Electric Surf Board

Boats, Jet Skis, Kayaks etc., including hovercrafts
bbq870
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Re: Electric Surf Board

Post by bbq870 » Jul 26, 2017 5:23 am

I live in Shenzhen and can contact him
his board looks like it has some serious power.
@ropower86 I saw your post about using a gasoline engine :D

dirkdiggler
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Re: Electric Surf Board

Post by dirkdiggler » Jul 27, 2017 11:54 am

That would be nice to get an update on how far along the Chinese company is and what the quality is like.
Here's another interesting vid from the crazy jet surf nation guy visiting the Onean factory:

ropower86
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Re: Electric Surf Board

Post by ropower86 » Jul 29, 2017 12:30 pm

bbq870 wrote:I live in Shenzhen and can contact him
his board looks like it has some serious power.
@ropower86 I saw your post about using a gasoline engine :D
Yeah, I gave it up because I live in an apartment now so gas is a big no no. Also, there is a lot of hassle involved with small gas engines Unless you invest in a really good carb. 8)

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Chalo
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Re: Electric Surf Board

Post by Chalo » Jul 29, 2017 4:14 pm

ropower86 wrote:Yeah, I gave it up because I live in an apartment now so gas is a big no no. Also, there is a lot of hassle involved with small gas engines Unless you invest in a really good carb. 8)
Propane/LP gas? Both the above problems solved. And less polluting emissions.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

bbq870
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Re: Electric Surf Board

Post by bbq870 » Jul 29, 2017 10:15 pm

Propane gas is a good idea!!
I saw a conversion of a small motorbike with a "gas-bottle". It's not impossible.
From cars I know the combustion is hotter and puts stress on the engine.
but that could be solved, I guess.

ropower86
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Re: Electric Surf Board

Post by ropower86 » Jul 30, 2017 5:57 pm

Chalo wrote:
ropower86 wrote:Yeah, I gave it up because I live in an apartment now so gas is a big no no. Also, there is a lot of hassle involved with small gas engines Unless you invest in a really good carb. 8)
Propane/LP gas? Both the above problems solved. And less polluting emissions.
Running on propane will not provide the engine ultimate power. Just like putting a regular gas in a BMW which it is made for premium gas. There will be HP loss significantly.

ropower86
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Re: Electric Surf Board

Post by ropower86 » Aug 02, 2017 8:12 am

Bazaki wrote:Hey Guys,

No secrets here anymore.

Months I have thought to set up my own company with an electric jet surf, so I could not really share my details.
But I'm doing other things lately and the jetsurf is just standing here. So I want to share all details now.

I found out the exact details of the Lampuga jetsurf.

Lehner motor 7040/6 about 1000 euro
MHZ jetdrive 64mm about 650 euro
Mgm compro ESC ( 25063 ) I think it was their industrial ESC not the hobby esc. about 1000 euro
14s lipo

I bought the same motor and jet drive, very expensive. and bought the cheap flier waterproof 420a esc.
First I bought the swordfish 300a + but gave only 50% throttle, never worked well.

Here is the old video:



The board is a surfboard with too much rocker and the board is too small. Also I had some water leaking in.

Now I made a plexi glass box, so I can test it at home under water and everything is 100% waterproof, even the lid that is on top. Works perfectly dry.
Watercooling is running good, and I use 14s lipo, the motor runs 320rpm kv unloaded and with load 280 rpm kv. So that is about 15.000 rpm for the jet.

It is not as with an ebike, with this you need 11kw continiously, so the efficienty needs to be as high as possible, everything needs to match perfectly.

At 55kv it takes about 200A and everything stays pretty cold, but somehow I burned 2x a Flier 420A esc. I'm also not sure why the esc broke, it was running fine under load, cut off throttle and it didn't work. Now I wanted to invest in the mgm compro but cost about 1000 euro.

I also found a company that can make me custom board, so the next step is a board about 80cm width and almost flat, no rocker line.



This box can fit inside and out a custom board, so easy to install and no leaking. So you don't have to work inside a board or make the board waterproof.

