1 Building the jig
The jig shown at left allows you to rout sliding dovetails (inset) without a router table. Cut the fence, table, and support piece from  /4-inch plywood. Make all the boards 16 inches long; the fence and table should be about 10 inches wide and the support piece about 3 inches wide. Screw the table to the table support so they form an L. Position the table 4 inches from the bottom of the fence and bore two holes through opposite ends of the fence into the table support. Use a router with a straight bit to lengthen the hole on the outfeed side of the fence into a curved slot. Attach the table support to the fence with carriage bolts, washers, and wing nuts. Leave the bolt at the infeed end loose enough for the table to pivot when the slotted end is raised or lowered. Remove the sub-base from your router and use it as a template to mark the screw holes and bit clearance hole on the fence. The bottom edge of the clearance hole should line up with the top of the jig table when the table is level.
1 Building the jig
Cut the two base pieces and the stop block from plywood the same thickness as your stock. The base pieces should be wide enough to accommodate the edge and end guides and support your router’s base plate. Use solid wood strips for the four guides. Next, mark the shoulder of the half-lap (inset) on one workpiece and butt the base pieces against its edges with the shoulder mark positioned near the middle of the boards. Install a straight bit in the router and align it with the shoulder mark, then mount an end guide across the base pieces and against the tool’s base plate. Repeat the procedure to position a guide at the opposite end. Now align the bit with the edges of the workpiece and attach the edge guides, leaving a slight gap between the router base plate and each guide. (The first half-lap you make will rout reference notches in the base pieces.) Finally, install the stop block under one end guide, against the end of the workpiece. Countersink all fasteners.
1 Making the jig
The jig shown at left will guide your router and secure the workpiece as you cut a mortise. The dimensions suggested in the illustration will suit most routers. Cut the jig sides from %-inch plywood. Make the base of laminated solid wood. Attach the sides to the base with countersunk screws, making sure the pieces are perfectly square to each other. Fashion each stop block from solid stock by cutting a rabbet % inch deep and 1 inch wide, then routing a 4-inch-long slot to accept a ‘4-inch hanger bolt. Mount the bolts 3 inches from each end of one side, slip the stop blocks in place, and fix them with washers and wing nuts.
Cutting a mortise
Mark a line down the center of the mortise outline on the workpiece. Loosen the wing nuts and secure the stock between the jaws so the mortise centerline is aligned with that of the jig top; make sure the top edge of the workpiece is butted against the underside of the top. Also align one end of the mortise outline under the end of the notch—offset by the distance from the edge of the bit to the template guide’s edge—then tighten the hanger bolts. Align the edge of the bit with the other end of the outline and clamp a stop block to the top flush against the router base plate. Rout the mortise (left), starting the cut with the template guide butted against the end of the notch and stopping it when the base plate contacts the stop block at the other end.
1 Setting up the jig
The jig shown on this page allows you to cut the notches for a box joint on a router table with little setup time. It consists simply of an extension board screwed to the miter gauge and fitted with a key that determines the spacing of the notches. Install a straight bit sized to the desired width of the notches and mount the router in a table. Set the depth of cut equal to the thickness of your stock and feed the extension into the bit to rout a notch through its bottom edge. Reposition the extension so that the gap between the notch and the bit equals the diameter of the bit, then screw it in place. Feed the extension into the bit again, cutting a second notch (left). Fashion a wood key to fit in the first notch and glue it in place so it projects about 1 inch from the extension board.