International Guild of Knot Tyers Forum

General => Practical Knots => Topic started by: dmacdd on March 30, 2011, 07:39:42 PM

Title: A tensioner inspired by DL's binder
Post by: dmacdd on March 30, 2011, 07:39:42 PM
The binder invented by Dan Lehman, photos attached to
http://igkt.net/sm/index.php?topic=2981.msg17780#msg17780 (http://igkt.net/sm/index.php?topic=2981.msg17780#msg17780),

inspires the tensioner shown in the photographs below.

You could simply use the binder unmodified, but the structure shown
is more convenient for use as a tensioner.

Note that the second pass of the cord through the turNip must enter
the turNip by the same side of the turNip as that by which the first pass
entered it, as shown in the first photo.

The tensioner may be loosened even when very tight by pushing toward each other the turNip
and the knot which provides the loop in which the turNip is formed. The technique for pushing
the turNip is to insert finger or hand into the loop that encircles the right ring in the photos,
and shove to the left against the turNip. The other hand grasps the knot forming the loop
in which the turNip is formed, and pushes it to the right.
Title: Re: A tensioner inspired by DL's binder
Post by: roo on March 30, 2011, 08:34:51 PM
From the weak sauce that is the Gleipnir comes this weak sauce.  In the small rope I'm using, this doesn't even hold.  Looking at the final image leads me to believe that you might need some clarification of what is being done in the previous step.

Also, can we stop using a vegetable name for the central coils involved in these things?  Inventing words or re-assigning their meaning on the fly is bad habit that only serves to confuse people.
Title: Re: A tensioner inspired by DL's binder
Post by: Andre on March 30, 2011, 09:37:20 PM

Also, can we stop using a vegetable name for the central coils involved in these things?  Inventing words or re-assigning their meaning on the fly is bad habit that only serves to confuse people.

Can I call the coil a "round turn"? Or is "coil" better? Just working on the description of another knot.

Thanks.
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on March 30, 2011, 10:06:09 PM
From the weak sauce that is the Gleipnir comes this weak sauce.  In the small rope I'm using, this doesn't even hold.  Looking at the final image leads me to believe that you might need some clarification of what is being done in the previous step.

Successes (holds ferociously in these, not backing off from the maximum tension I can apply):

1 mm cotton laid string;
soft 3 mm nylon braid;  
firm  and solid but flexible 5 mm nylon(?) braid;
hard stiff 5 mm kernmantel static accessory cord;
550 paracord;
soft to touch, firm to squeeze, but very flexible  10 mm kernmantel nylon braid with unknown linear core;
smooth, round, firm, flexible 1.6 mm nylon braid;

Failures: (backs off to some degree from the maximum tension I can apply):  Stiff  10 mm kernmantel climbing rope with moderately high-friction surface,  holds a kg-f or two of tension, but backs off to that level, moving by about two cm, after I release the maximum tension I can apply.

It will not hold at all, however, in any kind of cord,  if the passes through the turNip are not in appropriately related directions. The direction for the first pass is arbitrary, but the second pass must enter the turNip by the same side by which the first pass entered it.

What material were you using?

I find the term turNip very useful for discussing this class of knots.  I should not have lower-cased the N, thereby turning it into the name of a vegetable.  I just edited the first post to correct this error.

To create the configuration in the second photo, I pulled to the right on the free end sticking up in the first photo.




Title: Re: A tensioner inspired by DL's binder
Post by: roo on March 30, 2011, 10:55:15 PM
What material were you using?
3/16" braided nylon.

Quote
I find the term turNip very useful for discussing this class of knots.  I should not have lower-cased the N, thereby turning it into the name of a vegetable.  I just edited the first post to correct this error.
"Coil" works just fine.  It's an English word that has meaning.  "TurNip" is Lehmanese nomenclature that has no meaning to outsiders besides being a triPping haZard to readers' eyes.  Is it a knot?  Is it part of a knot?

