A proper jig serves two basic woodworking functions: securing a workpiece and guiding a cutter. It should add control (and thus precision) and speed to the joinery process. The jigs in this article meet all of these demands, allowing you to cut a mortise-and-tenon joint in the time it takes to hone a chisel. I tested them by cutting roughly two dozen mortises and two dozen tenons on each. Most of the test samples measured within 0.002 in. of their intended dimensions, which is well within the recommended tolerances.

You can make a stand for the WoodRat, but the recommended wall-mounting is better because it’s simpler, sturdier, and saves floor space. Unique to the WoodRat is a power feeder that moves the workpiece side to side against the router bit, which is mounted vertically overhead. Although the power feeder is a hand-cranked system, it’s a smooth and sure way of climb cutting. Workpieces are held in place against an aluminum angle by a locking cam lever that slides along a slotted track.

The WoodRat produces square-edged tenons and rounded mortises, so you’ll have to either round off the corners of the tenons by hand or chisel out the mortises to get matching profiles in the finished joint.