Ok, More!
I figured out a way to complete a groove into a dado many years ago. This is particularly helpful when building cabinet face frames what have groves and dado's to receive the sides, tops, and bottom, panels.
Normally this is pretty easy to do on the back of a FRONT face frame, you don't have to be very careful as that will likely never show. Because I also use back face frames that detail has to look perfect, or close to it.
I actually contacted Routerman, about 11 years ago to see if he has a jig or suggestion to accomplish hits. He did not. Remember Routerman?
Anyway I will share the jig that I came up with. I have literally cut hundreds of dados in face frames with this jig.
The problem. The joint is reinforced with a Domino but to make the pieces quickly I batch cut the groves and then assemble. But the stopped grove needs to extend into the other grove.
formatting link
The jig uses a piece of material the same width of the grove with 1/2" Baltic birch plywood rails attached to both sides. These rails guide the guide the top bearing 1/2" diameter router bit to form the dado to intersect the grove.
formatting link
The result.
formatting link
And now the upper 2 cabinets are assembled.
formatting link