Two-step stop defines a dado
Don't have a dado set? Or do you need to machine a dado wider than your stacked set can handle? You can cut consistently wide slots using this double stop. The key dimension is the distance between the ends of the stops: Subtract the width of the desired dado from the width of the saw blade or dado set, and then offset the stop ends by that amount. Position the stock against one stop, make the first cut, and then reposition it against the other stop and make the second cut. (If you're using a single saw blade, "nibble" away the waste between the kerfs.) To keep the jig accurate, we created a dust relief by adding a 1/4" plywood spacer, slightly offset, to the bottom of the fixture.