a while back I was making some EXACT sized dowels for some wooden screws and made this carrier for my trim router. It worked like a charm, though it felt like cheating. You use it with the lathe turned off to begin with (and the router on) and then when you get close to the exact size you turn on the lathe and router and it leaves a very clean surface. I'll have to make a slightly bigger one to cut 14 inch long pieces (I designed this one for 12 inch dowels) but the concept is the same.
Hope this helps,
Lawrence