ADJUSTABLE ROUTING GUIDE

1 Building the jig

The jig shown at left is ideal for routing rectangular grooves; it can also be fitted with templates for curved cuts. Rather than following the pattern with a piloted bit or a non-piloted bit and a template guide, you feed the router base plate along the jig’s inside edges. Saw the guides from l-by-2 stock and rout a groove і inch deep and wide along the inside edge of each one. Cut a two-shouldered tenon at one end of each guide to fit in the grooves and bore a pilot hole into the middle of each tenon for a %-inch-diameter hanger bolt. Screw the bolts in place, leaving the machine thread protruding to feed through the adjacent edge guide and lock with a washer and wing nut. Finally, rout %-inch – wide mortises through the guides; start about З/2 inches from the end with the tenon and make the mortises 4 inches long, separating them with about 54 inch of wood. Assemble the jig by slipping the tenons and bolts through the grooves and mortises of the adjacent guide and installing the washers and nuts. For curves, make tem­plates like those shown in the illustration.

2

Routing the groove

Outline the pattern on your stock and lay it on a work surface. Loosen the wing nuts of the jig and position it on the stock so the edge guides frame the outline. Place the router flat on the workpiece and align the bit with one edge of the outline. Butt one of the edge guides flush against the router base plate. Repeat on the other edges until all guides and templates are in position. (Use double-sided tape to secure the templates to the workpiece.) Tighten the wing nuts and clamp the jig and workpiece to the table. After plung­ing the bit into the stock, make the cut in a clockwise direction, keeping the base plate flush against the edge guide or tem­plate at all times. For repeat cuts, simply clamp the jig to the new workpiece and rout the pattern (left).

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OVAL-CUHING JIG

Paired with a router and a circle-cutting guide, the jig shown at right enables you to rout ovals of any shape and size. Rather than fixing the guide to a single point, as you would to cut a circle, the jig anchors the guide to two sliding dowels. The slides are positioned so the distance between the bit and the dowels determines the long and short axes of the oval. As the router is rotated around the jig, the tool moves in an elliptical pattern, cutting a perfect oval.

Make the jig base from a piece of 15-inch-square 3Л-іпсЬ plywood. To cut the channels in the base, install a dovetail bit in a router, mount the tool in a table, and set the cutting height to Уїв inch. Align the middle of one end of the base with the bit and butt the fence against the adjoining edge. Clamp a featherboard to the table flush

against the the opposite edge. Then feed the base across the table, routing a dovetail channel. Rotate the piece 90° and repeat, cutting a second channel perpendicular to the first one. Shift the fence Vs inch away from the bit, reposition the featherboard accordingly, and make four more passes, running each edge of the base along the fence. Continue until the channel is about 1 inch wide (left). To finish preparing the base, use your band saw to cut an arc out of each corner; this will prevent the router from striking the base when you use the jig.

Cut the sliding dowels on your table saw, making both slides from a single board at least 12 inches long. Measure the edges of the dovetail channel with a sliding bevel and transfer the angle

to the saw blade. Then rip a bevel along both edges of the slide stock, guiding the board along the rip fence and feeding it with a push stick (right). Size the board to slide smoothly in the dovetail channel. Crosscut two 2-inch-long slides from the board, then drill a hole for a vi-inch dowel into the center of each slide. Finally, cut two 1 VS-rnch-long dowels and glue them into the slides.

To prepare the circle-cutting guide, drill a row of V«-inch-diameter holes along its centerline, spacing them at Уг-inch intervals. To ensure that the router sits level when it rotates around the jig, cut an arc-shaped shim the same thickness as the jig base, sized to fit on the underside of the guide between the bit clearance hole and the

wide end of the guide. Fasten the guide and the shim to the router base plate.

To use the jig, clamp your workpiece to a table and mark perpendicular ref­erence lines from edge to edge and end to end, intersecting at the center of the surface. Then position the base on the workpiece, aligning the center of the dovetail channels with the ref­erence lines. Mark the long and short axes of the oval you want to rout on the underside of the guide, measuring from the bit to the appropriate holes. Spread a little wax in the dovetail channels and slip one sliding dowel into each channel. Place the guide over the base, fitting the dowels into the marked holes. With the shim flat on the workpiece and the guide flush against the jig base, plunge the bit into the stock and feed the router around the base to cut the oval (left).