Brushless Hub motor as 3 phase generator

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Gotwind Ben

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Post Wed Mar 10, 2010 12:54 pm

Brushless Hub motor as 3 phase generator

As i assumed these Brushless Hub motors would make very efficient pedal generators.
Has anyone got any ideas where I can get one from, second hand ideally with a rear sprocket?
The 48v versions have a 9 rpm per volt open circuit generating ability.

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shawn

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Post Wed Mar 10, 2010 4:42 pm

Re: Brushless Hub motor as 3 phase generator

Much like the PMA's Tim and I are using.
Getting a cheap one will prove hard though these days.
Sometimes best to buy a full bike that is a none runner(usually needs new batteries) and sell the rest of it back on ebay to get a cheap motor. Especially if its "pick up only" and its local to you. ;)
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microgreen

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Post Wed Mar 10, 2010 5:35 pm

Re: Brushless Hub motor as 3 phase generator

There's this on Ebay for £96 plus P+P

Not much info, but would guess that its 36v

http://cgi.ebay.co.uk/Electric-bicycle- ... 1e5aa08c12

Saw quite a few second hand electric bikes with hub motors, but it looks like they sell for a fairly high price.
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microgreen

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Post Wed Mar 10, 2010 5:38 pm

Re: Brushless Hub motor as 3 phase generator

Just seen this, 700w 48v at around £155 inc postage

http://cgi.ebay.co.uk/700W-48V-electric ... 3efce4e678

Could recover some of the cost by re-selling the controller and lights?
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Gotwind Ben

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Post Wed Mar 10, 2010 5:58 pm

Re: Brushless Hub motor as 3 phase generator

I've found that the wider, smaller diameter hub motors are internally geared (planetary gears, quite clever)
A great piece on them here.
http://www.ebikes.ca/hubmotors.shtml

The larger ones are better for our purposes and are direct drive, like Shawns and very similar to the Futrenergy alternators ;)

I like the idea of buying a spares or repairs complete bike for maybe £60 locally, I hadn't thought of that avenue..
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Gotwind Ben

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Post Sat Mar 13, 2010 5:49 pm

Re: Brushless Hub motor as 3 phase generator

I've got this electric bike company in London to have a search for one.
You never know, a buckled rear wheel is not a problem, and may be common with our crap pot holed roads :o
http://www.electricbikesales.co.uk/about/
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Tim L

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Post Sun Mar 14, 2010 9:59 am

Re: Brushless Hub motor as 3 phase generator

Ben
One of my cycling friends tells me that a common amateur cack after changing tyres is to overtighten the nut on a normal bicycle axle and damage the thread. Of course then the hubs are useless and need to be replaced.

It just might be that with the increasing number of electric bicycles around, bicycle repair shops could be throwing electric hubs with one stripped thread away in quantity soon.

If the stripped thread isn't on the side the wire pokes out, then we'd be in business.

In fact, what a good sideline for an electric bike shop - sell those motors on eBay as suitable for wind turbine......at the usual huge markup.....I think I spotted the flaw in my optimism here.....
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Gotwind Ben

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Post Sun Mar 14, 2010 11:08 pm

Re: Brushless Hub motor as 3 phase generator

Good thought Tim.
In my experience the nut 'strips' before the thread on the harder shaft (sounds a bit rude, but you know what i mean) :?

I suspect there are a good few of these hub motors scrapped, I would happily pay up to £100 for such working units.
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Gotwind Ben

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Post Sun Apr 04, 2010 5:35 pm

Re: Brushless Hub motor as 3 phase generator

Well,
I have bought myself a hub motor - at a price.. - £100 :o
I can test and resell it if it's not appropriate, certainly sell the front wheel anyway.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT
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shawn

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Post Mon Apr 05, 2010 9:24 am

Re: Brushless Hub motor as 3 phase generator

Lloyd Christmas?
Wasn't that the name of Jim Carey in Dumber and Dumber? :mrgreen:
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