Recently, I built the tablesaw box-joint jig from WOOD® magazine issue 108 (also available for purchase at The jig works great, except I was dissatisfied with the quality of cuts I got with my inexpensive dado set: The outside blades left little "devil ears" on the bottoms of my box-joint cuts. To make more heavenly joints, I retrofitted the jig for use with my router table. Here's how you can do the same.Begin by building two trap fences about 12" wide out of 1⁄4" hardboard or scrapwood. These trap fences should be as long as your router table, plus the width of a cleat attached to each trap fence. The cleats align and help secure this false top to your router table. In the bit-side trap fence, make a slightly oversize cutout for the bit because the jig's slide base will need to pass clear of the bit.Next, make a slide base for the box-joint jig, as shown, center it under the jig's push handle, and screw it to the jig. To reduce friction, seal the slide base with finish and apply a generous coat of paste wax.Install the trap fences by first clamping the bit-side trap fence in place on the tabletop. Place the box-joint jig with slide base in the middle of the table, and clamp the second trap fence in place.—Dominic Greco, Richboro, Pa.