Electric Outboard for inflatable (hub motor - open design)

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nioko   10 W

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Electric Outboard for inflatable (hub motor - open design)

Post by nioko » Aug 18 2014 1:19am

Hello Everyone

Ever since I was a kid, I wanted to build an electric outboard motor. I even started once, but I think I was too young back then. Anyway, I always liked the Idea of running a chain directly through the water because of the simplicity. When I Saw ES Member Bazaki's belt driven, hub motor based outboard, I was motivated to start again.

I also really like the one from Jeremy Harris, with the chain in a tube, but I gave up on that.

Anyway, I've made a prototype (it looks horrible), nothing is aligned properly, and the lower sprocket is not centered at all, that's why you can hear the chain in the video:
https://www.youtube.com/watch?v=U2oupqztFU0

Now I'm planning to rebuild the whole thing, but I think going belt drive would be better than using the chain.

Any ideas about what belt I should use?
I'm running one of these Propellers:
https://www.hobbyking.com/hobbyking/sto ... eller.html

Cheers, Nico

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Lebowski   1 GW

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Lebowski » Aug 18 2014 1:59am

Hey another fellow Zurcher ! Welcome !

some belt info:
http://www.roymech.co.uk/Useful_Tables/ ... belts.html

I've been thinking about using LibreCad and having HTD-5mm timing belt pulley's cut at www.blexon.ch

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Harold in CR » Aug 18 2014 7:47am

Google up "Gator Tail mud motor" and search their site. There is decent detail of how they build the same thing you are thinking about, only, it's a gasoline engine drive.
Thanks to Justin, the forum is open source and NON-commercialized.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Aug 19 2014 1:29am

Hey Lebowski
Thanks for the belt info, will read through it ASAP.

Harald, I've seen the Gator Tail, but couldn't find any info on how they build it. Mine will be open (belt through the water) and submerged drive, whereas the Gator Tail is a surface drive. But the concept is very similar.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 14 2015 5:34am

I didnt have a much time to work on my projects, but I did make some progress..:
ImageUploadedByTapatalk1434278010.750899.jpg
Hope to get it on the water soon...

Ah, and I've decided to stay with the chain, it's just less complicated for me, and I can easily get the parts locally

Cheers

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 14 2015 5:35am

ImageUploadedByTapatalk1434278125.393467.jpg

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Bazaki   10 kW

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Bazaki » Jun 14 2015 6:26am



I have made something like this too. Works ok. But I was aming for planing speeds. That didn't work

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 14 2015 11:47am

Bazaki - I know, yours is much more professional though, and mine runs the chain through the water (primitive, I know, but simple on the other side.
I won't be using it very often, I just want to use it to zip arround with my intex excursion, when I'm at Isle Ufenau on lake Zurich (with the real boat then)...

But I really like yours, sad that you didn't get the performance you aimed for out of it.

Jeremy Harris did one with a chain inside a tube,.. Thats what I would have loved to do, but I just don't have the tools, time and the workshop to do it.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 23 2015 4:15pm

Tested in the water - but without boat, and without a good battery:

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 27 2015 2:24am

Was on the lake yesterday:


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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Bazaki » Jun 27 2015 1:17pm

Nice. Keep experimenting. It is pretty silent I think

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 29 2015 2:48am

It is - I've changed the upper chainring, and went on the lake again. Lost a propeller, but luckily had a replacement with me. Anyway, it pulled 30 amps, but didn't go much faster (actually only 1 or 2 kph). So i either over-geared it (that's what I I think) or I've already reached the max RPM of the prop while it runs efficient.

Will check the gearing ASAP, if it's the prop - I'll be looking for a smaller one. Video will follow.

happy boating - Nico

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jun 30 2015 2:16am

Here's the video, I need to find a better way to hold the camera...


Prop is: JXF 15x13 / 381 x 330mm

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by amberwolf » Jul 01 2015 1:39am

That's pretty nice...would a toothed belt drive be any quieter than the chain rattle and still work ok in the wet over time?