Posting images or diagrams also works.
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on March 30, 2011, 11:07:06 PM
What material were you using?
3/16" braided nylon.


What does "did not hold" mean?
Title: Re: A tensioner inspired by DL's binder
Post by: roo on March 30, 2011, 11:19:09 PM
What does "did not hold" mean?
Usually, I find it hard to get the central coiling mechanism to clamp down, and the free end slips out immediately.  Looking closely, I can see that portions of the line are actually serving to hold the coils open.

In the isolated cases where I can coax the coils to close down more, the end still tends to slip backward.  Any movement exacerbates the issue.
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on March 30, 2011, 11:25:54 PM
What does "did not hold" mean?
Usually, I find it hard to get the central coiling mechanism to clamp down, and the free end slips out immediately.  Looking closely, I can see that portions of the line are actually serving to hold the coils open.

In the isolated cases where I can coax the coils to close down more, the end still tends to slip backward.  Any movement exacerbates the issue.

That's really weird.  Even in the failure case I had with the 10 mm climbing rope, it did not behave
that badly.  The behavior you are describing sounds exactly like the behavior I get very reliably when I put the second pass the wrong way through the coil.
Title: Re: A tensioner inspired by DL's binder
Post by: roo on March 30, 2011, 11:41:25 PM
That's really weird.  Even in the failure case I had with the 10 mm climbing rope, it did not behave
that badly.  The behavior you are describing sounds exactly like the behavior I get very reliably when I put the second pass the wrong way through the coil.
Going the wrong way also does not work for the material I have, as you'd expect.
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on March 30, 2011, 11:41:55 PM
   Have you tried to pass the worknig end through the ring and the double coil two times, instead of just one ? You will gain a mechancal advantage, AND, have another U to press the tail and secure it into the double Gleipnir coil. If you do this, you will arrive at a double coil, Tucker s hitch-Gleipnir variation of the binder I had posted at (1). If you do the same with two loops, you will arrive at a double coil, Versatackle-Gleipnir variation of the binder I had posted at (2).  

1). http://igkt.net/sm/index.php?topic=1870.msg17364#msg17364
2). http://igkt.net/sm/index.php?topic=1870.msg17414#msg17414
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on March 30, 2011, 11:44:04 PM
That's really weird.  Even in the failure case I had with the 10 mm climbing rope, it did not behave
that badly.  The behavior you are describing sounds exactly like the behavior I get very reliably when I put the second pass the wrong way through the coil.
Going the wrong way also does not work for the material I have, as you'd expect.

Is there any attribute of this cord you have not mentioned? Could you give a very complete description again?
Title: Re: A tensioner inspired by DL's binder
Post by: roo on March 30, 2011, 11:50:20 PM
Is there any attribute of this cord you have not mentioned? Could you give a very complete description again?
I don't find much extraordinary about the line.  It is not the most supple rope, but neither is it very stiff.  If I very carefully tie an uncompleted bowline, the line will hold it as long there is no fluctuation of the load, and no imbalance on the legs.
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on March 30, 2011, 11:57:12 PM
  Have you tried to pass the worknig end through the ring and the double coil two times, instead of just one ? You will gain a mechancal advantage, AND, have another U to press the tail and secure it into the double Gleipnir coil. If you do this, you will arrive at the double coil, Tucker s hitch-Gleipnir variation I had posted at (1). If you do the same with two loops, you will arrive at the double coil, Versatackle-Gleipnir variation I had posted at (2).  

1). http://igkt.net/sm/index.php?topic=1870.msg17364#msg17364
2). http://igkt.net/sm/index.php?topic=1870.msg17414#msg17414

Doubling the loop worked to convert the failure with the my 10 mm kernmantel climbing rope into a success.  I wonder what happens with Roo's cord.

