Author Topic: A Crossing knot with a helical finish  (Read 1043 times)

enhaut

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A Crossing knot with a helical finish
« on: March 12, 2020, 09:04:39 PM »
Did I miss this crossing knot loop somewhere in the forum or in Asley's?
tsik_lestat and Alan Lee did a number of those, maybe it is a revisit.
Tell me if it is new or not.
Anyhow I find this loop interesting for various reasons.
One would be the finishing route of the outgoing leg; a helical path that almost act (I am not sure here)like a nipping device, a strange behaviour if you test it by pulling the outgoing leg.
The ring loading profiles is very solid.
It also seems that this structure can be loaded by either end.

The fact that it his TIB make it a good middle-of-the-line loop.
 
image = Crossing knot helical finish side A

image = Crossing knot helical finish side B

image = Crossing knot helical finish loose
« Last Edit: March 12, 2020, 09:06:51 PM by enhaut »

tsik_lestat

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Re: A Crossing knot with a helical finish
« Reply #1 on: March 13, 2020, 07:11:46 PM »
Hello enhaut

Quote
Did I miss this crossing knot loop somewhere in the forum or in Asley's?

It appears that the class of crossing knots is an uncharted territory, Xarax has always been prompting people to conduct further investigations in this field.

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Tell me if it is new or not.

Your fresh decent creation, bears out my initial claim, introducing familiar components synthesized in a new knotting scheme, to the best of my knowledge.

What's troubling me, is if half of your outgoing leg structure (one turn), could be considered as a Carrick variation (in a proper carrick structure, the tail is lying in the side near the eye, and not in the side near the collar as this one does). If that's the case, then you have managed to develop a TIB `pseudo`Carrick based variation, by adding one more turn of the WE before exiting in a parallel two end configuration.
 
Quote
One would be the finishing route of the outgoing leg; a helical path

Undoubtedly, the helical carvature routing of the returning eye leg weaving through the crossing knot nipping, while enjoying full constriction from the SP, which i think is the main nipping device, acts as a stabilization lever and enhances security.

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if you test it by pulling the outgoing leg.

This strange behaviour by pulling the out-going eye leg, i think is an interesting property, as the helical curves are breaking apart by that action, making the structure pliable and easy to undo if heavily loaded.

Quote
It also seems that this structure can be loaded by either end.

That said, despite the fact that the reverse structure is alleged to have an edge by being adjustable (from the SP side!!!) , i would not be amenable to form a reverse loading profile, because under high strain, the helical now nip, as mentioned previously, might pry open and turned into a noose, loosing its initial shape.

That's basically the reason i prefer this current instance.
« Last Edit: March 13, 2020, 07:17:23 PM by tsik_lestat »
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enhaut

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Re: A Crossing knot with a helical finish
« Reply #2 on: March 13, 2020, 08:44:54 PM »
Hi tsik_lestat

You always provided a well-written analysis and I thank you for it.
Your views on the reverse loading profile are indeed spot on and I agree with your conclusion.
That said I was expecting more of a pretzel-related family from that structure but pseudo Carrick can be of use.
I wonder if a third voyage into the nip could ensure a reliable reverse profile, if not those who claim that the more rope into the squeeze (enlarging the curvature) equals a lesser breaking point would be satisfied.

jr

tsik_lestat

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Re: A Crossing knot with a helical finish
« Reply #3 on: March 15, 2020, 12:42:24 AM »
Indeed, adding an extra curve might work for the reverse profile, if someone wants to extend to a three turn complexity level with the aesthetic cost of some bulkyness.

Yet still, keeping the elegance of this current tangle, i have emulated this helical pattern of the outgoing leg structure in order to buckle down a slightly different crossing knot nipping structure.

Almost similar properties in this loading profile, but the knot lacks in Tibness even if the WE would be tucked down through the helical loops, with an aditional maneuver.

Despite that, the trick with the pull of the outgoing leg, continues to remain in a functional mode, strangely desirable and usefull for the untying process  :).
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enhaut

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Re: A Crossing knot with a helical finish
« Reply #4 on: March 16, 2020, 10:38:09 PM »
@tsik_lestat
There is a nice and well balance structure in the loop you did.
Elegance indeed!
The fact that the WE is exiting alongside the eye would please Ashley who referred to those as having 'a good movement' in accordance with the water resistance.
The ring loading profile seems as solid as with the precious loop.
I will explore the properties of the nip for bending purposes.
th.
jr.
ps I like the tablecloth background.

tsik_lestat

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Re: A Crossing knot with a helical finish
« Reply #5 on: March 17, 2020, 04:31:50 AM »
@ Enhaut

Allow me to persist in highlighting the reverse loading profile of your creation, a structure that appertains to the helical loop concept, a specialised category of knots, where this very spiral/helical pattern, is foremost an SP continuation, rather than a collar structure formation, which frames your initial presentation.

