Building a hollow Division 2 sailboard

Can't reply to the old thread of this title so started a new one

Just playing around with Rhino3D, I imported the co ordinates into rhino as a point cloud from the blog infinity1971.bitbucket.io/ by jonesmb and then used them to draft a hard chined version of a Lechner 390 with a view to producing templates for ply or cnc cutting files for a foam product.

Red lines are the original Lechner curves that the hard chined surface is based on. rocker line, width, length remain the same.

I haven't taken it as far as doing internals yet but just wanted to see what a hard chined Lechner would look like





Green shapes are the components of the port side exploded, unrolled and flattened

I went through phase of making hollow wooden surfboards, knocked out about a dozen or so before I got back into windsurfing.

I found it easiest to use dedicated shaping software (I used AKUShaper) then Jedail Hollow Wood Template maker to convert it into the outline, spine and ribs. Not sure if the Jedail is stiff around but I think there's another option AKU points you to to get the same result.

It was super time consuming to knock out a board but super satisfying to ride, even took one on an Indo trip.

Enjoy the process.

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Jethrow said..
I know it's a bit more work, but maybe consider adding another surface to create a bevel where the deck joins the sides.

This will make the more than 50% of time you spend upwind on the rail a tad easier underfoot...

It's more of a CAD exercise than anything else, I wont have time to build it. I just wanted to see if I could draft a design that would not look to ugly and be easy to build, like a stich and glue dinghy concept that could be assembled from a precut kit by giving cnc files to a supplier or lofting templates yourself.

Developing surfaces that could be "unrolled" in rhino and cut to size from templates or cnc files was the main aim of the exercise. I spent minimal time on the curves to create those surfaces, I agree it could be a lot more refined, the volume is to low for starters it's only 267 litres.

I like the concept though of producing designs that could be home built in kit form.

The other option Rhino could produce would be a foam core cnc file complete with cut outs for mast tracks, fin box, centreboard case etc that could be ordered from a cut to size foam supplier, they do one off custom foam designs for corporate promotions. I don't know what would be easier to build for a DIYer.

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cammd said..
It's more of a CAD exercise than anything else, I wont have time to build it. I just wanted to see if I could draft a design that would not look to ugly and be easy to build, like a stich and glue dinghy concept that could be assembled from a precut kit by giving cnc files to a supplier or lofting templates yourself.

I know exactly what you mean, I used to love just CAD modelling stuff that I could build from plywood.
The last craft I was doing was a DW style wingfoil board.

I only ever got the rush of blood to the head to go ahead and build one a couple of times.
The link below is to an old Seabreeze page of the last ply craft I built...

Edit: and before people ask (and people have), no I wouldn't send you these files, as a lot of the build was in my head and just having the cut pieces wouldn't be enough to finish it...
www.seabreeze.com.au/forums/Stand-Up-Paddle/Review/The-How-I-built-the-Jethrow-480-thread?page=1