By the way, I could not find anything that looked like this at those links you gave.
Title: Re: A tensioner inspired by DL's binder
Post by: Dan_Lehman on March 31, 2011, 06:55:49 AM
Usually, I find it hard to get the central coiling mechanism to clamp down, and the free end slips out immediately.
 Looking closely, I can see that portions of the line are actually serving to hold the coils open.

In the isolated cases where I can coax the coils to close down more, the end still tends to slip backward.  Any movement exacerbates the issue.

That's really weird.  Even in the failure case I had with the 10 mm climbing rope, it did not behave
that badly.

That's because you're using a turNip and Roo's recoiled from that.

 :D

This structure was previously presented (but without any fanfare (attention))
by me in the Gleipnir thread, post#69/70; I used the structure with
success in setting up some shelving, in cordage similar to Roo's, it seems.
(Fiddling right now w/1.Xmm soft-laid PP it is taking a double turNip
to get some reasonable gripping.)  I initially saw this structure as a possible
way for lobster-pot builders to tension various parts in prelude to tying
off the structure with an overhand stopper or half-hitches (i.e., I didn't
trust the nip to suffice over time & circmstance).  In the #69 image --in which
I have *fused* a white cord to make the extension of a bowline's tail--,
the eyeknot feeds a long tail for stabilizing the coil, there being a single S.Part
above the eyeknot (bowline).

Somewhere, I have some other variation(s) on this theme.
--out in some vegetable patch.

--dl*
====
Title: Re: A tensioner inspired by DL's binder
Post by: Hrungnir on March 31, 2011, 11:13:56 AM
What does "did not hold" mean?
Usually, I find it hard to get the central coiling mechanism to clamp down, and the free end slips out immediately.  Looking closely, I can see that portions of the line are actually serving to hold the coils open.

To me it sounds like you have passed the tails through the coil like this:
(http://bildr.no/thumb/852090.jpeg) (http://bildr.no/view/852090)
When pulling the tails in this situation, the tails will actually hold the coils open. You have to pull the tails vertically to have any chance of closening.


If you pass the tails like the pictures below, the coil/coils will close:
(http://igkt.net/sm/index.php?action=dlattach;topic=2981.0;attach=3729;image)
(http://i53.tinypic.com/vi2nnr.jpg)
(http://bildr.no/thumb/852089.jpeg) (http://bildr.no/view/852089)

Title: Re: A tensioner inspired by DL's binder
Post by: roo on March 31, 2011, 04:36:18 PM
When pulling the tails in this situation, the tails will actually hold the coils open. You have to pull the tails vertically to have any chance of closening.
The primary factor that I see holding the coil open is the tension on the portion of the rope highlighted in yellow in the attached image.
Title: Re: A tensioner inspired by DL's binder
Post by: Dan_Lehman on March 31, 2011, 05:56:52 PM
When pulling the tails in this situation, the tails will actually hold the coils open. You have to pull the tails vertically to have any chance of closening.


The primary part that I see holding the coil open is the tension on the portion of the rope highlighted in yellow in the attached image.

Which can be referred to as the "coil-stabilizing strand".

It's possible that some improved behavior attaches to slight changes
in the overall structure, in either of two ways:

Anchor Eye Side : fix the structure w/cow/girth hitch at the left side
(as shown here), so that the eye-knot's strand is fixed, not turning,
around that ring

EyeTail : have the stabilizing strand be from the eye-knot's
tail (and the eye-knot's S.Part is anchored, or runs around some
object to form the opposing eye/ring sheave).

Consider how the forces arise:
1) tail is hauled away from the eye's coil --(1) unit force ;

2) given friction, perhaps only 0.5 applied force obtains
in the continuation of the tail through the coil to the right
ring;

3) so the eye strand has about 1.5 force upon it;

4) of which some lesser portion survives the turn around
the left ring --about 1 unit (0.66 x 1.6),
which is a boost over what would be coming to it from
the right ring (0.66 x 0.5), but that should nearly hold
(the 0.5  vs. 1.0 : friction enables the balance).


