Table Saw Tapering Jig - Part II

Stack Dado

Now that the guide strip has been fitted and the base trimmed to size, I can proceed to cut the dadoes that will house the aluminum T-tracks. Although I could use the router here, I elect to use my stack dado set. The resulting cut tends to be rougher but the setup is much faster.

In order to accommodate the dado set, I have installed a different throat plate (shown in red) on the saw. The wider opening offers more than enough clearance for the 1/2" dado set. In fact, it would have been better to make a zero-clearance throat plate here to avoid splintering the wood, but I was in too much of a hurry at this point to be done. As we will see, this created extra work later on.

Note that the riving knife has been removed for this operation as it cannot be used for dadoing. The small oval hole in the upper left corner of the throat plate provides finger access to the catch that holds the knife in place, so it is easily removed. Use of the stack dado set is inherently dangerous, susceptible to kickback because the blade is buried in the work, and it essential to keep track of where your hands are in relation to the blade at all times. It is especially important to keep in mind the exact spot where the blade will emerge from under the work as the cut is completed.

Making the Cut

The next image shows how the dado will be cut using the miter gauge for guidance. While it is possible to use the rip fence to guide dadoes that run the length of a piece, either the miter gauge or a specially made dado sled should be used for crosswise dadoes. I am planning such a sled for a future blog entry. Since I used both hands to shoot the photo, it does not show my hand position while making the cut. My left hand grasped the handle of the miter gauge and my right hand held the far side of the work, keeping it snug against the gauge as I cut. I made two passes with the 1/2" wide dado set to produce each of the four 3/4" wide cuts I need.

A Nasty Cut Indeed

As I mentioned earlier, this setup is prone to splintering or tearout along the edges of the cut. The lack of a zero-clearance throat plate, the fact that I am using an inexpensive 6" dado set purchased when I had a smaller and less powerful saw, and the fact that I am working in plywood all contributed to the spectacularly splintery cut I got. I will be adding a top quality stack dado set to my workshop wish list.

Although the poor quality of the cut offends my aesthetic sensibilities, it in no way affects the functionality of what is, after all, a jig. I will repair the damage with filler to prevent further splintering and to protect myself from splinters. I will then seal the base with a couple of coats of thinned shellac for protection and to make it slide smoothly across the saw table. In my next entry, I plan to show how to fabricate wooden hold-downs for the jig and install the T-track, hopefully concluding this project.

More to come...