Jet-Drive build Switzerland

Interesting construction. What was your approximate speed that you reached?

I think an SUP is not designed for higher speeds and does not glide.
I’m curious how efficient the drive on the windsurfing board will be. After all it is designed for planing and early planing. But I have to reach at least 20km/h for it to glide.

Today at noon I found an app from Trelleborg for Android. (Just enter Trelleborg in the Playstore)
In the app the bore diameter is entered and the matching o-ring and groove is calculated. exactly what i was looking for. I will now test the suggestion from the app.

Max. speed was 16kmh - but with 100amp at 10S not really efficient - all in all nearly 4kw.
A similar construction with outrunner and propeller need less than half.

A electic power SUP or windsurfing board is a nice thing - but believe me, once you are efoiling that’s all you want :surfing_man:

Hey very nice. I also want to build an Jet-drive Foil.
But out of aluminium…

Vowo besch us de Schwiz?

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Bi vo Pfäffike ZH. Du bisch vo Bern? (for the Englisch readers: I’m from Pfäffikon ZH and you?)

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Cool, ich aus Stäfa ZH. Habe mehrere Jetsurf Boards gebaut…

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Nice. What Jetdrive and motor are you using in this video?

It is a modified MHZ jet with 64mm. The motor is a Lehner TorQstar 7040.

It was one of the first runs with the new and improved setup in Corse. Was a really long way to get the whole setup stable.

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I more and more want to give the MHZ 64mm Jet a try.

But what Motor and KV for an e-foil? I want to use the Vesc 75/300.

How to atach a trustbaring and the shaft,

Könntest du mir helfen? :grinning:

For jet propulsion a high KV motor and for propellers a low KV motor.

Since I am still in the test and optimization phase myself, I cannot yet make any engine KV recommendations.

For a jet drive a thrust ball bearing is not really necessary. The pressure is created at the nozzle of the jet, at the moment the water leaves the nozzle.

However, to be on the safe side, I have installed a double angular contact ball bearing. This can take axial load well.

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The acutal motor is a 7040/6 so around 280-290 rpm/volt.
I am using LiPo cells in a 14S/1P configuration.
The can handle 300 A continiously (per cells).
15S was bad for the ESC…
If you need more, we can talk it Whatsapp

Some time has passed in which I have continued working on my project. In the meantime I have found the right O-rings and groove combination.

For the final assembly I am still missing two washers and nuts, unfortunately the DIY stores are closed due to corona.

Some parts I have printed again to simplify the maintenance. (easier assembly and disassembly)

I have built a water filter to prevent dirt from getting into the cooling jacket of the engine. In the video I have tested the filter with a syringe, it is tight. (With a 3d-printed sealing ring from TPE)

https://youtu.be/lO9tp9xXYgo

Some pictures:


the water filter has space under the cover:

I know the cables and hoses are very bad because of the drag:

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Nice job,

I’ll watch the progress with a lot of interest, and even more because we’re certainly close together (I’m on Geneva and you ?)

Good job

Today was good weather after a week of rain. Finally I could test my drive on the lake for the first time.

My conclusion is that it is worthwhile for me to invest further (e.g. waterproof electronic box, waterproof remote, mounting on the windsurf board, optimizing the impeller and nozzle)

With the standup board and drive in my hand I reached a speed of 8km/h, current consumption was about 60A with 6S Lipo. Throttle was at about 75%. More I could not give, since I could not hold the drive with one hand otherwise.

I also had the problem that I always created a vortex in the intake area which sucked in air and lost thrust.

My next test will be with my Windusrf board, which probably has better gliding characteristics than the StandUp board.

https://youtu.be/VBorXsHx_F4

https://youtu.be/EdJued0OFfs

https://youtu.be/_MG0zeBqHMc

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Can someone help me make an extrusion? I am using fusion 360 and would like to extrude the sketch (image 1) along the second sketch (red arrow).

What do you want exactly ? I work in rhino and will try to make the extrusion. I just need the profiles…

Try loft feature.

https://www.google.com/search?q=fusion360+loft&oq=fusion360+loft&aqs=chrome..69i57.5537j0j4&sourceid=chrome-mobile&ie=UTF-8#

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Thank you @Fruitygreen. Your Video helped me and i found the right function to do the extrusion.

@Tigerkiki: thanks for your offer. I could draw it myself by now.

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Very welcomed. Not my video but just passing the knowledge.

Built a 3D printed tool to prevent the O-rings to get “bites” from the holes.
Screws are M4, the tips are reduced to 3mm and fit into the holes in the tube. screw them into the holes in the tube before installing the end part with the seals. Add some silicone grease for lubrication.

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