Maybe I will sell this whole set up if anyone is interessted.
Hey, I just realized something, Your Lehner motor 7040/6 has more demand than other brushless motors. Lehner motor 7040/6 was designed to run with a higher quality ESC like the 400a MGM (industrial version). MGM has better quality mosfets and few capacitor with 1000uf rating while Flier capacitor has 200uf rating a significant difference. So conclusion you did not a have the matching ESC for the Lehner motor 7040/6. That motor is designed way different than the rest, yet to only run on MGM ESC.

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Bazaki
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Re: Electric Surf Board

Post by Bazaki » Aug 03, 2017 2:25 am

Hmmm that is interessting. I now have the 500A flier controller. Of is very very big and Heavy. I was hoping that this 500a controller can do it better.

ropower86
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Re: Electric Surf Board

Post by ropower86 » Aug 04, 2017 4:14 pm

Bazaki wrote:Hmmm that is interessting. I now have the 500A flier controller. Of is very very big and Heavy. I was hoping that this 500a controller can do it better.
Is the casing black or white? The black casing is the newer improved version with better MOSFETs and CPU. Something to look out for. Flier is stepping their game up and it seems like they may figure it out after all. By the way, I changed my motor to a bigger outrunner that produces 5,3kw. Just need to find a way to make a cooling block and install it. Where can I find that magnetic safety switch?

ropower86
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Re: Electric Surf Board

Post by ropower86 » Aug 04, 2017 4:16 pm

Bazaki wrote:Hmmm that is interessting. I now have the 500A flier controller. Of is very very big and Heavy. I was hoping that this 500a controller can do it better.
By the way, what is the motor wire gauge?

ropower86
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Re: Electric Surf Board

Post by ropower86 » Aug 04, 2017 4:49 pm

ropower86 wrote:
Bazaki wrote:Hmmm that is interessting. I now have the 500A flier controller. Of is very very big and Heavy. I was hoping that this 500a controller can do it better.
By the way, what is the motor wire gauge?
Check this out:
https://endless-sphere.com/forums/viewtopic.php?t=84783

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Re: Electric Surf Board

Post by attila0216 » Aug 07, 2017 3:27 am

Good Morning to everyone,

I'm following this topic quiet long time and considering to make my own e-jetsurf. The place i live has a huge lake but very shallow and that's why would be ideal a jet system for the board. Gas is prohibited(environmental reasons) so electric the only option. As i was reading the posts i have realized the biggest issue is to find the right size brushless motor. At MHZ watercraft website they have this 64mm jet, but require 12KW of power in order to thrust 400N which approx. 40kmh on water with board. They also have a Scorpion motor with 23KW output, but the battery to operate at a reasonable 20-30 minutes runtime is cost a fortune. So i was thinking why we couldn't just use a smaller brushless with half of the power required but double rpm and just gear it down to half with metal helical gears. For example the Skyrc Proteus X524 is a 5300W brushless with 30K rpm and if geared down to 2:1 will be 15K but double the tourqe so should be enough to power the board and than not needed a huge battery pack and an expensive ESC.

So would love to hear you guys what are your opinions about it.

ropower86
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Re: Electric Surf Board

Post by ropower86 » Aug 07, 2017 5:32 am

attila0216 wrote:Good Morning to everyone,

I'm following this topic quiet long time and considering to make my own e-jetsurf. The place i live has a huge lake but very shallow and that's why would be ideal a jet system for the board. Gas is prohibited(environmental reasons) so electric the only option. As i was reading the posts i have realized the biggest issue is to find the right size brushless motor. At MHZ watercraft website they have this 64mm jet, but require 12KW of power in order to thrust 400N which approx. 40kmh on water with board. They also have a Scorpion motor with 23KW output, but the battery to operate at a reasonable 20-30 minutes runtime is cost a fortune. So i was thinking why we couldn't just use a smaller brushless with half of the power required but double rpm and just gear it down to half with metal helical gears. For example the Skyrc Proteus X524 is a 5300W brushless with 30K rpm and if geared down to 2:1 will be 15K but double the tourqe so should be enough to power the board and than not needed a huge battery pack and an expensive ESC.

