e-surfboard 8.5hp

denaxel

10 µW
Joined
Apr 9, 2014
Messages
6
Hi,

I'm making a electric surfboard.

I already have:
  • I also make the electronics with an arduino. It measure the cell voltage and current.
    Also it measure the temperature of the motor, esc, battery pack

the problems:
  • A waterproof thumb throttle.
    I looked a long time for this. Do you know where i can get it somewhere?
    Or have a better idea?
  • A good bms for the battery pack.
    I'm also stuck at this. I don't find one that is capable of the current that i draw. Around 150A

A video of the test of the drive system:
[youtube]vdpr8zT0rdI[/youtube]
The esc is out of sync on low speeds. But i still need to configure the esc to a 4 pole motor.
We did the test with 2 start-booster for a truck, a 12v and 24V booster. I wired them in serie so i became 36V.
 
I would love to see what you are using for your drive, but the google user links are 403'd. Curious what needs a 30k rpm.

As to the remote, you will have to make your own. You can either tear down an existing remote and make a waterproof enclosure, or waterproof the existing one. I've used ziploc bags when testing my stuff and haven't had an issue, yet...You might be able to use a custom made waterproof bag. AFAIK there isn't any waterproof remotes for sale. You can check the eboard forum where they have a smaller remote that is in the works. Might be easier to work with that one.

I looked at a few jet pumps and props the other day. It might be worth it to try and get back to using a jet instead of the prop. Jet seems to be the obvious choice for safety and higher rpm of the electric motors. Aliexpress did have some cheap props that were in the 5" size range, which are a better fit than the Torqeedo props.

Batteries - I use Lipo, so can't help you much on that.
 
The first link didn't work.
Their you see that i already use a jet.
And for the watertight thumb throttle.I was looking for a throttle used by drive by wire jet ski. But didn't find that much.
Or don't they exists?
 
Works now. Looks like a good setup. Should work great. I do think the jet is the best way to do it.

Where did you get the jet pump? Link? Also the attachment to get the motor connected to the pump? That bumper thing (don't know what it is called) is what they use on jetskis. I was looking at the Rc pumps and there are a few that work, but pretty expensive to try out. I am more than happy to spend that kind of money to get it working. The cheapest working board is $5k, so a few hundred for a pump isn't that bad.

Having your motor fully enclosed like that might cause some issues. Heating and electrical problems.

If you want a wired throttle to use with that boat esc, you will have to use a servo tester. There is a thread on here on how to hook it up. A thumb throttle should be fairly waterproof. I know most use them on ebikes in the rain without issue.
 
Yes, If you fall of the board you don't want a prop in your legs.
The jetpump is from hobbyking:http://www.hobbyking.com/hobbyking/store/__13388__CNC_Precision_Jet_Boat_Drive_X_Large.html

The motor is water cooled, so the heat wouldn't be an issue.
But why would i have electrical problems?

For controlling the ESC I already made a controller with an arduino.
I can read the output voltage of the throttle with the ADC of the arduino and control the ESC.
 
You might get eddy currents with the motor being enclosed in a conductive material. Only one way to find out though.

Did the coupler dampener come with the jet drive, or where did you get that? Looks really nice.

If you are using Arduino then you should be set. Lets see how this thing goes! Good luck with it.
 
I would love to see this in action, so please post a youtube of the final result ! :D

If you drill a hole and make a connector you can route some of the water from
the jet to the water cooling inlet of the motor.. (looking at the jet again I think it already
has this connector)
 
hi,
I am currently making something similar, however I am using two RCMK k30rz engines and two MHZjet 52's. I was considering electric, but I could not find a suitable option that would sustain around a half hour of use. Do you know what your board estimated time of use would be?
 
I have a battery pack with a voltage of 36V and a capacity of 40Ah.
On the test we used also a voltage source of 36V and the max current was 128A.
So the battery will least 18 minutes and 45 seconds on full power.
But if you surf moderate on the board than it will least around 30-40 minutes.
 
How fast are you expecting your board to go, this is somethings that I have had a hard time gauging.
 
I have seen the jet from hobbyking. But I can't find the best rpm for this jet. Wouldn't 30k rpm be too much ?

How much litre volume is the surfboard. ?
 
hey denaxel, hows the project going? i'm looking into different jet options now and wondering if the hobbyking jet was enough thrust for the surfboard?

thinking the Gravitix 50mm impeller or... an old kawazaki js300/js440 jet pump.. but i think that the jetsurf.com guys have got it all right with their all carbon fiber water turbine.! would love something like that:)

Cheers
cwt
 
I dont know that jet pump but I think your going to fry the esc trying to spin it at 30 000 with a low tourqe motor.
 
Hi,

I am in Western Australia and i have been working on a similar project last couple of years, i am using the same motor and a graupner jet mounted in a fiberglass 9 ft board i hit a wall last year when using the aquastar 200.. at burst it would cut out.. i put it all in the shed and havent touched it since plenty of others have hit market now so lost motivation haha.. would love to have a chat and see where your at with it.

Cheers
Ben
 
hello there, great project. I am trying to do something similar, with your permission I would like to have a look at your arduino code. I am having trouble communicating with my esc
 
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