| Archive for Downsizer For an ethical approach to consumption |
| sally_in_wales |
Spin your own electricity?http://www.flexitron.diytrade.com/sdp/194986/4/pd-699352/5454575-0/e-charkha.html |
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| RichardW |
Thats sooo funny.
1 hours winding to get 4 hours LED light Your average LED tourch will run for 20 mins from 2-3 mins turning. So could do 4 hours after 24-36mins. A LED light is prob about 1w so you are making about 4wh's (or 0.004kwh) Even better is the elec bike conversion kit 250w motor 2 x 12ah bats 30km max range that means it does 52 km per hour. 2 x 12ah discharged to 50% SOC (or you kill the bats) = 12ah = 144wh 144wh is 0.576 of 250w so it needs to cover 30km in just over 1/2 hour = 52 kmh (32.5mph) Never mind that discharging the bat to 50% in that time would actually mean it only lasts 20 mins not the 30 plus you would need. |
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| sally_in_wales |
I rather like the idea, it actually looks like quite an efficient little hand cranked spinner working from drafted pencil roving, and if it can do something else useful too, then I quite fancy one | ||
| Frewen Feltmaker |
Excellent 
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| Minamoo |
They have those bike conversion kits here and they do work and really well. There's no need to be so condescending. Sally found a link she thought was interesting and cool. And a lot of people happen to agree. There's loads of people in developing countries and elsewhere who do hand spinning of yarn to make money to feed themselves and their families and loads who do it for fun. If by spinning that yarn, they could also be generating power so they can have an LED light instead of a dangerous hurricane lamp or kerosene lamp that has led to more fatalities than I care to imagine, then I think that's a bloody fantastic idea. |
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| sally_in_wales |
ok, fair enough, efficiency therefore appears to be less than possible. If you were going to modify the type of spinning wheel many of us have here, to provide a useable by product of a few hours light as per this model, how would you go about it then? | ||
| RichardW |
Yes its a good idea just badly applied.
The amount of elec made is so small its almost nothing. Even over a 12 hour working day its 48wh or 4ah at v12v. It would be easy to make one that was still hand cranked but produced more power that could actually be used for some thing or even just add a solar panel for charging the bats to run the lights. Would be even better if it was foot cranked. Then you could up the power to nearer 50-100w (instead of 4w) There are lots & lots of these type of products coming onto the market where they could be lots better if they actually tried. Yeh elec bikes work I dont doubt that. Its the claims that suck (just like the EV car mpg equivilent claims based on very short 99% elec only mileage). To get what they say you would need to kill the bats in very short order. People will see the 30km range & then wonder why the bat dies after only a couple of 30km trips or they will wonder why it only actually does 15-20km's per charge. With the bats being so small (12ah) & only 24v (2 x 12v) I think that the 30km range is in "assist" mode as well. |
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| RichardW |
Good question & one I was going to cover in my last post but dint. Should be easy enough to mount an elec motor to the wheel dep on type poss on the rim. What sort of rpm do they run at? |
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| sally_in_wales |
just 'elephanted' the wheel Gareth is working at and he's treadling at about 80-100 rpm at the moment | ||
| RichardW |
Thats faster than I though it would be.
Should be able to direct drive from the rim using a tyre / wheel to drive the motor. Even with a tyre of 1/4 of the wheel circumferance would give 320-400rpm which is more than usable (my 200w turbine runs at 480rpm at full output but your wheel wont power that much). Also thinking a strumney archer dyno hub could work mounted on the wheel. One issue would be the extra strain on the working parts of the wheel might need upgrading to proper bearings etc. For the motor you should look in the 60-200watt range as used as a genny they only do about half. Better if it has perm magnets as well. Forget car alts they need much faster speeds & also need exciting to start making power. |
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| Chez |
What about the bike-motor things? I like the idea of getting one I can add to my bike to give me a bit of help going up hills towing a trailer with two children in; rather than buying a whole new electric bike ... | ||
| sally_in_wales |
many spinners are a bit slower, Gareth has a fairly fast wheel so maybe the 80rpm is more accurate for most users | ||
| RichardW |
Just get more / bigger bats. Then be realistic on range if you use it in elec only mode. They have been around for a while now so should be easy enough to find one. linky has some for £200 ish on bigger motors but you need the bats on some so read the adds well. Just found this as well The max power to be legally classed, as a pedal cycle is 250watts (1/3 hp) and a maximum speed of 15 MPH |
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| Cathryn |
 You are going to completely alter that new spinning wheel aren't you.
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| RichardW |
ME?
No lol 
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| Minamoo |
Haha! They better not find out about dpack's (and now misdemeanor's) leccy bike which can go at a LOT more than that. 
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| RichardW |
You can have faster / more powerful ones but you then need tax MOT & Ins. | ||
| vegplot |
Electricity generating exercise bikes spring to mind. |
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| Ginkotree |
It would be amazing to be able to light the room while you spin,especially as I mostly spend the winters evenings doing my spinning.  and great for people abroad who rely on kerosene lights.
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| tvjohn |
The folk here have several years experience doing just that, living in Somerset
http://www.atob.org.uk/ Their "folding bicycle" magazine is increasingly devoted more to electric bikes, & they also cover & review ecologically friendly home devices. There's also probably a sample copy from: http://www.exacteditions.com/ HTH, John |