Aluminum mast as negativ pole conductor

EFOIL.builders Electronics (ESC, remote, batteries)
1

Hello.
Did anyone tryed to use aluminum mast for negative conductor, and run signle thick wire for positive.
Ofc in this configuration you need to place esc inside motor housing,
That can also be benifical for esc cooling and sorter vires from esc to motor will reduce losses.

2

You always should keep the wires between battery and esc as short as possible!

3

Yes i know, because lossen i long wires and ripple,
Ripple can be solved with some nice capacitor bank. and losses will be minimal because you are using whole mast as conductor, and you can run single huge wire for positive end thrue the mast.
I need to do some calculations but i think it will work great.

5

i made a bubu in my calculations before…
Ok with 6awg wires for motor phases you are lossing cca 50-150W depending of your speed and load
But if you use mast and one 1Awg wire for positive pole, and keeping your esc happy and cool at the bootom of foil you lose 10-60W max

6

go for it, and let us know about results and corossion?

7

i just asked if anyone done it?
Im planing to build my efoil next year and mabye will make somthing like that. 3d printed mast iwth two aluminim 12mm rods inside for strenght and two layers of carbon .
Will try to use rods for conductor…

8

are you riding fresh water or salt water? Nevertheless, you should read a little about galvanic corrosion when using Al and CF
https://digitalcommons.du.edu/cgi/viewcontent.cgi?article=2120&context=etd

9

planing to do both. have lake near my home, and in summer time i will got on sea.

10

ohh. i see didnt know that.
thanks. will read that cearfuly

11

btw my aluminum rods will not have contact with water nor carbon tay will be seald inside 3d printed mast in the midlle, carbon will be outer layer

13

I’ll put ESC in mast and was also thinking of grounding mast to battery minus and use only an external + cable. Advantages I see:

  • One less cable and thus one less waterproof cable-cable connector between mast and board.
  • If isolation breaks or water reaches ESC, current has low-ohmic return path through mast (in favor of rider body).

However, I know very little about chemistry and galvanic corrosion. But, I don’t see how/why there should be more corrosion with current going through the mast, than with no current going through the mast. Wouldn’t there need to be an electric potential difference between anode (mast) and catode (mounting screw or other attachment detail) for this to be the case? I would see the problem if there was a salt-water-filled gap in the conduction path between the mast and the board.

I might well be missing something, and would be happy for someone to point it out, before I commit to building a board with this design.

14

…if I’m wrong about corrosion (still unsure), would there not be a point in grounding the mast to batter minus even when using a separate insulated return cable inside the mast? This way, if the plus cable (or anything downstream of it) is damaged, the mast will short the battery, rather than your body.

I also intend to put a fuse (or other over-current-protection) on the plus lead inside the battery compartment. Any specific fuse or other protective circuitry that others here have used?