Will this work?

Hi, I would like to try and build a cheap efoil. I’m into ESK8 as well and have some spare parts so was hoping to only need to buy the motor. can anyone on here let me know if the below will be suitable

65111 motor, VESC4.12 50a, 10s 15ah li-ion pack.

Haven’t seen a working 65111 motor build here yet. There are succesful 63100 outrunner builds, that’s a lower priced motor but you’ll need a bearing swap and to epoxy the rotor and stator. It’s not hard or expensive to do.

A 50A vesc is too weak, you’ll need 150-300A at startup depending on your weight, board and wing.

Not all 15Ah batteries can supply enough current, make sure your pack can output at least 100A for longer durations, that’s easier (and could even be cheaper) with a larger pack.

Without too much effort it’s totally possible to build a 1000$ efoil that’s nice enough to have fun with.

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Hi Larsb, thanks!

Am i missing something though, the motor specs say 30amp continuous 70amp peak, how come i need a 150-300amp VESC? my mountainboard has a pair of max 85amp motors and only uses twin 100amp controllers?

The motor has to provide a lot of torque to get up, especially if water is rough and it’s windy. High torque means high current and a lot of heat to get rid off.

  1. Peak torque of a 63100 is 7.5Nm (at least according to alien power) and t=9.55/kVi
    Solve for i=t
    kV/9.55 → Needed current:7.5*120/9.55=94A for kV 120 so a 100A controller should suffice in theory. In reality at peak torque the motor has begun to saturate so the current will need to be higher than the theoretical current to compensate for this.

  2. The other thing you compensate for is manufacturer overspecing. A hobby rc esc is rarely capable of the spec so to get parts that you will be able to use at 100A then it needs to have a ”hobby rating” a bit higher. If you’re into eskating then you know this already but for efoil it’s a make it or break it limit - either you get up or you don’t.

  3. Heating in the esc is normally less the higher the current rating is and heat can be a problem since the heat transfer from ESC to the outside always is an issue due to the waterproof boxes.

I’ve run 100kV and a 300A controller since i started and never had any issue getting up even at 130kg total weight. The high power controller gives you margin to wind/waves/less than optimal propeller/heavy users/small board/small wing

The motor size needs to be able to take the current and actually produce torque with it, it makes no sense to overdrive a motor just to create heat - if you don’t find any succesful efoil builds with the 65111 then i’d choose another motor.

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Ok thanks!! I’ll give a 75100 flipsky a go with it then.

haven’t folks here had issues with those?

I’d go with either Ztw Seal 300A or makerx hi200: Go-FOC HI200/HI100 4-16s 75V 300A electric Surfboard Electric Motorcycle Electric kart bicycle ESC VESC - MakerX

Or the firduo 75200 https://firduo.com/collections/efoil-products/products/hgltech-hi200-75v-high-current-200a-esc-base-on-vesc-with-water-cooling-enclosure-for-e-foil

I have both the seal and firduo here but haven’t used them yet so i cannot solidly vouch for them.

Did you mean a 75200 flipsky? Maker x hi200 is another option that works well.

I have a Maker x hi100 working well on a tow boogie. I use up to 100A at the motor (60-80A at battery 13s) for plenty of grunt to waterstart on a 5’ prone board with a 65161. It is cooled with a fan inside the enclosure, and heats up quickly if you constantly hold full power, eventually thermal throttling.

If you get the propellor and motor combo wrong, or use an inefficient foil wing, you will waste a lot of power and will need far more than 100A. Or if you weigh a lot more than 75kg, or want to go really fast.

Hi200 or a new (fixed) 75200 will have plenty or headroom.

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Cheapest 75200 option of the chinese knock offs would be makerX Hi 200 75V version. The orinals work as well, 75300: VESC 75V 300A Black Anodised Non Conductive CNC housing