There was a time that Xarax was exploring these helical loops, and his thought process was to realize a knot structure with an open helix nipping system, in contrast with the closed form helix nipping loop of conventional bowlines, that would be functional and well secured. The design goal here, was a stiff loopknot, with the less possible convolution and deformation, where those helical wraps would keep their helical form without untwisting at high tensile forces, if stabilized with an appropriate interwoven collar structure.

Those well-aimed efforts, are pretty much summed up in the links i have attached. Check out the first link and emphasize at reply#2, third image, where you might notice that the rightmost knot, with the double helical coil, resembles with your (reverse) creation. The difference, is that the WE, after capturing the ongoing eye leg, continues its route through these helical loops, retaining its tibness, rather than exiting directly through the collar, as it occurs in your instance.This was noticed by Xarax.

Both structures look decent, though we would be somehow forced to run some tests and find out which one of them is more stable and holds its initial shape, considering some other parameters such as the number of helix coils, as you have correctly pointed out previously, the loading and rope stiffness.

Nonetheless, you have demonstrated, that a geometrically reversed oriented structure, is a very interesting approach, very stable and well secured, definitely with less deforming issues, that worths further investigation.

1)https://igkt.net/sm/index.php?topic=5301.msg34978#msg34978
2)https://igkt.net/sm/index.php?topic=4949.msg32601#msg32601

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ps I like the tablecloth background.

I guess its pattern, is compatible with the whole knotting concept  :) :).
« Last Edit: March 17, 2020, 06:28:54 PM by tsik_lestat »
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enhaut

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Re: A Crossing knot with a helical finish
« Reply #6 on: March 17, 2020, 02:03:13 PM »
Quote
Those well-aimed efforts, are pretty much summed up in the links i have attached. Check out the first link and emphasize at reply#2, third image, where you might notice that the rightmost knot, with the double helical coil, resembles with your (reverse) creation. The difference, is that the WE, after capturing the ongoing eye leg, continues its route through these helical loops, retaining its tibness, rather than exiting directly through the collar, as it occurs in your instance.This was noticed by Xarax.

I was well aware of Xarax's discoveries in helical loops, in fact, when fiddling with that tool I always wonder if X has already explored the form I come up with.
In seems to me that X putted a great care in confining the helix between two stopping elements, a collar or sub-collar.
That may be the correct and secure way to do it.
My proposition is more lightheaded, I trusted the helix to singlehandedly do a job that may require assistance.
I always choose simplicity sometimes for the wrong reasons but often it pays off.
jr

tsik_lestat

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Re: A Crossing knot with a helical finish
« Reply #7 on: March 20, 2020, 12:41:25 AM »
All i know is that xarax had directed all his attention to helical loops, without paying heed to the reverse knots with the helical curves as collar structure components ( neither tied nor tested by him).

His viewpoint, is/was that a demand for a closed form helix nipping loop does not constitute a necessary condition for bowline formation, open helices could be functional as well, as part of the nipping system.

Getting back in the OP, i understand you have another innovative implementation of a helical hitched pretzel based knot structure, that resides in practical knots  https://igkt.net/sm/index.php?topic=5227.msg34168#msg34168 .

Well, tying this instance and performing a couple of transformations, i have found out that it is topologically equivalent with the reverse knot (or similar/mirror) of this bowline presented here (first image/virtual bowline that may jam)
https://igkt.net/sm/index.php?topic=6434.msg43120#msg43120.

The steps starting from yours and arriving at mine, are as follows .......

1) Bring the middle helix downwards as a two end collar.

2) Flip the upper collar near the eye, that encircles both eye legs, and make it the new two end collar, down from the previous one.

3) Dress the knot.

I am not making any comparisons, just simply pointing out the equivalence of two geometrically different TIB knots.

