ebike hub motor for marine propulsion

Geoff V

100 mW
Joined
Jul 30, 2012
Messages
39
Gentlemen

Last year I constructed an electric outboard leg based on a Turnigy 80100 motor with a 3:1 reduction belt drive which I operate at around 300w, with the option of 750W when necessary. Having recently constructed two PV panels which output 170w in good sunlight and in excess of 100w under light cloud, I fancy building a smaller boat, probably based on a Canadian canoe, such that the panels will provide most if not all the required power for cruising. After extensive reading of the work done by Human Powered Boat enthusiasts I believe the power to be quite practicable if losses are kept to a minimum.

Looking around for an appropriate motor and transmission I feel there is merit in driving a suitable propeller by a spring steel shaft directly from a 250w ebike hub motor which would remove the need for a geared or belt reduction.

The only problem to be solved is the typical hub motor runs at around 200rpm and for my proposed installation I would like to run at nearer 5-600rpm.

My question, how does one persuade a hub motor to run at higher speeds?

GeoffV
 
Use a boosting voltage converter between the power supply and ESC. But why on earth use a hub motor? It will be mechanically very difficult to attach to a shaft. For your power level you can use the smallest low Kv outrunner you can find and the smallest toothed belt reduction. I built a rig at work using a belt just 6mm wide, the sort of thing you find in a printer, to power a research device. It transmitted upwards of 200w for hours at a time while being used for phD level research and several graduates completed their research with the one device. Once, the soldered connections to the brushed motor melted because the device was run so hard. I never had to change the belt.
 
Gentlemen

Thank you both for your suggestions.

Alan

The appeal of the hub motor, for me, is low noise, splash resistant, no reduction drive losses and easy installation, I have a good machine shop to hand. I plan to mount the motor fairly low on a cross beam to minimise the curve of the unsupported prop shaft and it will get splashed. Not keen on a voltage converter due to the inevitable losses, but thank you for your help.

Lebowski

Geared hub motor run direct drive, brilliant!

If I can't find a suitable donor hub motor and have to rewind can you suggest any links to calculate the windings necessary and guidance for rewinding, it would be my first rewind!

GeoffV
 
Im thinking of making a ecraft of some type , one idea is use a 16 or 20 inch front hub motor with paddles for propulsion.
I have some 100w semi flex pv panels that make me want to make a Solar powered epaddle wheeler. Made with poly pipe pontoons for low drag.

Solar is perfect for eboating

I like this leg idea , If I can find a good price on one I may well go this route

This one is rated up to 7 hp gas motor , others go up to 11 and 15hp

s-l1600.jpg


LongTail length : 1,7 METERS / 5.5 ft

Professional longtail for use in shallow water. Speed and strength.

This longtail is indicated for engines until 7.0 hp. It´s compatible with most engines

Although the attachment was design to fit most engine, we cannot guarantee that the longtail is compatible with all engine brands. Know to fit briggs, honda and toyama

Title on eBay - Foldable Longtail 1,7 m for 7.0hp, Boat, Swamp Motor Outboard (Engine not incl.)
 
eCue I like that idea of a hubmotor converted into a paddle drive, can you expound on why a front hub motor would be preferable to a rear one? An epaddlewheeler would be very cool!
 
Raisedeyebrows said:
eCue I like that idea of a hubmotor converted into a paddle drive, can you expound on why a front hub motor would be preferable to a rear one? An epaddlewheeler would be very cool!

I was not wanting to pedal it and changing gears in a rear hub will not do anything unless your pedaling.

But.. It could be made to work with the back half of a bike frame with a mid drive and say rear IGH to keep the chain out of the water.

With the front hub motor you would have to tweak its Rim size or paddle width to match the ecrafts resistance in water , I imagine its much like propping a stern drive or outboard.

For me being Solar powered I would be happy with 5 knots or 10 kph or so traveling speed anything more would be gravy :D

Edit: With the rear hub motor in the boat you could use the cassette and chain to a paddle wheel with no electronics near the water
 
Part boat part plane :D

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It looks like if uses water and air now to find it in a 1000w or so size.

Good enough for a Billionaire it must have merit. Maybe a RC Props could be used or tested. It also looks like a Good DIY Prop project
 
That is one quick Motor you made and good job propping it too , planes in 5 to 10 feet by the looks of it :D

I suspect its belt drive ?
 
Bazaki said:
https://youtu.be/QYR_sgHDU-4

This i made a few years ago. Silent

I'd enjoy reading the build thread or more details and photos on that, very nice and about exactly the level of performance I'd like to have.
 
maybe one of these
https://endless-sphere.com/forums/search.php?keywords=&terms=all&author=+Bazaki&fid[]=39&sc=1&sf=firstpost&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
 
I did a much more primitive version, but technically similar to bazaki's:
https://endless-sphere.com/forums/viewtopic.php?f=39&t=62510

Running the Cute Q100 with reversed freewheel at the moment. If I ever find the time I'll build something lighter and with the chain inside a tube (thinking 3d printed enclosure under water, but should learn to draw...).
 
As for your idea, why not build a one stage gear, with a short chain or belt, running your spindle in parallel to the motor (I hope you understand what I mean).
This would lift the motor a few centimeters, and you'll be able to play with the gearing.
 
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