Electric Hydrofoil/E-Foil

[Jimmy22]

http://m.ebay.com/itm/SSS-56114-360KV-B ... 0408.m2460

The very basic thought behind a gearbox is this : The voltage is typically 50V to keeps Amps low , the RPM needs to be very roughly 3000 , now how many KV do you need ? 70Kv or so ( roughly) , who makes a 70Kv inrunner , and how smooth is that motor at startup and what size is that motor that must be dragged along under water . This is why everyone runs a gearbox currently. In one case i know, the guy runs a 2:1 gearbox and 90 degree drive , perhaps this will be the future or motor in the deck not in the Mast .

[John in CR]

... In one case i know, the guy runs a 2:1 gearbox and 90 degree drive , perhaps this will be the future or motor in the deck not in the Mast .

No way is that the future. Motor belongs in the water to take advantage of cooling. Also, no way is any gearbox the future...Use that weight, length and expense for more motor and get higher efficiency with less noise as benefits. Ultimately it will be inrunner motors designed and wound to a Kv specifically for the task. Possibly instead of one long thin motor there could be 2 in a line, since redundancy of motor and controller are good things to keep current lower and give you a way to get back under power in the event of a failure.

BTW, I haven't seen any 70kv motors without going to a diameter large enough to create unnecessary drag.

While I'm sure the foil designs are great for those with real skill, I think there's a far bigger market for something far more forgiving even at the expense of efficiency. eg have some foils that provide stable lift that is tunable and/or sized based on rider weight, and then a smaller set of foils similar current designs yet smaller, to make it still able to steer/carve using greater weight shift as input. Ideally a foil design that provides stable lift that is only speed dependent to eliminate the need to focus on CG forward/rear , while allowing left/right turning from weight shift input...ie something closer to a skateboard in terms of control.

[Jimmy22]

... In one case i know, the guy runs a 2:1 gearbox and 90 degree drive , perhaps this will be the future or motor in the deck not in the Mast .

No way is that the future. Motor belongs in the water to take advantage of cooling. Also, no way is any gearbox the future...Use that weight, length and expense for more motor and get higher efficiency with less noise as benefits. Ultimately it will be inrunner motors designed and wound to a Kv specifically for the task. Possibly instead of one long thin motor there could be 2 in a line, since redundancy of motor and controller are good things to keep current lower and give you a way to get back under power in the event of a failure.

BTW, I haven't seen any 70kv motors without going to a diameter large enough to create unnecessary drag , i am hoping Alien Power http://alienpowersystem.com/custom winds something to help us all out

While I'm sure the foil designs are great for those with real skill, I think there's a far bigger market for something far more forgiving even at the expense of efficiency. eg have some foils that provide stable lift that is tunable and/or sized based on rider weight, and then a smaller set of foils similar current designs yet smaller, to make it still able to steer/carve using greater weight shift as input. Ideally a foil design that provides stable lift that is only speed dependent to eliminate the need to focus on CG forward/rear , while allowing left/right turning from weight shift input...ie something closer to a skateboard in terms of control.

Yes i know there are no suitable 70Kv motors at present and that they will be pretty big to have dragging sub surface. Last weekend we had two foil riders at 85 kg and a rider at 50 kg, it was roughly a 3kmph difference to get all of us foiling so the rig just needs a roughly 700 to 900 cm2 front foil to suit near anyone.

Regarding self stabilization , the "foiling Moth" and a few catamarans have mechanical lever mechanisms to self level which are OK but the challenge to foil is more than half the fun, once you can foil around it becomes mundane and then you try carving around, then wave riding then kite flying then look for something new huh ? https://www.youtube.com/watch?v=CK5_nMYdmgE and a more detailed video on the concept https://www.youtube.com/watch?v=m4OWY1MgZIU

[Hiorth]

We destroyed our first Gearbox. It was expected, as it were about 10 years old, and probably been running for more than 30 000h. Will soon be ready with our V2 with a new and better gearbox solution.

