Propulsion System in Fuselage of Hydrofoil - Ideas anyone?


#1

Hey guys,

Has anyone managed to build a integrated propulsion system into the fuselage of the Hydrofoil itself?

Run the cables etc. up the mast to the usual electronics box but have the propulsion system integrated for better hydrodynamics?

Also wondering would the jet impeller design be better for this option or is there much point in it?


#2

Yes, see Peter’s build: Peters Concept (Bavarian style)


#3

Im not convinced the hydrodynamics would be better.
The cross section of a foil fuselage is very small and doesn’t create a lot of drag.

I think the efficiency of the foil could be compromised by putting the bulk of a motor pod too close to the lifting surfaces. Especially the stabiliser. I could be wrong. I like the the idea of the foil doing its own thing away from the prop.


#4

I like the idea of motor at the fuselage, it would cut a bunch of weight not having the long aluminum fuselage. could affect the stabilizer a little but don’t see it being anything crazy.


#5

Ya im thinking the same. Maybe for version 2. Ill try get version 1 up and running first similar to @pacificmeister with it seperate. @VeFoil if i did go as part of the fuselage, your design would be best but efficency is a pain and i woulnt want lost ride time. I noticed on some forums you’ve gone for safety ( understandable) but you mention your ride time is retuced by your setup vs others. What ride time are you currently getting?


#6

Yes we do it this way. We could increase efficiency and decrease weight to about 10%. Alltough more compicated and more expensive build it is the way to go…
Our values foiling with 22km/h 0,97KW and integrated in fuselage 0,85kw…at the battery!
Not shure what the Liftfoil values are as reference, but I assume around 1,4kw…


#7

I hadn’t considered weight. Yes the alloy fuselage dose weight a bit. I am so used to riding full carbon foils and boards that as soon as I got an aluminium foil for my build, I knew it was going to be a tank. I chose a windsurf foil for that reason. I probably should pay more attention to weight.

I got a new carbon SUP foil board made a couple of months ago. 8kg! 12kg with carbon foil!


#8

Yes Safety has been our focus from day one for both Electrical and propeller/impeller.

Well we are still testing a few things and falling a lot so we are starting a lot, but based on what our ride times and usage looks 1:12 seconds per Ah, so a 44mAh pack which can fit in our electronics box and custom board would be 52 min ride time once you master efoiling. We have done a couple interesting things to boost efficiency/ride time and we are still learning more :slight_smile:


#9

If you are using 12s that means you draw about 1,9KW power with the impeller, that is not bad… But still double of best efficiency of prop drive…


#10

Ya, thanks Elevate!
It is tough to beat the efficiency that a larger prop has but if you think about a 500kv motor using a reduction gear that motor is still spinning very fast to turn that reduction gear, plus the reduction gear resistance, plus drag in general of larger prop, and even more so the drag of a large duct.

There are a lot of things that hinder a reduction gear drive setup in my opinion and if both setups can get 45-60min ride time Ill take the sleek, lower cost jet design, and not worry about when the $400 reduction gear will break, plus the added safety the enclosed jet impeller design offers.


#11

Hi Foxyirish1987,

My V2 has propulsion system into the fuselage.
I have the feeling that it works much more better than the V1 (classic style on top of the fuselage)
but i do not have any measurement…


#12

Wow looks really well! Which motor and gearbox did u use on the latest model?