Rotor thickness

[WoodSpinner]

I'm still working on my first attempt(mini windmill) from what I've read I'll bet better results from using metal rotors, how thick should these be? I'm using 3/4"x1/8" mags stacked two to a pole.

John

[Flux]

For mechanical reasons you need about 1/4", magnetically I doubt that you would see much improvement over 1/8" thick but thin discs tend to warp and you have a very considerable attraction force between them.

Flux

[JeffD]

I used a 1/8" (3mm) thick rotor on the front which is bolted to the blades and blade hub.  The back rotor is 1/4" (6mm) thick.  I originally used 1/8" thick for the back rotor but it slowly deformed over a 3 month period.  The current configuration has been in operation for 24 months and the plates are still flat.  The photo was taken in May of 2009 (14 months in operation) but things still look the same today (Mar 2010).

[gotwind2]

1/8"(3mm)minimum thickness I would suggest.

That looks like an interesting setup there Jeff.

From the image above, it looks like you have a small dual rotor setup.

I had a look at your files/entries and didn't find any further information on your project.

Would you mind sharing your project details?, images are good also.

Thanks

Ben.

[JeffD]

I've been putting together a diary entry since about 2007 when I started the project and some day I'll post it on the board.  My wife calls me a turtle, it takes a long time for me to get things done .

[WoodSpinner]

First I'd like to thank you all for your responses, I was thinking of the magnetic end of things primarily since I could laminate some thin plate to some wooden rotors(I have a woodlathe) but if they need to be 1/8th thick minimum magnetically I may as well have them cut from 1/4" thick as either way I have to have it cut, I have turned aluminum and copper on my lathe but my only attempt at cutting steel was a dismal failure, the bit dulled way too fast to even bother with it.  

Thanks again

John

[hiker]

you could use some used sawblades as well..

double up two per rotor-or one per rotor if you dont mind the small amount of mag leakage on the backside of blade..

couple of block bearings-some allthread and short pieces of 2by4 for base mount..

and of course some mags and wire!

thats about all i used on my little mill..still flyin..

  http://s153.photobucket.com/albums/s208/hiker_07/?action=view&current=mudflatsandbikeandnewalt00
6.jpg&newest=1

[WoodSpinner]

Thank you Hiker, I hadnt thought of that, using saw blades would a lot simpler.  BTW, I love the look of your windmill.

[JeffD]

Hmm, I should have checked my build notes, WIP diary entry, and other photos before relying on my memory.

The front hub plate and front rotor were cut from 3/32" (2.4mm) junk steel obtained from the local land fill.  The rear rotor plate was cut from 5/32" (4mm) flat stock also found at the local land fill.

I used a small electric drill and hack saw to cut the circular shapes out.  I then used a grinder and hand file to clean up the cut outs.  Not the quickest way but it works.

[hiker]

drop a  email if you need more picts on construction..........

[ghurd]

For stuff that size, I borrow the neighbor's high-quality hole saws!

The $3 HF hole saw kit isn't up to the job.

G-