Author Topic: Dual-loop Butterfly tying  (Read 5476 times)

Dan_Lehman

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Re: Dual-loop Butterfly tying
« Reply #15 on: August 07, 2022, 06:47:24 PM »
Whether you like it or not, English is the defacto language for science and research papers.
Indeed, which means we see already plenty of it.
Now, for an acronym which could be much of anything
--if it is used & well understood-- we can do what
English itself has done over time, and include some
non-English phrases.
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The term 'TIB' (Tiable In the Bight) works for me
--there aren't too many 'edge cases' where the concept is muddled.
The problem is with the word "bight" --and it's smack in "TIB"--;
that is what needs to be excised, for clarity (that doesn't depend
upon gobs of context & likeliness for a meaning).

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I usually define 'TIB' as follows:
A knot is TIB if it can be formed without access to either end.
Ha, I've been reviewing knots books on these knotty definitions,
and you've scored a gain over most if not all :: i.e., that it is
access to the ends and not specifically using an end
--one might do a BoaBight-like "back-flip" maneuvre that must go
around an (accessible, thus!) end but cannot be said to be using it!

Also, though I do NOT support "bend" as Ashley wanted (and many
copy) but use "(ends) joint" for that, it is so far I think alone Brion
Toss in his Chapman's Guide to Knots (not Rigger's Apprentice)
that he wises up to "join two ends" and nevermind how many ropes
--just one, if making a sling, e.g.-- are engaged!  (--in which sling case
the definitions will have trouble with there being no "standing end"
in this case : both are "working"!).

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The key underpinning concept is .... without access to either end.
Which <sigh> can put "NSUE" to question, as just noted.

Quote
Loading is in axial alignment with both SParts, which are 180 degrees opposed,
so that load transmits through the knot core in a straight line pathway.


This definition requires the presence of two (2) SParts (standing parts).
And the SParts must be in axial alignment.
Load propagates from one SPart, passes through the knot core, and continues through to the opposite SPart.

Load can be bi-directional (coming from, or going in both directions).
An assertion sure to win the applause of "one hand clapping"!
Now, for those not so clever, what would it mean to have an
(implied...) UNI-directional load?
.:.  No, there is one axis of tension with those S.Parts in
"through loading" (also called "cross loading" in reference
to eye knots just *randomly* (w/o special consideration/design)
and loading the tail-vs-S.Part).
Though, loading the eye ALSO ... and at some range of angles
to the S.Parts ... and all can assume various angles per forces,
but still will be a condition separating wheat from chaff vis-a-vis
"mid-line" eye knots
 --as you note ("Not all knots can sustain this type of 'through loading' profile")

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I have used the term 'biaxial through loading'... to make it clear that both SParts are involved.
Its not just a case of having the knot axially aligned... it also the fact that both SParts play a role.
It is also implied by these definitions that a 'TIB', through loadable eye knot can also exist mid-line.
Again, there is no sense to your implied 1-fewer-than-2 (uni- vs bi-axial);
there is a single axis of tension (and it has been argued that loading the
eye, e.g., brings in a SECOND axis ... though showing a trio of directions;
Hmmm, I'm more of a 3D person on this : blow apart the
union point and formerly attached pieces are going in THREE
directions, methinks).

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Dan Lehman has raised the issue of #1408 and #1452...
[CONFIRMING] that these knots can exist in 'TIB' form with double eyes, and be through loadable.
That is, #1408 and #1452 can exist mid-line, without access to either end,
and be capable of sustaining a through loading profile.
If this is true, then it also needs to be confirmed if a pulley can be easily attached
(in the same manner as with the 'Girth hitched' double eye Butterfly).
At least in this way :: make the twin eyes with one long,
the other not-so ; reeve the long eye through pulley eye
and other eye; then "backflip" it around to sort of make
a *squared larkshead* to complete the both-eyes-contain-pulley
state (this "square" structure would encompass all four eye legs,
yes).
(A scarier attachment would be having the shorter eye
go through the swivel eye and the longer eye go through
the shorter qua toggle (though some fright could be shed
by taking this toggling eye around (backflip'd) the pulley,
I suppose  --but for which then one wants pretty close
sizing of the longer one : enough to surround pulley
without being much loose.   (The load on the shorter
eye would be sort of *stopper*-like, as it pulls through
the swivel eye but then surrounds the other-eye-qua-toggle
and not (as for a girth h.) U-turning back up & around itself.)
)
((And here is where knot-book pub.s rush out the big-font
red signage stating no responsibility for accuracy and please
--no, you MUST-- consult with exp'd  knot tyer before using
anything in the book you've just  paid $$ for!!  :o   ;)  ;D  ))

--dl*
====

Dennis Pence

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Re: Dual-loop Butterfly tying
« Reply #16 on: August 13, 2022, 06:02:04 PM »
Hello Mark,

I have been away for a while as well (quality time with a grandson!).  I did come up with the tying method in Reply #7 by myself, although I am sure others could come up with it if they had noticed the request.  Of course, I was greatly inspired by the tying method of Richard Delaney for the "Girth Hitch Double Butterfly".

