Foil Drive Assist, DIY

Perhaps the people spending $3,000 are the people who just like the combination of a cheap Chinese motor and a few 3D printed parts?

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I just looked at Foildrive AU site and the price listed for Assist Plus + Cedrus (mast) is $6,000 AUD. The Assist Plus is $4,600 AUD so $1,400 AUD for the mast add on.

nice design… will do the same but the drag for take off is not a huge issue and when you are flying (above the pod) you have no more drag which is the most important `!

I will test soon an enclosure to put the vesc right on top of the mast for cooling reason …since I run on 12S my 6384 …im flying above water so fast … indeed will bring even more drag


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I used a similar solution for my regular F-one rocket board. Unfortunately, the resistance was too big.

Do you mean that the drag was so high it prevented the board from taking-off ? ?
It is possible to add a plied alu or plastic sheet 45° ‘visor’ or “deflector” in front of the enclosure inserted between it and the board to facilitate the take-off.

I could hardly take off against the wind and could not take off with the wind. Thanks, I’ll think about the visor.

I have been following this thread and others like it and haven’t been able to find any definitive guidance/data to determine the “best” position for the drive unit below the bottom of board. Perhaps “best” is really an individual rider/board thing.

I would like to shorten my learning curve by asking the collective experience of the group.

Of course there are many variables involved in defining “best” position but it would be helpful to people like me to have a starting point rather than go through all the trial and error / frustration that many have gone through.

To help with definition let’s say that the centre of the prop/jet is bottom and top is where the mastplate attaches to the board. The “best” position is the distance between those two points that lets a new rider with the majority of their weight on top of the board to transition smoothly from idle floating to the point where the foil starts to take effect.

My assumption is if the position is too high it risks either cavitation or just powering forward for too long and too deep would force a too aggressive angle of attack of the foil. “Best” would be a good compromise of those two extremes.

Opinions or pushback welcome :grinning:

Really depends what you’re doing with it. If I’m efoiling, as low as possible. If I’m surfing then as high as possible to only get ground speed while on the water still.

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Thanks

The low as you can get for efoiling makes sense to me as you want to have the prop in the water all the time.

The high as you can position I assume has a limit where the prop would come into contact with the bottom of the board.

Can I assume that there should be some “additional” gap where the prop doesn’t experience some type of cavitation effect caused by the board bottom?

It all comes down to personal preference.

I like the motor low enough that I can get on the foil and use the efficiency of the efoil withought the board in the water, but high enough so that I can get the motor out the water and still foil without it once on a wave…

some update on the design of the box on top of the mast pros :

  • keep the vesc very cool , 31 degres all the way (I live in dubai so 31 degres is cool, without this option my speed control was above 75 degres)
  • make the connexcions very simple, added a bluetooth dongle so ,I can program without opening the box
  • I drown the whole inside in silicone paste to make it 200% waterproof

cons:

  • the enclosure is 1.4 kg with the silicone and vesc + cable is around 2 kgs so some significant kg added
  • obviouls the drag

now I can take off on flat water no problem ( I m 85 kgs on 45 kg board because i m running 12s on EML folding prop)…so some very good torque here

I will add a front deflector (as per SoEFoil) and update on perf…

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@Strongarm any update on this pod and set up?

Starting my build for an Armstrong mast and struggling to find any files for the 85a+ mast. Love the look of the strap set up.

Any update would be great.

Thanks

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Hey Tobi - I’m away this weekend, but will try post the files for my clamp tomorrow. What format would you like?

hello everyone. Can someone have a lot of influence on the speed reached before taking off, the fact of having the engine at a depth of 70cm or 25cm?

and… at what speed do you take off?

I do not go over 8 km/h, I think I lack some speed

I had this in mind but @Sarcomere did it first. The front deflector could be added to a folded aluminium sheet structure to add roll stiffness… the back can be hollow and will let you organise the cables freely. Ideally, the whole thing could be recessed into the board bottom… This open folded box with front deflector could be enlarged x9 to welcome a flat SK8 battery, an ESC, a receiver and become a DiY Vortex with waterproof elements… kind of removable gun case bellow any board fitted with US rails or a 90x165mm screw pattern.
image

'Lightweight efoil build

The ESC could be the new MAKER-X GO-FOC 300A 100V compact size 124x78x38mm
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'🌴 Go-FOC DV6 / PRO <High Current Dual ESC > - #761 by Evwan - Vendor Corner (SERIOUS) - esk8.news: DIY Electric Skateboard Forums

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So literally re-inventing what Pwrfoil has done? He started with a box on top, then put the box on the bottom and then finally moved into the bottom of the board…

Hey guys I’m happy to share a video of my recent maiden ride off my faux drive assist plus.

I’m using a slingshot dwarf craft 3’6 with 19L. It’s a 6384 motor, battery is 8s3p molicel p42a and controller is a flydragon 150A. Prop is Fold by propeller king:

After my 6s setup wouldn’t get me started I’m quite happy that 8s is going that well. Total weight of the setup is 11.3 kg.
I’m riding on an Axis 1150 HA wing, which I am learning to foil pump on.

Here’s some pictures

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Super awesome! Pity the only way to get it flush is to cut into the board. I think I might build a simple dedicated board at some stage.

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I just modified my board to have the box in the middle. I can still paddle square stance fine and the swing weight is much improved. I can now pump the sup board and it feels almost as if it isn’t there which it what I was hoping for.

One disadvantage on my narrow board is that if I feel I am losing sideways balance, I can often recover it but with the battery in its new location I have less time to recover on the sideways roll. I’m sure I will get use to it as the more natural feel and weight distribution feels great.

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