Routing dadoes and grooves with a shopmade T-square works great. The setup is quick and easy. But most T-squares are usually made for a specific diameter of router bit. The auxiliary router base and T-square you see here solves that problem. This allows me to accurately position and rout four sizes of dadoes and grooves by simply rotating the router.
To use the jig, align the notch in the cleat with your layout mark. Butt the appropriate edge of the baseplate against the fence and make the cut.
The acrylic baseplate for the router is really the star of the show. The bit opening is offset from the center as you can see below. This means each side of the baseplate can be used to rout a different dado. The T-square is simple — it’s just a long fence attached at a right angle to a cleat. The cleat holds the fence square to the workpiece. I used the router with the baseplate to rout an alignment notch for each bit size. Each notch corresponds to one edge of the baseplate. The notches are used to accurately position the jig on the workpiece.
