I am trying to make some diagonal "slats" - something like this (attached). How would I cut the mortises for a diagonal "tenon" like that (the slat itself could probably go directly into the mortise rather than actually cutting a tenon on the end of it, no?)? It seems like a router bit would have to be at an angle with respect to the bottom rail, and I don't know how to achieve that setup.
Any thoughts? Perhaps this joint has a different name that I can look up?
Any input is appreciated!