This vertical cutting jig idea, I got from a Woodsmith magazine (Issue #209). It’s great for cutting slots the full length of a board, or for making cuts for splines.
I made some improvements from the magazine model. I used sections from a 1 1/8” thick Formica countertop, for the fence, and also for the section that slides on top of the fence. This lets the guide slide effortlessly. The guide is a section of 5/8” thick melamine, which also glides easily along the face of the fence.
I epoxied ¼” t-nuts, recessed in the guide, for bolting on the different vertical and diagonal supports.
The vertical clamps hold the wood steady when running it through the blade.I also cut extra supports to accommodate clamping thicker wood.
½” aluminum channel is readily accessible, as well as PVC board for making the miter slot assembly.
Someone came up with a great idea, when they invented this dovetail clamp. You simply make a dovetail slot in the wood. Then the clamp easily slides in to position.