A build with a feminine touch?

[3rd_ave_Lien]

So, while my friend is modifying the board to accept the mast mount (more about that later), the work on the ESC is proceeding. After blowing many many parts, and finding out that 20A will cause the PC board traces to blow up also, my husband Charlie is building the real thing. Finally… As Rick says, if I wanted it next week, I would have ordered it next week!

Need to put this…

… into that!

[spork]

Need to put this…
…into that.

I recommend leaving the soldering iron out.

[3rd_ave_Lien]

Building the CSESC (Charlie’S ESC):

And that piece of modern art is the wiring diagram:

[3rd_ave_Lien]

The ESC is built inside a small AN-04F aluminum box (https://www.polycase.com/an-04f). Since the box is small, and Charlie required that all the wires exit from the narrow side, and also that we can disassemble the whole thing, and that the wires enter the box with a very specific placement… that ruled out a lot of neat solutions that I saw on this forum.

I built an extension box to accommodate 5 IP68 glands. The extension box will be glued onto the aluminum box.

Couldn’t come up with anything simpler. Bright ideas are welcome!

[3rd_ave_Lien]

WATERPROOF BULLET JUNCTION
While I am waiting for the ESC, I am building various bits and pieces.

Here is a waterproof junction to connect the motor and battery wires to the ESC. It is inspired from to many designs found on this forum. I wanted to make something that is easy to disconnect.

The base is the junction box below that I got from amazon.

Since the central connector is designed for 3 wires, I am replacing it with a 3D printed one that can accommodate a 6 AWG wire with a 8mm bullet.

(STL files available upon request.)

[tacktun]

Wow looks super sleek.
And you were even able to reuse the original gasket.

Sorry to bother in your thread but since we are speaking about connectors…
Are there beefy AntiSpark Connectors without a housing, I’m speaking 8mm or higher. All I found so far are the AS150. But I’d like to go bigger.

[3rd_ave_Lien]

Hi, sorry, I know nothing about antiSpark connectors. I am not using them, since we have a different mechanism.

[3rd_ave_Lien]

I’m back! The project was considerably slowed down by the early start of the wind season, here in California.

Here is what we are doing for the battery (the ESC is in a different box, don’t look for it here…):
Initially, the battery will be housed in a waterproof “Nanuk-made-in-Canada” 915 suitcase, with an polycarbonate panel for added waterproofing.

The suitcase will be tied to the top surface of the surfboard, for now.

1. Battery: 14s5p pack (21700 cells), courtesy of my good friend G.T.
2. BMS: XiaoXiang 14s
   (Something like that, not sure if this is the exact one I have. 10S 11S 12S 13S 14S 15S 36V 48V 60V BMS with Bluetooth and PC communication APP PCB board of electric bike – LLT POWER ELECTRONIC)
3. Circuit breaker: 50A (we are still under the delusion that it will be enough)
4. Car relay: was cheap, that’s all I know. Activated by the house alarm switch to provide a “dead woman” off safety.
5. House alarm switch: a magnetic switch that is opened/closed by another (external to the suitcase) magnet. This magnet is attached to a leash and opens the house alarm switch when the rider falls off. This, in turn, triggers the car relay to open.

Et voilà… We’re using 6 AWG wire… The (redundant) polycarbonate panel still needs to be installed, and the 2 holes for the waterproof glands are not there yet, but I’m scared to drill my beautiful suitcase!

Anyway, this leaves the top half of the suitcase free to carry a beer, a sandwich and a change of clothes.

[loveefoils]

So if I’m correct your battery should be around 58.8volts and 15-25amps
Because all 21700 cells are 4.2v fully charged and about 3 to 5 amps per cell

[3rd_ave_Lien]

Yes, that’s what we are starting with. We just happened to “inherit” a 14s5p pack.

[loveefoils]

Got it, if you draw more then 25 amps your going to get under a hour of ride time(witch you probably know). also what is the size of your front foil?

[3rd_ave_Lien]

For the time being, I’ll be happy if I get any ride time at all!
The wing is not very big… It’s from a Cabrinha kitefoil.

[3rd_ave_Lien]

Testing… Waterproof! Also, it floats quite well.

[3rd_ave_Lien]

The charging set-up. For now, we are limiting the voltage to 56V.
The XiaoXiang BMS works in mysterious ways, but it works.

[loveefoils]

what are you using for a charger, or are you just plugging it straight into the wall outlet and letting the bms handle the charging?

[3rd_ave_Lien]

We found some central office power supplies on eBay for cheap. You can program the voltage (max 57V) and limit the current (max 20A). Was something like $30.

[loveefoils]

got it, i think i am going to use a aliexpress one

https://www.aliexpress.com/item/32828158048.html?spm=a2g0o.productlist.0.0.61245317kZ7GDp&algo_pvid=19ee2067-243a-4af0-8bbf-38e9ddc1363e&algo_expid=19ee2067-243a-4af0-8bbf-38e9ddc1363e-1&btsid=0bb0623116216453576636842e6953&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

[3rd_ave_Lien]

Testing the battery
Battery -> ESC -> Motor (MTI65162) -> propeller in garbage can full of water.
Ran at about 750 to 1000 W, steadily to check the discharge of the battery. Seems OK, for what we know…

[loveefoils]

how are you doing your tests, is it under load? on a dock, bath tub.

[3rd_ave_Lien]

Hi,
I’m back after a loooong break. We are testing by placing the motor and propeller vertically in a garbage can filled with water. The load is provided by a variable weight placed on the lid. It’s not ideal, but we get a vague idea of the relative efficiency of the propellers, by looking at what rpm and current is required to lift a given weight…