Author Topic: <<Improving>> the Gleipnir binding knot  (Read 15482 times)

xarax

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<<Improving>> the Gleipnir binding knot
« on: September 18, 2010, 12:48:58 AM »
<<Improving>> the Gleipnir binding knot

    
« Last Edit: January 18, 2011, 12:05:39 PM by xarax »
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SpitfireTriple

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Re: <<Improving>> the Gleipnir binding knot
« Reply #1 on: September 25, 2010, 03:01:53 PM »
These look beautiful xarax.  Of course, beauty is not the best test of a knot, but beautiful knots are often effective ones.  I look forward to having a play with these.
« Last Edit: September 25, 2010, 03:02:46 PM by SpitfireTriple »

[Inkanyezi] gone

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Re: <<Improving>> the Gleipnir binding knot
« Reply #2 on: September 26, 2010, 09:21:33 PM »
i have a couple of objections.

One of the most practical properties of the Gleipnir is the ease of undoing the knot. The nip disappears almost instantly, when you spread the two parts either side.

Also, when tying in slippery material, there is less nip if the "turNips" are tight together, than when they are wider apart. It is a bit difficult in some materials to accomplish a separation of the two or more turns when drawing it taut, but in essence, each nipping twist should be separate from any other.

i have used the Gleipnir a lot now, and I am still impressed by its simplicity and efficiency. Not a single time has it slipped. It keeps the load of my bicycle rack secure, no matter how bumpy the ride. i use it for any kind of small cordage; it is not picky on the degree of elasticity. As far as I can see, it fulfills every claim done from start.

I don't think it would benefit from any more complication.
« Last Edit: September 26, 2010, 09:22:11 PM by Inkanyezi »
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Dan_Lehman

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Re: <<Improving>> the Gleipnir binding knot
« Reply #3 on: September 28, 2010, 01:48:42 AM »

  One of the most practical properties of the Gleipnir is the ease of undoing the knot. The nip disappears almost instantly, when you spread the two parts either side.


... The double nip/ the two interlocked nips dissapear almost instantly, when the two tails are pulled out of it/of them.

I don't follow your words, Inanyezi : in a tightened Gleipnir, two lines
run away from the turNip on each of opposite sides along the axis of tension,
and the tails are at a slight angle to these; spreading the tensioned lines
can pry out some of the tailsl, but also increases tension into
the turNip.  Yes, of course the nipping structure which is "TIB" evaporates
absent the tails.

Quote
I have a couple of objections ...

A fundamental objection to employing the Constrictor is that
one then increases frictional resistance to tightening the turNip
of the Gleipnir -- a bad thing.  (I sense that there is some
added resistance on the tails from the bulk of the Constrictor's
crossing part, but that comes into play only after tightening.)



I don't think it would benefit from any more complication.

  You should nt use the word "more" !  :) There is no complication in the Gleipnir whatsoever, ...

You forget or don't count the subtleties of the structure that led
to a sad & protracted effort to squeeze details out of you re those
"Xarax transformations" that begot Eskimo Bowlines & other things
-- that took my revelation of 4 orientations to this structure with
"no complication" to mind!  I find the original (upper-left of the
four orientations I presented in a photo'd sketch) to be one that
enables better tightening, hauling tails at somewhat 45-degree
angles to the axis of tension against themselves.

And that has been my complaint with the Gleipnir from the start :
that it doesn't tighten so well --doesn't transfer tail-tensioning so well
around the bound object(s) to the turNip.  (Which, yes, means I'm
somewhat puzzled at how well Inkanyezi gets on with it!)

As for improvements vis-a-vis this shortcoming, I have presented
some in the original thread, p.7? (cf http://igkt.net/sm/index.php?topic=1449.60
and have another couple to share as of this reading & mulling over.

One structure can be illustrated verbally simply:

"Middle" the binding cord (i.e., make it into a bight),
and wrap it around the objects to be bound;
form a round turn in the bight end,
and reeve the tails through this from opposite sides;
pull the tails roughly perpendicular to the wrapping
to tighten; one can also pull the tails in opposite
directions aligned with the wrapping, alternating
the direction of the tails (my sense is that one will
be really holding/resisting pull with the tail pulled
straight, while hauling to tighten in a sort of 2-to-1
pulley effect with the tail making the U-turn through
the round turn ).

