Electric Hydrofoil/E-Foil
- Thread starter Jezza
- Start date
dirkdiggler
10 kW
- Joined
- Oct 17, 2012
- Messages
- 641
It's great to finally see some success on all this. The e-surfboard thread is like 6 years old now and only a handful have gotten a working board. Now there are like 7-8 efoils that are rideable. Hopefully this will bring the costs down for Lift and others, so that we don't have to DIY it. E-skateboards at were around $1500 to begin with and after everyone started making there own the costs have dropped a ton. Maybe Lift will have to rethink charging $12k for a product that people can make at home!
Anyhow, congrats to everyone that has a working board and to all the people that have helped along the way. ES is amazing in that way! I hope to be riding my own soon, but winter is closer than I'd like to admit.
Anyhow, congrats to everyone that has a working board and to all the people that have helped along the way. ES is amazing in that way! I hope to be riding my own soon, but winter is closer than I'd like to admit.
beonwater said:Hiorth said:I angled the rear wing of the foil, and the foil mast to make the foile fusalage more parallel to the board, It made huuge difference in riding experience! much easier now
Also did a thrust test, with no rider:
https://www.facebook.com/nikolai.hiorth/videos/10159559344945144/
Its amazing how much power you get out of these small motors/propellers!
It seems logical as you have the thrust so far down. And depending on the boardsize and distribution of the volume you may need to be to far back when start riding and when the foil lifts you you need to be further forward to keep it down.
Have you measured how much current you use when starting and foiling?
I you got my "MYLB-FT08 RC 150A High Precision Watt Meter and Power Analyzer" that I´m thinking of using to see peak current and power. But further on I´m thinking of logging current, voltage, speed (GPS-module or syncing with a smartphone) using an ESP32. I think these figures would be valuable for optimizing prop and wings.
Have you published your 3d models yet?
Havent measured amps. It works nicely, so i dont mind
will maby do it later when optimizing propeller duct etc. Will try do some cfd calculations also, at least calculations!Working on a instructables.com article now. With all 3d models part list and so on. Will publish in the weekend hopefully.
Efoil boards are many times more efficient than jet surfboard, so they are in our mind 100 times more interesting (and fun, as you can fly). I guess that combined with the 12000$ price tag is the reason for it being diy built.
Just bought 4x 10000mah 6s lipos. Will also build another pack of 3 e-bike batteries. Will make a compartment in the board that suits both packs, so we get loads of foiling time!!!
The foil skills are improving:
https://www.instagram.com/p/BX6QyXOnhP_/
The epoxy was used as a thin barrier coat to seal the pla parts prior to assembly. However the end pieces were epoxied into the aluminum tubing so it would not be easy to disassemble. The rear cone with the shaft seal is screwed to the main body with an o ring sealing this area. I can access the rear of the gear head area and drive shaft coupler to change the driveshaft.
The board is a 5'8" long x 22" wide x 2 3/4" thick. Not sure of the exact volume. It will not allow you to stand on it until you start moving forward. The next step is to build a larger custom board with all electronics concealed inside.
The board is a 5'8" long x 22" wide x 2 3/4" thick. Not sure of the exact volume. It will not allow you to stand on it until you start moving forward. The next step is to build a larger custom board with all electronics concealed inside.
Hi All,
Great work on getting your own Efoils up and running, we are working on one also and the success here is heartening.
In the mean time we have been tow foiling for a few months and testing prototype production foils and making our own entire rigs .
I would like to share a few thoughts with you in the hope it helps someone progress faster.
We put a load cell on our ski rope and towed our foil boards slowly on to the plane and then popped to foil , directly behind the boat, the current sup foil popped at around 9kmph and loaded to 30kg force max ,then down as low as 7kg force when popped. The kite foil loaded 35kg Max, (partly due to a 50cm wide 185cm board vs 70cm wide) then fell to 7-10kg force popping at 15kmph .
I note when most people are learning in the videos they have the nose really, really high which makes everything highly unstable. I have noted that when every rider of our foils and boards gives the thumbs up to indicate they are really feeling it and comfortable with the ride the boards rear section, which in our case has no rocker and exactly parallel to the fuselage, is parallel to the horizon line, e.g. the fuselage is parallel to the water. When going too fast the board points downward like Americas cup boats on the down wind leg, this is not to say cavitating, just reaching the foils limit and near cavitation. Always best to fly flat folks, and in ten or so different boards and foil setups, it is always the nicest possible way to go.
Also If your foil ever gets 1x the foil chord from the waters surface the drag increases a LOT so that may help you sense you are about to breach the foil, lol.
