Efoil "East Frisian Style" (Early lifting & slow speed -> optimized for waves)

yes, the Graupner Speed 200 ECO runs on 11-19V, nominal is 14.8V. So I decided to try with 5S. I have no experience with these motors, but I hope that if the cooling (by oil) is fine, then it will be ok with 5S.

Looking good. Did you CAD design the foil yourself ?

Hey Chris, did you test things running with 14.8v yet? I’m curious the current draw and results with that motor and ESC?

Mast connection was adapted in order to fit the Slingshot mast:


Also a package from Hobbyking arrived: The controller fits easily into the tube. The tube length can probably be shorter as expected:

Heat transfer to the wall needs to be implemented

Looks nice, hope it works out well for you.
Are you water cooling that with rubber tubing or using the large aluminum tube as a heat sink?
That ESC seems really small at only 120A and using 12AWG wiring. It’s going to run hot, be sure to put a breaker between ESC and Batteries to try and protect batteries if things overheat and meltdown.

Hello! Any news on your project?
Can you share your wing model?

Loved your post! Are you still using this forum? I’ve done a foil design addin for Fusion 360 and I’m looking for an engineer like yourself to check if it looks OK…

Hi Chris @cnd,
the screenshot of the plugin you shared looks very promising :slight_smile:

I studied mechanical engineering with a focus on aircraft systems and work as an power plant engineer in the overhaul business.
That beeing said, I’m not an expert on aerodynamics and propeller design but have a decent understanding on what’s going on in general.

I’d be interested to try it out and provide some feedback. Is the plugin available yet?
Cheers, Nik