Author Topic: Rope "ladder" secure cross pieces to two vertical pieces  (Read 4678 times)

Bercky

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Rope "ladder" secure cross pieces to two vertical pieces
« on: June 04, 2010, 08:59:26 AM »
This should be simple.

How do I tie knots in a rope in a very precise spot on the rope.

I am tying small brown twine into a rope ladder with solid cross pieces.   But I am not familiar with a method to insure that my knots end up right where they should be to make the two side pieces come out even.

Alternatively, since the "ladder" is not going to be supporting much weight, I could tie the cross members directly to the vertical pieces.  I may actually prefer this as my knots would probably be smaller.

Thanks!


Transminator

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Re: Rope "ladder" secure cross pieces to two vertical pieces
« Reply #1 on: June 04, 2010, 10:35:27 AM »
This should be simple.

How do I tie knots in a rope in a very precise spot on the rope.

I am tying small brown twine into a rope ladder with solid cross pieces.   But I am not familiar with a method to insure that my knots end up right where they should be to make the two side pieces come out even.

Hi Bercky

If the solid cross pieces are cylindrical, you can use a marlinspike hitch, which is the same as the slip knot.
The only difference is that the slip not is used in such a way that it does not capsize into a noose.
Have a look at the article in wikipedia.
http://en.wikipedia.org/wiki/Marlinespike_hitch
(btw. in the German version it is specifically mentioned that it is used for rope ladders, along with its weaknesses when doing so)
Finding the right spot for the knot is always a bit of trial and error, but because of the simplicity of tying the slip knot/marlinspike hitch, it is easy to undo and re-tie a bit further up or down as needed.

It is not designed to work with square rungs or flat boards and another draw back  is that
the rungs only stay in place, as long as there is a load on the ladder (gravity might suffice, when the ladder is kept hanging down)
and the rungs could also slip out the sides.
To adress these problems, you could fix the rungs into place with lashing techniques.
You can find some in this document: http://www.bsatroop996.com/Lashings.pdf



Alternatively, since the "ladder" is not going to be supporting much weight, I could tie the cross members directly to the vertical pieces.  I may actually prefer this as my knots would probably be smaller.

The above Lashing document should give you the right idea.

P.S.
if the twine your are using is long enough, perhaps this might be an alternative (it does not need any solid cross pieces at all):
http://notableknotindex.webs.com/ladder.html

Sweeney

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Re: Rope "ladder" secure cross pieces to two vertical pieces
« Reply #2 on: June 04, 2010, 11:09:39 AM »
I recommend you use Ashley's constrictor knots to fix the string (I've done this on a toy rope ladder and it works well). When pulled tight the knots will not loosen - make the constrictor in hand then slip it over the end of the wood and work tight.

Barry

roo

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Re: Rope "ladder" secure cross pieces to two vertical pieces
« Reply #3 on: June 04, 2010, 03:15:16 PM »
I am tying small brown twine into a rope ladder with solid cross pieces.   But I am not familiar with a method to insure that my knots end up right where they should be to make the two side pieces come out even.


Have you seen this thread?:

http://igkt.net/sm/index.php?topic=1237.0
If you wish to add a troll to your ignore list, click "Profile" then "Buddies/Ignore List".


SS369

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Re: Rope "ladder" secure cross pieces to two vertical pieces
« Reply #4 on: June 04, 2010, 10:12:19 PM »
Hello Berky,

If by chance the rope you will use for the verticals is of laid construction, you may well open the lay of the two vertical ropes, insert the rung and then tie a suitable/decorative knot (Turks head) above and below the insertion point.
It would do well if the rung did have a groove at these locations to aid the grip and deter coming out under load.

I have done this technique in the past, but in my case I used another rope woven into the places that you aim to put the rungs.

The above should allow you to place the rungs, solid or not, anywhere you care too.

Be careful on it.  ;-)

SS

jcsampson

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Re: Rope "ladder" secure cross pieces to two vertical pieces
« Reply #5 on: June 05, 2010, 04:25:41 AM »
If I were to attempt to build a rope ladder, I might first try a design like this:

- Use many short, pre-determined, even lengths of rope between rungs, on both sides, instead of using just one long length for each side of the ladder

- Connect two adjacent rungs by using a Three-Coil-Ring Fixed-Gripper Coil Hitch on each of the two ends of a short length

Since I haven't yet tried such an application, I can't say whether there would be a problem with the slightly different positions (the "offsets") of the short lengths, on the rungs, between rungs. . . . You will need to be consistent with, and alternate, the pattern from one rung to the next, so as not to have the distance between the vertical structures grow as you progress up or down the ladder. . . .

I would use Three-Coil-Ring Fixed-Gripper Coil Hitches because they grip posts remarkably well and, with three coil rings instead of four, wouldn't offset the short vertical lengths that much. If the offset causes a problem with the ladder structure, I would try to reduce it by using two coil rings, which would still grip the rungs fairly well.

I might try this design using three pencils and four shoe laces.

See

http://igkt.net/sm/index.php?topic=1839.msg12439#msg12439

for info about the Fixed-Gripper Coil Hitch.

JCS
« Last Edit: June 05, 2010, 04:56:00 AM by jcsampson »