(For the particular structure Inkanyezi has shown on his
bike rack, this one of mine just presented would need
TWO cords to implement -- a closed sling on one side
in which the round turn would be formed, and
then the other would be reeved through.)

--dl*
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Dan_Lehman

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Re: <<Improving>> the Gleipnir binding knot
« Reply #4 on: September 28, 2010, 05:16:22 PM »
   Thank you Dan Lehman,
   You seem to be concerned more about the initial tightening properties of the Gleipnir, and less about its subsequent anti-slippage properties, while I do feel the oposite/inverse. Of course, if you first tighten the naked original knot, and then secure it with additional half hitches, you will not have any slippage problems... My modifications were meant to improve the anti-slippage properties after the tightening, without taking advantage of any additional structures, and without the added complication of having to tie - and then having to untie- additional hitches - a process that, in a way, spoils the great elegance of this knot.

Yes, I am.  For I find sometimes that the tightening
of the binding structure around what is bound will
see the turNip rather loose, and unable to hold the gain;
so I want to have this nip lock surely, immediately.
And, yes, adding just a Simple knot (overhand) finish
(and it seemed last night that a Granny orientation locked
better than a Reef on the turNip !?) should take care
of post-tying slippage.

Look, if you have such friction built in such that no further
precaution is needed for later slippage, that friction is something
to be overcome in the binding-tightening.  (The Versatackle
to some degree cheats this by moving parts within other parts
whose added friction is escaped until release, when then a slight
retreat and loading brings the other parts more surely up against
the tightening tails to lock.)

My other just-conceived improvement is to (also) double the rope,
wrap the objects, and reeve just one tail through the bight (but
w/o any round turn) and take it back through a turNip
in itself, reeving the 2nd tail through the same nip in the opposite
direction (for turNip stability).  Here, hauling on the 1st tail will
2-to-1 pull the bight-end, and this tension in itself is put into
the turNip rather quickly; the opposite tail is held as resistance
to this 1st tail's tightening action.

--dl*
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Dan_Lehman

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Re: <<Improving>> the Gleipnir binding knot
« Reply #5 on: September 29, 2010, 06:32:48 AM »
a Granny orientation locked better than a Reef on the turNip !?)
I noticed the question mark, right after the exclamation mark, though. ( In comments about chess moves, this notation indicates some evaluation ambiguity... :))

I think you got it (chess, indeed).
Which is to say that this one-time testing before typing
is only that, hardly thorough (whatever that might be).
!?

Quote
The Constrictor works differently, by the accumulation of the tensile forces under the
main nipping loop of the hitch. So, each time we pull the two tails again, the constrictor constricts more and more,

Nah, too much friction to overcome, in general -- an added Simple
Knot before it begins to try to nip the tails, AND then the nipping
structure/loop doesn't even make a good surrounding of the tails
as does the Gleipnir.  (just "!" here)

Quote
...reeve just one tail through the bight (but w/o any round turn) and take it back through a turNip in itself, reeving the 2nd tail through the same nip in the opposite
direction (for turNip stability).  Here, hauling on the 1st tail will 2-to-1 pull the bight-end, and this tension in itself is put into the turNip rather quickly; the opposite tail is held as resistance to this 1st tail's tightening action.

   Interesting, but this forced symmetry-breaking of the Gleipnir tying process  is not my favourite cup of tea, I am afraid... :) However, I would like to listen what Inkanyezi, and other fans of the Gleipnir, will tell us about this.

In some uses, there isn't "symmetry" -- tying up bundles of rubbish,
e.g., suffers in the Gleipnir precisely on account of the hauling-tight
coming via extraction of material (resource) of both tails, and how
then then to cut away without waste?!  -- or to size well ... .  In
contrast to the simple method of tying off with a Rolling Hitch,
and cutting off the line hitched to, when done.

--dl*
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Dan_Lehman

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Re: <<Improving>> the Gleipnir binding knot
« Reply #6 on: September 30, 2010, 07:46:40 PM »
  I know that you detaste the Constrictor more than the Gleipnir... :)

Now you're confusing topics/threads,
for there is absolutely no tasting of knots here
-- that occurs only in the flossing situation
(and most of them taste like chicken).

Try to be relevant, please!


