SUP e-assist with 66112 Motor - Newbie need help!


I’m newbie here and probably on a wrong forum too. But I DIY a lot, coming from RC airplane world and have all the necessary machines at home to make the project (Metalworking CNC, Carbon fiber cutting CNC, 3D printers, lathe, electronics lab…) but I would need a help to cut down on time required. I’ve checked tons of threads and I see you guys have lots of experiance with setups.

I have a lot of 18650 cells leftovers from other projects that I want to use to electrify my Voyager 12’0 Sup, that has plenty of space for battery box etc.

I have option to buy this set locally from a friend (leftovers):

What I would like to do is electrify sup and achieve best efficiancy (speed vs consumption). Since I don’t want to redo my battery setup multiple times (I will probably make watertight box and seal it down, and also I’m not able to spend tons of time for R&D on this thing, I would be super super happy if somebody would point me in right direction about:

  • Is propeller provided in kit any good? I saw you guys using same foldable props we use for airplanes. Which one would work best for low speed (10km/h?) and best efficiency with SUP?
  • What battery configuration (anything from 6s to 12s would work for me) would you suggest for maximal efficiency at low power setting (I will probably need 300,400W to go 10km/h?). Should I go low voltage and limit throttle less or high voltage and limit throttle more?
  • Do I need to make any negative motor pitch to reduce propeller lift?

Thanks a tons guys! I really appreciate your help! :pleading_face:

Best regards,

Don’t buy that motor, it’s got too high phase resistance to give good efficiency.

Thanks for that input. I’ve seen some measurements about internal resistance. What would be a good motor choice? It’s quite difficult to find waterproofed motors online…

A lit of people here motor proof outrunners. Not over complicated to do. 6384 or 63100 would be good.

Depending on range an efficiency a low kv motor would be the way to go.

100kv motor running on 6s with 7 inch pitch propeller should get you pretty close to your 10kmph but I think there would be too much load for the 63xx motors. If you could find a 50kv motor and run it on 12s would be better imo.

I will look into the waterproofing outrunners, but I’m not sure if I understand this correctly. If buying some other motor than set which I have on offer, shouldn’t I be looking at 200 or 300gr motor, not 1kg beast capable of 3kW, where I’ll be using probably up to 800W or something? Does there exists some kind of calculator for this? We used e-calc for airplanes, but probably won’t work for this type of vehicles.

What about this for example?

The chinese specs are often a set of unrelated numbers which makes it impossible to use them for motor selection.

One thing that is true though is that electric motors are most efficient when run at a low load and propeller drive is most efficient when run at large diameter/low rpm (high load)

This means that you need an overcapable motor to get high efficiency for motor and propeller at the same time, probably in the 60mm dia range to get the required torque at high efficiency. For a loadcase like 10km/h SUP i’d guess a 6374 would be a good option.

Another thing to look at is the battery internal resistance, too small battery (or even a larger battery with high internal resistance cells) can create as large losses as the motor/controller and this is a fact which most people forget.

Hi Jure,
I also have a Voyager 12.6 as a companion boat for my wife when i travel with the efoil.
Fortunately, the board has two finboxes and thus two motors make sense - with a light person up to 20kmh.



What propultion setup do you use? (Motor, prop, esc?)

So far I have tried

Best motor recommendation from me is still the 6516x motor type (for efoil)

Esc: i’ve tried some VESC types but i have the most hours on a prototype ESC a friend built.

Prop: tried FR prop, eml prop 2-blade and 3-blade, Manta prop, flite prop, quite a few 3d-printed ones. I don’t have logged numbers so i can’t really compare objectively but I like the flite prop the most, dull edges, quiet and powerful.



First - welcome to the forum😀

I don’t have enough experience to offer an informed opinion on various motor types etc but I will offer my perspective on your project

It would appear that you enjoy the DIY process so perhaps it would be a reasonable decision to purchase components that offer a broad range of capability. Start with your SUP project but if you decide later that you might want to efoil etc you have the components in hand to do that. I would add my vote to @Larsb comment on the 65161 motor as it is commonly used and well documented here on this forum

I would recommend you take a look at Flipsky’s group 7 water sports kit

and possibly something like this product as it would preserve the original spec of the SUP you have.

Motor => APS 6384N POWERGLIDER OUTRUNNER modified with thrust bearing and shaft seal
Prop => Self made folding prop with 3d printed blades and milled hub
ESC => 2 x VESC 6

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Nice design. How much difference is the draft of the board with the two motor pods in VS the original fins?

It would be cool to have two remotes and be able to steer with the twin motors😀

:+1: draft depends on what fins you are using - compared to the original fins, the draft is slightly larger.

I wanted to make a arduino based remote control which can control both esc - but I don’t have the time.

If you shift the weight far enough, cornering is also possible.


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Waiting some time for my thoughts to clear and searching around this forum a lot - I’m just getting more distracted on what I actually want now :smiley: (I love the creative DIY people&projects btw!!!)

Going for full e-foil drive (I have in total 254 unused li-ions in my drawer (Samsung 30Q and something similar) doesn’t add THAT much cost when selecting motor & esc. I already have tons of batteries, remote, receiver, 4x 12s chargers from RC career…

Should I buy a foil and install it on my sup? Has anybody lifted with the full size sup before?

Voyager 12’0 is to long to fly :surfing_man:
And how you want to mount the foil :question: FoilMount will not really work :no_entry_sign:

What i’ve thought to do was to cover the sup up with stretch foil, then laminate a portion of bottom hull (for example 80x60cm piece) with mast attach point and then do a 2 or 3 ratchet straps, that would on top side at same time hold a similar built battery/esc box. So basically easily removable. About the size of the sup I have no idea what that means to overall experiance. It’s kinda fast and really strong SUP so don’t expect trouble about that - maybe that my mast has to be kinda more forward, to compensate a nose heavy and long board :slight_smile: I’d leave fins and finboxes as they are. No idea on what to expect. when in air, it guess it shouldn’t be much of a difference and in landing and takeoff, there is not much angle of attack you have available to go vertical or nose plant it.