"Safe at home" build - Wisconsin

State shutdowns, work from home, and furloughs all due to Corona virus has opened up opportunity to make good progress on this build.

Board shaping:
Started out with a blank from https://greenlightsurfsupply.com/

Printed a twin I beam rails with SS nutserts that get pressed in to top sides of the rails. TPU plugs keep the high density foam out.

plywood sheet taped on to the bottom to keep foam from expanding too much out the bottom, also holds the I-beam rail in place.

8lb pour foam on top

After sanding down:

Pull TPU plugs, mast plate fits perfect!

Firs layers of glass going on:

Board after routing out battery tray:

Printed out a jig to drill out mast clamp holes after fiberglassing:

Primed for paint

Trying several mast clamp concepts (lots of filament consumed):

Prop development:
Printing props from MaB and others to dial in my prints and pick materials.

Started designing props using B-series prop generator then dropping into solidworks and modifying to make them fit the motor:

Experimenting with 3d pring epoxy coating:

So far, liking the results.
Attempt at a “rice nozzle”

Ran out of filament at 98% complete.

Power system:
Maytec 200
Flipsky high current switch
4 6s 20AH Multistar battereries 2 in series, 2 in parallel for 12s

Test stand evolution:
First attempt was way too shallow.

Second attempt with a larger tank, and a lid. Setup below works better, but still getting a cyclone and aeration that obviously affects the results.


Looks like my test set up.

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That looks great. Do you have issues with sucking air into the prop with your setup? Have you been able to get any thrust measurements? Curios what you are seeing if so…

That was over a year ago. I did not do any thrust measurements. I have used that board 27 flights. It has a 83100 out runner. Tons of torque. I knew it would fly.

that board has foam under it so it seals the tank quite well. I fill the tank to the top, It does cavatate at full speed. But full speed in a tank is a lot more power than I needed.

This is my first test tank I built, It was huge, and it took up to much room. https://efoil.builders/uploads/default/original/2X/1/1277f4cf180f42b36b5aa23d3b2286a1788ed814.jpg

alright, cool… I use a door seal around the tank on the backside, and that seals the tank fairly well. But air comes in from the front side that I have open. Based on your experience, think I’ll try closing and sealing the whole top and filling all the way to the top. Thanks!

Did you end up sticking with the sealed 83110, or switch over to direct cooled?

My first build used a dry pod. Using a APS out-runner with a water cooled core. No body knew what worked and what did not back then. That was overly complex and I eventually stopped using it.
My second build used a dry pod, partly filled with mineral oil. That still works good. I’m keeping that build as is. I never liked the popular direct cooling out runner that so many people used, but I would have done it if my dry pod did not work out. Now there are much better and easier motor options.

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Finalizing board layout:

First leak test. I used a plexiglass lid to try and see if any leaks were present. I planned on venting my lid, but didn’t vent this plexi one. Found out that the cool water pulls a vacuum on the and will try to suck water in past the sea. Main lid was planned to have a vent, so no not a big deal.

Mast mount an seal seam to be working really well. getting a little water in through the main lid.

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Finished product:

Second build starting:
Plan for this and subsequent builds are to try different components to find out what works best. Family and friends have been super interested, so having a fleet should be fun.
Foils: Naish windsurf foil, Naish Jet HA 1400, Axis HA, slinshot Infinity 76
Motor: 63100, FR (if I can get one, lol!), 6384?
ESC: Trampa VESC6, 75/100, Others recommendations?

Starting mockup of second foil setup. Should be able to interchange this whole mast/foil/motor and ESC with original build to test things out as I get them ready:

New ESC setup with VESC6 about half the size and weight of my first box. 3D printed cooling manifold is bonded to bottom of waterproof Al box.

sealing pad printed out of TPU:

Mast and motor asm coming together:


Do you have any dimensions for your board.
I would like to have your measurments when Im cutting up my old surfboard…
The grey one… :grinning:

Very nice project. Why do you need two water tubes in your mast ? A closed circuit ?

Sure, 60" long, 23" wide at the widest part, 3.75" thick. Overall, I like the size, although it’s a little on the small side for beginners to get started on. I’ll make my next boards a little thicker, as I have almost no thickness in the bottom of the battery box. this would also provide a little more buoyancy to make start up a little easier for those who try it out for the first time.

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Thanks! One is an inlet and one is an outlet. Inlet is located in the nose of the mast clamp. Outlet is located at the back of the mast clamp by the motor. I did this for a couple reasons. 1) I’d done a powered paddle board a while back and had trouble getting the water up to the ESC (granted that was much lower speed, but also less distance/height). To address this I made an inlet with angled tube like RC boats use, and an outlet the same shape, but mirrored and facing backward. The thought was that inlet would be on high pressure side and outlet would be on low pressure side. This ended up working, and was the only way I could get the slow speed paddle board to self prime and cool the ESC. The way I made my cooling manifold on this efoil, I was a little worried about air bubbles and not self priming, so Thought I’d try the same thing. seems to work well so far. 2) Slightly simpler reason…I didn’t want to put an extra hole/ leak path in the battery tray :slight_smile: Sealing pad that I’m using for wires and coolant tubes seems to be robust, so no worries adding a second tube.

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Prop fits pretty decent on the 63100


More than decent IMHO :wink: Which prop is this ?

Thanks! I’ve playing around with design, print and try to optimizing props. The one in the pic is the my favorite so far for the 65161 motor on my first build, but with the hub adapted for this 63100. I’ll post files after I’ve done a little more testing.

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Where in wisconsin are you located? I am building from Oconomowoc currently

I’m over on the other side of the state… Osceola area.

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