What kind of splines do you want? Vertical, inside the miter? Horizontal,
perpendicular to the miter? Either way, I don't think I'd use a hand held
router. If no table mounted router, I would use a table or hand saw.
I'm not sure a handheld router is the tool for the job. I would do this on
a table saw. See my spline jig on my web page. This jig could also be
adapted for router table use.
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