Router Table Indexing Jig

Recently I had to cut a series of evenly spaced dadoes across the sides of some small display shelves I was making. I wanted to make the dadoes on my router table, and I needed a way to space them evenly. That's when I came up with the idea for an auxiliary table fitted with an index pin as shown in the photo.

To make the auxiliary table, I started by cutting a piece of ½" MDF (medium-density fiberboard) that fit on top of my router table. Then I drilled a hole in the center of the MDF for a router bit.

Next I inset a strip of wood into the top to serve as an index pin for spacing the dadoes, see Figure 1. I made sure that the distance between the router bit and the index pin equaled the spacing I needed for my dadoes, then I clamped the top to my router table.

Now cutting evenly spaced dadoes is easy. Simply butt one of the workpieces against the index pin and push it forward with a backer block to cut the first dado. Now just shift the workpiece so the dado you just cut fits over the index pin and cut a second dado. Repeat this process until all the dadoes have been cut, as you can see in Figure 2.