Author Topic: self locking reef knot?  (Read 10178 times)

knot4u

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Re: self locking reef knot?
« Reply #15 on: September 26, 2013, 03:49:04 PM »
Hi Luca,

Thanks! I'm having a hard time thinking of an easy way to tie that. Am I right, or is there a trick?

Dan_Lehman

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Re: self locking reef knot?
« Reply #16 on: September 26, 2013, 06:51:38 PM »
Hi Dan and knot4u,

It may be that this is so?(There is also the handle for easy transportation of the object!)

  Bye!

1) I don't see how this fits the need;
i.p., where is the bound, "central" object to fit?

2) I don't see --as best I can figure, given #1--
how this can well sustain tension.

In the structure that I illustrated verbally,
the Prusik (or variant) hitch will be loaded
by the object-surrounding wraps, which wraps
will be what can be drawn ever tighter by the
ends (which run through the gripping hitch).
Upon release of ends-tensioning, each of the
two wraps will at one end pull on hitch coils
(and its other end --an actual "end"/tail--
will be taking half of the 2-wraps' tension
INTO this knot, which we'll hope is not too
much to be arrested by the tightened coils).

I considered some structure of two pieces of
material, but that didn't lead to a happy result.

--dl*
====

Luca

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Re: self locking reef knot?
« Reply #17 on: September 27, 2013, 01:05:17 AM »
Hi knot4u,

I'm having a hard time thinking of an easy way to tie that. Am I right, or is there a trick?

It is true, the knot is not exactly fast to tie, but is designed for a certain situation in which it can be repeatedly reused,once removed from the object that wraps, without having to repeat each time the operation of tie it. One can imagine wanting to keep it completely tight around himself,to use it quickly,when the occasion arises,simply enlarging the two wraps used to envelop the object. Anyway thank you for having the patience to decipher my diagram!(below there is another that shows a version based on the "doubled" Clove hitch, on the model of of how it seemed to me that described by Dan Lehman (although it seems that in fact I did misread his words!))

                                                                                    _                _                  _

Hi Dan,

I've probably made ​​a so-called "epic fail" in interpreting your description:excuse me,I beg you for having comprehension for me.
I think it's likely that what you mean in your description is something better than what I've shown in the diagram;however, what I have shown is not entirely meaningless, as binding knot still seems to me close to decency, the binded object in the diagram is the gray "pole" , while the "handle" is the large bight with the two arrows above it (the arrows in the diagram indicate the directions for pull to fix  and tighten the knot,as I (not)understood;it is from this that,in my case,is formed the "handle",of which in fact you do not talk, since I have not found something better for well tighten the coils of the initial Prusik directly connected to it).Forgive me if I insist below with a diagram that shows the Clove hitch version(seems better,and is symmetric) of what I(not) understood. But at this point, I join the exhortation by knot4u for an illustration! Because I have to say that I also still can not entirely figure out the knot that you described.

                                                                                                                        Bye!

Dan_Lehman

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Re: self locking reef knot?
« Reply #18 on: September 27, 2013, 06:45:30 AM »
Luca, excellent diagram of the wrong orientation!
--you need the ends to run the opposite direction
(so that the coils are pulled on like for the rolling
hitch
and not like ProhGrip (Blake's hitch)).
It's good that you showed the clove orientation
rather than the cow for the Prusik-like gripper.
.
.
.    [ but then Dan tries Luca's "wrong" way :   :o   :D   ::)  ]

Okay, maybe I like your orientation better --the loading
of the knot pulls coils together.  (I'd half-wittedly thought
that loading against each other would defeat gripping
--as the extending *away* coil can push against the
other in a Prusik hitch--, but these just get better.)
!!
Cutting down the bulk with Occam's Razor, I find that
the Gleipnir-like versions using the (mere) clove hitch
--in both orientations as we're discussing above--
work quite well (in some nylon, fine-braided venetian-blinds
cord (2mm?), tied around 3"dia PVC pipe --so, slick and able
to transfer force around pretty easily).
I.p., they grip much more tenaciously than the constrictor
(which loosens by putting pressure on the tails pretty easily).


