firewinder (wind powered led ornament) - ideas on how to make the "fan" ?

[Polossatik]

Just happen to stumble on http://firewinder.com/story.php

According the site it's a high tech, eco friendly (no really... wich product is not "green" these day's?) product and "the development involved the expertise of numerous world-class professionals, including a professor of Aerodynamics from Bristol University, a specialist electronic system design consultant and a leading consultant in environmental management & sustainable product design."

*grin*

and it costs 49 £ (about 80 usd / 60 euro )

The product is clearly dead simple, take a (brushless) DC motor that you place inside the turbine, do some kind of current limiting for the leds and hook this up to the helical turbine (not sure if this the correct english term) .

If you throw in a µcontroller and a sensor (and some kind of battery/capacitor and volt regulator to even out the dc input) you can even do POV.

I must say I'm inclined to play around with something like this, the actual big Q for me is how to make the fan.

While looking up "Vertical Wind Turbine" I came across

It's a bit oversised of course for a garden Led ornament, but the I see no reason why you cannot do a similar thing with smaller bottles.
(Or even go for 100's of leds with this size  )

The reason I post this is to ask if someone has any better idea's on how to make the fan and/or other things of interest (aka used other keywords in google than I did   ).

[JohnS_AZ]

Could look at this ...

http://greenterrafirma.com/diy-vawt.html

[.o:0|O|0:o.]

1 plastic Coke bottle.
Remove labelling.
Slice vertically into two symmetrical halves.
Cut out a disk for the base of the device (diameter of disk > diameter of base of bottle).
Attach bottle fins to the base in such a way that they are not perfectly mirroring each other.
Drill hole through the center of the base disk and insert motor.
If you place the motor between the two fins then you can have the leds attached to the inside of the unit.

Build on the above concept to get something that works. A quick Google search shows that others have tried something similar with larger bottles, but they mostly look like half-assed attempts. Instead of using Coke bottles you could cut out strips and make helix fins... Transparent plastic means that you can have the leds attached to the fins themselves.

As a side note, does anyone know where I can buy very thin flexible sheets of nitinol type metal (not strips, but sheets)? I have an idea...


.o:0|O|0:o.

[Hypernova]

I don't see any sealing for the bearings? They would gunk up pretty quick outdoors.

[saturation]

firewinder?  You think twice when someone begins a product description by describing himself first, see first sentence.

You can either power it directly from the turbine or store the energy in a small battery before lighting up the system, but as you surmise, the key problem is the turbine and gearing.  The right trasnmission ratio gets more charge out of each turn plus reduce the friction and interia of the fan.

Sounds like you'd like to see what the wind energy folks have already done in terms of efficiency in rpm:

http://www.mdpub.com/Wind_Turbine/

The key value of the original firewinder is its aesthetic, that may be hard to duplicate.