Parts question for DIY Electric Surfboard using RC Motors

[jr42922]

Howdy everyone.

I have been doing some research online to see if it is feasible, or even a good idea to try to build an electric surfboard using RC parts. Goal would be to propel a surfboard with a 170 lbs rider on calm water at 20 mph while keeping the parts list under $2000.


There are ready made options on the market already that range from the slightly above resonable Kymera ~3600:
https://www.kymera.com/shop/

To the scarcely believable prices on the boards from companies like onean (9k+)
http://www.onean.com/product/carver-x/

There is one DIY board supplier I've found, based in germany, MHZ watersports plus. However these motors, escs, and jet drives are also crazy expensive (escs alone are going for +$1000, any some builds recommend two of them)
https://www.mhz-watercraft.com/shop/en/jets/

There really isn't to much I found about a DIY surfboard on youtube, save for really unhelpful stuff like this:
https://www.youtube.com/watch?v=bC7b5FkzmuM.

I've also looked at trolling motors, but found them to be too slow (usually they only are designed to do 5mph) and outboard motors, but they tend to be gas powered and too heavy. Hydrofoil surfboards are also the focus of some development, but it seems too hard to get a motor system spec'd out AND build a foil so I don't want to go down that path.

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So that brings me to my question. Does anyone here have any experience specifying parts for a powerful build like this? What parts should I look into? Any particular vendor or solution I missed?

As for my own abilities, I have experience in sizing components for RC cars and airplanes, but very little experience in the electric rc boat world (save for the occasional rip around the lake with a Traxxas Spartan).

[RaceMechaniX]

I am not sure what kind of power requirement is needed to drive a surfboard at 20mph. It will be significantly different between a pump versus a submerged prop. I am familiar with the MHZ unit and believe you could probably build that style of system a little cheaper although the performance may not be there.

Let's assume you buy the MHZ pump, you could buy a large 150cc or 100C equivalent outrunner from HK and use a water cooled ZTW or YEP 14S capable controller.

The big problem you are going to have is cooling the motor. Only Scorpion and LMT have liquid cooling options for outrunners.

IMO, I would spend the money on the MHZ set-up since it's a matched system.

[TheShaughnessy]

https://www.rcgroups.com/jet-drive-boats-1004/ Check this site out. A couple of guys are messing around with it.

[fins]

I'm currently working on something similar.
I've opted for a pair of 360Kv SSS 56114 paired with a 50mm Gravitix "Jet propulsion unit D50" jet drives. I'm using 160A 3-8S Dynamite marine ESC's, 8S Lipo's (2 x 4S) batteries. I don't inititally recommend this combo; the 8mm bullet connectors on the motor don't match up with the 6.5mm ESC ones (d'oh!)

I have under bought on batteries, I wanted to test the proof of concept first.
From looking at the MHZ, their ESC on their 64mm powertrain is a 400A (500A peak) 16S hand built deal; I think something comparable but less expensicve is the Alien 400A 3-16S , which I think I will siwith to in the future, when I inevitably burn out the first set!

I'm currently building out the motor mounts using lasercut 3 x 6mm acrylic, and am taking a similar approach to design as the MHZ powertrain, except I want to make it modualr and fit into a "reciever" in the board ( so that I can switch out the powertrain to another project).

[grsboats]

Try the site of https://liftfoils.com/
They have a forum where you can find interesting things.
Gill

[fins]

http://efoil.builders/ is another good resource

[gavsbikes]

Hello mate, Have you gone any further with the electric surfboard as Im in the same boat and looking for an affordable reliable set up.

[gavsbikes]

Hello Tyler,
Have you gone any further with you jet board. Im building a petrol powered version and doing the math on an electric. I dont need to go too fast (10kph) but want a couple hours of use. Thinking of using a Graupner or MHZ 49mm drive. (64mm looks a little expensive) Plan on parting a 1.4kw electric chainsaw for the power plant.
Do you have any advice as it seems were all recreating the wheel and buying equipment thats not so compatible