RIWI’s third build


My third build. Building board from scratch. Eps 300 core. Prefab electric box and carbon fiber+epoxy shell.

Maytech Vesc 200A.
Flipsky antispark
Water cooling(no pump)
12s NMC 42Ah.


Foil and propulsion:
Gong mast 65cm
Hiorth design propulsion
Moses wing and stab




Regarding water cooling of the esc and the anti spark.

The anti spark from flipsky (v.2 280A) comes with wires the size of spaghetti. I changed the to 8awg on the battery side and used the 10 awg from the esc on the other side.

I used chain saw file, approx 5mm, to create grooves in which the 6mm copper break pipe could be soldered. In order to solder copper to aluminum I used a special flux and solder. You need an open flame to join the two materials.

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Would you have pictures of box + lid fabrication ?

For the box I made a mold in wood which a sanded with 400 grit, painted and waxed before laying up the fabric. I don’t have time for two part molds so I made small holes, three per side, through which I blow air in order to release the finished box from the mold. Works like a charm. This is the mold, you can see the first layer of peel ply.


After the box is released and fitted to the board it looks like this:

The lid is another story. I always do the lid after the board is almost complete, this will give the best fit.

I make a “plug” in eps that fills the box. I don’t make the plug flat, it’s stronger if it’s a bit curved.

The eps is covers with vinyl, epoxy does not stick to it.

After this I apply epoxy, fabric, core material and so on. I used vacuum to extract any extra epoxy and air.
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How far is the middle of your mast plate to the back of the board?

Approx 16cm


It is way back! So I’m assuming you are standing further back on the board? Any pics of you riding it?

Same as my two earlier boards. Works perfect.
This one has not been in the water yet but you can see pics and videos of the other two at instagram.com/wildtech.eu

I also think that it is good to have it so far at the back. I always have to stand so much at the front.

Mast as far back as possible is the best solution :+1:

First run last night. Current was to low, set to default 80A by Vesc motor wizard. Did another test this morning, setting the current to 120A. Still not enough power to get it planning.

Have now loaded the “no limit firmware” and set current to 150A.

The board is small, only 53L, so it will require a lot of power to rake of. Hopefully I can test later today.

Setting current via metr work fine.