We bought 2 used ones, so we cut our propulsion unit open, changed the gearbox and patched it back together with epoxy and fiberglass.

[beonwater]

How far up from the fuselage do you guys set the motor?
I suppose that this depends on the ducted propeller size but also it maybe easier to not have to far down.
On kite hydrofoil we tilt the board when going upwind and therefore you need a long mast to get above the waves without getting the wingtip above the surface. But with efoil we will ride the board more flat I think.

[Jimmy22]

How far up from the fuselage do you guys set the motor?
I suppose that this depends on the ducted propeller size but also it maybe easier to not have to far down.
On kite hydrofoil we tilt the board when going upwind and therefore you need a long mast to get above the waves without getting the wingtip above the surface. But with efoil we will ride the board more flat I think.

the prop has to be in the water at all times to drive, with most blade shapes if it sees any air it will ventilate like foils do (unless it is a cleaver prop style or surface drive propeller) , lower the better because even with a 1000mm mast you only have about 700mm workable range left when you consider prop ventilation too

https://www.google.co.nz/search?q=cleav ... 45&bih=864

[dirkdiggler]

Got one more quick attempt. Waterproof container instantly took on water and fried the ESC. Still don't know if the setup works or not. It's already getting cold around here. Might have to wait again till spring! Another year goes by and no riding for me!

[nanni]

Got one more quick attempt. Waterproof container instantly took on water and fried the ESC. Still don't know if the setup works or not. It's already getting cold around here. Might have to wait again till spring! Another year goes by and no riding for me!

Your setup should be for sea water or fresh water?

[dirkdiggler]

Only fresh water for me. Salt water would eat that alive!

As for a new ESC any recommendations? I've seen a few that look promising, but don't want to burn up any with water again.
These Flycolor are questionable as I don't think they are fully submersible. I hope to not run it under water.
$90?
$64?
$150
$160

I keep telling myself that I'm under the $12k budget by a ton, but still tough to shell out extra cash!

[kiter_UK]

Lots seem to go for the seaking. But different set up.

Some inspiration - Kai Lenny shows how it's done.

https://m.facebook.com/story.php?story_ ... 6105545407

[parabellum]

Ecyclist made some small hypocycloidal transmissions recently, those things can be tinny as you need and handle ridiculous torque, power and gear rates (there is a guy with 1:1bilion rate transmission on youtube, smaller then my fist). All this at over 90% efficiencies and unprecedented durability, if made right. It seems to be as close as you can get to reliable and durable transmission for hydrofoil.
viewtopic.php?f=3&t=90432#p1319628

[Hiorth]

Looks like a nice gearbox! But also looks pretty expencive :/

[parabellum]

Looks like a nice gearbox! But also looks pretty expencive :/

Looks like unavailable. One man made it (several), just for fun of it. Make questions, create design, find a way to produce not one but thousand cheep, sell. I will be the first one thanking you for.
Just to motivate you a little (I know, you invested more): I bought and waiting for 3D printer just to print a propeller, I am also learning to design in FreeCad for that mater and tomorrow will run 24V brushed motor on 36V in river (it works out of water fine). That is ES.
P.S. Thanks for your dedication and input, you are much more quick, flexible and decisive than me, old and crusty ES'er!

[yoyoman]

ran across a Kickstarter today, https://www.kickstarter.com/projects/83 ... ote-propul

He reached his goal, which didn't seem that high, so hopefully we'll see more from him.

[Hiorth]

Looks like a nice gearbox! But also looks pretty expencive :/

Looks like unavailable. One man made it (several), just for fun of it. Make questions, create design, find a way to produce not one but thousand cheep, sell. I will be the first one thanking you for.
Just to motivate you a little (I know, you invested more): I bought and waiting for 3D printer just to print a propeller, I am also learning to design in FreeCad for that mater and tomorrow will run 24V brushed motor on 36V in river (it works out of water fine). That is ES.
P.S. Thanks for your dedication and input, you are much more quick, flexible and decisive than me, old and crusty ES'er!

