Electric Surfboard hydrofoil update

The printing of the electric surfboard hydrofoil is progressing well.  I have now printed the front and rear wings, fuselage and the mast is on the printer at the moment.

Hydrofoil Fuselage Printing
Hydrofoil Fuselage Printed


I wanted to make some changes to the foils design so that the power cables to the motor could be run down through the mast.  I have never experimented with any CAD software but thought I would give it a try.

“Hiorth” from the Endless Sphere forum got in touch and suggested that I try an online CAD service called Onshape.

It took a few Youtube tutorials but I managed to add a nice oval hole down the centre of the mast.  I didn’t go all the way down as we will be coming in either out the back or the side of the mast above the rear wing with the motor mount.  I’ll just use a soldering iron to make the final hole through to the main wiring channel.  You can see the outline of the hole in yellow on the image below.

Kitefoil Mast 3D Rendering

I printed a test piece to make sure it worked ok.  The part is still very strong.

Kitefoil Mast Test Piece

The mast was then cut into 6 parts for printing.  First three are still going on the printer.  1.75mm white PLA with 20% cubic infill.  The cubic infill is both very strong but its also a little like closed cell foam so if the hydrofoil does get damaged, water should not be able to ingress far.

Kitefoil Mast Printing

I’ll start assembling all the parts soon and get ready to laminate them in carbon.

4 Replies to “Electric Surfboard hydrofoil update”

  1. Thank you for sharing your project with us and it´s really exiting to follow the progress.
    Would you mind sharing your 3d models with us? I would also like to start building a hydrofoil using my 3d printer reinforced with carbon fiber. What size do you print the hydrofoilmast in and how many layers/thickness of wove would you laminate on it?

    1. Hi, the 3D models are actually by Prof. Michele Fiorentino so I can’t take the credit there, he posted his designs on GrabCad here I did however take his files and split them into the different parts with separate .stl files that you can use on your 3D printer. You can find these here. You will need to split the files using something like Slic3R or another slicer to fit your printer and then just join with CA glue if you are printing in PLA. Cubic infill is recommended. The size should be correct straight from these files.

      Think of this core as the equivalent to foam, you are not looking for a lot of strength from it, the laminate will provide that.

      IU have just received the resin and carbon cloth. We are going to go with 2 layers and for pieces like the mast will lay it up with the cloth at a 45 degree angle so it folds nicely around the curve. The trailing edge of the foil is a sharp edge so you will need to join the cloth together and then sand back rather than wrapping around this.

      I’ll post an article once I get started.

      1. Thank you. Do you know what carbon weight you will use (200gram?). The mast seems pretty thick, when I look at it in the computer I measure it to 16.71 x 102.13 mm. And this is before you laminate this. 2 layers of 200 gram carbon will add about 1.2 mm. My Sroka aluminum mast is 12 mm. But it´s only 800mm high. My Moses Vorace carbon 970 mast is about 14mm. These are kite hydrofoils so I think maybe they will need to be much stiffer than a efoil mast.

        1. Hi, yes it will be 200g carbon cloth. We have ‘t laminated yet (lack of time). This is really a prototype so we will have to see if the thickness etc is right. There needs to be sufficient width to run the wires down the mast and there is ample space in this current design.

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