Author Topic: 3D lash  (Read 2339 times)

Tha

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3D lash
« on: November 15, 2010, 11:22:18 PM »
L.S.,

Some venture scouts from a scout group in The Netherlands designed a lash to connect three poles at once. This new lash replaces two square lashes when applied. Background information, images and instructions for use are available at http://home.kpn.nl/tha/scouting/3D-lash/index.html

Happy knotting!

DerekSmith

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Re: 3D lash
« Reply #1 on: November 18, 2010, 07:43:44 PM »
   snip...
 And this problem looks, to me, quite hard indeed.

I agree whole heartedly Xarax.

Since you posted your challenge a few 'days' ago, I have had three short lengths of bamboo on my desk that have seen an array of bindings - only to teach me that there are many 'pretty' ways to bind these three spars, but nearly all of them fail in any number of ways.

During the exercise I have learnt repeatedly from the Chinese bamboo scaffold lashing techniques - the method seems so simple - it is - but its simplicity hides a number of important subtleties that each in turn convert this simple lashing into a fast reliable binding that can hold up scaffolding many stories high.

The scouts are using the 'Minimal Manifold' that binds each spar to its two neighbours in a uniform manner.  But his simplistic manifold has no self tensioning mechanisms, so the scouts have resorted to tangential tensioning to create some desired binding tension (at least able to stop the poles sliding down under their own weight)

But how is this assembly to be put to work? (presuming that it is not intended to be purely decorative).

The vertical pole is presumably buried in the ground to resist lateral forces and to take any vertical loads.  the horizontal rails then presumably are to keep animals either in or out ?

So in use, pressure is going to be applied both vertically and laterally to the horizontal rails and the binding must resist these forces and transfer them to the vertical pole.

The first tiny subtlety then is that the poles are much stronger than the bindings, so we need the binding to utilise the strength of the poles to our advantage.  The  horizontal poles then should be 'animal side' of the vertical post, so that any lateral force is pole against pole rather than pole against binding.

The second issue is to consider the response of load applied to the tops of the  horizontal rails (sitting on them) or to the undersides of them (something trying to force its way underneath) - what is going to happen to this proposed binding when these forces are applied and how will the binding respond?

Derek

JohnC

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Re: 3D lash
« Reply #2 on: December 23, 2017, 01:38:47 AM »
L.S.,

Some venture scouts from a scout group in The Netherlands designed a lash to connect three poles at once. This new lash replaces two square lashes when applied. Background information, images and instructions for use are available at http://home.kpn.nl/tha/scouting/3D-lash/index.html

Happy knotting!

So frustrating that this person claims to have exactly what I want, but the link is dead.
John