So would love to hear you guys what are your opinions about it.
That is funny that is what I was planning to do over this past weekend. I was looking at this motor for 4 months now and a little hesitant on buying it. Yes the MHZ propulsion jet units have lower pitch which demands more RPM and power. That's stupid! Because it will create more heat than can cause MOSFETS in the ESC to burn up, over heated brushless motor if water cooling not set correctly and needing more expensive battery, everything will add up to around $3000 to build or more problems.

But for what??? :?

Conclsion: I think it is a good idea, go for it.

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Re: Electric Surf Board

Post by Jetfreak » Aug 21, 2017 6:04 am

Hey guys, maybe you can help me. Iam building my own Jetsurf stuff but the main question I have is how to control the controller... the RCs arent waterproof and a cable solution isnt available on the market or? I was thinking of the Controller from an electric scooter, but how to connect it with an rc controller? Thanks for any answers.. have a nice day

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Re: Electric Surf Board

Post by philgib » Aug 25, 2017 3:17 am

Hi. Such an amazing thread, I just can't stop reading it...

There is something I do not understand though, can you please enlighten my tiny brain... That must be a basic mechanics principle I do not understand. Why is everyone using high RPM plus an expensive gearbox when one could find 50kv 10S 6000w engines for about the same price ? Do high RPM + gearbox give better torque than slow RPM without gearbox ?
http://alienpowersystem.com/shop/brushl ... 0kv-6000w/

Also, I see dangerous unprotected props. Why are you guys not using Kort Nozzles which would not only protect from the prop, but also is supposed to increase efficiency at low speeds ? Here is a free STL (not mine) : https://cults3d.com/fr/outil/rov-kort-n ... ated-mount

Thx a lot

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Re: Electric Surf Board

Post by Frizzo » Sep 11, 2017 7:08 pm

Jetfreak wrote:Hey guys, maybe you can help me. Iam building my own Jetsurf stuff but the main question I have is how to control the controller... the RCs arent waterproof and a cable solution isnt available on the market or? I was thinking of the Controller from an electric scooter, but how to connect it with an rc controller? Thanks for any answers.. have a nice day

Here is a tutorial about that

https://www.youtube.com/watch?v=-gy25dL ... RDWkMw7nDP

Cheers

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Re: Electric Surf Board

Post by chris_kline » Sep 20, 2017 10:07 am

hey guys

great thread. stumbled across it when i decided i needed an electric surfboard in my life, and this thread has been the most useful for ideas and inspiration.

anyway, here's my progress so far.
Attachments
prop shafy assembly.jpg
prop shafy assembly3.jpg
jetsurf 4.jpg
jetsurf 6.jpg

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Sep 20, 2017 10:22 am

so, i ordered these motors and esc https://www.alibaba.com/product-detail/ ... 179apjm9wP

i know its from china, but if the kv and kw rating are as they advertise, then it should work pretty well.

the board i intend to shape from eps foam, then cover with carbon fiber.

the impeller itself will be 76mm diameter, with a 70mm pitch, made from carbon fiber. (luckily i have a small carbon fiber shop at my disposal) im going to machine a top and bottom aluminium mould. i would usually use pre preg carbon in the autoclave, but this time i will use dry carbon cloth, and inject epoxy resin into the mould.

the rest of the water jet will be made from a selection of laser cuts, some custom machined parts, and some off the shelf bearings and water seals. (luckily i also have a fabrication shop at my disposal)

personally, i think the thrust problem mathias was having was not down to the motor, but i think he needed a more diverging nozzle. i guess ill find out over the next weeks.

anyway, if anyone wants the designs/models etc to use for their own project, or to improve them some way, then i can upload them or email them or something

Frizzo
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Re: Electric Surf Board

Post by Frizzo » Sep 20, 2017 7:01 pm

Thats actually a really awsome thing you are going to do!
Do you have already any experience in mould making for carbon fibre?
Why is the stator directly in the nozzle?

