I AM NOT SURE what I was doing today that I was not doing yesterday but this was sure a better day for bending maple. four maple sides in a row without a problem. then I bent the rosewood sides, came out just right;. I might have been using a bit more heat. almost got to 400 degrees a few times.
I made two sets of sides for future builds. This is about as good as you can make them, look at that lovely bend with no cracks.

You must carefully cut off the excess length of the sides and fit the sides to your top. Here is a nicely fitted set of sides ready to be glued in. This is an easy job if you have bent the sides well. In that case there is little tension or stress on bending things into shape. If the bending did not go well this can be a very difficult job. This assembly jig that I made really helps. Those three adjustable braces on each side hold things in place perfectly. Now for the glue
You apply a thin bead of glue to the bottom edge of the sides, plenty of glue on the butt block, and then clamp everything into its proper position. Brush a little glue around the joint on the outside afterward to make sure there is glue still there after the fitting operation. Tightly clamp the bottom of the sides using a caul that mimics the curve on the butt block. Not let the glue set for a couple of hours.
Now glue in the tentelones. This will firmly attach the sides to the top. When the glue sets on those you are safe, your sides are attached. A Major step in the making of a ukulele.
These tentelone clamps are made by cutting them out of 3/8ths plywood. Very simple, very effective.