I agree that a gearbox like this would be nice, but It seems like a difficult design to mass produce to a decent price/quality.

Great that you are starting with 3d drawing and printing. We use Onshape and fusion 360, think onshape is a bit easier to learn, and fusion have some more features if you would like to test different softwares (they are both free, under certain conditions).

Thanks for the encouragement We are currently developing one solution with gearbox (v2) and one without(v3). Will see how they turn out.

It's super fun to ride! Cheers

[Vincentbraillard]

Parabellum you were right. With a aluminium bell, the no load current was high, more than 10 amp and it become hot. So I decide to keep the alu to cool the motor at the back and to machining a new bell in POM. Now it work well and the no load current driw to 3amp a 4500 rmp

[parabellum]

machining a new bell in POM.

Nice, POM seems to be a good choice, that I was ignorant about till now.
Did you get the motor starting to spin under load (in water)?
Many people got no success with sensor-less set up, loaded start, which is easily solved by adding (epoxying in) sensors and connecting to sensor type, or sensor start controller.

[JustinSK]

Hi Everybody -

Been researching things for a couple months since seeing pacificmeisters videos- what a great job he did.

As with others, I'm planning on the SSS 56104/420KV. I've got a liquid force foil setup and plan on building around that for starters I'm fortunate to have a CNC and 3d printer somewhat accessible.

A couple questions before I make some purchases:

1) Has anybody figured out an optimal prop size / pitch yet? Some of the videos I've seen so far look like they're going slower than I'd like and I'm wondering if too small a prop is the cause.

2) I'm in the US and have been checking out these gearboxes - anybody had any experience with them yet? I talked to the manufacturer and they said running at 18K input RPM was no problem for up to 4000 hours. http://www.anaheimautomation.com/produc ... 089&cID=30. I'm thinking the "GBPN-0401-005" model which will take up to 18K in and put 3600 rpms out.

Thanks for all the work and posts by everybody else - I'll be doing the same as I make some headway.

[superlefax]

@Vincentbraillard: Your printing looks quite nice. Which propeller are you using?

@all: I think I found a good solution for cooling the ESC:
https://www.banggood.com/AEORC-Large-si ... mds=search

The radiator (without the fan) goes outside of the box and should get enough air stream for taking the heat away.

And I've found also an interesting remote controller for our purpose:

https://www.banggood.com/2_4Ghz-Mini-Wi ... mds=search

[Vincentbraillard]

Hello. Thank you for the printing.
Concerning the propeller, I buy a sollas one at 30 euros!

To cool your esc there ia a easy way. Juste buy a water cooled esc and a self pumping pump like that!

http://www.conrad.com/ce/fr/product/224 ... 12-V-Kavan

Regards

[beonwater]

@Hiorth: I´m thinking of using your propeller for my setup. Do you know what rpm you used it with when foiling?
I´ve ordered a PLE040 5:1 but the manufacturing/delivery got delayed (everyone needs a gearbox for their DIY Efoil ) so I bought a used PLE040 but with 8:1.
As I´m using a 290KV with 15S battery I would not be able to spin it above 2000 rpm.
Do you think that would be enough or do I need to create a larger propeller or with more pitch?

[Hiorth]

We have max rpm on around 3000rpm, 2/3 throttle is enough to foil so 2000rmp should be enough, but it is hard to tell. You should just try

[tclark]

Hello all! I have decided to give this a go myself!

Feel free to checkout my page for documenting: http://efoilbuild.com

And my parts list: https://docs.google.com/spreadsheets/d/ ... edit#gid=0 (Yes, I spent way too much money)

Cheers!

[slanton]

Check this out
https://www.eldoridedo.com/

[fruitygreen]

Wow! $13,999 USD.
No thanks.

Lift is a better bargain.