Volker’s Build - 80100 18650-30Q

Only for you @Mat, or cause i had to open the motor anyways:

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Tested on mine, also smaller one such as 8072,63100 does not have this bearing and the motor is still rigid enough.

Maybe i’ll give it a try…
I was thinking about to replace one of the small bearings by a spacer, cause there is almost no radial load on it, only axial…
I think, there is no need to double up the bearing at the Propeller end

Propeller
As i know, the Foil will need less power than other foils, i decided to shave the proven design of @Mat link down to 140mm, while rising the pitch by 10%.
I hope, that i can foil with less rpm and less current.
I have the original Pitch and a +20% pitch on spare, so i can compare.
https://www.tinkercad.com/things/4uWjfWiH4ms


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Let us know how it goes… best way to find the most efficient one is trial and error… once you have it, it will be worth making a mold to get a nice carbon prop! :slight_smile:

ESC & Switch

OK, 56 screws for the hatch(es), but:
The Back one with 30 screws i only have to open for Service or programming ESC.
The Front hatch is to charge the Battery.

At Home, everything is screwed tight.
To switch on, i have 3 reed-relais
First one switches the 12V3A/5V0,5A Buck on.
Second one switches a small 12V Relais with the 50Ohm resistor to load the Caps (Antispark)
Third and last one switches a 200A Relais and Powers the ESC fully on.


So at/on Water i dont have to open the Board at all, i can turn on and off easy by inserting a small magnet in a hole. The Magnet stays in place, cause i glued a small washer inside.
100% waterproof switch kinda IP99 :smile:
Highly recommend is the Progbox for easy setting changes. Works like a charm.
Changing Timing for testing, no problem. Or limiting forward to 25%, that the kids can have some fun, without flying…

Last, but not least:
Amperemeter:
Easy installation, cheap, good readable, programmable, low battery warning and more

Sure, i will…
as soon i dont have fiever :face_with_thermometer: anymore and my bearings arrived… :triumph::angry:

The mold and Carbon may be a good idea, but i am not that talented with fiber and resin.
I am happy, that everything went well with my board :joy:

Thread and posts updated, added pictures, links and files…
If anyone uses my files, i would be glad, If you leave a comment :blush:

First day “open water”
I am a bit scared and nervousIMG_20190814_144541

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Good luck with this beauty!

Omfg, thats so fun :smiling_face_with_three_hearts::heart_eyes::smiling_face_with_three_hearts::heart_eyes::smiling_face_with_three_hearts::heart_eyes::smiling_face_with_three_hearts::heart_eyes::smiling_face_with_three_hearts:

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Foiling with this Propeller
46V 33A min for foiling and 40-45A for nice riding speed
Going full speed, Low ride and ditching watersurface takes 105A 44V

Overall 2kW for nice riding speed is not Bad.
That Foil seems to be really Magic.

If i throttle too fast up at low speed, i loose sync. 22degree timing.
Any Suggestion?

Nice. Did the same thing, riding my 63100-foil with original bearings for two or three weeks. 5/7 would not do it again.

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Riding the original pitch prop uses less Amp to get on foil, but once foiling i need about 10% more amps.
Conclusion so far:

140mm Prop +10% pitch
Round about 70-80A to get up, once foiling i need at least 35A 45V 1600W for foiling
When i go down to 30-33A, soon or later i stall the wing.
40-45A gets alrady quite fast
I guess reducing diameter and increasing pitch was a good idea.
Next time ill test +20% pitch, but i guess, that will be too much.

140mm original pitch:
50-60A getting up, 40A 45V 1800W for foiling

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Resumee:
Charging pack up to 4.2V/cell
Discharging down to 3,3V/cell
Using 40Ah
1h-1,25h foiling fun, Battery doesnt get over 40Degree Celsius

Going below 3,3V/cell doesnt make sense, voltage starts dropping fast, and to maintain 1800W you need for example at 3V/cell already 50A. At min Voltage of 2,5V it would be already 60A
Half full - Full i only need 35-40A, wich i think is a good value.
In theory i could get 8 more min, if i would go down to 2,5V/cell, but why should i?
I hope, my packs will last for a long time this way

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That is very nice , thank you for the numbers , I use 12s8p of 30q and I can not get more then 17A of my pack before voltage sag or over heat if I set the battery amp max above 70A

I think the double bearing is important, it takes the axial load and distributes it to the double bearings.

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Wind issues
Ok, now i know, why we need so much power. Its a matter of angle of attack of forces.

If i go downwind, i can easily foil with 30A, against the wind i need at least 40A.

With just “a little bit” wind in the back, i need much less Power to maintain foiling.

Maybe a Backpack Motor like paraglider have is the solution :thinking:

Then why bother with a motor underwater at all?

Or cheaper, lighter and easier to pack we could see our motors as electrical assistances for foil wings to facilitate take-offs and/or waterstarts which are today the 2 pains of the activity… motors positioned mid mast to avoid folding propellers (1). We know ebikes, we could have ewingfoils for those 8 to 20 knots of wind days…:wink:
@ELEVATE.rocks, a market for you and your autonomous pod (to be presented here in a few days ?). The idea being that it is swiched-off and out of water most of the time.
(1) Water touch downs won’t be an issue without folding prop if a water detector switches the motor on automatically when detecting water
ewingfoil_2