Two sets of blades to choose from, grin!

[Boss]

Howdy again, here is a little update in an otherwise lacking of progress phase of our first home built axial flux wind turbine.



On the left are blades made from Sugar Pine a lightweight softwood. On the right side the blades are made from Douglas Fir. Both woods are locally cut and then kiln dried at a local flooring manufacturing shop. Both sets are made from what the shop calls scrap. One of the people in my group made these for us as his first attempts. He told me to go ahead and blow these out right away because he would have the new and improved blades ready to go in short order.

 

Here is a closer image of the Sugar pine blades. We like them a lot, this wood has a real nice feel, but it may not be strong enough to withstand the northern New Mexico winds.



Here is a closer look at the Douglas fir blades. These may have too many imperfections to fly right, not to mention he made them backwards, although we don't see why they wouldn't work, I mean the axial flux generator doesn't care which way it turns, right?

Check out my daily newsletter for many more updates on the progress of this wind turbine as well as see how the shop I talked about building last Spring came out.

http://outfitnm.com/index.php?option=com_letterman&Itemid=140

[SparWeb]

"backwards"

As long as the front is flatter and the back is rounder, it's fine.  They can turn clockwise or counter-clockwise.  Some people suspect that the direction of rotation affects the ability to furl, but that is far from being proven.

[oztules]

Time for cogitating about their imperfections has passed.

It is now time to do as "One of the people in my group made these ".. exhorts you to do....... whack em up and see....

Backwards/forwards it's all the same I reckon.

Your right though, those sugar pine blades do look cool, and my crummy radiata pine ones have performed admirably, so I think they'll survive fine if you impregnate them with say west systems epoxy to give them some "surface hardness". I found making it hot and runny helped it to soak in well. A couple of coats of two pack on top of that doesn't hurt either.

So Boss, the time has come

Look forward to seeing em fly.

.........oztules

[Ungrounded Lightning Rod]

It affects the way the mill "nods" when it furls and unfurls.  Furling is more abrupt and the gyroscopic forces stronger from the higher RPM, so you want the mill to go "chin up" on furling and "chin down" on unfurling to avoid a blade-mast collision.

If your blades are designed for the wrong sense of rotation you can just mirror image the mill, swapping the sides for the turbine axis offset and tail angle.