structural characteristics regarding slippage, strength and jamming, "work" differently, and so be different knots.

I understand your point that the knot I have shown will respond quite differently under load compared to a Butterfly Loop (without dressing changes) used as an end loop. I can see that 'my' knot is different enough from a Butterfly Loop to potentially be called a 'new' knot. Half of me thinks that, the other half just thinks that all I did was fool around with a Butterfly Loop and get a variation  :-\

Somewhere between those points of view I believe there exists a grey area where small dressing changes effect how the knot behaves enough to call it a completely different knot. This is what I was thinking when I gave the original post the title I did.

To make things more complicated one can think about different loadings on the same knot potentially creating different knots. The knot I show here is quite close to symmetric so that really is not an issue, the loading structure of the knot will arguable be very similar regardless of which end is loaded.  Other knots will shift their geometry (perhaps a little, perhaps a lot) to accommodate different loadings. An example of what I mean might be a bowline that is designed to be either end loaded (EEL). Bowlines are typically quite asymmetric and will experience different loads within the nub depending on which end is loaded, and the nub may even look slightly different (distort perhaps) under different loads. Depending on which end we load it, do we have one knot or two in this bowline case?

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So, what we see is a very different geometry from the Butterfly loop - we DO NOT see any "collared" Butterfly loop, so the name "collared Butterfly loop" would be, IMHO, not descriptive enough, and may even be misleading... I can imagine many other knots that could be named by this name, and BE such loops.

I really do not care much about the name, or even if the knot deserves one. The knot originated from a Butterfly Loop (without new tucks) and has collars, and I was simply trying to pay homage to where the knot came from and highlight a feature of the loop I show. To be frank (and assuming 'my' knot is new) it can remain nameless unless it is deemed useful by somebody. Anyone can make up a name for it if they want to. If that gets accepted, fine by me :)

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    The only thing one has to consider, is what I had mentioned in the last paragraph of my previous post : Is this "new" knot stable ? When it is loaded as it is meant to be loaded, or as it will be loaded most of the times ( so, not under very special situations, whn anything goes...), will it retain its shape ? Or will it capsize to the Buttefly loop ?

I do not know how stable it is, it feels stable to me when I cinch the nub and start tugging away (by hand) at one and all ends/eye legs. I have my test rig built now, so I can run a few trials for strength/slippage and untying if anyone is interested. I designed the knot as an end loop, so using it in the fashion of an end-2-end mid-line loop might well result in a collapse into a Butterfly Loop. Or maybe it was a Butterfly Loop to start with anyway  ;D

Cheers,

mobius
« Last Edit: May 13, 2015, 01:05:13 PM by mobius »

Mobius

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Re: How much redressing makes a new knot?
« Reply #3 on: May 13, 2015, 12:33:51 PM »
One quick trial of this knot (as an end loop) in 3mm 'Smooth (16 plait) Synthetic Braid' showed the knot held without any signs of slipping and broke at ~140kg. One manufacturer specification tells me the average breakload is 169kg for my diameter rope. Another source indicates 200kg.

The next trial will be to take the knot to ~100kg and then see if I can untie it.

My home rig is just for fun and my results need not mean much. Interpret them as you see fit.

Cheers,

mobius

« Last Edit: May 13, 2015, 01:08:36 PM by mobius »

Tex

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Re: How much redressing makes a new knot?
« Reply #4 on: May 13, 2015, 02:11:00 PM »
Is it just me or... ok, yes I can capsize a standard alpine butterfly loop to look like this, but I don't have to.  If you just zoom the picture in on the knot it already looks like a standard alpine butterfly, but you would guess wrong about which ends are the bight and which ends are the rope!

I am having a hard time seeing how this is any different than tying the ABL with these bits swapped.  This seems to prove some symmetry of the knot that I don't find very surprising, although I had not fully proven it because I did not consider how the final tucks affect the symmetry when I looked at this knot before.

Anyway, it's a neat trick, and surely better than a Honda knot.


Tex

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Re: How much redressing makes a new knot?
« Reply #5 on: May 13, 2015, 02:18:16 PM »
By the way when I clicked the image and it first popped up on my screen, it was huge and I had to pan around to see the knot part, so this is exactly how I saw it.

I wonder if this might make a better end-of-line form than the standard way? It seems the loading is more symmetric then for whatever that's worth.

Anyway, the neat thing to me is not that this exists, that if I'm not confused, seemed already obvious.  The neat thing is that you can create it by capsizing the standard form.

