JT, I meant to comment on this but forgot. The circles are easier to cut on a band saw no doubt. But, the point of my comment was the inner circle and try as I might, I just can't seem to keep the blade on the line. Either I'm turning the piece too fast or too slow but I seem to wander every time. My answer is to try to stay just outside of the line so I can clean it up with my spindle sander. But I'm trying to strive for as close to perfection as I can get and it just seems to be the one thing that I can't seem to master. Well, one of many but the one that bothers me the most.
To edit, I also wanted to answer your suggestion to chamfer the outside edge of the top ring. I'm going to do something with it but I can't do what I have done to the other pieces I made. The wood is not there to work with. But I'll figure something out. As for the biscuits, well they were necessary to keep that ring together. What happened was, I messed up twice with the router and came away with two pieces of wood that were ok so I decided to join them but to just edge glue with not other support would not have been workable. I could have maybe used dowels but either way, I should have made sure to position the biscuits toward the center of the wood knowing that it would be cut away. As it is, that top ring is very fragile, even with the biscuits that you can see. I was being a wood miser because that stuff is expensive. As it was, Cherokee Woods did me a favor by planing the piece to 1/2". They don't normally do it but he did it for me. If I had known then what I know now, I'd have just gone ahead and bought a board 12" wide and planed it myself but I just thought it would work out. Information for another day. Lesson learned.