I had put steps on each side of the outer ring blanks. These steps were to be used to have a reference surface parallel to the trough axis. But after I had to sand the trough to a constant radius I was no longer sure that the trough radius was parallel to my steps.
I used my tall fence and the core to cut a new edge parallel to the cylinder.
Referring to the picture below, the goal for fitting these pieces is to have a feather edge on the left and the top surface match the top of the feather edge.
I do this by running the pieces through the thickness sander to a trial thickness and then trimming the left side to a feather edge. I ended up removing too much material and had to add back a shim. You can see that in the detail below.
After I removed too much material I was much more cautious. I finally got a good fit – on one end.
This is when I found out that after all my effort to create a constant cylinder I still was off. You can see the gap on the other end.
So I had to SLOWLY trim a taper to each piece. I used layers of tape to sneak up on the correct taper. When I got close I started to check my fit after increasing the taper on each piece.
If I remember right, it took me 12 test fits to get to a match.
Then I could move on to the glue up. The clamp up was a challenge. I had to clamp across the faces on each end of each blank as well as clamping the blank to the core.