Mobius

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Re: How much redressing makes a new knot?
« Reply #6 on: May 13, 2015, 02:24:55 PM »
1. To make things more complicated one can think about different loadings on the same knot potentially creating different knots.
2. Other knots will shift their geometry (perhaps a little, perhaps a lot) to accommodate different loadings.
3. Depending on which end we load it, do we have one knot or two in this bowline case ?

1. I had answered to that : If the geometry / shape of the knot does not change, but only some parts of it shrink more than others, the knots are not different.
2. Noope ! ALL knots shift their geometry to accommodate different loadings ! Segments are tensioned and elongated here more than there, curves get sharper, collars rotate, etc. In fact, it is amusing to watch what the poor knot has to do, to bear the load !  :) However, the difference between a stable knot which just "accommodates" loading, as you say, and a knot which capsizes under loading, is not a grey thing, it is a black or white thing. I do not believe there is gradual capsizing ; When it starts, it will go straight to the end, and will generate a completely different form.
3. I had answered to that, too. Different loaded ends, different structures, different knots. Shape is NOT the only thing it matters - and it may even be different, and yet the structure be essentially the same

I think I might have been typing as you were, I see some of what was said was the same thing by both of us :) I think your statement 1. and 2. actually contradict each other, however I will read things tomorrow again after sleep ;)

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The knot originated from a Butterfly Loop ...

   A totally irrelevant remark, regarding what knot it is NOW !  :)
   ALL knots start from the straight, unknotted line !  :) :)

Irrelevant to you perhaps xarax, others might not see my reasoning given above that way. I could have called my knot the Monday Loop, since 'I discovered it on a Monday', that reason would have been irrelevant :)

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   As far as I can see, this knot is not just the Butterfly loop loaded by its one end. If it does capsizes into the Butterfly loop, when it is loaded by its one end, it is but a capsized Butterfly loop:) :) If it does not, it is a nice, stable "new" knot ! Personally, I have not seen it anywhere, but what is perhaps more interesting to me is that I had never tied it - and I had tied many hundreds of known and unknown loops. Perhaps Alan Lee had tied it - but even if he did not, I am sure that, if it turns out that it is a stable knot, he will appreciate it.

I have only done one trial, however I pretty much know to my own satisfaction that the form I tied the knot in (using my rope material) won't collapse into a Butterfly Loop if it's loaded as an end loop. I'll be the first to tell you if it does, however sleep beckons now and you'll have to wait for more trials tomorrow :)

Cheers,

mobius

Mobius

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Re: How much redressing makes a new knot?
« Reply #7 on: May 13, 2015, 02:39:23 PM »
By the way when I clicked the image and it first popped up on my screen, it was huge and I had to pan around to see the knot part, so this is exactly how I saw it.

I wonder if this might make a better end-of-line form than the standard way? It seems the loading is more symmetric then for whatever that's worth.

Anyway, the neat thing to me is not that this exists, that if I'm not confused, seemed already obvious.  The neat thing is that you can create it by capsizing the standard form.

I always have to enlarge images after I click on them, you have the opposite problem it seems. I don't know why.

I think it does make a better end-of-line loop than the standard way. That is largely just based on some of the posts I read in the forum concerning jamming in particular (can't think where at the moment). I was quite pleased the knot held to 70% breakload and held it's form while doing so, even if it was only one trial. Tomorrow I'll see how well it unties after load.

That you see the knot as a 'reversed' Butterfly (I noticed this too) might mean we don't have to name my version anything :)

Cheers,

mobius

Tex

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Re: How much redressing makes a new knot?
« Reply #8 on: May 13, 2015, 02:46:22 PM »
I did not see it as a reversed butterfly at first.  I just saw it as a butterfly knot, was confused why there was a question at all, for half a second, and then remembered what things looked like before I zoomed in.

I think the way you pressed the butt cheeks together might have made it potentially less obvious, but I saw the other side first.  If it deserves a new name is not clear.   I think the existence of it was in a sense obvious in that anyone who's given it any thought knows that all loops (all knots even) can have their ends swapped around.  However, I had never thought about actually doing it for this knot, maybe nobody else ever did, and it might even be useful.

Tex

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Re: How much redressing makes a new knot?
« Reply #9 on: May 13, 2015, 02:53:59 PM »
And apparently it is possible to twist the meanings of peoples' words just as much as it is possible to re-twist this knot!