I have also been trying to come up with a way to insert a pulley or ring for this variant as well.  It would be nice if it would turn the pulley or ring 90 degrees compared to the Girth Hitch variant.  Below is the best I could do.  You simply insert the device and carry out the steps shown in Reply #7.  But this leaves the ring in an awkward position between the two loops.  The trick is to do a half twist of one of the loops, much like the half twist that Wright and Magowan insist should be done in a single Butterfly Loop. (It does not seem to matter which one you twist, but you only twist one.)

I also thought about applications for this.  When you tie a Trucker's Hitch, you usually tie the Midline Loop each time in a different position to adjust for the size of the load.  But if you are tying the same load every time (say a canoe or kayak on the top of your car), you might want to leave the Midline Loop.  Tying this Double Butterfly with a Ring would cause much less wear on the rope, and it would give you much less friction to get closer to the 3-to-1 mechanical advantage when you pull through the ring instead of a rope loop.
« Last Edit: August 13, 2022, 10:33:58 PM by Dennis Pence »

agent_smith

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Re: Dual-loop Butterfly tying
« Reply #17 on: August 20, 2022, 06:21:08 AM »
Thanks Dennis,
We've now got 2 different 'thread topics' dealing with double eye Butterfly's... its not easy to keep track of developments.

I feel you are very close to a way of figuring out how to avoid overlapping/crossed eye legs (in one of the double eye Butterfly's).
I remain optimistic that there might be a tying method (starting from base #1053 Butterfly and without untying it).

Then again, I am always the eternal optimist...because the human mind seems to have no limits on what it can imagine!

KC

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Re: Dual-loop Butterfly tying
« Reply #18 on: August 20, 2022, 03:36:42 PM »
Also, though I do NOT support "bend" as Ashley wanted (and many
copy) but use "(ends) joint" for that, it is so far I think alone Brion
Toss in his Chapman's Guide to Knots (not Rigger's Apprentice)
that he wises up to "join two ends" and never mind how many ropes
--just one, if making a sling, e.g.-- are engaged!  (--in which sling case
the definitions will have trouble with there being no "standing end"
in this case : both are "working"!).
i use Bend as you de-scribe as 'pirated parroting'; but please forgive w/o plank walking as is for clarity and consistency across the (p)ages and newbs.
But internally i see and describe to self either a termination or continuation of the rope force line in more precise speak.
>> and really go with rope was loaded on great ships, but were called a line in typical usage.
That is a line of force at the end of the day to me, that the unused rope loading onto great ship does not have, but only promises the capacity of.  The geometry reigns all thru rope works (to include knotting) from there !
.
A base example to me is primary rope lessons w/Half Hitch(HH) as a termination of rope(Hitch type) force line or continuation of same as if a Bend type logic of the node(node: deformity swell in straight line run; as in plants)formed as pass-thru/continuation.
If take the nip point of continuation HH is like a dual shared termination to that single nip point from either input/output side.  Each leg could be HH termination type w/o Bitter End.
From this view the continuation is a dual in/out terminating HHs, that forms single axis thru the force line.
The continuation line parts will be of greater tension than the 'sideline' ring formed, as it is not in this 'electric' linear path that the ends line up to.  Until with too long a collar in Bowline as to allow the fault of Sheepshank and get the roll out of the continuous HH (90, 180, 90 degree geometry parts) to just a combined sum 360 that is now folded down into inline with the  line of force, and so now tension increases thru the loop, where was lesser before.  There is no 'shorter electrical path' to skip the loop with; now that loop is folded down into the linear of force.  i find it much better to look at force as in more a liquidly flowing electrical sense thru rope pipeline as wire, and as such takes opportunities to pass from one rope part to another, even if partially, to leave then less behind of the finite source force.
.
A sling crosses a line to me here tho bro, to go from a linear to radial device...
Choked tho, i do see 2 SParts, as do in Girth Hitch.  Difference is the SParts in sling are self adjusting set on a hook, girth does not have self adjusting SParts, so must manually set/guess this key point, then should only use at that angle for maximum sharing between the 2 SParts as legs of support.  The sling by contrast is microscopically self balancing adjustment on the fly at many angles of pull but still 2 legs of support, sharing load evenly, as ports force as SPart(s) into the controlling arcs, as like gas hose into car to power/energize i always think.  So to me, a SPart in 'Tensionless' Hitch and HH both start at load and end halfway around round host where the primary arc180 starts in both.  To model have formed in head SPart is a linear, even if deformed in HH, as the pull of the load at one end of SPart and that entrance to arc180 as primary arc are in OPPOSING directions for that specific rope element.  Does not need to be rigidly aligned , as no rigidity to the cross axis, so can be just DIRECTIONALLY opposing to qualify, is less efficient tho than 'Tensionless'.
.
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An assertion sure to win the applause of "one hand clapping"!
Kinda an alma mater please(might explain a lot..  :P )
Of c(o)urse Dad artfully schooled in the sound of 1 hand slapping as well(he was 5th Chicago cop in the family, nicknamed by piers as the disciplinarian; witch too might explain a lot  :-X ) ..
.
Quote
Now, for those not so clever, what would it mean to have an
(implied...) UNI-directional load?
.:.  No, there is one axis of tension with those S.Parts in
"through loading" (also called "cross loading" in reference
to eye knots just *randomly* (w/o special consideration/design)
and loading the tail-vs-S.Part).
Though, loading the eye ALSO ... and at some range of angles
to the S.Parts ... and all can assume various angles per forces,
but still will be a condition separating wheat from chaff vis-a-vis
"mid-line" eye knots
 --as you note ("Not all knots can sustain this type of 'through loading' profile")
Can have uni-direction if want i guess of travel if no force against i guess...
but NOT force, that needs antagonistic twin, 'dueling' points.
To me can cross-load Bowline eye, to use as if Binder from internal force w/o SPart loaded.
>>but spread eye and as also hang from SPart is a bit outside as 2 separate handled forces, sharing a system.
Best clean simple view would be as separate function models.

