”The barge” efoil build

Boats, Jet Skis, Kayaks etc., including hovercrafts
larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 06 2020 3:29pm

I tried to epoxy the rotor magnet gaps to lower drag losses under water, turned ut uneven and it was too late to clean it. f*cking hell! It will be totally unbalanced, it's likely unfixable so i basically scrapped the rotor. :x

I have one more try, i'll do the other rotor with just silicone. if result is poor again i can just scrape it off. doh!

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amberwolf   100 GW

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Re: ”The barge” efoil build

Post by amberwolf » Jul 06 2020 3:45pm

You can sand, file, or dremel most epoxies just fine.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 06 2020 11:23pm

This is a rubber modified epoxy, doesn’t sand so well and i doubt i can make the rotor round again by hand..

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Clanarn   1 mW

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Re: ”The barge” efoil build

Post by Clanarn » Jul 07 2020 8:08am

Maytech has some nice e-foil dedicated motors and propellers. 65162 for example. I think there it some videos of them on youtube also.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 07 2020 9:11am

Yes, but the maytech and other clones are quite expensive and efficiency seems poor from the dyno sheets. I think they might have been tested at too high current/torque though.

80100 is a quite good motor for the price and i had it already :thumb:
Last edited by larsb on Jul 07 2020 1:03pm, edited 4 times in total.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 07 2020 9:15am

I got a new pwm dimmer rated at 24v/30A. I don’t see a use for more power really for the hotwire cutter. Hopefully it works together with my computer charger, we’ll see when i do the next board :D
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 08 2020 12:22pm

Motor mount for the mast is finished. I hope it fits, had to draw it from an outline sketch of the mast and i was aiming for a tight fit so it’s not 100% sure.
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I have glassed first layer on the top, now i’m cutting cloth and vacuum bagging material for the bottom. Quite happy with the progress so far. :D
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 09 2020 4:36am

Prepping for glassing by sanding the sides and top layer. I haven’t done this size of glass fibre build before, it’s a fair bit of work. Just making a two meter vacuum bag took about an hour :wink:
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V-cut in the rear is to evacuate water from around the electronics box lid.
Last edited by larsb on Jul 10 2020 3:51pm, edited 2 times in total.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 09 2020 11:32am

Bagged and ready, i had a couple of holes in the bag that evaded my sealing attempts for too long. I’ll not be suprised if i need to do some touch-ups tomorrow when i see the result.
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 10 2020 10:55am

Made a spacer plate for the mast mount to be able to route the wires into the mast without cutting a large recess in the board. There’ll be a cut in the rear (left) side of the plate that’s not done yet in the picture.
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Last edited by larsb on Jul 10 2020 4:21pm, edited 3 times in total.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 10 2020 1:14pm

Some dremel grinding later, recessed also the mast mount to make it easier on the wires.
They are 6-7AWG/10mm2 cross section so it’s a tight fit both into and through the mast.
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 11 2020 2:54am

Final glassing, electronics bay done.
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the cloth in the bottom didn’t want to lay completely flat so i added some weight on top of it.
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It’s time to get the motor and electronics connected :D
Last edited by larsb on Jul 11 2020 5:24pm, edited 1 time in total.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 11 2020 5:43am

This section of ES is dead these days. I can understand why everyone went to efoil.builders but i really don’t like the ad driven forum over there. ES is way better in this regard :thumb:

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 12 2020 2:54pm

Mast mount nuts and cable outlet glued,
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mast mount and spacer plate finished.
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Tomorrow it’s electric time.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 13 2020 2:27am

Added some coats of electrical varnish to the stator for waterproofing
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I’ll switch to stainless bearings also but later, need to order them.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 13 2020 7:34am

Motor mount fits perfectly on the mast :D
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Instantly i wish i’d done a larger cutout for the phase wires in the motor mount but it’ll fit anyway.
Last edited by larsb on Jul 13 2020 4:41pm, edited 1 time in total.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 13 2020 4:39pm

Drive unit put together:
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I cut the hole for the wires in the mast with my dremel, that’s a 400 euro cut :wink:
Started to thread the wires inside the mast but realised i need to open up a bit more in the top to get the last wire through.
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 14 2020 5:04pm

Final push to get the barge ready for water!
Wired motor, and most of the rest. Only throttle and phase connectors on motor side left
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 19 2020 2:17pm

Finishing the two printed props with some layers of epoxy glue. I’ll also receive a professionally printed nylon prop tomorrow, should be enough for some first trials.
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I’ll buy a prop once i know what i need as balancing and surfaces will never be 100% on the printed props.

Unfortunately i'll now have to wait for two days for the throttle cable, it's being shipped. I have a VESC ESC with receiver and handheld remote but i don't feel like learning to set it up yet :wink:

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 20 2020 6:01am

Sanding the ridges and defects after the vacuum bagging took an hour, it needs a finishing coat to look OK but i don’t have any tools or epoxy where i am now - it will have to do :wink:
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larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 22 2020 3:34am

I compared inductance of the motor and extension wires to previous proven settings for the controller. It's way higher than expected. I wonder if my measurement was correct and i didn't bring the meter here. Hopefully i can do the first trials today, we'll see then.

neutro   100 mW

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Re: ”The barge” efoil build

Post by neutro » Jul 22 2020 6:04am

Great build, I'm interested to see how it performs.

Thanks for documenting it.

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 23 2020 3:57am

everything is assembled and ready :D First trials today!

I cannot take any pics since i crashed my phone and my family is out picking cloudberries. Let's hope i don't need any emergency rescue :D

Biggest win of the day is that i still fit in my 15 year old wetsuit (even though i remembered it to be a bit roomier :wink: )

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 23 2020 6:13am

first runs done, total success! :D :D :D
The board barely floats with me but it was no problem to stay on it or get on my knees. Enclosure stayed completely dry. There was a bit of power lacking from the drive to reach flying, i need to set the controller parameters better.
I'll do some readouts, charge the batteries and try again :flame:

larsb   1 MW

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Re: ”The barge” efoil build

Post by larsb » Jul 23 2020 2:22pm

I set some new parameters on the controller, it runs so much better now that i am really looking forward to tomorrows trials :D

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