Author Topic: NOOB - I invented... now what?  (Read 71792 times)

Sweeney

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Re: NOOB - I invented... now what?
« Reply #30 on: August 26, 2009, 08:18:48 AM »
I tried this last night as a bit of a last resort. I have 8 roughly one foot long pieces of ex-curtain pole each one is round cross section and about an inch diameter. The pole was waxed before I cut it up (and I haven't got round to degreasing it) so holding this heavy lump together to carry it has proved frustrating; a constrictor won't grip properly and alternatives are difficult on this slippery (and heavy) bundle. So I tried this knot using a trainer shoe lace which has some elasticity (and happened to be handy!) and a piece of 2mm cord again with stretch. To start off I used a bit of old string and a reef knot just to hold the bundle roughly together and then applied 2 fastenings with a single nipping loop each. It is holding really well - so much so it is difficult to slide one rod from the bundle (before they all fell on the floor as soon as I picked it up). Its uses may be limited but I think this knot has a niche market where it scores highly.

Barry

PS you may wonder why on earth I want to carry round 8 lumps of wood.................!

roo

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Re: NOOB - I invented... now what?
« Reply #31 on: August 26, 2009, 03:02:55 PM »
Yesterday, I did a quick and dirty test around a bathroom scale (non-convex surface, but not open air).  I only had a few minutes, so the results are equally quick and dirty.  The rope wasn't particularly slick.

The mechanism in question had roughly half the tension of a Verstackle.  Both methods retained roughly half of their peak pulling tension.

Then, on to my favorite method of bundling sticks:  Running loop around bundle (or a hitch on an anchor point), and roll up the bundle as you compress the load and pull the line, allowing friction to hold previous wraps' tension.  It spreads the compression out over the whole bundle, but uses more line (which isn't a big concern with twine).  Then I finish with a utilitarian hitch (half-hitch based), since it's just sticks.  With not too many wraps, this method also achieved more tension than the mechanism in question.

This isn't a condemnation.  Just an observation.  If I was not interested in a lot of tension, but in simplicity, I might use a Trucker's (single loop) setup instead of the mechanism in question.  

It may be worthwhile for the original poster to do some open air tests with a hanging scale.  
« Last Edit: August 26, 2009, 03:18:05 PM by roo »
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Dan_Lehman

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Re: NOOB - I invented... now what?
« Reply #32 on: August 26, 2009, 05:43:11 PM »
Barry,
your example should be put under my separate and more general thread on
binding structures; and that initial structure could serve you.  BUT,
your case of multiple cylindrical objects makes a good contrast to my
photographed binding of square lumber:  it would be frustrating to try
to implement my binder with a collection that was not *sitting still*,
in neat order; rather, Roo suggests a method to work with such dynamic
cases, among various.  Conceivably, an overall method might even entail
an iteration between something done quickly just to roughly *settle*
the material, and then a better binding put on for the final securing.
Again, in your case, that formed-in-hand-in-the-bight sort of inversion
of Dahm's structure could be fit around the quickly bound set of things,
once they indeed got so bound.

--dl*
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Dan_Lehman

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Re: NOOB - I invented... now what?
« Reply #33 on: August 26, 2009, 06:03:49 PM »
I tried with two turns, but then the double turn is like drawing the ends through a pipe,
it won't twist back under tension, as the double turns provide leverage,
and friction in the remaining elbow will decrease the nip of the turns.
It becomes more difficult to set, and the nip seems poorer.
Interesting.  I'd post a photo, but am not eager to click-&-download for
just that.
As what I just did, upon reading this report, it to run some 5/16" (hard
to figure hollow-braid size) fairly slick (but collected from the Wild)
PP hollow-braid (quite compressible cross section) through an oval
'biner (very smooth, round, 1cm dia) and a slightly fatter hook of
a 5:1 pulley, running the ends through a double turn of the continuous
side of the simple loop (two strands bearing load).  I tightened it pretty
easily, and then stood on the pulley.
NOW, "5:1" is TMA, but as it's a quite lousy (one bad sheave) pulley,
let's chop actual MA by half:  5x180=900#/2 ~=> 400# say.
AND, after initial loading, I tightened the loop further (just hands),
and stood upon it again.  There was little slippage (the sort of yield
that might better be seen as a setting-settling of material.

