Spinning scarecrow head / kinetic art

[madlabs]

Howdy Folks,

It has been a while since I have worked on any kind of wind project. I finally do have a micro wind project that I would like to ask your advice on.

I have a large garden and for some reason the birds are just hammering the raspberries this year. I usually have 10 pounds frozen by now and have only 2. So I have been working on a bunch of deterrents, among them a scarecrow. The scarecrow looks great, enough like a man that it keeps me looking thinking someone is there. Hopefully it does the same to the birds. For fun and hopefully to add to the bird deterrent factor, I'd like to give him a glittering, spinning head. I am thinking of a 6" diameter by 10" tall cylindrical squirrel cage type of a thing. I'd like to use simple sheet metal construction and have already cut out the discs.

My question is: How many, how wide and what angle should I make the blades? I don't want to get fancy or spend a lot of time on it. The unit will be light and have low friction. I'd just like it to spin in a light breeze.

Thanks in adavance!

[Mary B]

Old AOL CD's put on a spinner so they flash in the sun... works well... I hang them over my tomatoes to keep the dang rabbits out. Run a string through the hole and tape it at the top edge so the CD is vertical. Stagger 4-5 on a line and the wind flutters them constantly.

[madlabs]

Hi Mary,

I have a lot of shiny tape hung which does pretty well. Aren't old AOL cd's collector items by now? 

I just want to make a cool shiny spinning head. I miss my old windmill spinning as I walk around and if it scares a few birds, all the better. I never made any kind of VAWT so I'm just looking for some basic advice.

[DamonHD]

I made this thing in about 10 minutes with a big drink bottle.  No doubt it could then be decorated:

http://www.earth.org.uk/wind-power-pilot-autumn-2007.html#Savonius

Not in FL's usual class, clearly!

Damon

[Mary B]

Hi Mary,

I have a lot of shiny tape hung which does pretty well. Aren't old AOL cd's collector items by now? 

I just want to make a cool shiny spinning head. I miss my old windmill spinning as I walk around and if it scares a few birds, all the better. I never made any kind of VAWT so I'm just looking for some basic advice.

Friends saved them for me for years. I have used them in the garden, to make a solar cooker, played with putting some into a parabolic dish and using that heat to generate steam(worked but the tracking system was complex)...

[madlabs]

Well, you put the CDs to far better use than anyone joining AOL. I do remember when they were everywhere.

Damon, a Savonius is probably the way to go. Hopefully I'll get a chance this weekend to give it a shot and see.