bananaFoil's first build from scratch

EFOIL.builders Builds
#1

Hi Builders

After a friend sent me a video from an e-foil rental in Spain, I was convinced: “I can build this myself!”

With loads of free time due to corona, and it being winter so no other outdoor sports, here are my first plans… I don’t need to end up with a high performance board, as long as it foils and I can surf it ill already be happy…

Drivetrain
Maytech kit with motor(MTI65162-SF), remote, 300A esc, ubec and pump

Batteries
2X Turnigy High Capacity 20000mAh 6S 12C Lipo Pack w/XT90

Board
Shaping one myself out of (probably XPS) foam and glassing it with fiberglass and epoxy. The mockup is below. It has a volume of about 105L, but that will probably be reduced a little after shaping and making cutouts.

Any suggestions about glassing shedule? which mat weights and how many layers?

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So, first thoughts from more experienced people? Any bets whether this can work out?

Greetings from Belgium!

#2

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I will make room for an IP67 box for electronics and batteries during shaping. As well as a hole for the cables.

Mast & Wing
When all you have is a hammer, everything looks like a nail… well… I have a 3D printer so…

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Made of multiple parts to be printed in PETG. NACA0010-35 profile. Room for cables and pump tube.

The holes are for threaded rods to pass trough, and bolt the whole length together and give it some extra stiffness. They will be epoxied in the holes. And the whole mast will be covered in fiberglass as well. No sure whether the stiffness will be enough, but I want to give it a go anyways…

Should I go for carbon fiber or will I be able to get adequate stiffness like this? How stiff does this thing need to be anyways?

The wings I found on thingiverse: https://www.thingiverse.com/thing:2525409
It is based on an Eppler 817 profile - Wing area ~600cm2 / 200cm2

Cause I’m not yet sure about the position of the mast on the board, I plan of making rail boxes to give some freedom in placement and adjustment.

I’m aware I can integrate the motor mount in the mast since I’m making everything from scratch, but I decided against that to have a bit more freedom in placement of the motor and such.

A few more questions I haven’t figured out for myself:

  • The mast, since it is hollow. Is it normally waterproofed such that it does not get filled up with water? or is it the opposite, not filled, and a nice little drain hole at te bottom the evacuate the water when it starts foiling?
  • Length of the mast: How long, pros and cons of a longer or shorter mast
  • Distance between front and back wing?
  • Position of the mast on the board. How critical is it?