I have not seen any data on the efficiency matter yet - at least not a side to side comparison on an efoil. My main concern is safety - especially once I think about letting someone else use my board - this overrules efficiency in any case.
There are products on the market making it work - so I should be able as well.
Also I would go the minimalist-foil-assist route - just enough to get me on foil and a few 100 meters to the next wave.
Here you can see the cross-section of the impeller - 3mm at the thickest part. At the moment it is plenty strong although relatively flexible and reasonably cheap to be printed at 2,28€.
At this price I can afford many test setups to find the optimum rotor by trial and error - best case on a test bench. Same for the stator
This leads to excessive heat built up in the shaft. Is this problem ignorable since cooling is good in the water anyway or should I worry about quick wear? Please keep in mind this is not meant as 100% efoil but assist only.
Alternatives would be:
(ceramic) sliding shaft seal as with most waterproof motors
Labyrinth seal
I excpect all the other traditional boating seals to have even more friction/ thermal issues right? Even more at 800 KV 52 V
Fair point that efficiency isn’t always the primary consideration.
One of the places I’ve seen jet/prop data is from Fliteboard’s foil time calculator:
They state it’s based on rider data they have gathered. So not controlled test data, but likely averaged real world data that I suppose their owners can upload.
Can you provide more info on why you needed disassemble your ESC? I bought a FlyColor Xcross HV160A ESC and it doesn’t work, just wondering if it has the same issue as yours.
@mekanism
I accidentally ripped off a component when I disassembled the aluminium cooling plates. I did this in order to mount it in that aluminium clamp to get cooling on both sides MOSFETs.
If you did not mechanically work on your ESC and something could have been broken off in a similar way I expect it to be a different kind of problem.
Had a great time on vacation and emptied a total of 15 full batteries. I had the Indiana kid aspect wings with me, also calle “ride”. With the 1500cm2 wing I was able to do quite some pumping and training of transitions. The smaller 950cm2 wing was getting really fast and fun, but quite hard to pump, since only mod aspect ratio.
No issues with the Bopla box. Great recommendation @hangloose
Only some small corrosion on the aluminium where it is close to the carbon board and water likes to stay in between.
Now working on some further ideas - smaller/ lighter battery and waist mount.
I sketched up this design quickly. The idea is to pott only the cell terminals, strips and wires. Benefits could be better cooling of the cells an lower weight since less potting material.
