Here’s a jig for a tapering a piece on a tablesaw. For the base, take a straight 1×10 or 1×12 and measure the length of the taper, squaring off the end marks. On these lines, mark the width of the taper (A and B in the drawing) at each end by measuring in from one edge of “the base. Connect these points with a chalkline. Tack the piece to be ripped to the base along the chalkline, and adjust the saw-fence to the width of the base. Set the blade deep enough to cut both pieces, and you’re ready to run it through, as shown.
If the piece you are tapering is finish trim and you’re concerned about the nail holes showing, calculate where the nailing will come on the piece and use these same points for tacking the trim down to the 1x base for the saw run.
Sam Yoder, Cambridge, MA