1st build low cost - France

Build, Repair & Mod
1

Dear community of DIY Efoilers,

Thank you all for all the amazing builds and advices that have been shared on this forum, this gave me hope to be able to own one day my own efoil !
I fell in love with this activity 2 years ago but entry price is really high, so after many readings on your builds, it’s my turn to start mine (slow build I think, family life + living in apartment ;-))

My build will be a mix of several of yours that seemed to be successful, so finger crossed the choices made are correct as most of products have already been ordered (11.11 discount on Aliexpress).

The global idea is to have an efoil simple bolt-on style, meaning a waterproof box strapped on inflatable wing foil board, which would allow to ride ~1 hour at 25-30 Km/h (I weight 65 Kg)

Here are the components :

  • Gong hipe 5.5 (2nd hand 2021 model only front foot straps) 150 Purchased
  • Foil Gong Curve LT + 43 cm stab + 85 cm Mast (2nd hand) 256 Purchased
  • 8 smart batteries Parkside 8Ah 350 Purchased
  • 2 double charger parkside 53 Purchased
  • Waterproof box (inner dim : 28,5x31x10,7) 45 Shipped
  • Motor 6384 120KV No Hall 64 Shipped
  • ESC FLYCOLOR X-Cross HV3 160A 61 Shipped
  • Waterproof connector IP68 (btw motor and ESC) 3 Shipped
  • UBEC 15A 7 Shipped
  • Flipsky Vx3 81 Shipped
  • Circuit breaker 200A 6 Shipped
  • Cable gland PG 16 (on Box) 4 Shipped
  • V_S prop to be printed

I liked very much the idea of @nicolasLGM about using Powerdrill batteries as it would require less soldering + I already have parkside tools + 3 year warranty. I missed the 54€ price on lidl website, but there are many new batteries sold on « Leboncoin » (craiglist like french website). I will organize the 8 batteries like 2 groups in series of 4 in parrallele = 40V32AH

Also I wanted to go low cost, and @bbe project showed that efoiling on a budget 6384 motor + ESC was possible.

I am still waiting for most of the part to arrive from China, so I have been looking at the electronic connection part and I have some questions :

  • I would like to connect the box to the motor with a big « 3 wires » cable . I understood that it is advised to have 8 AWG wires and also that amp reaches 30A flying and 80A to lift, so I am trying to look for a waterproof IP68 connector being able to receive the big « 3 wires » cable and to support 80A. I purchased one but it is only 30A. Do I really need 80 A ?

Also do you think, I will need to replace the original 3 wires of the motor (they look small on picture), and replace them with 8 awg, or I could just connect them to 8 AWG (sorry maybe this is a stupid question, but I have nerver soldered before…)

Again thank you for all you advice !
See you soon,

David

2 Likes
2

30A and 80A is battery current, motor current is much higher, 100-150A during lift. You don’t need more than 10AWG with silicon wire but i would advise to not go smaller either.

1 Like
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Hi FlyDude,

happy to see some of my project in your project :slight_smile:

Regarding cable, I advise you to keep 3 separate 10 AWG (or 12 AWG) cables, if you chose a 3 core 4mm² cable, it will be too big to go through the gong mast), and if you want your efoil to be efficient, the best way is to have tha cables in the mast.

For a lightwieght like you (I’m also aroung 65Kg), you only need 30-40A battery current to start, so maybe max 70A motor current.
With my 7070 motor with 12 AWG cables, no issues.

To limit the number of cable gland going from the box, I connect a 3cores cables (50cm) between the box and motor cables with :
https://www.amazon.fr/dp/B0BFVYHB66?ref=ppx_pop_dt_b_asin_title&th=1
https://fr.aliexpress.com/item/1005003931439736.html?spm=a2g0o.order_list.order_list_main.101.58225e5bvnkPXT&gatewayAdapt=glo2fra

Regarding the box, I first bought two aliexpress boxes supposed to be waterproofed, but it wasn’t. I strongly advise to buy box with a brand :

(My box used for 20 efoil sessions without any issue)

Are you going to waterproof your motor alone ? (curious to have you feedback on the difficulty to do it)

1 Like
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Thank you @Larsb for information about battery vs. motor current, I’ve looked at some explanation to understand better the concept. However I still see a maximum of 55 A for 10 AWG, is there another table than this one that we should refer to :

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Also, I understood that if I want to have 3 wires included in 1 cable, I need to look at “power transmission max amps”, which maximum amp is a lot smaller.

Thank you @nicolasLGM for you advices. Concerning the box I have ordered a B&W 3000 (there seems to have enough place for my configuration). I found a good deal here with 30% discount (KOFFER30 code)

image
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For the wires, I will follow you advice, I will keep 3 seperate 10 AWG wires from motor through inside the mast, to go in a waterproof connector that will connect to a 3 core wire to the box so that I can have only 1 hole in the box.

Globally my configuration will be like this :

image
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Does-it look correct ?

Thank you for any advices.

5

The ampacity charts are from a different use case, you can see them as a worst case table (continuous use of power, no cooling, any type of insulation)
It’s a different situation with silicon clad wire in free air, the silicon wire is hard to burn even with a blow torch (i should know, i’ve used a torch to solder 8 awg wire before i got a more powerful soldering iron :smile:)

I run 8awg on my efoil but for an assist it’s a better balance with a bit slimmer wires.

6

OK, I will trust your experience :wink: In my case it will be an efoil and not a foil assist, but I understood 10 awg works also for an efoil. Anyway I will see what I can find to buy.