Whereas with the first structure, the stabilizing strand gets
no force from the left, so only the 0.6n x 0.6 surviving the
turn 'round the right ring, and thus is more readily deformed,
enabling better turNipping ?!

 - - - - - - - -

Working with structures that involve combinations of these
sorts of "two-to-one" mechanical-advantage structures can
lead to surprises, as some parts don't move as expected and
parts go WAY slack while others shift unexpectedly --and maybe
much is "YMMV" depending upon materials (smooth steel rings
vs. rusty vs. cordage sheaves; smooth flexible vs. firmer rough
cordage; ...).

I just collected on a bike ride some white, hard-ish fibrillated
PP (PE?) white twine --hard-firm as in not wanting to *bend*
so much as *kink/sharply fold".  I played around with some of
these binding structures trying to bind a coil of moderately firm
poly-Dac 3/8" rope (of maybe 18 coils?, x 2 (i.e., binding from
the outer sides the long oval of coiled rope)).  The Gleipnir
performed well, even though showing some slack on tensioning.
The #35 did well, even with both ends slipped --i.e., when
finished with slip-bights (so, 4 diameters through the coil (single).

And ... then came a *new* knot, as I sought to answer the rope
problem How to efficiently bind a collection of branches?
--or so I think, on first impression.  (I was getting concerned that
some need to haul one's stock of binding twine through a coil
would not be all so easy/time-efficient.)


Somewhere, I have some other variation(s) on this theme.--out in some vegetable patch.

   By the time you will finally decide to present them to us mortals, along with your ...

???

Really?  The structure you started this thread with was presented by me
on 2009... --nearly TWO YEARS AGO.  What difference did that make?
Where were your electrons, then?   ::)
That post --no ghost-- can still be found,
and has been referred to above; its electrons yet function.


--dl*
====
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on March 31, 2011, 09:48:27 PM

The primary part that I see holding the coil open is the tension on the portion of the rope highlighted in yellow in the attached image.

Which can be referred to as the "coil-stabilizing strand".

It's possible that some improved behavior attaches to slight changes
in the overall structure, in either of two ways:

Anchor Eye Side : fix the structure w/cow/girth hitch at the left side
(as shown here), so that the eye-knot's strand is fixed, not turning,
around that ring

EyeTail : have the stabilizing strand be from the eye-knot's
tail (and the eye-knot's S.Part is anchored, or runs around some
object to form the opposing eye/ring sheave).


I tried using the tail of the bowline forming the eye as the coil stabilizing strand.
The s.part of the eye passed only once through the coil. I tried having it pass
both ways with respect to the direction through the coil taken by the tail of the eye knot.
I tried these combinations with and without fastening the s.part of the eye to its
support with a cow hitch.

All of the arrangements I tried that included the use of the tail of the eye knot as the coil
stabilizing strand degraded the performance of the tensioner.  I used the same hard stiff
5 mm static accessory cord that I used with the tensioner as pictured at the top of the thread.
When used previously, as pictured there, it performed perfectly, not backing off at
all from the maximum tension I was able to apply. There was significant slippage
with the eye knot tail as the coil stabilizer.

I also tried fixing the s.part of the eye knot as the only modification of the original
configuration, in other words the s.part of the eye knot passed twice through the coil.
This modification seemed to produce no change in the performance of the tensioner,
but I think there might have been improvement I could not observe because of the generally
excellent performance without this modification with the materials available to me.