This hollowbraid flattens in the double loop, to a nipping width
of about 3/4"-2cm.  Your 3-strand rope looks to be rather firm
and round (and *grooved*).   => YMMV

!?

--dl*
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lcurious

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Re: NOOB - I invented... now what?
« Reply #34 on: August 27, 2009, 04:34:56 PM »

I think your knot is quite brilliant!! It is presently holding together my bundles of hedge clippings etc. awaiting the garbage truck.


There is only one name for it. Its a    -   GLEIPNIR  -

roo

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Re: NOOB - I invented... now what?
« Reply #35 on: August 27, 2009, 05:18:49 PM »
It is presently holding together my bundles of hedge clippings etc. awaiting the garbage truck.

Be careful.  If the garbage guy grabs certain parts of the twine, it will cause the bundle to fall apart.  Finishing with a tuck or two of the ends would help
« Last Edit: August 27, 2009, 10:28:14 PM by roo »
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[Inkanyezi] gone

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Re: NOOB - I invented... now what?
« Reply #36 on: August 27, 2009, 05:43:10 PM »
I was using it for the third time today for a real job. The Media Markt had remodeled the store and there were special reopening offers. I needed a new vacuum cleaner, and the actual store is about 25 miles away and I don't have a car. So I went there on bicycle, bought the vacuum cleaner and tied it to the bike with two turns as it's a very slippery PP cord. It held for 25 miles without the slightest slip, and part of the way is cobblestone. I really like this knot, it is really the answer to a few needs.

The pictures were taken after I got home.
« Last Edit: August 27, 2009, 05:45:03 PM by Inkanyezi »
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roo

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Re: NOOB - I invented... now what?
« Reply #37 on: August 27, 2009, 05:58:11 PM »
I needed a new vacuum cleaner, and the actual store is about 25 miles away and I don't have a car. So I went there on bicycle, bought the vacuum cleaner and...

 :o
Maybe you can talk a friend, neighbor, or relative into giving you a lift sometime. :)
« Last Edit: August 27, 2009, 06:01:05 PM by roo »
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[Inkanyezi] gone

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Re: NOOB - I invented... now what?
« Reply #38 on: August 27, 2009, 06:36:35 PM »
Cycling is healthy. I had the possibility to use the underground, but I don't mind going a few miles on bicycle. And it's on the other side of the town, which is not car-friendly.
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Dan_Lehman

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Re: NOOB - I invented... now what?
« Reply #39 on: August 27, 2009, 07:48:31 PM »
Cycling is healthy ... I don't mind going a few miles on bicycle.
I.e., the ride was not too short to be worthwhile!    ;D
Indeed!

 :)


Gleipnir

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Re: NOOB - I invented... now what?
« Reply #40 on: August 28, 2009, 01:56:58 AM »
Thanks for the kind words.  IF it does turn out that this is a new knot, then I guess I will need to give serious thought to the naming issue.

As some of the early responses noticed, my command of knot terminology is somewhat limited.

I would appreciate any assistance on offer.



The Fly

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Re: NOOB - I invented... now what?
« Reply #41 on: August 28, 2009, 06:27:16 PM »
I tied that Dahm knot around a bundle of flattened cardboard this morning with twine--worked beautifully! The ratcheting effect is like magic.

[Inkanyezi] gone

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Re: NOOB - I invented... now what?
« Reply #42 on: August 28, 2009, 07:56:13 PM »
When I tied it on the bike, I used a slightly different form, a variation, where I took the twine around the rack on each side and then back. This form of the knot can of course be used for pulling any two things together. It could also be used in this way to complement a versa-tackle.

I also found that a simple way to tie the knot is to first pass one turn and have a sufficiently long end for the second turn, then making a half hitch around the standing part and continuing with the next turn and reeve the end through that hitch, which is the middle after the second turn.