Cheers

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Sep 21, 2017 5:40 am

thanks. well im hoping it will work out pretty well!

the motor will sit further up the tube into the board, but if by "stator" you mean the fin like things in the nozzle, they are to stop the water/jet from just spinning/vortexing the water jet. it should increase thrust, and efficiency. they will be welded to a laser cut "bearing cradle" just behind the prop, this should cut down any vibration of the prop, and mean that i can get my prop super close to the tube walls.

well, on the carbon side, i own a small carbon factory that i setup about 5 years ago producing low volumes of high precision carbon parts, so it shouldnt cause too many unsolvable problems
Attachments
prop shafy assembly7.jpg

srn
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Re: Electric Surf Board

Post by srn » Sep 21, 2017 9:01 am

The 7kw of your motor is the peak power I guess. Same for the ESC.
Did you already order ? Would be very interesting to see a test of this motor under load. (alienpowersystems offers same motor)

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Sep 21, 2017 9:49 am

yeah ive already ordered about 2 weeks ago, should be arriving any day.

the motor is listed as 8kw, but i guess ill see how it is in the "real world" after some testing.

i looked at the alien power systems motors, but this motor is apparently 250 kv, and 300amp, so its in the right rev range, and should have some decent torque, plus it was pretty cheap. im guessing all the alien power systems motors are probably made in china anyway.

personally, i think (and maybe im completely wrong) that 8 kw motor should be more than sufficient. i mean its basically 10.7hp gas equivalent. i think that its a case of the prop and jets being properly tuned toward optimum thrust. partly thats why i plan to injection mould carbon fiber props, so i can change the design easily, and the jet nozzle will be detachable, made from a laser cut flange, and piece of pressed stainless tube, so i can change the nozzle angle and find a good balance

srn
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Re: Electric Surf Board

Post by srn » Sep 21, 2017 10:03 am

I am also building a jet surfboard. Carbon Jet-tunnel, selfmade carbon impeller and aluminum nozzle.

As I spend so much time in building the board and parts, I currently tend to buy a Lehner Torqstar + MGM controller.

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Re: Electric Surf Board

Post by chris_kline » Sep 21, 2017 10:33 am

yeah i was looking at the lehner motor, for sure thats gonna have some power!!

i decided though to start off playing with some cheaper motors and see what power i can get out of that, then maybe upgrade if i had to.

post some pics of your progress, i would love to see what you've been working on, plus maybe get some new ideas/inspiration i didnt think about :D

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Re: Electric Surf Board

Post by Frizzo » Sep 21, 2017 2:32 pm

chris_kline wrote:thanks. well im hoping it will work out pretty well!

the motor will sit further up the tube into the board, but if by "stator" you mean the fin like things in the nozzle, they are to stop the water/jet from just spinning/vortexing the water jet. it should increase thrust, and efficiency. they will be welded to a laser cut "bearing cradle" just behind the prop, this should cut down any vibration of the prop, and mean that i can get my prop super close to the tube walls.

well, on the carbon side, i own a small carbon factory that i setup about 5 years ago producing low volumes of high precision carbon parts, so it shouldnt cause too many unsolvable problems
Yeah, i know the function of a stator :)
I was just asking because every jet drive I´ve seen has the stator and the nozzle as 2 different parts.... So I was wondering if it may be more efficent to build it like you.

How do you know that 70 mm pitch should do the work?
Would be nice to see some pics of you too!

Currently I´ve also started with this project. I already have a Lehner 3060 with 9/19 windings. On the official website they say that this motor reaches 17 kw at 50.000 rpm. I´m planning to build a watercooled gearbox with a 1:3 ratio. That schould do the trick for the torque...
For the impeller I´m planning a cnc mashined aluminium one. I was thinking to reconstruct a solas 3 blade jetski impeller but with a 80 mm diameter... don´t know guys... what´s your opinion about that?

Cheers

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