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Motorize a foil board?


(Andrei W. Konradi) #1

Hello All,

Would any of you like to participate in the following project? I could use help.

I am trying to motorize a hydrofoil board. Recently, this has been achieved, as shown in the below video. But, I think there is still room in this field for hobbyists.

Based on the below video, which involves propulsion by only wind and waves, I think only 100 W may be sufficient.

https://youtu.be/h7XupqFOFSg

I started on this project with a 210 W trolling motor. Pictures of my limited progress are at the link below. But, now I think a Blue Robotics M200 might be a superior motor. Reducing diameter, and/or increasing power, would be good.

Best to all,

Andrei W. Konradi

Burlingame, CA USA


Powered SUP on board speed control?
(Mark Langille) #2

Any more progress on your project?


(Andrei W. Konradi) #3

A little. Settled on a twin, counter-rotating M200 design. Just started to 3D print some plasticware. Might be ready for water tests this spring.


(greg LEPEZ) #5

Hi Andrei,

Did you try with a single T200 and a 16V battery ?
Is power not sufficient ?
I am working on teh same idea,

Thanx for sharing


(Andrei W. Konradi) #6

Hi Greg,

I did not try with a single T200. I am still working on my twin motor design. Sent you a message.

Best,

Andrei


(alexandre diver ) #7

Hello i would love to participate in anyway i can in this project. I am a machinist and tig welder. I have access to multiple cnc machines. I was recently tempted to purchase a lift electric foil but the price is WAYYY out of my league. I am an avid kiteboarder and this is really something I would like to build for the no wind days. Let me know if I could help in any way.


(alexandre diver ) #8

Did you guys look into the Lift electric foils … Im wondering how much thrust is needed.


(Andrei W. Konradi) #9

Hi Alexandre, I saw the Lift videos, but I have not studied the Lift design carefully. Just sent you a message. Best, Andrei


(Andres) #10

Hi Guys, I’m joining in this project! I kite foil and will be ready to sup foil soon. I have done research and found a great water-cooled motor that is more powerful, the issue is propeller… Here is a link.
https://hobbyking.com/en_us/turnigy-aquastar-t20-3t-730kv-1280kv-water-cooled-brushless-motor.html
https://hobbyking.com/en_us/turnigy-aquastar-240a-water-cooled-esc.html

Also there is this youtube project very similar to what I’m thinking to do… https://youtu.be/ku9bYjklwtc
However the way to mount will be simple, exactly as in lift-efoil. On the mast and over the back wing.

Could you share the MAX speed (MPH) you have been able to reach with a T200 motor on your board? (Foil or SUP!)


(Andres) #11

Hi Andrei, I just posted some info in the forum. do you have any max speed results from your tests? I have some electrical components selected for the remote control if you are interested.


(Andrei W. Konradi) #12

Hi Andres, I am still in the design phase, so I don’t have any data. I just sent you a message. Best! Andrei


(Andrei W. Konradi) #13

Hello All,

I am gratified by the interest in this project. I would be happy to coordinate communication and action involving any persons.

Best!

Andrei W. Konradi
51-year-old medicinal chemist
Burlingame, California


(david huebert) #14

Any progress yet? I saw the Lift Foil video as well. Price is way outside of what I can justify for a toy. In my research into cheaper DIY options I came across this forum.
My background: lots of SUP experience but no foiling experience and zero electronics experience.
After a few hours of internet research I am leaning to buying an off-the shelf board and hydrofoil combination. I don’t have the expertise to build my own foil and my friends who kitefoil have plenty of warnings about the board-foil interface failing, so a poorly designed home made solution would be trouble. I would also worry about getting the foil/board balance right.
It then comes down to how much thrust is needed to get up on the foil, where to put the batteries and how to waterproof them, and how to work the remote control. The picture of the Lift shows a single motor with prop in the midline above the main wing. It looks pretty small. A two-motor solution would be easy to balance (one on each side of the foil mast), but I would think that this would make drag go up significantly enough that much more thrust would be needed, thus needing much more battery. Any idea of how much thrust is needed to fly the foil with a person on board? For batteries, I would probably try to make some type of waterproof case for the top of the board. It would have to be centered right over the foil mast to balance the board and it would have to be thin enough to be able to have the surfer move around on the board.
I looked at the youtube water jet project. While interesting, it looks to have insufficient thrust to make this work.
Anyone have any direct experience yet?

David Huebert
52 year old MD from Winnipeg


(Chad) #15

I am happy to contribute as well. I too looked at the Lift efoils and was shocked by the price. I decided to build my own. I am engineer by trade. Mainly a surfer and just starting to get into kiting and eventually foiling. I recently bought a book on foil design and am hoping to run some numbers on how much thrust should be required. I too am curious if one T200 will have enough thrust to power a foil.


(Wayne) #16

you need at least 600w to get foiling, we have a sup foil which pops up at 9kmph and with a 200 watt (12v) motor running 24v we could not get past 6 kmph even removing the foils . if the rider were a small child pumping the board, maybe , mean while its almost 50 amps @12v if propped up so batteries need to be sizable. i have seen a couple at around the 40Ah mark capacity wise . a gearbox seems to be needed to power a good sized prop . Note that RC air craft props work under water thanks to Reynolds numbers being kind you just need 15x less of a prop that you do in air because of the density being near 800x more in water. My aim is 1000w plus motor, geared down to swing a 2 blade 300mm diameter prop with variable pitch to perfect the top speed vs launch . it isnt easy though . :slight_smile: the turnigy water cooled esc is my pick https://hobbyking.com/en_us/turnigy-marine-180a-bec-waterproof-speed-controller-with-water-cooling.html , Turnigy aquastar motor with the lowest possible kv and a reduction box . no idea how to easily pistol grip control the esc yet . im quickly seeing the reason the efoil is $12500 usd ! https://www.liftfoils.com/


Foil board project
(Rich Hughes) #17

Hey,

Have you guys looked at this? Suggests (to me) that (theoretically) much less power should be required.

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwjAyaebjpbVAhVSbVAKHS7PBeIQFgg1MAI&url=http%3A%2F%2Fpeople.cst.cmich.edu%2Fyelam1k%2Fasee%2Fproceedings%2F2011%2FDATA%2F36-187-1-DR.pdf&usg=AFQjCNH1F9Z49eGxBHiyBN7BaKVuB0QY_A

Assume you have a pretty large foil driving very high lift at low speed. (less fun once up…)

Interested as I am thinking about a retrofit kite foil project. I only need a sniff of a breeze to get and stay foiling, so feel that this must be possible. (not withstanding the motor drag).

I wonder if two vertically mounted thrusters could help - the first higher one to temporarily provide power to get on the foil. The second lower one to provide the lower power, lower drag, higher speed one up on the foil…just thinking out loud.


(Philip Krug) #18

I talked to NICHOLAS (Nick) LEASON yesterday. I think he is the owner of Lift Foil. I emailed them awhile back but no response so decided to give them a call.

According to Nick, their eFoil setup uses a very powerful ducted thruster. Somewhere in the 6KW range. This is a custom design that they manufacture. Their battery pack is no lightweight in terms of power.

I got interested in the eFoil because of my fishing kayak project, but it became obvious to me while talking to Nick their thruster/controller/battery setup was way more than I needed. :wink: When I mentioned to Nick my hull speed was around 4 mph he laughed and said their setup would probably be able to get my kayak to plane, even without their foil setup.

From what I read on their site the eFoil setup will run for about an hour at 15 mph with a max speed around 25 mph.

I would strongly suggest giving Nick a call at +1 787 609 6198. They are located in Aguadilla, Puerto Rico (EST).

Phil