First up, if you SAVE the inside piece from your middle ring, you'll have a perfect starting piece for the skirt.
Once you cut the circle out to the indicated radius, you'll want to mark the center lines. Fairly simple.
For the sides that are cut out, you'll want to ensure that they are as close to 11" as possible!
From this view, you can see the pieces that are about to be hacked away.
Next, set up your table saw!
Make sure the blade is in the right spot............
Next, hack off the sides!!! I free-handed them, and it was very simple to do.
Next, mark the inside cutout and start Jig-sawing.
All jigged out and ready to go!!
Do some sanding on the edges (especially the outside) and make it look clean!
Finally, got some dimensions together to help box up the inside of the skirt!! More to come tomorrow.