Pictured above you see the wooden pillow block bearings. I simply drilled a hole, slightly under 3/8" diameter, and then using a gas stove, heated the shaft to almost red hot, and forced it through the holes. This makes for a good tight fit, and it serves to harden the wood, and the inside of the holes has a layer of carbon, which makes for a better bearing. These bearings are from pine, certainly a harder wood would work much better! In the top of the pillow blocks I drilled a small hole so that the bearings could be oiled/greased. Once the alternator was assembled, there was no play in the shaft at all, and it turned freely. Even after several hours of hard running, the bearings are holding up well. It's interesting information, although I would certainly encourage anybody building a windmill to use steel ball bearings. I just did wooden ones for the sake of fun, and simplicity. Odds are, on a slow running machine, like a slow water wheel, wooden bearings, properly made could last for years. This is actually a high speed windmill and I should think these would wear out quickly.
