The next step in making the middle ring for the frame is cutting the slots for the uprights. I could have used the same jig that I used to cut the slots in the top and bottom plates before cutting out the center of this one, but there are a few reasons I didn’t want to do this. First, the slots in the uprights are going to be easy to cut with square bottoms so it also makes sense to square cut these instead of having the rounded ends that the router produces. Also, since there are through cuts, I would need to setup something to hold he piece up off the bench. Finally, even if I did take that route, I would still need a way to cut the slots in the ring segment pieces later.
So to make these cuts I found an idea for a jig in another builder blog,
which I can’t seem to find again. Here is my version of the jig.
The back is a large piece of plywood that is attached to the table saw’s miter
gauge. Attached to the bottom of the plywood are two pieces with the same curve
as the ring which support the bottom of the ring. I cut these pieces using the
same router table setup that I used to cut the inside of the ring. I cut these
out of a piece of 3/4” MDF.
Once the jig was assembled I installed a 1/2” wide dado blade in the saw, set it
to the proper height and then carefully lined up the first slot with the blade.
Once I had the slot aligned I transferred the lines for the edges of the slot to
a piece of tape on the table. This will be used as a guide to make it easier to
line up each slot. You will notice in the first picture that I held the ring to
the jig with two springs clamps. I realized after the first cut that this didn’t
hold the ring firm enough, so for the rest of the cuts I put a c-clamp on one
side and a spring clamp on the other. With everything setup it was an easy
process to cut all the slots.