80100 direct cooling

Do you plan any water inlets and outlets? Do you plan to print a kind of cap for the motor hub to have less pumping effekt from the arms to reduce friction?

Do you plan any water inlets and outlets? Do you plan to print a kind of cap for the motor hub to have less pumping effekt from the arms to reduce friction?
==> Yellow Picture was original idea to cool down the outrunner. Create external cavity around the “encapsulated” strcture to have internal inlets all around my Alien Motor. By doing so is increase surface and this surface with water going inside was supposed to be colder than without this approach.

As I said ; you can image plenty stuff in 3D printing but making things happen with metal such aluminium becomes an other story. I m sure this is a good idea but not easy to reach with my skills and tools.

For you second point ; not sure I got it…sorry :wink:


Hi Mat,

I have several questions to make my own motor water protected. I hope my English won’t be too bad.

About the Resin ; Can I substitute it by something similar ? Quite boring to find it in France.
Equivalent might be epoxy for Aquarium or for Art Design.

In the video ; you are using a kind of Green Tape to protect some part of the motor. I remembered something during my study but couldn’t find it anymore

New Shaft ; Why replacing the shaft by this titanium ? Does the original one won’t be ok ? Rust issue ?
Can I keep orignal one at least for first run or it is really mandatory to be replaced ?
Also why cutting the shaft so short / Shaft may help to avoid rotational issue with the prop ? By removing it your prop must be perfectly “centered” which can be quite difficult.

Connector : Electrical connector to easily Plug / Unplug it Water proof. I would like to avoid to “insert” connection inside the foil mast and putting some Glue or stuff to make it waterproof.
Any idea ?

Bearings : Have you replace original bearings ? Is it mandatory because it is damaged during disassembling ? More robust bearing for salty water ? Did you add some “greased” ?


I think any epoxy should work, as long at it’s sticky enough… may be try to find a surfboard epoxy as it will cure faster than the one you linked.

The green tape is a regular painters tape, it’s usually blue or creme color. It’s used to do masking when you paint something… it’s just to keep the resin from going on places where you don’t want it .

I replaced the shaft because the original one was way to long, and difficult to cut, I found cheap titanium ones of the right length, and I was 100% sure that titanium will not rust.
You can definitely keep the original one, if it’s stainless steel it should be fine for a while…
For the length I used exactly the piece i got. But you’re right that a little bit longer can help to center the prop. I just wanted to make sure it didn’t extend past the back of the motor to avoid touching the wire and to keep the overall length short.

For the connectors, I’m not sure you can find some waterproof ones that can handle the power, but you can use regular bullet connectors and protect them with good electrical tape, it’s easy to remove when you need to disconnect it.
I have no connection inside my mast, just the wires going through.

For the bearing, I didn’t damage the old ones, but I replaced them with some 316 stainless completely open (no seals) to be sure they will resist enough against the rust and that they can be easily cleaned after going in salty water. I was afraid salt water would stay stuck inside
Also, I protect them with “corrosion X” spray.

I hope this help!

@Mat How can I log data on my Flier 400. Went out for a long session today and literally have no details besides GPS. How do you log?

Nevermind @Mat. I found your post here:

Are you saying with the 150 amp limit it could blow? You know any good alternatives with that Flier ESC? Or do I need to switch to another ESC?

Thks, cristal clear you clarified all my doubt or pendings

IMHO, Ketos is a quality kitefoil maker but makes the worst candidates to become a efoil.
1- Not sure whether Ketos manufacture hollow masts. You should enquire first.
2- If they do, their KFbox head is so compact/optimised/perfect that if you remove the necessary material to let the 3+1 cables in, you will fragilise it in addition to the higher strain for a efoil board… double penalty.