Mobius I would say this is certainly a different loop than the usual one, but not a different knot.  (Others might add the qualifier "PART")  I'd have trouble saying you "discovered" even the loop, but you might have created awareness of its potential usefulness and if this configuration gets used a bunch, it's going to need a word to go with it, so sure, why not a name, but one that reflects its nature.  Oddly enough, your handle works quite well.. Mobius Butterfly Loop seems to be quite descriptive, although the spelling might be abrasive to somebody ;)

Oh.. and I also had read the comments about jamming the standard one and it was in the back of my mind when I said this, but somehow also in the front of my hand (as I was holding one tied/flipped your way).  I will need to learn an efficient way to dress this tied with the end.
« Last Edit: May 13, 2015, 03:11:59 PM by Tex »

Tex

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Re: How much redressing makes a new knot?
« Reply #10 on: May 13, 2015, 03:49:05 PM »
So, which is the "reversed" of the Butterfly loop ? We have just to tie a loop which is still an inline loop, as the original Butterfly loop, but where the pair of free ends and the pair of eye legs are swapped. And THIS knot is NOT the one tied by Mobius ! Mobius s loop is an end-of-line loop, where the free ends are pointing to the same direction, just like the " Interlinked Englishman s loop". Therefore, it is NOT a reversed Butterfly loop...   

Except that if you put the knot you described inline, it is in fact exactly the knot he tied.  I think it will NOT capsize back to the regular form or maybe even a significantly different form.  The only difference between that and the end of line "version" is the angle the ends are bent (or not) out at. I think we all agree that it is more useful end of line though.

There is actually an intermediate dressing where, all four ends want to come out parallel, but it too has two sides, and in the usual orientation, the standing ends, while more inclined to be parallel than the usual orientation of mobius's form, are still separated a little thus creating more moment arm and more torque, and more tilt to the knot when hung end-of line.  This way seems "nicer" even than that.



« Last Edit: May 13, 2015, 03:59:47 PM by Tex »

Tex

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Re: How much redressing makes a new knot?
« Reply #11 on: May 13, 2015, 04:08:58 PM »
I suspect that this knot has been tied or loaded "wrong" many times and if it can capsize in some loadings then it has done so many times.  Yet it is the fact that no matter, under all crazy conditions, it has held, that has made this knot SYSTEM, known though only as a knot, so popular.  Mobius butterfly loop seems right to me though.

To be very clear, because sometimes I'm not sure from your words xarax, I think we're on the same page here, but this knot PART is IDENTICAL to an ABK knot part.  There is no difference in dressing, certainly not before its loaded. 

Tex

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Re: How much redressing makes a new knot?
« Reply #12 on: May 14, 2015, 12:05:39 AM »
What would I do without The Great One to show me the one true path to enlightenment.  I have walked in darkness but he shows me the light.  Amen.

Tex

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Re: How much redressing makes a new knot?
« Reply #13 on: May 14, 2015, 01:28:42 AM »
I will add that the butterfly bend and butterfly loop are given associated names as are the zeppelin and carrick, and a double dragon is so named as a loop or a bend, as an end of line loop, or in its probably less favored mid-line use.  An Eskimo Bowline while behaving differently as a loop still inherits the family name as well, as do others with different knot part topology.

The hitches are the only knots that seem to almost consistently break this trend, with the distinction usually applying to if they are tied around an object or further "entangled" with the rope itself.

We can wax philosophically all day long, but I proposed a name, one that has much precedent, the Mobius Butterfly Loop, and I have not seen another proposal yet to consider amidst all the words other than "reversed" Butterfly, which also works.   Until there is another proposal, if I need to refer to this configuration in words, these will be the words I use.  I'm sure if used often it will get shortened to simply Mobius Loop often, and that's fine too.

Luca

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Re: How much redressing makes a new knot?
« Reply #14 on: May 14, 2015, 01:57:39 AM »
Hello all!

Maybe one could see something very close to the Bull hitch within the geometry (and possibly something within the functioning?) of this fixed loop,so I decided to take a step forward (following a path that someone else opened) and try to realize a sort of Bull-Clove hitch version of this loop(below).
Actually I do not expect that this (completely untested) knot has a practical value greater than the simpler version (and I have not yet ascertained whether there is a method of tying, TIB or no-TIB that is acceptable in order to be able to be considered as a practical knot(but I had fun and ,after all,we are in "Chit Chat"!)

                                                                                                                           Bye!