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!!!

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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?

The one piece design is still in my colleague hands, cnc lathe specialist… in the meanwhile I reworked the alu one: increased the grub size to M5, but last 3mm milled to 4mm diameter to fit the gearbox key slot, everything washed with Acetone and flooded of green Locktite… finger crossed. I know it’s not the ultimate solution but I’ve to live with that, untill the day my friend would find 1hour free for me!

Congrats!!! I am jealous!!

Don’t be! Yours will be more neat than this and I have so many details to solve…
Further than this, I won’t get to any result without all of you guys, @pacificmeister first an this great forum! Fix that VESC and if not, go for a classic esc in the meantime!

High gear! Ready for speed and to burn some serious Amperes! 148mm/pitch 305mm. Let’s see how it affect performances. Tomorrow I will epoxy this prop and make it silky smooth


Unfortunately I hit the water too early for my photographer today, no video no images…should never happen, nobody will trust me :wink:
But new propeller (no duct, it doesn’t fit) did the magic! Full throttle, on the knee, board foiling bouncing on water: 70 to 77Amp, very nice speed but I don’t have gps. Foiling it’s been easier, but at half speed, 3/4throttle, faster than that I felt uncomfortable (too scary!). Water piss off the tailpipe warm, batteries went to 43.5V in half hour then the max current dropped to lower sixties and performances also.
Very happy.
Will try different prop but now I’ve to adjust foil AoA further… and improve my ride. I’ve a 2weeks surfing “pause” to Portugal now, then back to electricity!!


Very cool! Where did you get your prop from?

Designed it, javaprop and Solidworks, printed in PC-max, epoxyed&sanded. If you want I can give you the file, no problem

147-305 solidworks
this is the Solidworks part, you could see the imported blade from Javaprop, sliced and each slice scaled to obtain a more sensate prop.
You could add your own hub, join the parts and print it.
Like this.


Yes please!
But I need 70mm centre diameter.

I’ m not at home for a while… calculate a pitch, diameter and tipe of hub, as soon as I’ll be back I will draw something.

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MaB on Facebook
Video of this morning. I did a long run on 4x 16Amp batteries, new remote waterproof… 3degrees wedge to charge the stabilizer, now I can’t squeeze the throttle to the end because the board go foiling and bounce on chop! But stand up foiling is more stable.
Crappy editing on my mobile…standard orrible music…sorry for that

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I had to modify the remote design, print, glue and epoxy two of them, just because the first had a wrong connection but the Arduino couldn’t come out of the bottom cap, because of short wires… Bugger. I lost one week in troubleshooting before to redo the whole case!

Nice work! that prop is kick ass. I got one of yours printed in SLS nylon from shapeways for $40 US. I was going to ask how you made the remote, but that Arduino stuff looks a bit beyond me for now. Love the remote design! Yours?