Quote
Again, there is no sense to your implied 1-fewer-than-2 (uni- vs bi-axial);
there is a single axis of tension (and it has been argued that loading the
eye, e.g., brings in a SECOND axis ... though showing a trio of directions;
Hmmm, I'm more of a 3D person on this : blow apart the
union point and formerly attached pieces are going in THREE
directions, methinks).
Totally agree, 2 OPPOSING directions (compression or tension) constitute a loaded axis, can leverage a 3rd direction on separate axis, rooted from the resistance of the primary axis.
Working in dimensions, there is no Zer0 dimension point of force in my terms;
Must have at least 2 points of Equal (force) & Opposite (direction) here for force, so at least 1dimensional, no uni!
The line of the loaded axis in rope gives these competing, antagonistic, dueling twins.
This gets more complicated when not a flexible class like rope, but rather a rigid that has resistance on the cross axis AND can load in tension (as rope only does) or compression.
So, from that view, rope gives clearer lessons in these things; with less complications, but we tend to start with rigids in understanding, and then this simpler now seems a twist i think (psyche self is simpler and go on)!!  It is rather counter intuitive to our initial L-earnings that rope works by rigidity against force, as it lays slack in your palm.  But in use is a rigidity against (or for) physical and/or force displacement as any other structure ever.  Rope is just easier to form for our repeated usages than other substances; but must follow the same  rules of rigid architecture geometry along it's tensioned linear length.
.
Bi-axial in plants etc. is NOT a continuous line or plane , but rather separate parts, in separate, not continuous linear single dimension(s).  Thus stem it self is not biaxial, but rather alternating parts to either side of stem dichotomy are biaxial.  Even if somehow could find a straight line to the separate sides of stem, they would be fed separately, structured and therefore shear separately they are not a continuation of each other as in rope line.
.
i believe that rope can physically lace in 3Dimensions, but only handles force in 2dimesnions force wise, or forms another system.
i think this is as Ashley shows/represents in choice of right angle to host Hitch (1D hold host and load in 1 line))or lengthwise, 2 dimensions(hold host and hold load).
Simplest right angle Hitching example:primary dimension linear is the load force as standard, the 2nd deflected force overrun of byproduct side force not aligned properly to primary linear dimension(for accounting purposes).  Would have to have cross-axis rigidity on the 2nd Dimension to need the 3rd Dimension deflections of force as in rigids.  But rope as part of flexibles class definition does not have cross-axis(to the linear length) rigidity.  Rope length in linears can be shown as cosine work, cross axis sine by product.  Rigids could then have a byproduct(sine) of the byproduct(sine) as 1st sine is rigid; but not in rope/flexibles.
In flat rope/webbing do have a scrunch across width consideration of deformation, but is not a Native rigidity to then fight and have force byproduct to show.   Round rope does not have this problem as the cross section profile across length is the ultimate equilateral(in 2D) of circle , where webbing has flat and wide.  Radial or Linear again here is key.
.






