UK Efoil build V2

So, I’m thinking about my V2 Efoil already, component’s will get built slowly over the year and assembled next winter. V1 works great so no urgency.

Bits I have bought so far

  • APD 200F3 ESC
  • Gong v2 mast 85cm and top plate

If my 65161 is still OK after this season it will get transferred to the new build.

I’m thinking of doing a passive cooling build again but mounting the ESC in a cast aluminium box under the board.


The APD f3 200a is fantastic. Tested one today and its so simple and runs the motor faster than a vesc.

Good news, thanks for the heads up.

Did you setup the ESC manually or leave it as auto detect?

Left it as auto. Its slightly noisier than my arc200 and vesc, but runs faster and is just way easier.

Hello, for my second project, I am looking for some similar solution - passive cooling and ESC located on the mast.
My question: do you have a drawing of the Gong plate and could you send it to me?
The regulator I have is a Makerx - much larger than yours.
I like your approach and my second question is, would you share your development in a file that can be modified?

Hi, yes sure I can share the mast plate. I’m a bit limited in file format with the design program I use.


Hello, if your software allows export to a STEP file, it would be the optimal option.
If not possible, STL can also work. I can also modify it with Fusion, but much more complicated.

Very nice job, the first bow attempt. Are you thinking of doing foundry work ?

Yes :slightly_smiling_face: I built an electric foundry a while a go which worked pretty well, I tried the lost pla method of casting and some perfect casts. This time I will use proper investment plaster instead of playing sand and plaster of paris.

Looking forward to seeing the project evolve. Could you document your foundry steps ?
How will you prevent water ingress ? An O-ring seal ?

On a side note, I didn’t realise that this APD 200F3 ESC packing so much power was only 34mm wide and 12mm thick … leaving so much free space inside the 90x165 mast plate screw pattern … Will you use this space only for connectors ? A receiver (@ludwig_bre’s ?) could nearly stay there with an external antenna like the Lacroix Vortex…

How will you ensure the thermal contact between the ESC and the cast aluminium box ? Paste, liquid, nothing ?

I will definitely show the foundry steps.

Design evolving slightly, the esc moved to the side to allow easier cable routing and no need to cast the bow shape, the black beak/bow will be 3d printed and glued on, this saves weight and makes casting easier.

Still plenty of space inside the box for reciever but the antenna will need a long extension to front of the board.

The box is only 24mm thick BTW :slight_smile:


Sorry I missed the other questions.

For sealing I was just going to use a PU sealant on the joint, if everything works OK then I’d expect not to go back in but it would be possible.

For thermal contact I would use paste but I would need to machine the casting smooth just under the FETS and perfectly machine the top heat sink stand offs either side so the height is just right when clamped down.

Hatch seals.

I’m a bit stuck with what kind of hatch seal to use, I’ve trawled through many many posts but I can’t get a definitive view on what to use.

  • I feel the most commonly used seal is a D seal
  • what material, epdm or another type of rubber?
  • what size would be best?

An recommendations on what people are using would be great with make and model.


Many use the Toto seal.

Qishare Dichtungsstreifen für Türen Fenster, Mehrloch Design selbstklebende Anti Kollisions Schalldichten Wasserdicht Staubdicht Winddicht Silikon Fensterdichtung Türsiegel 9x6mm, 6M (Weiß) : Baumarkt

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You could use the @michion way, pouring Moldstar 30 silicon between frame and hatch.
'Michion's Build - #18 by michion

This stuff works well.

APD 200F3 esc testing

I’ve been doing some testing with the APD esc in my V1 efoil but I’m having some problems.

When running the APD esc it cuts out after 2 minutes, if I try and restart straight away the motor stutters, if I restart after say 10 seconds it starts again but cuts out in a shorter time of about 20 seconds or so.

I have ruled out over current as my setup only pulls 60amps max at full power but mainly 25amp at cruise.

It’s not over temp as the thermal cut out should reduce motor power to 50% but it just cuts out, plus its not getting hot.

If I swap back to the Castle creations 160HV everything works fine.

Anyone have any ideas pls?

Is that heatsink cooled externally?
It might be overtemping but not driving the heat into the heatsink…

I know a guy thats been running one with watercooling for 3+ months now and it works brilliantly.

Yes, the aluminium block is connected to an external heat sink, the esc is set to reduce throttle to 50% if the temp limit is hit but the motor just cuts out and stutters. I’m pretty sure it no where near the temp limit.

I’m not sure but it feels like a timing or sync issue, it’s set to auto timing but I’m wondering if I should set a manual timing setting, not sure what though.

I just left everything default when I set up my mates one. It just worked… But his is water-cooled and has thin silicone heat transfer pads between esc and heatsink.