MaB 1st attempt


Finally, my creature kissed the sea! Could be a coincidence but in my town, today is an ancient fest called “Marriage of the Sea”, the Bishop trow a golden ring to the sea, from a boat, and all the fishermans swim and fight to catch it. So, what a perfect day to trow my jewel into the sea today!!

I’m running an SSS 360kv on Apex 5:1 planetary, 20A 12s Lipo, Flier 200A boat ESC watercooled.
First of all, to prime the “selfpriming” pump I had to suck with my mouth from the tailpipe, smartly placed near the tail of the board… then it worked.

The other issue, last night I went to test my waterproof Arduino remote and it start to lose signal, the receiver might have something on the soldering… I don’ t know. So it’s been HK GT2B and sack… sack ended with water in it…


This after the test run, no water in!!!


Let’s say that the thing is quite heavy, on sandy beaches under the sun could be good workout even assembling it and getting to the sea. On water, once passed a couple of sand banks with no power (don’t want the pump suck sand and debris), it floats just perfect. I’m quite light, less than 65kg so kite raceboard floats me just right.

Power is there, you can feel it as you squeeze the trigger, no matter for the 2.8 seconds 0/100% ramp, the thing can run. It took me few attemps just to realize that as soon as the ESC and receiver box goes under water… the signal is lost. Placing the transmitter undewater on the box and leaning to keep the box out I manage to stand up, settle, push and… the grub screw on the gearbox/shaft joint blows. Further than this… GT2B got wet. End of the games.


Hi MaB,
did you buy this foil from ICAN?


No, I got a custom mast from RL Boards and the fuselage, wings are from my Ketos kitefoil, thin but 70sqare cm the front one, which for my weight is on the big side using kite… can’t tell efoiling yet, but the I’ve the feeling that could be alright.


This is the part incriminated:

I knew that a stupid grub screw would not held the torque but I was more concerned about the propeller shaft… this goes as lesson: never cut corners when designing similar projects.
I will try to get a stainless steel rod shaped in a single piece on the lathe, with a slot for the key. The problem is that slot…


Today, finally, 40 minutes of pure joy, after months of work!
I trashed the GT2B remote during last attempt, but it was good because I understood that the problem is my aluminum box: side walls gets underwater and the only dry part is the lid, the lid has a size which exceed the very short 2.4GHz wave hence hisolate the receiver, signal won’t go thru or it does but extremely weak.
315MHz have huge antenna and I still have to find a way to transmit the esc signal, I don’t know why but I got only hexadecimal caracter… whatever.
So I soldered an extension,biaxial antenna cable, thru a PG7 goes into the box and the Arduino NRF24i 2.4Gmodule antenna is glued on the nose of the board. Bam! That did the magic, my remote modified (ramp is now on receiver instead than remote… I thought that was safer for gearbox in case of disturbs or interferences).

I have to hide those cables and junction into the board because they drag a lot, I pinched the on/off buttons under the battery compartment seal and water got in… ruined a balance plug (repaired already) and the Vedder switch got wet, I hope to have saved the electronics…
Further than this, and the fact that my remote is not completely waterproof but it lasted all the ride, this run it’s been a success!
For who asked for the 200mm pitch prop: it’s not enough, I don’t know if the Arduino somewhat limit the ESC, I hear the motor run effortlessly but not overrevving, I made a run on my knee,full speed, the current never went over 45Amps and the speed was ok but not that thrilling.
I can foil, the motor will push and the speed is sufficient despite kite wings, but I designed it to run faster and I calculated something around 90Amps at full speed, so I designed a new prop.
Next time I try 300mm 155mm diameter, no duct.


Awesome work mate! Must be a good feeling, finally riding after all the hard work put int!

What did you end up doing for the shaft coupler?