Concept for new eFoil assist built from switzerland - FD2 style

[Vanadon]

Hello everyone, this is my first post. I am 27 years old and live in Switzerland. Since I want to start foiling as a hobby, I would like to build an efoil. I believe this is a great way to learn.

I find the concept of the FoilDrive Gen2 very appealing and I am strongly inspired by this design. However, I have no experience in building efoils, batteries, or other RC-related things. Professionally, I am a mechanical design engineer and therefore have some knowledge in mechanics, but not so much in electronics.

This forum is 99% of my information source, but it is difficult to keep track of everything… many posts, builds, ideas, and opinions.

For this reason, I have developed a first, very rough concept and would like to hear your opinion on it.

The main body, which will take the load, is to be milled from an aluminum block. This will be sealed with aluminum covers and O-rings. The aluminum covers will be glued with end caps from the 3D printer. To make the PLA watertight, I would use Dichtol, an impregnating agent to make 3D prints watertight. I plan to have the aluminum parts manufactured by PCBWay, and I expect the cost to be around $600.

I would use the same components from @hangloose :

• 6384 120KV BDUAV
• Flycolor Flydragon 150A
• Molicel INR21700-P42A 4200mAh (8S3P config)
• Flipsky Remote VX3

The ESC should be cooled well by the aluminum body. Due to space constraints, like @hangloose, I have to desolder and reposition the capacitors. The battery should be inserted like in the FD2 and connected via a 2-pin connector. Regarding the connection of the motor cables, I am still unsure. I would like to run a 3-pole cable through a waterproof cable gland and then connect it to the ESC inside using a 3-pole connector. The covers at the front and back will be attached with 4x M5 screws.

Dimensions approx. 525x115x70mm

Here are some screenshots:

[hangloose]

Very nice project and well thought out.
I would choose 10S3P because 8S3P is a bit borderline. Take a look at the Kontronik Jive Pro.

It works really well for me and is a bit smaller than the Flycolor and, above all, safer.

[sat_be]

Nice project. Be aware that a foil drive or foil assist is not quite an eFoil. The Battery capacity is much smaller, so you have less time on foil/takeoff attempts compared to an eFoil with a bigger battery.
Unfortunately you can‘t use it leagally in Switzerland. Depending on where you‘re based, there are possibilities in neighboring countries. I‘m from CH as well, we can PM if you want to.

[rttn]

8s3p is not enough for the box located under the bottom and for such a battery 525 mm is too much. My prototype has 530 mm with a 11s3p battery and 420 with a 11s2p battery.
Otherwise the project is really good and I wish the author good luck in its development.

[Vanadon]

Yes, it seems that adding more power is necessary, which likely requires a smaller ESC. Unfortunately, they are significantly more expensive. I will take a look at it, thank you!

[Vanadon]

I am aware of that. It’s intended for the beginning - some pumping, some gliding, etc. later, maybe as support for wing foiling or prone foilung somewhere at the ocean. I know it’s illegal in Switzerland, but I would have taken the risk. I will message you. Thanks!

[Vanadon]

I have seen your 3D printed prototype, i like it as well. How do you ensure the cooling of the ESC? And do you have a picture showing how you arranged the electronics next to the battery? I am having some difficulty making everything more compact.

[rttn]

Unfortunately, I don’t have a photo with the cover removed. The dimensions of my electronics compartment are approximately 115x50. The ESC radiator is brought out and cooled with water.