Foil Drive Assist, DIY

this looks great mate, any updates on A+ 85cm Mast pod profiles and if any 3d files available

I’ve stepped away from the faux drive and been focusing on the Boogie, but the mast profile should be in this thread somewhere. I’ll uploaded it to a drive and share in this comment when I’m back at my computer. Strap On Files

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hello, after quite a few sessions with my foil assist (flipsky 7070 waterproof, 10S2P lidl batteries), it worked perfectly. I decided to remove the circlip to be sure that the inside of the motor wasn’t rusty, and to be able to clean it after each session (idem foil drive assist). Since I removed the circlip, as soon as the motor gets a little too close to the surface with a little speed, I hear a noise like cavitation and I lose quite a lot of power. I put the circlip back on, no more problem. It’s as if the space between the rotor was receding a little into the stator, and the hole between the two was creating cavitation. Is it possible? what’s the solution? (it’s really handy to remove the circlip permanently and be able to clean the motor properly, as on the foil drive assist, without having to dismantle everything).

You shouldn’t do that. I lost my complete bell and prop. The magnet force seems strong during disassembly, but the force from the water during landing is strong too.

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how come foil drive works this way ? (without circlip)

I think because of the folding prop, forces to the bell are much smaller compared to a fix propeller.

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Designing an 8s3p… wanting to split into 2 x 4s3p (so I can use my exiting charger - iMax B6) - is it just a matter of making these up and using a Y cable to join them (before feeding into ESC)? or is there too much loss from additional connectors? ie are you better having 3 outputs (2x4s and 1x 8s)?

I also have a folding propeller :frowning:

If you want to charge them in parallel, you have to totally split them and connect two separate balancing cables. Orherwise you short one battery when charging! For discharge connect them with a Y cable. Works fine for me with 2x6S.

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Lots of us are used to have 2 x 6S2P connected by a serie cable, nothing special about power loss with this cable. You just have to think about the correct passage around batteries because it takes a bit of place. By the way, we use xt60 on both batteries finishing by a xt90 antispark

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I can second this. No issues with the folding propeller pulling the rotor off without a circlip.

Every time I touch down with the fixed 3 blade prop I am fearful the rotor is going to be dragged off.

Although after a dozen sessions I am yet to have a problem.

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and no cavitation issue ?

Hi Nicholas,

Can’t really say I’ve noticed much cavitation, certainly couldn’t remember a difference since removing the circlip.
I would suggest the gap would get smaller between the rotor and the base of the stator due to the force of the prop.

The only time cavitation is an issue is when the prop is close to the surface of the water and it is really noisy. But I put this down to the motor being mounted a short distance from the board so it’s quite often breaching.

Goodluck!

Cheers mate

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FYI I looked a the Vapcell store on AliExpress - looks like they bumped the prices up.
Instead i found Huizhou Boot Energy Co., Ltd. on Alibaba - good price $2.5USD per cell (Molicel P42A) plus shipping (to Australia), taxes etc - ordered 50 cost $357.78AUD (/50=$7.14AUD each landed). Great service from Bob Hu.

Just watching this excellent video on how to calc what size and how much nickel strips to use…
How do know how many amps the system will draw? (I’m going for 6384 motor, 80aESC, 8s3p battery and either 3d printed folding prop or propellerking)

That is a better price per battery - $2.5, I got $3.5.
If only the shipping was not that high - $200 …
Please report back about the quality when you receive them - voltages should be very very similar and the qr code should reflect the code written on the battery.

From reading on the forum I got the conclusion that 8s is to low as under certain conditions it will be hard to start, though there are people succeeding. And the 80A esc is too low as start current may reach this value. The on the foil power consumption supposed to be around 1kw.

I came to conclusion that 0.15X8mm pure nickel is enough, just make sure it is pure nickel and maybe put more layers on serial line. For 0.15 also easier to find welder as oppose to 0.2.
I have ordered Fnirsi on AliExpress, this company is hot now, people review their products as high quality, they also do oscilloscopes, multi meters etc.

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As a beginner how hard it is to learn foiling with the help foil-assist on a regular prone board ?

(The common recommendation is to start with a large board, but it is pity to buy it only to learn e-foil)

I intend to do pumping, surfing etc. E-foiling will just assist me.
At the start I intended to do dock-start. For pumping people choose small board.

And how to choose begginer foil? Does it matter the make/model or just choose low aspect and high surface area?

Thanks

You’re right for a low aspect and high surface area to learn on. If your foil assist is 8s or more you should be able to efoil for short times which will help your initially progression.

0.15 x 8mm nickel is not enough for an efoil battery. I would highly recommend copper nickel sandwich.

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Myself and son paid for lessons where a guy towed you up behind a boat - using a large sup with large foil. Def worth doing so you learn what it feels like when up and how to trim the board. Learning via proning would be very very lengthy - I still struggle proning although my son is now an ace. We set up a small dock in the local lake and have been using this - I reckon one could start straight off with that - while it takes a few attempts to get used to taking off -you are starting already up on foil… so just take it slowly, start with simply gliding and once you can run, jump on then glide down to surface without falling off then you can try starting to pump. Another option is buy an old SUP foil - as you are already standing would be way easier than prone. The trick with both prone and SUP is start by keeping the nose down and slowly take turns at coming up on foil then down again. - If you rush you will get kicked off the back.
Oh - and yes larger foils are much easier, particularly to pump with - see the Axis PNG foils 1150 and above for pumping. Note that very high aspect foils (Axis HP and ART) require a high speed so not as easy for pumping for newbies but, apparently, when you get good, they are the ticket for in the surf (I’ve not tried these but my son reckons the large PNGs are too slow for our beach breaks) .
Pumping requires an ollie type movement - jump upwards off back foot (leaning forwards) then down on front foot. Pretty much all your weight on front foot except when doing this kick with the back foot (which is more about changing the angle of attack of the wings while taking weight off the board so it can glide up the water column, then down on front foot to change angle of attack back down to gently glide forward/down)
HTH

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It’s interesting to see how pumping techniques and gear evolve.
At least on short boards, masters who do it effortlessly are against the “Ollie technique” and recommend a more classic “jump flat on two feet” one. Here, the “Kane method” post n°10 on his 2,5’ (75cm) board. See also the McKite vid post n°4.
image
As a good daily cardio and muscle routine, don’t use the lift, use the stairs each time you can … 6 floors (could be 3 times 2) or nothing :wink:

'How to pump back out for a 2 for 1? or