I believe the failure of the 10 mm climbing rope is due to its extreme unwillingness to bend
to a radius small enough to be effective with this tensioner. It would refuse to work with
many such knots.
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 02, 2011, 02:42:51 AM
  I have tried many variations of double nipping coil ( single turn, ABoK#41) Versatackle/Gleipnir binders. They all hold very well, but they are somehow difficult to dress and tighten properly. It seems that the double coil nipping loops are  too effective for this knot ! They often lock too early, and, when this happens, to tighten the binder, one has to pull all the four connecting lines, (not only the tails), the one after the other, to equalize their tensions. (See, at the attached picture, an example of such a binder, witlh double coil bowline loops.)
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 02, 2011, 06:54:28 PM
  Trying to combine some of the tricks we have learnt till now for the binders - the double nipping coils action, the tucker s and the Versatackle anchor loops, how to secure the tail through two tensioned U s ( 1, 2, 3), I arrived at an interesting tensioner-binder, shown in the attached picture. I believe that there should be many more knots that can achieve the same thing, and some of them might even be simpler and better holding. And some of them might be just under our noses, as was the great Gleipnir.

1.http://igkt.net/sm/index.php?topic=1870.msg17364#msg17364
2.http://igkt.net/sm/index.php?topic=1870.msg17414#msg17414
3.http://igkt.net/sm/index.php?topic=1451.0
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on April 03, 2011, 04:10:21 AM
 Trying to combine some of the tricks we have learnt till now for the binders - the double nipping coils action, the tucker s and the Versatackle anchor loops, how to secure the tail through two tensioned U s ( 1, 2, 3), I arrived at an interesting tensioner-binder, shown in the attached picture. I believe that there should be many more knots that can achieve the same thing, and some of them might even be simpler and better holding. And some of them might be just under our noses, as was the great Gleipnir.


My first reaction to the pictured one, it having defeated my attempts to figure out how to tie it, is that I have to figure out how to tie the constituent knot in the bight in order to tie the two constituent knots the same way, a necessity for ease of retention in memory, mine at least.  I'm not sure if even this is true, however, not having been able so far, to figure how to tie it.
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 03, 2011, 11:48:24 AM
to figure how to tie it.

   There is not much more there than what I have described as "binder tricks", the one after the other : Follow, 1 : the double nipping loop , 2 : the U through the coil "tube" it is formed by this double nipping loop (so the two U s (*) of the two ends of the rope - the orange and the white - are nipped intside this coil "tube" ), and 3 : the finall exit of the working end through the bight of this U, so the whole knot is tighten when we pull the end(s), and it stays in place as an anchor loop (such as the loops we find at Tucker s and Versatackle knots).
   If you manage to arrange those tricks in another way, you would probably end up with another valid canditate for a tensioner/binder, that might be better and/or simpler. Now, if you succeed to achieve this with a TIB knot, that would be great indeed !  :)  

*. Actually, because the white end does not pass through the white coil "tube" for a second time, the white "U" looks more like a half-U, an inverted L.
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on April 03, 2011, 03:57:59 PM
to figure how to tie it.
Now, if you succeed to achieve this with a TIB knot, that would be great indeed !  :)  


My point was that you can always tie the first of the two constituent knots with an end, but the second constituent knot has to to be tied in the bight because the ends of the cord in which it must be tied are not, in general, accessible. 
Title: Re: A tensioner inspired by DL's binder
Post by: dmacdd on April 03, 2011, 04:25:40 PM
to figure how to tie it.
Now, if you succeed to achieve this with a TIB knot, that would be great indeed !  :) 


My point was that you can always tie the first of the two constituent knots with an end, but the second constituent knot has to to be tied in the bight because the ends of the cord in which it must be tied are not, in general, accessible. 

There must some misunderstanding here...There is only one cord, with two accesible ends, with which piece of cord you bind together a number of objects. You can tension this binder pulling the two ends of the binder simultaneously.


I deduce from the fact that you are not understanding me that the working ends in the first photo are the pieces extending to the left and right. If the working ends are the pieces extending up and down, as I have been assuming, then one of the constituent knots has to be tied in the bight.  It should a  rigid convention that we do not picture knots without clearly distinguishing working ends from standing parts.
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 03, 2011, 04:40:57 PM
   If we wish to classify all the possible variations of this binder, we can follow the scheme outlined in the next posts ( plural, because of the limit of 4 pictures per post...)

