3D Printed Hydrofoil

A friend and I had been looking for a project and after deciding an electric motorbike was just going to be too expensive to build he came up with the genius idea of an electric surfboard.  There are a lot of these coming onto the market now and they seem to be either water jet pump powered or more interestingly hydrofoil boards like the eFoil

We started researching the water jet pump versions first.  The pumps themselves seem to be similar to commercial ones you can buy from the likes of MHZ Watercraft

But at over 500 Euro for one (we might need two) it was going to get very expensive. Add on top the motors, speed controllers, batteries etc and the electric motorbike may have been a cheaper project!  Boards retail at over $10,000.  They do look nice though, Onean have one coming out.

The challenge is that you need a lot of power and so the ride times can be as low as 20 minutes.

It could still be a lot of fun so I hunted around for a 3D printable jet pump of sufficient size that we could use.  Looking around I came across this design by Toto44 on Cult3D for $12.

It took quite a while to get the settings and supports right to print the pieces (trying to minimise the use of supports) but I now have all the main pieces printed.  It has a 65mm impeller so quite large and comparable to the MHZ Jet Pumps.  It weighs next to nothing.  No idea if it would be strong enough yet, I have ordered the shaft and need to get the bearings and shaft seal ordered before I can test.  The parts came out really well though using PLA.

I’ll write up another post when I get the rest of the parts and can test it.

In the meantime looking at the Hydrofoil boards, there was a great thread on the Endless Sphere forums here.

Pacificmeister came up with a working board although it did require a gearbox.  He used a commercial foil and a lot of 3D printed parts although he hasn’t yet shared those plans.  Looks great though,

Not wanting to spend a fortune on a foil though I want to see if there were plans that could be adapted for 3D printing with a view to then laminating in carbon fibre cloth over the print.  Much easier that designing the moulds.

Luckily there were such plans available here on Grabcad.  Looks very good and better still he has made one that works.

So I downloaded the CAD files and exported to an STL file in OpenSCAD.  Once I had that I could split and then cut the parts in Slic3R.

That gave me parts of a workable size to start printing.

I have the front and rear wings now printed and the fuselage is printing at the moment.  All in white PLA with 15-20% infill.  I’ll work out how much filament it will have taken at the end but it will likely be around £20 worth of filament.

Next stage will be to join the parts with CA (superglue) and think about laminating them in carbon.

The motor and propeller is still being researched so lots more to follow.