Speed Square Mitering Sled
For cutting 45¡ miters on my tablesaw, I use a crosscut sled equipped with a common plastic speed square. To build the sled, attach a runner to the underside of a scrap piece of plywood. Turn the plywood sled 180¡ in the miter track and cut off the waste along that edge, making it perfectly parallel to the blade. Turn the sled back around, then attach the top and bottom fences 90¡ square to that trimmed edge. Stagger the fences on both sides of the sawblade to make more room on the sled to handle long workpieces that need to be mitered. Now place the flange of a plastic 12-in. speed square against the trimmed edge of the sled and rest it against the bottom fence. Attach the square to the sled at this location with three or four small screws. Push the sled through the saw to make a kerf in the sled and to saw off the nose of the speed square. Now you’re ready to cut perfect miters.
Benjamin Retzinger, Mountain Home, Idaho
Fine Woodworking Magazine, January 2002 No. 153