   First, we can classify them in two broad basic classes, let us name them A and B. An example of the A class is the binder presented previously. ( Notice that the "white" knot is mirror symmetric to the "orange" one. This in not obligatory, of course, but I think that many people will inspect easier a pair of knots that are placed face to face to each other, if the one is a mirror symmetric copy to the other - and not a translated copy to the other). In the B class binders, the working end forms first the U inside the coil tube, (through which the other end will pass), and then the double coil tube. ( In the A class, we have seen an example of the opposite.
   We can pass the "white" end, first over the "orange" U and then under it, or vice versa. I denote those variations as (over-under) and (under-over), respectably. We can also have the working end cross with the tail before it enters into the coil tube (to form the U), or after. I denote those variations as (before) and (after), respectably.    
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 03, 2011, 04:51:04 PM
   We can also have the two coils tied in two different ways, the "normal", where the two ends of the coil leave the coil tube "far" from each other, and the "crossed", when they leave the coil tube "near" each other   I denote those variations as (far) and (near), respectably. Also, we can have a twisted collar around the standing end, or not. I denote those variations as (twisted) and (untwisted), respectably.
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 03, 2011, 04:59:19 PM
   Can we classify, with those 4 characteristics, all the possible variations of this binder ? Unfortunately, no !  :) See the two examples in the attached pictures, and try to figure out how we could possibly describe them...
   Now, all those variations hold very well, but their problem might well be the exact opposite ! Some of them, hold too well, they nip and gripp the "white" end too early, so it is difficult to tighten the binder even more. Of course, it depends, as always, on the material used.
   I have tied all the possible variations of this quite simple binder, but I have not tested them the one against the other in a quantitative/systematic way. OPT would be much welcomed !  :)
Title: Re: A tensioner inspired by DL's binder
Post by: xarax on April 05, 2011, 03:16:45 PM
It seems that the double coil nipping loops are  too effective ... They often lock too early, and, when this happens, to tighten the binder, one has to pull all the...connecting lines, (not only the tails), the one after the other, to equalize their tensions.

  When we use materials that are not slippery enough, or when we need a binder/tensioner where we have to pull one only end to tighten the structure, we can always tie the -simpler - tucker s hitch variation of the binder at (1), or the -more complex- double nipping loop variation of the binder at (2). Although here we have only one double loop nipping the two U s, we might also have to tighten the structure in three steps. ( First, pulling the tail, then pulling any slack connecting cord, and finally pulling the tail again.)( See the attached picture for such a binder/tensioner. I have used a simple bowline here, but we can also use any loop, (ABoK #1050,#1053, #1054,#1058, etc.). The white rope placed "vertically" in the picture s frame, is the free end.)

1). http://igkt.net/sm/index.php?topic=2996.msg17830#msg17830
2). http://igkt.net/sm/index.php?topic=1870.msg17364#msg17364
Title: Re: A tensioner inspired by DL's binder
Post by: Dan_Lehman on April 08, 2011, 06:20:02 PM
...
*. Actually, because the white end does not pass through the white coil "tube" for a second time, the white "U" looks more like a half-U, an inverted L.

I should remark that the orange structure shown here,
 [ Xarax's post with nicely loosened / open knot, to show structure ]
 if the inner loop is removed,
is my "symmetric Fig.9" : and I find that IT will adequately nip the white rope
(where that is simply the same line, closing the eye of this adjustable eyeknot),
in common materials (though one would often prefer to tie a stopper, 2 B sure).
The tail is strongly nipped between the turns of the S.Part & other eye-leg.
(But if the tail is pulled in isolation against the S.Part, it most likely will pull out
--the other leg must also be tensioned.)

And this "symmetric fig.9" structure seems to make a good mid-line
stopper, non-jamming (in common materials; really slick ones can jam);
such things are occasionally seen in dock lines, marking the point to which
the line should be set.  The same structure can be used as the hitch (with
various orientations of how it is hitched/entangled to ...) for a noose-hitch.

--dl*
====