Well I just learned something a few days ago about blade drift on the band saw. I found out how easy it was to get rid of. It was so simple that I couldn't believe it. All this time I have been adjusting my fence and could never get it consistent with blade changes. I ended up making the blade tracking on the center of the upper wheel and then proceeded to make sure the miter gauge slot on the table was parallel with the blade and then aligned the fence to the miter gauge slot.
I got a cheap home depot brand 3/8" blade that had a few miles on it and proceeded to rip a few pieces of wood and they came out straight and parallel. I couldn't believe it so I got a different piece of wood and got the same results.
Now the real test was putting in my good 1/2" blade I got from woodcraft. I checked the tracking to make sure it was centered and got the same results as the cheap 3/8" dull blade. No drift what so ever.
All this time I've been fighting with blade drift and all I had to do was a few simple alignment checks that we normally do on our table saws.