NEW DIY Foil Drive Assist KILLER from Austria

I created two prototypes of DIY Foil Drive Assists.
First prototype:

  • everything sealed, very compact/light
  • battery (12s2p) can not be changed
  • XTs90 “loopback” for anti-spark on/off

Second prototype:

  • replaceable battery
  • battery option A) 12s1p sealed
  • battery option B) 4 pieces 3s2p connected in a waterproof box
    (each battery 3s2p has 99Wh :slight_smile: perfect for traveling/flying)
  • No anti spark solution yet for the MT60 connector. Any ideas?
    (3 pole MT60 is used because BMS charging and uncharging need a separated connection)

Remote for both is a Flipsky VX3.
Antenna integrated in the build.
Connection test have been very sucessful.

Videos coming soon at

Here some pics, Regards Robert
PS: I am also working on a pure efoil with 14s6p. I will create an independent thread for this.

First prototype:

Second prototype:
with battery option A (12s1p sealed)

with battery option B (4 pieces 3s2p connected in a waterproof box, separate for flying…)

not finished yet:

Remote tests:


Looks bomber. What are the specs on the aluminum extrusion?

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Nice work @heiguga! I think you may have some posting limits if this is your first post, but it should get upgraded quickly automatically, especially if you engage a bit more on this thread (or others).
There’s been quite a few people thinking about doing one of these FD Gen2 style DIY builds, but I don’t think many (any?) have shared a finished project. Hopefully you can share more details soon!

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It is just a aluminum “U”-Shape → put all electronics inside and seal it.
I sealed it with epoxy which I got a few years ago from a guy from this forum.
I used it for my electric paraglider (winch).
I think his name was Thomas.
If he reads this, thank you again. You may can tell us what epoxy I am using here :-).

Some great ideas there!

Thanks for sharing ! Some nice idea ! :grin: is it a FLIPSKY VX3 or the new FLIPSKY VX3 PRO (with new RF) ?

I have tested and installed the old FLIPSKY VX3. Had no connection issues at all in the pool.

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The prototype seems a little unfinished to me. I think this detail, coordinated with his aesthetic, will make him perfect.

I hope you won’t be offended, it’s just a joke.


Some final tests have been successfully accomplished yesterday!
Both prototypes work perfect :slight_smile:
Water temperature was about 5°C.
First session on the lake will be this weekend!


Good luck with your testing. Working on a similar build and thanks for inspirational simplicity. I was definitly overthinking many things looking at this build :clap:

Did you consider potting the bms separately since they seem to fail more often than a good battery pack, to be able to replace it? Or is it soft potting epoxy you are using so it can be unwrapped?

What is the width, height and wall thickness of the aluminum tube? The 12s2p variant

The video of you paragliding your opensource DIY ewinch (your youtube channel you posted at the start of this thread) is very Wright Brothers inspiring. Love it. Good stuff!

testes every setup possible.
“travel” battery works great too.
first test ride:

“travel battery”


I am currently using a daly bms with charging only.
Next time I would put it in the very front to be able to change it on demand.
Do you have any recommendations for a reliable bms (12s lion)?

45mm hight, 100mm width
1,5mm alu

It was my first time on a winch ever (after a lot of testing of course).
I think the feeling was close to the Wright Brothers feeling :-).
I still have not yet tested any other winch but have already 100 of starts on mine and could not think of anything better.

STL for the front of the travel battery (bopla box)

STL for a improved gong motor mount (more stable + cable)

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And you have there additional support around the screws? Otherwise 1.5mm maybe too thin…

Many recommend LLT bms for 12s I have not used bms, another common option is having only balancing cables and jst-xh sticking out, for RC charger

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Thank you for validating the design :rocket:. I’ve started the same build now. Gave up the probematic gen1 box and took all the parts out.
I have a 5mm carbon plate 3k quality lying around. Considering as bottom plate instead of the alu, having M3 bolts sticking up to mount a 3d printed lid.