Is the in-between knot that ensues from the first step something similar to Ouroboros? Thanks

Edit ... Answering to previous question. After closer inspection it is not. The two collars were misleading, but now i got the whole picture.
« Last Edit: March 20, 2020, 09:22:57 AM by tsik_lestat »
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enhaut

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Re: A Crossing knot with a helical finish
« Reply #8 on: March 20, 2020, 05:51:38 PM »
@ tsik_lestat
You are giving me much to think about and to test.
Now I am in the middle of moving from my current place to another closer to downtown and its river, I will lose my preferred light and I hope that I will be able to adapt my photo set-up in the next environment.
So give me  a little time before trying  those helical wonder.
I am saying wonder because I my view they are surprisinly efficient.
Xarax did a great trailing blazer effort in that "field" and this got to be mentioned somehow.
« Last Edit: March 20, 2020, 07:45:31 PM by enhaut »

tsik_lestat

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Re: A Crossing knot with a helical finish
« Reply #9 on: March 20, 2020, 09:50:57 PM »
@Enhaut

Take all the time you want, there is no urgent request here.

I hope you find a spot in your new enviroment for your photo set up, as good as the previous one, or even better. We just can't afford to lose your fine quality photos. Anyhow you will figure it out ;).

Wishing for the best!!
Cheers!!

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Dan_Lehman

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Re: A Crossing knot with a helical finish
« Reply #10 on: March 20, 2020, 10:19:01 PM »
His viewpoint, is/was that a demand for a closed form helix nipping loop
does not constitute a necessary condition for bowline formation,
open helices could be functional as well, as part of the nipping system.
But it DOES ... --indeed, it's pretty much THE criterion
for *bowline*,
neverminding that such-formed knots can transform
into the more open helical ones, varied by force.

We need a line here, even knowing the physical-entity
transgressions, IMO.

Sometimes for some of the eye knots in trawler
dock lines I saw I had to wonder if the helical knot
was in fact WANTED --and tied either directly or with
a loose-enough more *loopy* knot expected to soon
capsize/shift into the helical one.

I had two such short-helix eye knots tested long ago,
in 1/4" laid (med. soft) nylon --one being a redressing
of the dbl./"round turn" bowline (so, it had ultimately
a U-turn whereas the other was pure helix and off it
ran into the eye-leg).  Strength seen there wasn't
stellar, though fine.  Softening/opening the helix
more would lead one to question nip-grip (as well
as knot length).  In material so slick as HMPE,
one can question whether any reasonably length'd
helix can deliver sufficient pressure & friction.
--or "back to the drawing board" for knots for that!


--dl*
====

tsik_lestat

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Re: A Crossing knot with a helical finish
« Reply #11 on: March 22, 2020, 08:37:15 PM »
But it DOES ... --indeed, it's pretty much THE criterion
for *bowline*,
We need a line here

Indeed, and it is generally a vulgate bowline convention, hence the name helical loops rather than helical bowlines was used, in order to be avoided any conflict with this criterion.
Nevertheless, Xarax crossed that line, considering that the naming is less significant than the very way they function.
Verily, his posted helical structures, were intensively tested, and they were found to be quite strong and well  secured, while their tail, did not slip beyond a certain point at maximal loading, that is, until rupture occured.That led him to believe, that the basic nipping mechanism of a closed form helix and its increasing compression due to high tensile forces, extends to open helices, as well.

Sometimes for some of the eye knots in trawler
dock lines I saw I had to wonder if the helical knot
was in fact WANTED --and tied either directly or with
a loose-enough more *loopy* knot expected to soon
capsize/shift into the helical one.

It is good to know that you have actually seen them in the field, earning their place in the world, and they certainly worth gaining further attention.

Softening/opening the helix
more would lead one to question nip-grip (as well
as knot length).  In material so slick as HMPE,
one can question whether any reasonably length'd
helix can deliver sufficient pressure & friction.

As you correctly point out,deformation phenomena, such us helix opening and knot length are indeed noticeable, as a consequence if subjected to heavy loading, but i have the distinct impression that no bowline structure could deliver sufficient friction in such a slick and strong material as HMPE.

I had two such short-helix eye knots tested long ago,
in 1/4" laid (med. soft) nylon --one being a redressing
of the dbl./"round turn" bowline (so, it had ultimately
a U-turn whereas the other was pure helix and off it
ran into the eye-leg).

I understand you have tied/tested your own helical structures, wondering if the reverse implementation has prompted your interest. If so, what are your thoughts about Enhaut's  reverse interpretation of this helical concept?
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