Overhand Knot is Natively a 90degree architecture to me, thus wrenched full 90 degrees to linear flat is thus worst position of pull and then around 1 diameter, and so jams hardest and weakens that rope part in the chain the most; in a parent system that is as strong as that weakest link...
The interlaced Overhands to extrude BFly works in 90degree Overhand to each side of eye together as a 180 flat continuous line and does not shrink to own diameter.  Similar view as HH termination or continuing model of shared terminating nip point; only here have input/output Overhands instead (seen best eye onloaded).  But, inherits that it is still best if the eye part of each Overhand was pulled @90degrees if any, or jams more easily from the still errant angle of lengthwise pull on Overhand(s), but BFly so sturdy shines thru such usage in Trucker's making only harder untie, and probably weaker structurally for the violation from premium position.  It kinda so good, can fool, but must follow same rules as then also stands as an example of.
.
Intertwined Overhands of BFly and Rigger's kinda overconcentrate force, unceasingly at high loading.(Zepp and faux form side by side SParts not intertwined, not over focused)
The BFly has a less rigid side of some relief to the overconcentration with both SParts to either front or back;
Rigger's has most rigid SPart(s) to either side as like front and back guards to the overconcentration w/o any softness/relief and jams by contrast i think.
Zepp gives the both side guards of rigid SParts as Rigger's, but is not over focused as a softener, so works super, but faux form has the same side by side but then the same open /soft side of no rigid SPart guard (both on other side), as like a double fault that fails as xTension is increased.
.
part segregation questions
produced eyes >>Will a doubled eye form hold 2x as much??
Linear length   >>If unloaded dual eyes, is the linear itself stronger from the softer bends?
« Last Edit: August 20, 2022, 07:51:14 PM by KC »
"Nature, to be commanded, must be obeyed" -Sir Francis Bacon[/color]
East meets West: again and again, cos:sine is the value pair of yin/yang dimensions
>>of benchmark aspect and it's non(e), defining total sum of the whole.
We now return you to the safety of normal thinking peoples

alanleeknots

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Re: Dual-loop Butterfly tying
« Reply #19 on: August 21, 2022, 01:34:32 AM »
         Hi All,  Here is how I descript Overhand knot.  Thanks.

         https://www.dropbox.com/s/wvqkedw3s9zah7x/Tie%20Overhand%20knot.MOV?dl=0

alanleeknots

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Re: Dual-loop Butterfly tying
« Reply #20 on: August 21, 2022, 03:21:55 PM »
     
            Hi All,  Just follow up, make it more clear and understand about how Butterfly knot function.
                       Thanks.  alanleeknots.

             Edit; The loop below is called  Lineman's Loop "ABOK # 1053" or Butterfly Loop.
                     Just getting old, old age issues start to come,. Sometimes I just don't know where I am.
                     Aug-21-2022. Thanks   
                       
« Last Edit: August 21, 2022, 09:56:31 PM by alanleeknots »

Dennis Pence

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Re: Dual-loop Butterfly tying
« Reply #21 on: August 24, 2022, 08:48:35 PM »
Here is another variation on Dual Loops from a Single Butterfly.  You would not want to do this with climbing rope, but with paracord and other cheap, slick synthetic rope you might want to double wrap the single Butterfly.  Then you can turn it into dual loops using the method in an earlier reply.

If you are going (say with a hand wrap method) directly to a Double Butterfly, you do not want to double wrap both loops.  The method described below only double wraps the first loop.
« Last Edit: August 25, 2022, 02:04:30 PM by Dennis Pence »

Dennis Pence

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Re: Dual-loop Butterfly tying
« Reply #22 on: September 07, 2022, 11:09:15 PM »
This thread would not be complete without showing how to get three loops from a single Butterfly Knot.  Dave Root shows how to get a Triple Butterfly via a hand wrap method at his site.
    https://daveroot.neocities.org/knots/Knots_MultiLoops.html
Below is how to convert a single into a triple.  Admittedly, the easiest way to get the "coil" needed early in this is to do a little "hand-wrapping" but this could be done other ways.  The trick when tightening the knot is to keep the three loops of equal size (if that is important).

 

anything