Hi All,
Waiting on parts, so I've got time to download photos and do some documenting. Don't know how much interest there will be, but here it goes.
A little background to start. I have been a member here for a couple of years and always wanted to build an axial flux turbine. Like bow-ties, wind turbines are cool! I can't justify building a 10' at this time, mainly because of tower costs.
Like many on this board, I'm a tinkerer and a recycler. I had an opportunity last fall to acquire a box of hard drives in a labor barter deal, perfect! Wire from a couple motors along with various hardware bits I had, I've got the start of a small turbine.I've read the books, practically read the whole board, but you have to have lab time. That's why we tinker!
State of the art testing facility:
![](https://www.fieldlines.com/proxy.php?request=http%3A%2F%2Fi889.photobucket.com%2Falbums%2Fac93%2Fklmurf%2FMini-Axial%2520dual%2520rotor%2Fbenchsetupresized_zpsf0632993.jpg&hash=ad3785562ecb584c30736e6d16a44a50d2215207)
My magnet rotors were 2 saw blades on each side though well aware of the problems.The blades happen to have a sixteen pole layout with good spacing.
![](https://www.fieldlines.com/proxy.php?request=http%3A%2F%2Fi889.photobucket.com%2Falbums%2Fac93%2Fklmurf%2FMini-Axial%2520dual%2520rotor%2Fmadualrotors_zps359f4a78.jpg&hash=567d156c1ce237d09fe8a94b5d29ea354ddebbd8)
The wire I had available in quantity was #24 and #21 AWG. I wound a test coil of each.
![](https://www.fieldlines.com/proxy.php?request=http%3A%2F%2Fi889.photobucket.com%2Falbums%2Fac93%2Fklmurf%2FMini-Axial%2520dual%2520rotor%2Fmacoilsoverlaid_zpsc0ee7415.jpg&hash=b780ff9bec46860d3e75c8c7a2ccb3138d1607c6)
Since I haven't played with magnets and coils since high school physics, I started with a few basic observations. I stacked various heights of magnets on each rotor and watched the voltage change. I also did the paper clip test on all variations. It stuck on all of them of coarse, but you could tell the strength by feel.
Up to this point, I had know idea what kind of power was possible. I took the voltage reading from the #21 wire and calculated that I could make a 3 phase, 12 coil stator that would work for a 4-5' prop. I compared my test coil to my CAD mock up and saw plenty of room to wind 2 in hand. I wound one of those coils and tested.
![](https://www.fieldlines.com/proxy.php?request=http%3A%2F%2Fi889.photobucket.com%2Falbums%2Fac93%2Fklmurf%2FMini-Axial%2520dual%2520rotor%2Fmacoillayout_zps2e60a1bb.jpg&hash=ca2afe4201f665e0ed2503d40c4fd7300688c334)
During this time of test, I knew there was all kinds of flux leakage. In fact, the third layer of magnets on each rotor didn't contribute much, it all seemed to leak out the back. I made a trip to the local recyclers a found some .25" plate and had some 7.5" discs cut.
![](https://www.fieldlines.com/proxy.php?request=http%3A%2F%2Fi889.photobucket.com%2Falbums%2Fac93%2Fklmurf%2FMini-Axial%2520dual%2520rotor%2Fmanewrotors2_zps80a26e36.jpg&hash=7f0a7acfcb84eaf591ccdd0615e9e29626d8cd37)
More to follow..... Kevin