If I had a Ketos foil, I would try to find a brand new or second hand alu mast, for ex Gong 65cm cost 59€ on their site + 30€ plate.
First you have to check that your Ketos fuselage screw spacing is compatible with the screw spacing of this mast,
If you think about enlarging your Ketos fuselage screw spacing, not sure it will resist as Ketos use a EPS foam core wrapped with carbon.
So the only solution left would be buying a alu foil.

I don’t know if it will blow up, i hope not, but the lead wires a significantly smaller than the 8AWG i’m using everywhere else. and looking at the deformations on the 3d printed support I have it mounted on, it’s heating up a bit during the sessions. But so far so good.
I tried other monitoring solutions (HTRC 200A not readable and no memory, and a 350A TK15 that blew up … probably because of the the few drop of water that i put on when opening the hatch while in the water :slight_smile: ) , but no other recording…

+1, alu mast won’t be very expensive compare to the rest of the build (and the motor attachment made for liquid force was already modified for Slingshot), so keep your good foil for kite :slight_smile:

Arf fuc…

I was thinking naively not to mak a hole but to cut with dremel on one side of the mast to insert Cable + water tube then stratify with resin and carbon. At kfbox level I was targeting to pullout Cable & so just before the kfbox as in fact it is not really useful to go straight except for esthetic and some friction

That, is my first plan, I have différents front foils winds, so going on gong or something else is annoying

Second, plan looking and reading other dyi project was to add at least for proto an extra shield at mast as picture, it simplifies a lot don’t U think so! Saving my mast…

that’s what i did on my first prototype too:

just make sure you cover all the way like the example you found, if you go only halfway like me it makes the board a bit unstable…

I am 120% with you. Building a efoil will cost you a minimum of 1000-1300€ (2/3 for the battery). If you can make a foil versatile enough without damaging its integrity, it is a huge saving and satisfaction.Then there is the aesthetic aspect that comes into consideration.
What is nice is that you already have a set of front wings. Which front wing sizes do you have ? Easy or 1200 ? Free Ride ? Wave ?
Looking at the picture, you obviously know @Gobbla 's work (from Lyon) who has done an awsome work.

Hy Guys,

I’m waiting my products but I still need to supply a couple of stuff.

  1. Electronics for monitoring. I have seen somewhere , maybe Mat’s post or maybe somewhere else some particular component : To check Battery, To Buzz when Hot , To records (For sure by Mat)… But checking all files and docs from Mat’s I couldn’t find what you have used for your build. Could you share again with some basic explanation.
    I google on AliExpress, some Lipo balance sensor, lipo alarms buzzer But I couldn’t find my happyness.

  2. Second point is about connection for 8AWG cable. I’m looking for a way to easyli connect cables together. Best appraoch to be able to disconnect it easily as well and waterproof of course.

Some people are using ““Domino”” connector under "Plastic, some use directly Soldering + thermal plastic., Other use Clamp tool kit with a kind of Gear in between to do the clamp. Have you any feedback on this.

If you have any feedback or advice I’m all listening !

The 3d mounting files and prop. In what kind of material should we print it ? Pla? I have done this before.

PLA might not last very long exposed to the sun…
for all my parts I made them in ASA, it’s supposed to be better to use outdoor.
I did one prop in PLA but covered in carbon fiber and it was ok, the second prop I printed was ASA used as is.

True, August 2018 my PLA motor pod exploded in my car under the sun

I know Its here somewhere but I can remember where.
Do you have this data.
Watts used at full speed out of water with no prop.
Watts used at full speed in water with no prop.
I trying to under stand how much power is used to cool the motor this way.

I’m not sure where it was… I’ll have to check.
In air, I should be able to do the tests in a couple days, I’m in the middle of servicing the motor pod, a bit of rust to deal with :slight_smile:

Has anyone tried 3D printing prop with a carbon fibre filament?

It might solve the blade throwing problem. Other than the filament you just need to change the printer nozzle from brass to a hardened metal one.

Depending on the way the prop is printed, i.e. with a high perimeter shell count, the fibre strands should be in the right direction to provide excellent tensile strength?