trust me on this one John, from experience, its impossible to do with a lathe, and the 1 out of 12 that might survive to make a shaft, are not worth the effort. they need to be flexible, and you can't turn something that flexible when its 30'' long
I either buy shafts, buy dowels and straighten and spine them myself (also alot of work) and then weight match them, or use cane, which is how ive been making my arrows lately.
ebay has some sweet deals