Electric Hydrofoil/E-Foil
- Thread starter Jezza
- Start date
There is one issue that needs to be solved with these boards. Jets are to ineffective but safe, props are effective but they are dangerous. The propeller will cut of your fingers and toes if they are placed inside the duct! Do you guys have any thought on this matter? Could of course add a net in front and back of the duct, but I think this will increase drag if you want shield it sufficiently.
I think I read that the lift foil controller cuts power when in contact with water, and if it´s far enough away from the board. which is good, but I dont think it covers a rather normal situation that we experienced when testing.
If you hold the controller above water, when you are in the water next to the board, your toes are really close to the propeller (your other hand may also be very close to the propeller).
My Idea is to incorporate a pressure sensor or something similar inside the board or in the traction pad, that can feel if there is a person on it or not (certain amount of force required to activate the full speed of the prop). The prop will turn slowly to allow some movement movement when there is nobody on top, so that you can drive it back to yourself.
I think I read that the lift foil controller cuts power when in contact with water, and if it´s far enough away from the board. which is good, but I dont think it covers a rather normal situation that we experienced when testing.
If you hold the controller above water, when you are in the water next to the board, your toes are really close to the propeller (your other hand may also be very close to the propeller).
My Idea is to incorporate a pressure sensor or something similar inside the board or in the traction pad, that can feel if there is a person on it or not (certain amount of force required to activate the full speed of the prop). The prop will turn slowly to allow some movement movement when there is nobody on top, so that you can drive it back to yourself.
FROGMANGEEK
1 mW
- Joined
- May 30, 2016
- Messages
- 12
A magnetic emergency relay switch could stop the main power source in case the rider fall. A magnet leashed to the rider could do the job.
Envoyé de mon F5321 en utilisant Tapatalk
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Clarin said:
Thanks :=)
Just sent them an email asking if their systems are watertight and so on. The downside is that its a on/off switch, not a sensor.
Talked to a electric guy, he had this funny idea to use a bicycle tube with some air inside and add a pressure sensor inside the tube. Then place the tube in a pattern below board deck. A person standing on the deck will increase the pressure inside the tube and activate the prop. This way you can sense if there are somebody on the board or just hands on the board (when you are getting on the board).
Will use som time to figure this one out.
Would work with a Leash, but I think its a nicer to not have a leash.
parabellum
1 MW
Is it probably enough to zero the throttle if you want to get up and use the pad to switch off if less them 15kg is on the pad? It is good to use as much of your own brain until machines take over IMHO.Hiorth said:
parabellum
1 MW
And yes, I got my trolling motor, advertised 86lbs trust and 1164W, it is huge and weights ~ 10kg by itself, it delivers only ~800W at 24V in real life, hauling 700lbs (all in) inflatable boat. I recognize there are some better candidates, like DD brush-less trolling motors, expensive though. Will order a controller to get it up to 3KW, hopefully.
Attachments
If any one is thinking of angled gearbox, got some info from supplier - 10 gbp for set of bevel gears, 12/22 teeth and M1.5 module
+ you will need main 62020 bearing and 6001 on small end for main shaft, and two 627 on vertical shaft. + aluminium foundry and some machining. It will be happy with 2kW ++ continuous power.
+ you will need main 62020 bearing and 6001 on small end for main shaft, and two 627 on vertical shaft. + aluminium foundry and some machining. It will be happy with 2kW ++ continuous power.
Has anyone considered a paddle to assist as per SUP foil?
Reckon you can get the first 5mph by paddling . Cf assisted e bikes.
Not as elegant but every W helps at lift off. Allows the set up to be optimised for higher speeds.
I'm intrigued by the contra coaxial "for fun" idea.
As well as canard foil set up I am looking into folding propellers. These look to really help with the low speed torque vs high speed drag trade off here. (Super expensive and not sized for this problem.)
Although I not that one of existing demos used aircraft style prop.
Reckon you can get the first 5mph by paddling . Cf assisted e bikes.
Not as elegant but every W helps at lift off. Allows the set up to be optimised for higher speeds.
I'm intrigued by the contra coaxial "for fun" idea.
As well as canard foil set up I am looking into folding propellers. These look to really help with the low speed torque vs high speed drag trade off here. (Super expensive and not sized for this problem.)
Although I not that one of existing demos used aircraft style prop.
parabellum
1 MW
Yes, I found 12" prop that will grab more water and raise current but I need variable speed controller in any way and a 3D printer as it looks to not depend on OTS props and parts.Bazaki said:
The fingers
10 TW
8) Laird Hamilton would be impressed.
FROGMANGEEK
1 mW
- Joined
- May 30, 2016
- Messages
- 12
Good job eager to know your set up !
Envoyé de mon F5321 en utilisant Tapatalk
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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!
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!
Jezza 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
I did say that it would
I know, thanks Jezza
will try to play around with the angles.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?
Glad to hear board angle helps with ride, presumably mostly during take off? How did you find it once the speed at levelled? Did you find the nose down?
(I still think having a positive lift for both wings (rather than typical positive negative or positive neutral set up) and a bigger rear wing than typical is perhaps a better answer than adjusting the angle of board to mast as I reckon this will create more lift early for less drag at higher speeds.... admittedly lots more work to figure out than and angled mast)
(I still think having a positive lift for both wings (rather than typical positive negative or positive neutral set up) and a bigger rear wing than typical is perhaps a better answer than adjusting the angle of board to mast as I reckon this will create more lift early for less drag at higher speeds.... admittedly lots more work to figure out than and angled mast)
Here is my setup, similar to the other ones that have been successful. Thanks to all of the previous designers for the information to make a successful efoil!
Custom diy foil, wood core with carbon fiber lamination, foil lifts at 4 mph
Parker PV17FE-010, 10:1 gear ratio
SSS 56104 500KV 6 pole brushless motor
HobbyWing SeaKing V3 130A controller
2x 6s 12000mah batteries running in series
Using a 5 inch diameter PLA printed prop, 4 blade.
I fried my volt/amp meter during the build process so I do not know the amp draw while riding (new one on the way). Rode for 10 to 15 minutes and each battery took 4500mah to fully charge.
Custom diy foil, wood core with carbon fiber lamination, foil lifts at 4 mph
Parker PV17FE-010, 10:1 gear ratio
SSS 56104 500KV 6 pole brushless motor
HobbyWing SeaKing V3 130A controller
2x 6s 12000mah batteries running in series
Using a 5 inch diameter PLA printed prop, 4 blade.
I fried my volt/amp meter during the build process so I do not know the amp draw while riding (new one on the way). Rode for 10 to 15 minutes and each battery took 4500mah to fully charge.