 ;D

knot4u

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Re: <<Improving>> the Gleipnir binding knot
« Reply #7 on: January 19, 2011, 10:18:06 PM »

"Gleipnir Clove Hitch" (as named by Xarax)

This "Gleipnir Clove Hitch" is more secure than a plain Gleipnir and also a two turn Gleipnir.  I'm glad I experimented on my own and didn't blindly accept what others have reported.

Thank you for the pic Xarax.  It just occurred to me what it is.  I stumbled upon this "Gleipnir Clove Hitch" independently.  I revisited this thread and realize it's the same knot that I tied.  By the way, the knot in the pic is sufficiently different from the Gleipnir that it deserves a different name without the word Gleipnir in it.  For comparison, the word "Clove" is NOT part of the name of every knot that has a Clove in it.  Neither is "Half Hitch", etc.  :-\
« Last Edit: January 19, 2011, 11:20:29 PM by knot4u »

Dan_Lehman

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Re: <<Improving>> the Gleipnir binding knot
« Reply #8 on: January 20, 2011, 06:15:10 AM »

"Gleipnir Clove Hitch" (as named by Xarax)

This "Gleipnir Clove Hitch" is more secure than a plain Gleipnir and also a two turn Gleipnir.

Can you quantify this, or prove it beyond *feel*?

One test design would be to put the structure into vertical
disposition and anchoring the upper end and turning the upper
turns of the binder to a fixed pin,
and having the lower end bear the tightening weight
while the lower turns wrapped a *bound* weight which should
be raised with sufficient load on the lower end.
Then, catch the loaded end and see what is lost from the
raising!?

And one can to a pure load-the-structure comparison,
maybe with some sort of vibration added (as I think
that many of these will prove quite strong on a steady
load) to tease out any slippage.

The "Clove" here is oriented in a way that tightens IT,
where as oriented the opposite way it would be simply
a 2-turn Gleipnir, turns close together.  What I find in
comparing them is that in this latter case, on tightening,
the turns get drawn closer together, a little, by the draw
of the ends; and then on release of tightening force,
there the two turns move away from each other (as the
crossing part of the clove has remained somewhat slack).


Quote
By the way, the knot in the pic is sufficiently different from the Gleipnir that it deserves a different name without the word Gleipnir in it.

OTOH, "Gleipnir" can serve to connote the overall general
structure of the wraps with ends taken through some gripping
knot --adding the name of that knot particularizes it.  This
nomenclature is readily understandable for any variety of
such component knots, thus.  "The <gripping-knot-name> Gleipnir"

--dl*
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xarax

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Re: <<Improving>> the Gleipnir binding knot
« Reply #9 on: January 20, 2011, 11:28:42 AM »
   I have suggested that the Gleipnir - due to its simplicity - can serve as a test bed for the effectiveness of many similar "double nipping loops", as well as for the slippage/friction characteristics of ropes. One can even envision a "Gleipnir scale", to compare those things ! Just a vague idea...

« Last Edit: January 20, 2011, 10:23:39 PM by xarax »
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[Inkanyezi] gone

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Re: <<Improving>> the Gleipnir binding knot
« Reply #10 on: January 20, 2011, 11:47:20 AM »
There is a significant difference between the orthodox Gleipnir and this variation, which is not only that it is complex and more difficult to accomplish.

The Gleipnir relies on the TurNip, the round turn that strives to capsize, while the ends oppose its capsizing. Upon tensioning of the central part, this tension is fed directly into the nipping turn with very little friction to counteract it. OTOH, when substituting the TurNip with a double turn, Clove or Constrictor, the turns themselves tend to lie more perpendicular to the line of tension, and there is considerable friction within the structure, which counteracts its nipping function. Whether two turn, clove or constrictor, the nip itself is less firm, but distributed over a larger area.

One important factor of Gleipnir's in its original version is its ease of tying. When tying it in shock cord, which I often do, it can be tied under great tension, and it is very easy to tie. The simplicity is one of the major factors that make this knot preferable over other well known bindings, as the square knot, butcher's knots and the simple fig8 around the standing part (ABoK #2083); the latter still preferred when the material shall be discarded. An advantage of Gleipnir's is that you can reuse the cord over and over. When you untie your bundle, the Gleipnir vanishes into thin air, while many other binding structures are not as easily undone. Even if you slip your last half hitch, the fig8 of #2083 might be difficult to open once the end is drawn out, while of the Gleipnir nothing will remain once you pry it open.

