The Hiorth Brothers Build

We did it by hand with knives, Loads of work! will use a CNC router next time! :wink: its about 90mm deep. We have 3 layers of fiberglass on the bottom and walls, the walls will provide additional strength to the board. But I guess 10-20mm (think we have about 20mm) should be left in place, but It also depends on your board type and what type of skin(fiberglass layup) the board has.

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Thankyou for the quick response and help @Hiorth Your efforts are appreciated. Trying to find the right enclosure for the batteries is my next challenge. So many that are the right dimensions, but too deep.
Cheers from Aus

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Building a box with FR4 plates would give you something that you could customise and it would be fireproof. You could then lightly sand the exterior and epoxy it into the board.

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Thanks @Jezza that sounds like a great idea

no problem how deep the box is if the walls are strong, my box is without foam.

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Thanks @virus I guess you have gained a lot of extra strength with the use of carbon too

Hi Jessa, what epoxy would you use to bond to the board

I am based in the UK, so would probably just use this epoxy:!/resin-gel-silicone-adhesive/epoxy-resin/SuperSap-CLV-Clear-Epoxy-Bio-Resin.html

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Ginger Bread Efoils


Impressing drive distance, must be very cold. Nice design, what is the nozzle and prop made of? Can you grind/sand it? You should get some percents in eta by better surfaces.
Can you recommend a modern book about hydro prop design?

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The prop and duct is 3d printed in PLA on a 500$ 3d printer. The picture is from an initial assembly, prop and duct are now Sanded smooth and epoxy coated. The prop design on the picture is not optimized at all, we drew it with very limites knowledge of props and no calculations, will start with a thorough theoretic optimization combined with hands on testing now!

Dont know any good books. We just read around on the internet, much bad information, but some gold nuggets here and there, research papers are mainly a good source. It will be interesting to learn more about prop design. Most of the litterature we find is based on large vessels, but we think It translates pretty well to our use.

Hi, you think to share your V2 files? Ho you fix and waterproof the screws on black alu pipe?

V2 is not ideal for DIY as its milled in aluminum, the seal is done with standard O-ring grooves, similar to the what @pacificmeister uses on his design. V1 is out and is a good starting point and people can do modifications as they like.

Update on remote all basic features work, and no longer any bugs with BT. Works very nicely. Will add a different On/0ff Switch soon, and also change the charger. Battery indicators will also be added and maybe a Oled screen as well.

Wil also do a redesign to make it look cooler.


Thanks for your reply and information. Giacomo

Hi guy’s great work!
I can see you used a water pump, can you share which one is it?? is it connected to the UBEC?

We used a rc boat cooling pump Not ideal as the motor om the pump is overheating. will find a better suited pump. Yes connected to ubec with a relΓ©.

What do you think about this type of pump??

Yes, I think they are good, not an expert in pumps but I think diaphragma pumps are suited for this type of use. They are selfpriming, have good suction, can also handle some larger particles, and can also run dry. I think the main issue with the pump in the link. Is that it will run to hot, because it is not made for continues use. The same pump with a gearbox would be ideal.

Santa testing his new wireless e-foil remote :blush: notice how the board powers up, once the bluetooth chips are connected. If there is a connection brake the throttle goes to zero after 250ms, and the main power is turned off after 2 seconds.