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 02 2015 5:30am

Amberwolf, I'm pretty sure a toothed belt would work, but it would make it more complicated to play with the gear ratio. The bigger top chainring on the 2nd video is hacked together with various part, and it does not run true at all, that's why it is so loud. Also the chainline is not good on the 2nd video.

So it can be quiet, if everything is right.

Still thinking about the prop.. I'm pretty sure the prop is not usable for the speed I want to achieve. On the other hand, 6kph is OK, but for 6kph, I could have just bought one of these Minn Kota clones, build a decent Li-Ion Battery, and maybe add an ESC.

My ESC went for a swim after I did the test, and it runs reverse now :roll: I hope I can fix this.. already gave it a flush with alcohol.. didn't help.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Bazaki » Jul 02 2015 7:31am

Esc runs reverse ? Just switch two phase wires and it runs the other way around.

Much faster is not possible without overheating and much more power. That type of boat is getting so much drag on the water that it probably will take twice as much input power and only goes 1 or 2 kmh faster.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 03 2015 11:14am

I know I can change the phase wires + Hall, but I want to find out what happened.. (if possible).

I know that this boat will not allow for much speed, but I expect it to go a little faster.. Will try as soon as I can, but hobby time is very limited :(

I would relly like to try another prop, maybe I'll try this:
http://www.aliexpress.com/store/product ... 83404.html

But I would need to make an adapter. I'm running a Square tapered bottom bracket and my current propeller is held by the M8x1 Bolt that usually holds the crank arm.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 06 2015 1:00am

I was in my workshop, and on the lake again.

ESC: Still don't understand what happened, when I set it to reverse (it has a reverse mode), it spinns forward, but with limited power (which is normal for reverse). So I've changed the phase + hall wires, and decided to not care anymore. Works.

Gearing: Tryed another top Chainring, 32T if I'm right. I begin to accept that it's the "hull's" limit:

Code: Select all

22T     9A      6kph
32T    19A     6.5kph
42T     30A     7kph
Will go back to the 22T.

I have also done some other improvements, but it will take a while until all is like I want, will post photos when I'm ready.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 22 2015 2:50am

I was on the lake again, apart from some cosmetic changes, this will be it.
Happy boating :D


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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Groper » Jul 22 2015 7:38am

Your boat hull is extremely inefficient. If you put your same motor on something similar to an Olympic rowing she'll, your speed could be triple, for the same electrical energy...

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 22 2015 9:28am

I know, and knew before.. but I didn't expect it to be that limited. If knew that 6kph is the limit, I would have gone another route. I basically built an Outboard that is way to "big" for what I'm using it :roll: . But since time and funds are limited, I'll use it as it is. If I ever get the chance to test it on a faster hull, I'll change the gearing again, and see how it can perform at ~1kw.
I think for a limited hull, going the modified / overvolted trolling motor route is the way to go.

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by Lebowski » Jul 22 2015 9:44am

Well, there is thunder and lightning now above the Zurisee, so if it's overvolting you want ... :mrgreen:

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 22 2015 9:53am

Really`? I'm at the airport, and no signs of it.. I was hoping for some rain before the weekly unmotorized Uetliberg-Run..

Storm (this is getting off topic):

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by joco » Jul 27 2015 8:14am

Great work

BUT why not simply get a used min kota motor,like 40-100$. Made for this!

Just saying

Me to like to play around,,but sometime,,its to mutch work for nothing


But ey keep up the great work

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Re: Electric Outboard for inflatable (hub motor - open desig

Post by nioko » Jul 27 2015 10:14am

Joco - You are right, as I wrote, I would go that path, if I would start again. However, you won't get a used Minn Kota that cheap in Switzerland.

The reason I did this: I just expected more speed, speed outside of what a Minn Kota can do, but I've had to realize, that it cannot be achieved with this "hull".
My Motor is good for 1KW or more, it does get some water from the chain, and stayed cold, when pulling 30 Amps at more than 40 Volts.. You cannot do this with a Minn Kota. Overall I think the efficiency is better as well.

I also have to say, that this project didn't cost me a lot, the Hub motor (including a controller, that I accidentally burned) cost me 23USD.

I hope that I will some day have the chance to test it on a faster hull, and pulling those 30 amps again, but going much faster.

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