I am quite confident that this knot will become a classic. It's one of the most useful knots that I have seen.
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roo

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Re: NOOB - I invented... now what?
« Reply #43 on: August 28, 2009, 08:48:02 PM »
When I tied it on the bike, I used a slightly different form, a variation, where I took the twine around the rack on each side and then back. This form of the knot can of course be used for pulling any two things together. It could also be used in this way to complement a versa-tackle.

I also found that a simple way to tie the knot is to first pass one turn and have a sufficiently long end for the second turn, then making a half hitch around the standing part and continuing with the next turn and reeve the end through that hitch, which is the middle after the second turn.

I am quite confident that this knot will become a classic. It's one of the most useful knots that I have seen.

Thanks for mentioning the variation.  One thing that bothers me about this overall mechanism is the same thing that bothers me about another tensioner someone asked me to show on my site some time ago.  It works on a similar principle:

http://notableknotindex.webs.com/guyline.html

As I note, if for some unforeseen reason, the legs are unevenly loaded such that the adjustable side sees even a little more load, the thing slips.  I've alluded to the issue before in this thread, but I get the feeling that people won't be aware of this issue and won't take steps to guard against it.  People don't like to read the fine print.
« Last Edit: August 28, 2009, 08:49:14 PM by roo »
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Gleipnir

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Re: NOOB - I invented... now what?
« Reply #44 on: August 28, 2009, 08:53:51 PM »
When I tied it on the bike, I used a slightly different form, a variation, where I took the twine around the rack on each side and then back. This form of the knot can of course be used for pulling any two things together. It could also be used in this way to complement a versa-tackle.

I also found that a simple way to tie the knot is to first pass one turn and have a sufficiently long end for the second turn, then making a half hitch around the standing part and continuing with the next turn and reeve the end through that hitch, which is the middle after the second turn.

I am quite confident that this knot will become a classic. It's one of the most useful knots that I have seen.

If I'm understanding your description correctly, I have a couple comments:

1.  It sounds like you are describing making a half hitch rather than a simple twisted loop in the middle.  This can be done.  And I actually tried this technique first when developing the knot.  In my experience it suffers from a some problems.  First as the tension on the system increases, the half hitch begins to tighten and BITE into the loose ends, but has no mechanism to relax when the loose ends are pulled apart when trying to further increase the tension in the system.  This results in the knot being more or less self limiting in terms of the tension it as able to absorb as at a certain point the half hitch has grabbed the ends so tightly that you simply cannot pull anymore through.  This is usually less tension than you would have otherwise been able to achieve.  Also, if at this point the load shifts creating slack in the system, it will be rather difficult to re-tension as the half hitch has too firm a grip on the ends.  This knot will also be much more difficult to un-tie for the same reason.  Though in twine this is not a serious concern since it can simply cut and discarded.  If the issue you are trying to address is an improvement in the security of the knot, then I would suggest half hitches either between the two ends in the case of a single twisted loop structure, or between the loose ends and the outside double loops outside the last twisted loop in each side of the multi-wisted loop structure.

2.  I'm not sure but I think you are describing having the two loops following different paths in your case around two separate objects.  I have not tried it around two separate objects each looped separately.  However I have tried it with a cross tied on a rectangular package.  There are two ways I have done this.  Suppose you have a box oriented on the compass.  Pass the rope going east and west around the box.  Where the rope ends meet underneath have the cross have each make a right angles such that they come back up on the north and south sides.  Form the twist the the middle on top and pass through as before.  Alternatively suppose you start at the middle on top with a right angle (this is where the twist will be made) such that the ends go to the north and east, then pass under the box and cross each other at right angles coming back up on the west and south.  When the ends meet the middle right angle, form the twist and pass through as before.

While these forms of wrapping a box works, I find the knot to be far less secure than simply making two separate knots.  One circumnavigating east/west and the other running north/south.  But I am interested to see your results.  I will also have to try making it a figure eight with the loops passing around separate objects.  That sound interesting.