Further it is not very nice to have anything but zero degrees of front (lifting) foil AOA as when the speed increases with front AOA the front foot pressure increases too much. The rear foil should be used to determine how fast your foil pops, leave the front foil at zero (exception is a flat bottomed foil which will be good with 0.5deg upward AOA) . Rear foil AOA is anything from 1.5deg to 5 deg but i run 2.5deg personally. A Robart meter is a handy tool to set AOA , but you can make one easily and add a digital level for a fraction of the cost. If you dont do as above your fuselage will be causing unwanted drag and you can feel the difference pretty easily, plus you push "dirty" water onto your rear foil and it is less stable.
If you kneel on the board to begin with it makes it way more stable, just put your knees where your front foot would be and give it a go for the first try, you can then learn to fly and feel the foil without the need to balance yourself as well, i would think it is 3x easier to control the flight kneeling. As for foot placement, begin with rear foot directly on top of the mast and front foot 550-600mm forward of that. Rear foot ever so slightly on the toe side of the centre and front foot slightly to the heel side , this gives better control of roll and makes it more stable , Dont run foot straps at the start ! Mark the deck with tape or something , your ankles will thank me .
On take off get the board planing and get the foil lifting, dont pop too early as you will pop with the nose high (stalling) instead of the foil more horizontal which is much easier to ride and the props ability to make the nose lift is partly cancelled out while the board is still on the water. Lean forward to hold the nose down as long as you can then shift your head back or your hips back about 25mm and it will lift, if it doesn't , your front part of your body is too far forwards.
When you are an expert find your own happy place but this little lot of info will get you going much faster. Also buy or make one of these balance boards with the half sphere lower , it halves the practice http://www.fitter1.com/Professional-Balance-Boards_p_20.htmltime you need on the water
Start with it on carpet then put a hard wood or tile under it for a greater skill level.
Gege2000
10 mW
- Joined
- May 15, 2017
- Messages
- 33
Hi guys,
Could you tell me what do you think about this ESC ? https://hobbyking.com/fr_fr/turnigy-aquastar-200a-watercooled-sensorless-esc.html?___store=fr_fr
Best regards,
Gege
Could you tell me what do you think about this ESC ? https://hobbyking.com/fr_fr/turnigy-aquastar-200a-watercooled-sensorless-esc.html?___store=fr_fr
Best regards,
Gege
FROGMANGEEK
1 mW
- Joined
- May 30, 2016
- Messages
- 12
Toto44 which airfoil profil did you choose for the wing ?
Do you plan to laminate the printed wing ?
Envoyé de mon F5321 en utilisant Tapatalk
Do you plan to laminate the printed wing ?
Envoyé de mon F5321 en utilisant Tapatalk
parabellum
1 MW
Looks like successor of aguastar 240. Thogh ESC, only one I did not kill in my early scooter and bike intents.Gege2000 said:
Unfortunately, topology is different and no beck, so its not same thing.
fruitygreen
1 µW
- Joined
- May 18, 2017
- Messages
- 4
I see that the SSS 56104 IS a popular choice for motors and gear reduced with a Parker.
Yet some of the guys are using different ratio gear reduction
Does anyone have a theory on the relationship between motor, gear ratio and propeller size?
A chart would be nice to see.
Yet some of the guys are using different ratio gear reduction
Does anyone have a theory on the relationship between motor, gear ratio and propeller size?
A chart would be nice to see.
I was told by someone that helped with the Jet Foiler that the motor they use is about half as powerful as the SSS 56104 and that for the 14Kw SSS 56104 he recommended a 225mm ducted prop. He wouldn't say what their setup was. I also saw on a forum someone who had spoken to Nick Leason from e-Lift who said that their motor is in the 6Kw range.
parabellum
1 MW
Bigger prop and lower rpm is always more efficient actually. At 9" D prop, it should not take 2HP output to fly according to info of Jimmy22 about 30-35 kg take off thrust, lets say 2KW IN due to low efficiency, Motor-gears-9x6 prop at 2500rpm max.slanton said:
IMHO: 14 KW on 56104 is probably a real data point where plasma ionises the air, creating more alternative conductivity paths, spitting vaporised copper dust all around a saturated stator and rapidly demagnetising rotor. Not considering, there are no ESC's to provide those 14KW reliably. :lol:
Jezza said:
I havent tested this, but the price is nice and it at least water seal.
http://www.ebay.com/itm/Flycolor-waterproof-150A-HV-Brushless-ESC-support-5-12S-for-Agricultural-Drone-/291873009188?epid=2124091235&hash=item43f4fcae24:g:95EAAOSwZQRYa3nW
Maybe install a 40mm fan if it gets to hot.
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