Designing Origami Boat in Rhino

[terhohalme]

This thread is started to make clear that there is nothing mystic in designing origami boats. In principle they are simply V-bottom or multi-chine hulls with conical plank ends. Their shape, dimensions and coefficients are contollable if you just check the hydrostatics before developing plates. And remember to engineer the structure as in multi-chine boats (e.g. using ISO 12215).

At first I design a decent hull shape (I use mainly 3 x 3 point surfaces and operate with point weigths and centerline cutting to tuning the hull). This gives me nice fair hull and easy controlling of displacement, Cp, LCB, Cw and Cm.

Secondly I draw planks (edgesurf) using longitudinal isocurves as chines.

Thirdly I unroll the planks, orient them below topside plank and cut the others at the middle.

Then just orient the lower planks to the lover end points of upper plank as a tangent. Clean the extra curve ends and voila! your origami hull plate is done.

Works with the paper model and in real world.

Terho

[magwas]

The process on Linux.
1. Create a developable hullform. I am using carlson's hull software. With wine most of its functionality is too unstable to be useful, but if you start with any hull with the correct number of chines, rename it to default.hul, and do saving by exiting, and answering yes to the save question, it is possible to design any hullform. Just save frequently.
2. Import it to freeship+ (works great witn wine). tools/develop frames, export as dxf.
3. Do the alignment in qcad. As freeship exports something which is not easily splittable, I first draw the chines and half chines to a new layer with "line with two points", point position at "snap to endpoints".

[MikeJohns]

Terho
Very interesting thanks. And a nice looking result.

Have you tried a single chine version? One advantage of a single chine would be a more acute chine angle, although to be considered a girder the plate has to be quite thick. From memory and as a rule of thumb if the chine angle <150 degrees it can be considered as a full supporting structure. As the angle decreases it still counts as a stiffener, the curve is assessed pretty much the same way by projecting tangents.

I'd be interested in any other hulls you have developed that way too.

[magwas]

A one-person kayak: Placement of seat in a kayak?
A two-person kayak (I won't recommend to build this one though): flax composite stitch & glue

[pavel915]

Very interesting idea terho,
Thanks

[terhohalme]

Here are more pictures of origami model of one chine: This has slightly too high Cp, but it is easyly changed.

Terho

[NoEyeDeer]

That's cool but I have to wonder what the advantages of origami boats are in practice. It seems to me that in some ways they could be as difficult to build or even more difficult, compared to just making a chine hull out of seperate panels.

[terhohalme]

This was just a study how to design them...

[NoEyeDeer]

Yes I realise that, and a very good study it is too. People do seem to be rather taken with the idea of origami boats though and I was wondering if it had any advantages over other methods of construction.

[Northman]

Originally Posted by NoEyeDeer

Yes I realise that, and a very good study it is too. People do seem to be rather taken with the idea of origami boats though and I was wondering if it had any advantages over other methods of construction.

... which is discussed here: The good, the bad and the ugly - Steel building methods that is....
and here: Origami steel yacht construction

Walter

[magwas]

Originally Posted by NoEyeDeer

Yes I realise that, and a very good study it is too. People do seem to be rather taken with the idea of origami boats though and I was wondering if it had any advantages over other methods of construction.

It is a subject of heated debate, and everyone have their very strong and very differing opinion on the subject. Read the associated flamewars to figure out to yourself.
However I would note two things to consider:
1. The optimal building method depends on the abilities and circumstances of the builder. There is no one-size-fits-all. To some opinions (including mine) origami is well fitted for the home builder.
2. Choice of method - especially for the home builder - is not just a matter of logical decisions. One may choose origami because one likes the way and feeling of bending a steel plate to itself. Or one may choose a frame first method because one likes the rithm and symmetry of erected frames.

[TeddyDiver]

Originally Posted by magwas

is not just a matter of logical decisions.

eeeerrrr.. What can I say? It should be a logical decision. Anything else is merely just day dreaming.. Logic in this regard says that if you don't have a shelter there's an advantage in "pulling" an origami hull together fast and then you have a shelter.. atleast inside the hull..
But even then you better to have a decent design to work with..

[marriemb]

beautiful designing never knew so much was possible with Rhino can u share the design file

[Tad]

terho......nice work

The second, single chine version looks a lot like a Passagemaker Lite hull, that gives me an idea........

Cool....