--dl*
====


kieranbarnard

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Re: self locking reef knot?
« Reply #19 on: September 27, 2013, 07:20:01 AM »
Thanks so much for all the suggestions - The surgeons knot seems closest to our needs - We're going to try that to start with to see if that holds adequately. If not we may need a more complex solution...

Kieran

 

knot4u

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Re: self locking reef knot?
« Reply #20 on: September 27, 2013, 08:02:20 AM »
I was asking the original poster, not Dan, to provide a diagram or pic of the problem.

alanleeknots

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Re: self locking reef knot?
« Reply #21 on: September 29, 2013, 05:33:22 AM »
大家好,
     
     道太玄,如何超度眾生呢?

        謝謝   alan lee

Sweeney

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Re: self locking reef knot?
« Reply #22 on: September 29, 2013, 09:53:56 AM »
大家好,
     
     道太玄,如何超度眾生呢?

        謝謝   alan lee

In English?

NotSure

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Re: self locking reef knot?
« Reply #23 on: October 01, 2013, 07:19:27 AM »
...The only issue now is that the constrictor does not hold it's shape: the two loops come apart when you let them go.  What I really need is a constrictor type knot that will hold it's shape and will tighten as the two ends are drawn apart simultaneously in opposite directions. does this exist?

Kieran

So... you are basically looking for a loop (that will hold it's shape as an open loop) until it's needed to throw over something to squeeze (and doesn't lose any tension after setting it).

I really enjoy tying the jug knot and seems like a good alternative knot for this application:

https://en.wikipedia.org/wiki/Bottle_sling

Looks complicated but it's actually pretty simple and quick to tie after a bit of practice.

Might be a bit bulky is all...

Cheers!
« Last Edit: October 01, 2013, 07:29:51 AM by NotSure »

Ruby

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Re: self locking reef knot?
« Reply #24 on: October 01, 2013, 07:40:01 AM »
大家好,
     
     道太玄,如何超度眾生呢?

        謝謝   alan lee

In English?


seems like chinese?

google translate:
-------------------
god, life's so complicated, can you tell me how to  save the living souls from the sea of misery?
-------------------



maybe not correct but obviously not related to knot

a joke ? :D

Luca

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Re: self locking reef knot?
« Reply #25 on: October 01, 2013, 11:24:22 AM »
Hi Dan,

--you need the ends to run the opposite direction

Thank you, it seems only right at this point also attach an image of the original version!(below).I personally found that if, tightening the two wraps around the object,I act in order to "separate" the "doubled" Clove hitch component into two "halves" (forming in this way a sort of rigid "bridge" between the two halves , instead of the loosened "handle"of which I was talking above)your version "bites"  strongly,and at the same time is not difficult to loosen;so it seems to me that, at least for objects of a larger size with respect of the diameter of the rope, your version maybe is better!

[ but then Dan tries Luca's "wrong" way :   :o   :D   ::)  ]

 :o :D Thanks!

                                                                                          _          _          _

I was asking the original poster, not Dan, to provide a diagram or pic of the problem.

knot4u,excuse me, in fact I misunderstood.

                                                                                                             Bye!



Dan_Lehman

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Re: self locking reef knot?
« Reply #26 on: October 01, 2013, 02:44:04 PM »
The surgeon's knot seems closest to our needs ..."

Kieran, I don't see how that knot is in the right class
for what you earlier described --the need, i.e.-- to be:
Quote
... a contrictor type knot that will hold it's shape (without biting onto anything)
and will go from large diameter to small diameter as you pull the opposing ends.
!?   ::)
With the an end-2-end knot (e.g. surgeon's),
you don't have such adjustability at all!?


--dl*
====
« Last Edit: October 01, 2013, 03:31:35 PM by Dan_Lehman »

Luca

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Re: self locking reef knot?
« Reply #27 on: October 01, 2013, 10:15:30 PM »
For a"single wrap joined by bend"that can be adjustable, maybe the solution below may be able to take advantage of the "jamming properties " of the Fisherman knot,but used with"melted" tails(which become the ring/wrap around the object),and perhaps might work: the only problem is that one needs to adjust the ring so that its circumference is less than the circumference of the object that wraps before the two Overands come into contact with each other, but  seems to be a rather simple solution(if by chance it works decently!).

                                                                                                           Bye!