Here is my prop and motor testing video. Part 6 of my build series. (18min)

It took 1.5 years between my last hydrofoil video which was the remote video. There were some other projects in life that I had to prioritise, but here is finally the prop and motor part. This was really pulling my nerves at some points. I always had this project in the back of my mind. But there was a steady stream of other tasks that piled onto my desk.

I tested the discontinued Alien Motor and then moved on to the Flipsky 120kV one. I used a 3d printed prop first, then the Yamaha propa and the Tohatsu prop. Finally I arrived at a cut down Tohatsu which resulted in 29kg of Thrust at 56A from the motor. This is without maxing out the VESC yet. I will increase the current if neccessary on the water.

Next up will be mounting the motor and finalising the whole board with all the little details.

Thanks for the support of everyone here! It took ages already to film all of this, but withou the help here it would have taken much longer. Hopefully I can get riding this spring. I am hopeful.


Its been a long time. Nice Video, Fun to watch.

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Thanks for the great video. You propose in your video that when the RPM is limited by the load (a prop that is too large) then the ESC will also limit the voltage to the motor. Is that true? If so, then there would be no advantage to a higher voltage battery pack (14s vs 12s), unless you use a prop that is small enough to spin over 5000rpm (for a 100kv motor).

You need a rpm drop for thing to work , you will never get on load the same max rpm that off load

20-30% drop is correct

So yes , prop will not turn faster if the motor max amp setting is hit , wan!t make much change 10s 12s 14s…

Here we try to control heat ( wasted energy ) by asking not to much on the motor , so limit is set at 90A ( motor ) so it gives torque limit so rpm limit , I don’t think we are talking about voltage but more about switching time and amp , voltage is just a result , no ? ( on motor side )

At the end it is just the « use »of the prop that control everything ? We just set limits not to burn everything and play with the trigger for the speed ?