The "power advantage" surely has been over-stated, and it is of course moot. If you wish to use this "advantage", it is easier to do before tucking ends through the nip, although if there is tension, you cannot form the nipping turn, much less tuck the ends while holding the TurNip open with your third and fourth hands. The trick is to first apply tension, then to form an inverted TurNip with both ends, whereupon they are drawn taut to collapse their double HH into the TurNip. The knot thus formed will not slip back. It can be done in highly elastic material as shock cord, but also in less elastic cord as PP or other usual types. In this simple form, it is quite as easily tied as a square knot, but without the necessity to hold the tension while finishing. It solves one problem for which #2083 was invented, holding tension while finishing the knot, disregarding the issue of spending material. Gleipnir is more suited where the material shall be used again, while #2083 is a better binding when it shall be discarded.

I would prefer not to use the name Gleipnir for other contraptions, in order not to introduce similar confusion as exists regarding the Carrick Bend. To me, it is just a whole lot simpler to think of the Gleipnir as one simple structure, just as the Carrick Bend is one and only one simple structure, or if you wish so, more complicated but still only one. All other "simple" variants are not the Carrick Bend, just as the thief knot and granny are not the square knot. To preserve the original name, I believe that the important original elements, its very heart, should be retained. When the last tuck of a Zeppelin is doubled, its main features are unchanged, just as the double sheet bend is an expansion of the sheet bend. The clove or constrictor put instead of the TurNip in a binding built upon the TurNip changes most of its properties and most importantly, its major characteristic, the main feature that distinguishes it from other knots. When it is made with two splayed loops, its main feature, the TurNip remains, just as when it is tied with a bight through which the end is turned back and the TurNip formed in the SP of that tucked end (structurally the same as two splayed loops). The latter gives no advantage compared to the original structure regarding pulling it tight as suggested by DL; you cannot lift yourself by pulling your hair.

Of course I have no say when it comes to how other people name a knot, but I think naming this knot by any expansion of Gleipnir is not a Good Thing, because the wolf might come loose, and IMHO it is not an improvement. To me, there are only two major types of Gleipniir, the canonical two round turns Gleipnir and the splayed loops type; both can be expanded by more than onte TurNip, but if the TurNip is substituted, it is no longer a Gleipnir.
« Last Edit: January 20, 2011, 12:53:37 PM by Inkanyezi »
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Dan_Lehman

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Re: <<Improving>> the Gleipnir binding knot
« Reply #11 on: January 20, 2011, 09:29:16 PM »
There is a significant difference between the orthodox Gleipnir and this variation,
which is not only that it is complex and more difficult to accomplish.

But there is a similarity in taking a line around what is to be
bound, and passing the ends through a *knot-lock*.  In any
case, the nomenclature here is I think well enough explicit
--even descriptive-- in distinguishing structures.  (And the
original would be, in such full nomenclature (where "G."
required  qualification/particularization), "the
turNip Gleipnir ", which was expanded to something
denotable as "the round-turn Gleipnir & double Gleipnir ".

I have discovered some other variations, which might be
named "the Bight-end Gleipnir & Gleipnir-on-a-Sling "
of which the former deviates from the double-circle form
of the so-far-considered overall structure (and it seems to
me in some ways better).

In any case, as Xarax notes, it is at the moment just a label
to fill a need of reference; it's future life remains to be seen.

Quote
When tying it in shock cord, which I often do, it can be tied under great tension, ...

But why not just use a rolling hitch?  (Why
not, in general, I should ask, I guess!

Quote
The "power advantage" surely has been over-stated,

... , as it is I think likely a DISadvantage, for many circumstances,
where friction of both material & bound material influence things.

But my first objection was to force distribution to the nip
--and what I find better done in one of the variants noted above

Quote
Gleipnir is more suited where the material shall be used again,

Agreed.  (Or when it's of no cost/concern, or can be carefully set.)

Quote
... confusion as exists regarding the Carrick Bend.

But with the Carrick, one has pretty much a ONE name being applied
to many; here, we have a basic denotation of a structure being
qualified. 


--dl*
====