Flying Fish Jet Drive Build

@MauiMan
Your build looks very good!

just wondering how did you approach regarding impeller size, pitch, and profile to work optimally with your motor. did you do any calculations or simulations?

interested in trying a direct impeller drive with a slightly larger motor sacrificing on efficiency but gaining on safety and glide in waves.

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Can you post the file for the connector you made I’m stuck on that haha this looks perfect

Hi @Hiorth

I did not use any formal calculations, however, I looked at what propellers which have been proven in a jet use case. The closest usage scenario I found was MHZ’s 58mm impeller and their motor setup. I figure once I get my 3D printed propeller working, I would just like to purchase the MHZ cnc impeller. So I based on my cad work on MHZ’s impeller diameter and motor. Also, I took into account my battery which is a 13S. The other critical factor was the esthetic design and the sleekness of the fuselage being the motor housing. I am eliminating the hydrofoil fuselage and just attaching the foil wings to the motor housing. With this in mind, the 64mm impeller from MHZ would have made it too wide and less hydrodynamic. This made it cheaper too because I just need to purchase the wings I like use whatever mast I can find. It was more of an intuitive approach based on form rather than all math.

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@Dandydan

Here you go.

The files are male and female stl.

https://drive.google.com/open?id=1bFbUQKMLiXjbXKDb1ykuoQn3PTL_pSFo

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Thank you this is perfect

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You’re welcome! Hope it works out, if not you have the fusion file to modify it.

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I finally finished my lithium ion battery pack. I should be able to get 1 hour of riding time with this 35AH but only a water test will confirm. I intentionally wanted a transparent cap so I can tell if there is a leak. Nothing worse than a water logged BMS.

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Great work! can you share the supplier for the BMS? Does it have art, usb or any communication bus?

@MauiMan Very nice pack, what is the model of your BMS?

What cells are those?

Thanks!

I am using a cheap 120amp BMS so I can switch between my propeller drive and my jet drive. This BMS is very basic without any interfaces from DalyElectric. My cells are the 21700 (5000mah) which is pretty common and affordable. I like this bms because it is sealed in case the battery pack gets wet, then I have time to diffuse. My hatch needs to be rebuilt to be more water tight.

Please see the photo.

I would like bluetooth capability in my next BMS but it is difficult to find a high Amp BMS with the bells and whistles.

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I did a battery pack test yesterday and came up short. My lithium ion pack only lasted 30min and I came in as soon as my maytech battery indicator was flashing. I found a little water leak in the battery pack so it may have reduced the battery capacity. I took a blow dryer to it and repacked. Going to test again today.

Here is a video, and apologies ahead of time for the long video.

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The pack looks like 13s7p, i am not sure, but 40AH sounds Impossible for me. That would be 5700mAh per cell!?
I am heading for 14p Samsung 30q, that should be 42AH.

7*3000mah= 21AH 30min Ride --> Average 42A current. Sounds legit
Or do you have 2 of those Packs parallel?

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That calculation looks good. I wonder if the cells are water damaged. I had a leak in the previous battery pack. My ride time has been 30min so far. Which confirms your calculation. I am going to confirm what the cell rating is.

What is the size of that case or do you have a link for it?

Here you go. I had to dremmel the extra materials on the bottom and the corners to fit my battery.

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@V_S I

am going to build a 14P for my next battery.

Hi mauiman. That’s my battery pack with 12s and 10p in a industrial waterproof box. It’s work well

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Wow, nice work. It looks very neat and tidy. Which battery meter did you use?

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Thank you!
https://www.aliexpress.com/snapshot/0.html?spm=a2g0s.9042647.6.2.58db36fa1wIRy7&orderId=97254615119866&productId=32820971654

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