Boris Smus

interaction engineering

ESUP Builders

Since May, I’ve been tinkering with brushless electrical motors, trying to make floating objects move more quickly. The proximate result is this electric motorized paddleboard:

Riding my DIY eSUP

This project is by no means finished. Traveling at 5 mph is fun, but not nearly fast enough. As we speak, a motor ten times the power of this one is sitting in a shipping container, en route to my basement. While I wait, let me pause and reflect on the project so far.


This summer I’ve been spending more time on the water. Sailing and stand-up paddling are great escapes from a sometimes monotonous routine. As a result, I’m slowly forgetting luxuries I once took for granted: work trips, visits to Vancouver, vacations to faraway lands.

After my forced sailing hiatus, I needed to find another way to get out on the water. SUPing was great fun, but a bit repetitive, and frustrating in even light headwind. Driven by the need for speed, I found efoil.builders. They are a community of crazy European kids building electric hydrofoils that scream above the surface of the water at breakneck speed.

I’m no stranger to strange electric vehicles, but I certainly was when it came to high voltage and high current. When my Solowheel broke down last year and I was unable to fix it on my own, I donated it to an acquaintance who promptly replaced the battery and brought it into tip-top shape. It took him no time at all, but I had no idea where to begin.

Happily, the last few months have presented many opportunities for electrical work around the house. I installed a ceiling fan in our bedroom and a window AC in my daughter’s. I wired up and installed new outlets in the basement. These are not glamorous achievements, just small victories that slightly reduced my fear of electricity.

Building for …

There is something very satisfying about creating physical objects with your own hands. In these strange times, I find this to be one of my most comforting escapes.

If the resulting object is of value to you or others, so much the better. Building for my daughter takes the cake, especially when she appreciates the results. Building for the community is also gratifying and surprising. Sometimes you just build to learn. This time, I’m building for myself. And in this case, a big part of the challenge will be learning to ride the damn thing. I think I’m up for the challenge!

Realizing that I’m dealing with a completely new domain, and my chance of failure is high, I decided to start small. The first milestone was to create some sort of vessel from a plastic IKEA bin (max 30A, 11V, 5000 RPM, 3cm prop). Having proved the concept, I moved on to something that would support my weight, and substantially larger components (60A, 22V, 1000 RPM, 15cm prop).

Let me conclude with a parts list for both builds.

Tropfast components

As you can see, this is not a seaworthy vessel.

HMS Tropfast, IKEA RC boat shelf

Electronics:

Mechanics:

SUPSMUS v1 components

ESUP assembly ESUP drive closeup

Electronics:

Mechanics:

3D print of propeller

3D printed mast clamp

Shared components

As you can see, both vessels have a lot of component types in common. So much so that I simply reused some of the same parts in both projects:

I plan to write up a technical summary of what I learned in the process. Stay tuned.