Author Topic: A tensioner inspired by DL's binder  (Read 13747 times)

dmacdd

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A tensioner inspired by DL's binder
« 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,

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.
« Last Edit: March 31, 2011, 12:33:58 AM by dmacdd »

roo

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Re: A tensioner inspired by DL's binder
« Reply #1 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.
« Last Edit: March 30, 2011, 08:56:05 PM by roo »
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Andre

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Re: A tensioner inspired by DL's binder
« Reply #2 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.

dmacdd

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Re: A tensioner inspired by DL's binder
« Reply #3 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.




« Last Edit: March 31, 2011, 06:17:38 AM by dmacdd »

roo

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Re: A tensioner inspired by DL's binder
« Reply #4 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.
« Last Edit: March 30, 2011, 11:52:27 PM by roo »
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dmacdd

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Re: A tensioner inspired by DL's binder
« Reply #5 on: March 30, 2011, 11:07:06 PM »
What material were you using?
3/16" braided nylon.


What does "did not hold" mean?

roo

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Re: A tensioner inspired by DL's binder
« Reply #6 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.
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dmacdd

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Re: A tensioner inspired by DL's binder
« Reply #7 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.

roo

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Re: A tensioner inspired by DL's binder
« Reply #8 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.
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xarax

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Re: A tensioner inspired by DL's binder
« Reply #9 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
« Last Edit: April 02, 2011, 02:09:47 AM by xarax »
This is not a knot.

dmacdd

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Re: A tensioner inspired by DL's binder
« Reply #10 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?

roo

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Re: A tensioner inspired by DL's binder
« Reply #11 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.
« Last Edit: March 31, 2011, 12:20:54 AM by roo »
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dmacdd

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Re: A tensioner inspired by DL's binder
« Reply #12 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.

Dan_Lehman

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Re: A tensioner inspired by DL's binder
« Reply #13 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*
====

Hrungnir

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Re: A tensioner inspired by DL's binder
« Reply #14 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:

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:




« Last Edit: March 31, 2011, 11:38:47 AM by Hrungnir »